EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
Quality Assurance Project Plan
For
Red River Flood - Disaster Response
Grand Forks, North Dakota
Environmental Monitoring
Indoor Air Monitoring
for
Residential Exposure
to
Hydrocarbons from Home-Heating Fuel Oil Spills
^0
PRO^°
Prepared by: C.P Weis, PhD, dabt
8EPR-PS, Regional Toxicologist
February 10, 1998, Denver, CO
approved
ate
Al Lange
EPA On Scene Coordinator
Red River Flood Disaster Response
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EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
„
¦1-h
(^f £ Table of Contents
DQO# DQO Element page#
A1 Title and Approval Page ¦
A2 Table of Contents 11
A. Project Task Organization
A4 Project Management and Key Contacts 1
A5 Problem Definition and Background 2
A6 Project Task Description ^
A7 Data Quality Objectives ®
B. Measurement Data Acquisition
13
B1 Sampling Process Design
B2 Sampling Methods Requirement
B3 Sampling, Handling and Custody Requirement 17
B4 Analytical Methods Requirement ^
B5 Quality Control Requirement 19
B7 Instrument Calibration and Frequency 19
C. Assessment Oversight
C1 Assessment and Response Actions 20
D. Data Validation and Useabilitv
D1 Data Review Validation and Verification 20
D2 Validation and Verification Methods 21
D3 Reconciliation with DQO's 2^
22
References
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EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
E. APPENDICES
E1. Exposure Questionnaire
E2. SOP for Air Sampling Procedures
E3. SOP for Calibration of Low Volume and Very Low Volume Personal Air Monitoring
Pumps
E4. SOP for Calibration of Field PID
E5. SOP for GC/FID Analysis
E6. SOP for TD-GC/MS Analysis
E7. Map of Sampling Areas
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EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
A. PROJECT TASK ORGANIZATION
Flooding of the Red River Valley has created extensive damage to residential,
commercial and public property in the vicinity of Grand Forks, North Dakota. On April 7,1997,
the President declared a major disaster in the State of North Dakota due to extensive
residential, commercial, and agricultural destruction in the flooded area. Pursuant to Public
Law 93-288 as amended by PL 100-707 (the "Stafford Act") EPA Region VIII was activated on
April 25, 1997, under Emergency Support Function #10 (ESF #10) to "assist the State with
household hazardous waste, retail/wholesale hazardous waste, and agricultural waste
collection, biological monitoring support, and indoor air monitoring support". Detailed
descriptions of the flood damage may be obtained from a variety of sources including Federal
Response Plan (FRP) documentation available from the Federal Emergency Management
Agency (FEMA) and through various Emergency Support Functions (ESFs) provided by other
responding Federal and State agencies.
On February 5, 1998 FEMA established an additional mission assignment (EPA-02) for
USEPA under ESF #10 to be implemented in coordination with the US Public Health
Service/Centers for Disease Control and Prevention (ESF #8). This additional mission
assignment directs EPA to"provide technical assistance to FEMA and assess public
health risk from fuel oil contamination inside residences due to 1997 Spring floods, to
determine if any immediate health threat exists".
This Quality Assurance Plan and Sampling Analysis Plan describes the technical
approach to be used for effecting EPA's additional mission assignment.
A4 Project Management
U.S. Environmental Protection Agency
Al Lange
On Scene Coordinator
North Dakota Disaster Response
Doug Skie, Director
Emergency Response Program
Ecosystems Protection and Remediation
EPA Region VIII Technical Advisors:
* Christopher P. Weis, PhD. dabt * Primary Technical Contact
Regional Toxicologist
Scientific Support Coordinator for the Response
Office of Ecosystems Protection and Remediation
PH: 303.312.6671
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EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
North Dakota Department of Environmental Management
Larry Shireley, Epidemiologist Francis Schwindt
Department of Public Health Department of Public Health
State of North Dakota State of North Dakota
Public Health Department - City of Grand Forks
Don Shields, Director Wally Helland
Department of Public Health Department of Public Health
Grand Forks, ND Grand Forks, ND
David Schulte
Department of Public Health
Grand Forks, ND
Consulting Scientific Peers (ESF #8):
Mark MacClanahan, PhD
Medical Officer/Senior Epidemiologist
Centers for Disease Control and Prevention
US Public Health Service
AS PROBLEM DEFINITION and BACKGROUND
Problem: The uncontrolled flood-related release of residential heating fuel and household,
commercial, and agricultural hazardous materials has resulted in Federal Response Plan (FRP)
actions by the Environmental Protection Agency (EPA) to assess and abate these hazards to
human health and the environment. On February 5,1998, USEPA was directed by the Federal
Emergency Management Administration (FEMA) to assess the magnitude of possible
hydrocarbon exposures in residential homes impacted by flood-related spills of household
heating oil (#2 fuel oil) and to determine in cooperation with the USPHS Centers for Disease
Control and Prevention (CDCP) whether an immediate public health risk associated with these
exposures exists (mission assignment EPA-02, 2/5/98).
Approach: This sampling plan describes the efforts planned by EPA to monitor indoor air
quality and characterize chemical hazards to residents in homes known to have flood-related
fuel oil spills. This plan also describes the rationale for choosing sampling locations and quality
assurance and control procedures planned for this sampling activity. At FEMA's request, these
efforts will be coordinated and coupled with efforts to protect public health in Grand Forks and
other areas involved in the Red River Flood of spring 1997 under ESF #8. Efforts will be made
to coordinate this sampling program with ongoing surveillance programs established by the
State, county, and local hospital staff under funding from the Robert Wood Johnson
Foundation.
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EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
The approach to exposure assessment addressed herein describes a biased sampling plan
which will net screening information regarding the residential exposure to fuel oil hydrocarbons.
This plan is not designed to assess the number of homes affected or to determine the range of
exposures presently occurring due to spilled fuel oil.
Risk Assessment. This quality assurance project plan (QAPP) has been designed to
produce analytical data for the purpose of qualitatively and quantitatively defining the potential
exposure and related hazards to residents living in homes where fuel oil was spilled. This
limited screening study is appropriate only for obtaining information on potential hazard that is
site-specific and the results of the study can only support one of two possible conclusions
regarding health hazards (and not necessarily for further quantifying extent or range of
exposures occurring at this time). If successful, this screening investigation should allow users
of this information to assess whether:
1. Air concentrations of mixed hydrocarbons (from #2 fuel oil) collected in severely
impacted homes are essentially the same as background (homes with fuel oil
heaters which were not flooded) levels;
If so. then conclude: no significant flood-related exposures are likely, thus no
flood-related hazard exists at this time from spilled fuel oil.
2. Concentrations of mixed hydrocarbons (from #2 fuel oil) collected in severely
impacted homes are substantially higher than background levels;
If so. then conclude: flood-related exposures to mixed hydrocarbons from home
heating oil are elevated in indoor.
Interpretation. Chemical analyses to assess possible exposure via the inhalation
pathway, when compared with adequate background concentrations, will determine the
potential (or lack of potential) flood-related immediate threat under present post-flood
conditions. Potential immediate threat will be established through comparison of potential
expousre concentrations of fuel oil hydrocarbons measured within selected homes with a range
of health-based criteria established by the Environmental Protection Agency in cooperation with
the US Public Health Service-Centers for Disease Control and Prevention.
A6 PROJECT TASK DESCRIPTION
This project consists of a three part process to define the magnitude of possible
exposures to residential fuel oil spills and to judge through standard risk assessment
procedures the health consequences of present and possible future exposures to these
hydrocarbon compounds.
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EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
Step #1 Exposure Questionnaire:
The first step in this process involves administration of a questionnaire (Appendix E1) to
home owners or tenants of homes believed to have been impacted by fuel oil spills. The
questionnaire will confirm the existence of detectable fuel oil odors in homes previously
impacted and establish the subjective reaction of the respondent. The questionnaire will also
establish the willingness of the homeowner to participate in quantitative chemical analysis for
the presence of fuel oil constituents in indoor air of the home and other basic exposure-related
information. Homeowners who use #2 fuel oil for heating but whose homes were not flooded
will also be polled and asked their willingness to participate in the indoor air sampling as the
"control" group. The data collected from this questionnaire will be used to establish sets of
homes for quantitative analysis for hydrocarbons in indoor air. These sets will be broken into
groups based upon the nature of the response from the responder. Those responders
indicating a strong odor remaining in the home, will be segregated into a "high exposure"
group. Those individuals who report low or absent fuel oil odor will be segregated into
moderate and low groups depending upon their response. This method of dose grouping is
subjective and may not yield empirical low, moderate, and high dose groups. Participants will
only be placed in empirical low, moderate, and high categories after final results are available
from the analytical measurements.
Step #2: Toxicological analysis:
Coordinated development of a toxicological benchmark or range of benchmarks for
inhalation of hydrocarbons derived from #2 fuel oil and or fuel oil constituents will be set in
cooperation with the Centers for Disease Control and Prevention. This step will involve a
thorough literature review and assessment of all available toxicological data on the effects of
hydrocarbon exposure to #2 fuel oil as well as to specific constituents of #2 fuel oil such as
benzene, ethyl benzene, xylenes, toluene, etc. Additionally, a review of the toxicological
literature on related chemical mixtures such as jet fuels will be conducted. This toxicological
literature will establish a range of toxicological benchmarks to be used in the comparison with
exposure data to be collected in homes impacted by spilled fuel oil. A separate deliverable will
provide the basis for the toxicological benchmark chosen and a list of the literature and other
pertinent information reviewed for the purpose of establishing the range of toxicological
benchmarks used.
Step #3: Exposure-based indoor air monitoring:
During the last weekend in February, 1998, sample teams (3 teams of 2 individuals
each) will collect air samples in homes of volunteer residents who meet the desired criteria
(estimated exposure level or control group and willingness to participate in the sampling effort).
Approximately 41 homes will be sampled using two distinct sampling media. The first is a
charcoal tube and the second is a multi-bed thermal desorption tube. In both cases, a known
volume of air is pulled through the tube with an air pump. Samples will be collected for
approximately 5 hours in each home and the sample tubes will be sent to approved commercial
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EPA R8 North Dakota Flood Response—CAPP for Hydrocarbon monitoring FRP-ESF #10
laboratories under strict chain-of-custody for analysis. A carbon disulfide extraction will be
performed on the charcoal tube samples and the resulting extract will be analyzed via gas
chromatography fitted with a flame ionization detector (GC/FID). The thermal desorption tube
will be analyzed via GC/mass spectrometry, using thermal desorption (TD) technology.
Procedures for calibration of personal air pumps, sampling procedures and analytical
quantification are detailed in standard operating procedures (SOPs) established for this
sampling effort (See appendices). This analysis will allow positive identification on
hydrocarbon constituents at reporting levels lower than the health-based limits established in
step #2 of this process.
Table 1: Summary of Target Air Samples'
High Exposure
Group (N)
Medium
Exposure Group
(N)
Low Exposure
Group (N)
1
Control (non-
flooded, fuel oil
heated homes)
(N)
Air Sampling
20
7
7
7
Quality control
duplicate
samples
2
1
1
1
*These sample numbers are estimates oniy. The actual number of samples may vary based upon availability, access, and
professional Judgement
A7 QUALITY OBJECTIVES and CRITERIA for MEASUREMENT DATA
Two types of objectives are identified in this QAPP: general objectives and data quality
objectives (DQOs). General objectives are statements of practical goals that, if realized, will
substantially contribute to achieving the purpose of the study. Development of DQOs is a
process that is intended to ensure that task objectives are clearly defined and that data
collected are appropriate and of sufficient quality to satisfy the objectives.
General Objective #1: to characterize constituents of indoor air at flood-damaged residences
where fuel oil was spilled relative to appropriate (fuel oil heated but not flood-damaged) non-
damaged control areas.
Null Hypothesis: Exposures to volatile and semi-volatile organic carbons components are the
same or similar in both flood-damaged and non flood-damaged residences where #2 fuel oil
was used for domestic heating.
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EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
General Objective #2: to compare airborne fuel oil concentrations in flood-damaged homes with
toxicological benchmark values used to detemiine whether an immediate health threat exists
due to flood-related fuel oil spills.
Null Hypothesis: There is no possibility or very low possibility that homes with spilled fuel oil
exceed the toxicological threshold established by the health agencies for immediate threat
under residential exposure conditions.
Data Quality Objective Process
The DQO process can be an iterative process which is designed to focus on the
decisions that must be made and to help ensure that the site activities acquire data are logical,
scientifically defensible, and cost effective. The DQO process is intended to:
• Ensure that task objectives are clearly defined
• Determine anticipated uses of the data
• Determine what environmental data are necessary to meet these objectives
• Ensure that the data collected are of adequate quantity and quality for the
intended use
The three stages of the DQO process are identified below and a discussion of how they
have been applied in the chemical characterization study described herein. The three stages
are undertaken in an interactive and iterative manner, whereby all the DQO elements are
continually reviewed and re-evaluated until there is reasonable assurance that suitable data for
decision making will be attained.
• Stage I - Identify Decision Types: Stage I defines the types of decisions that will be
made by identifying data uses, evaluating available data, developing a conceptual
model, and specifying objectives for the project. The conceptual model facilitates
identification of decisions that may be made, the end use of the data collected, and the
potential deficiencies in the existing information. The conceptual model includes
exposure to indoor chemical hazards from inhalation as a pathway for human health
risk.
• Stage II - Identify Data Uses/Needs: Stage II stipulates criteria for determining data
adequacy. This stage involves specifying the quantity and quality of data necessary to
meet the Stage I objectives. EPA's Data UseabiHty for Risk Assessment Guidance
(DURA) outlines general and specific recommendations for data adequacy. This
includes identification of data uses and data types, and identification of data quality and
quantity needs.
• Staoe III - Design Data Collection Program: Stage III specifies the methods by which
data of acceptable quality and quantity will be obtained to make decisions. This
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EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
information is provided in the SOPs. Stage III also details the rationale applied for
selection of the proposed methodologies.
Through utilization of the DQO process, as defined in EPA guidance (EPA540-R-93-071
and -078, Sep 1993), this QAPP will use several terms that are specifically defined to avoid
confusion that might result from any misunderstanding of their use. For each of the tasks
identified within this QAPP, a "Task Objective" is specifically defined. The Task Objective is a
concise statement of the problem to be addressed by activities under this task. For each Task
Objective, a decision (or series of decisions) is identified which addresses the problem
contained in the Task Objective.
For each decision, the data necessary to make the decision are identified and described.
For all analytical data, quality assurance objectives are specified that describe the minimum
quality of data necessary to support the specified decision or test the hypotheses. These
quality assurance objectives are specified as objectives for precision, accuracy,
representativeness, comparability, and completeness. In addition, data review and validation
procedures are specified in the QAPP that evaluate how well the analytical data meet these
quality assurance objectives and whether or not the data are of sufficient quality for the
intended usage.
The following sections apply the DQO process to the Grand Forks, North Dakota Flood
Disaster Response, Stage I and Stage II, where Stage I and Stage II identify decision types
and data uses/needs for the SAP. Stage III provides the specific task objectives, decisions,
and rationale for resolving the decisions necessary to complete this study.
DQO Stage I - identifying Decision Types
Stage I of the DQO process identifies a primary question and secondary questions that
need to be resolved at the completion of the sampling and analyses program.
• PRIMARY QUESTION: Are concentrations of airborne hydrocarbons either as individual
constituents of #2 fuel oil or taken collectively as TPH higher than background levels?
• SECONDARY QUESTIONS: Is there evidence for a range of exposures within the
sample population?
• SECONDARY QUESTIONS: Is there a reliable analytical method for conducting rapid
screening of a large number of homes to determine the likelihood of threat due to fuel oil
inhalation exposures?
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EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
DQO Stage II - Identifying Data Uses/Needs
Stage II of the DQO process identifies data uses and needs. The primary uses of data
are:
• Compare site data (air concentrations of hydrocarbons or hydrocarbon constituents) to
background levels of fuel oil #2 or its constituents.
• Make a qualitative or semi-quantitative estimate of the concentration ranges and of
exposures to spilled home heating oil (#2 fuel oil) which may be occurring in the City of
Grand Forks.
• Evaluate whether the portable PID is a plausible rapid indoor air sampling approach for
determination of #2 fuel oil in air.
Stage II of the DQO process also determines what type and quality of data are needed
to answer the questions developed in Stage I.
1. Organic carbon concentrations measured in indoor air from a sufficient number
of flood-damaged homes formerly using home heating oil as a primary fuel
source, collected with conventional methods (charcoal and multi-bed thermal
desorption tubes) and appropriately analyzed to meet risk-based concentrations
established by the health agencies.
2. A sufficient number of control homes (defined as homes which presently use #2
fuel oil heating systems but which were not damaged by the flooding that
occurred in April 1997)
3. Laboratory methods for chemical quantitation limits should be well (target <1/2)
below human health risk-based concentrations.
Within this QAPP, quantitative and qualitative limits are defined for precision, accuracy,
representativeness, comparability and analytical completeness. Target reporting limits for
chemical analytes are set as project goals based upon the lowest observable effect level for
acute or chronic health effect. The actual method detection limits, reported by the analytical
laboratory, are typically based on matrix, historical data, and comparison to EPA limits for CLP
and other methods. The OA procedures outlined in this section are intended to ensure data
quality and to administer corrective actions with the goal of producing data that satisfy the
following requirements. General guidelines, policies, and procedures to achieve these
objectives are presented below. Where additional, detailed, procedures are required to attain
QA objectives and to describe specific methods, these are provided in the SOPs (see
appendices). The following PARCC requirements apply to more standard chemical analytical
analyses.
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EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
Precision: Precision is defined as the agreement between a set of replicate measurements
without assumption or knowledge of the true value. It is a measure of agreement
among individual measurements of the same property under prescribed similar
conditions. Agreement is expressed as the relative percent difference (RPD) for
duplicate measurements if the reported values are sufficiently above the method
detection limit (MDL) (> 5 x MDL) or the absolute difference of two values near the
MDL. Additionally, agreement is expressed as the range and standard deviation for
larger numbers of replicates. The appropriate precision calculation will be reported for
the required 10-20% field duplicates, and a defined MDL will be reported as per EPA
guidance in CFR, part 136, Appendix B (7 method-replicates of a low-level [near MDL]
standard, with MDL = 3 x SD).
The RPD for field duplicates should not exceed 20% or, alternatively, the absolute
difference should not exceed 1 x MDL. However, these acceptance limits are arbitrary;
therefore, a graphical comparison of the original and field duplicate samples should
also be prepared. This comparison will include a linear regression and will report the
calculated correlation coefficient (r).
RPD = I 2 fA - B) I x 100%
A + B
Absolute difference = | A - B |
Where:
A = original concentration value of an analyte
B = duplicate concentration value of an analyte
Accuracy: Accuracy is a measure of the closeness of individual measurements to the "true"
value. Accuracy usually is expressed as a percentage of that value. For a variety of
analytical procedures, standard reference materials traceable to or available from
National Institute of Standards and Technology (NIST, formerly National Bureau of
Standards) or other sources can be used to determine accuracy of measurements.
Accuracy will be measured as the percent recovery (%R) of an analyte in a reference
standard that span the limit of linearity for the method. Acceptance range for recoveries
of blind standards will be arbitrarily set at 80-120% of the true value. Specific accuracy
guidelines for other accuracy measurements are detailed in the SOPs (See appendices).
%R = Ax 100%
B
Where:
A = measured concentration value of an analyte
B = theoretical concentration value of an analyte
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EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
Ideally, precision and accuracy estimates should represent the entire measurement process,
including sampling, analysis, calibration, and other components. From a practical perspective,
these estimates usually represent only a portion of the measurement process that occurs in the
analytical lab.
Representativeness: Representativeness is the degree to which data accurately and precisely
represent characteristics of a population, parameter variations at a sampling point, or an
environmental condition. For this QAPP, data and samples representative of chemical
exposures in the study and reference areas are to be collected from selectively chosen
residences that are within and outside of the affected flood areas, respectively. The
intent is to identify and sample a sub population which is likely to have higher levels of
indoor exposure to airborne fuel oil hydrocarbons than the average population of flood-
damaged (formerly fuel oil heated) homes.
Comparability: Data are comparable if site considerations, collection techniques, and
measurement procedures, methods, and reporting are equivalent for the samples within
a sample set. A qualitative assessment of data comparability will be made of applicable
data sets. These criteria allow comparison of data from different sources. Comparable
data will be obtained by specifying standard units for physical measurements and
standard procedures for sample collection, processing, and analysis. Please see the
attached SOPs for exact methodologies employed for sample collection and chemical
analysis.
Completeness: Data are considered complete when a prescribed percentage of the total
measurements and samples are obtained. Analytical completeness is defined as the
percentage of valid analytical results requested, and >90% of analyzed samples should have
results reported. For this sampling program, a minimum of 90 percent of the planned collection
of individual residential samples and a minimum of 90 percent of related parameters (e.g.,
observations of physical characteristics of the sampled residential dwelling and followup
questionnaire) must be obtained to achieve a satisfactory level of data completeness.
Method Detection Limits (applicable to chemical analyses only): MDLs are minimum values that
can be reliably measured to identify the anaiyte as being present in the matrix, versus
method quantitation limits which are the minimum values that can be quantitated with
reasonable scientific confidence. The method will also have a maximum linear value in
most situations, and analyses should occur within this limit of linearity range. The
method detection levels established for the GC/FID and TD-GC/MS analytical
methodologies to be employed for this effort are presented in the next section (Section
B). A range of detection limits, acceptable for end use, were established in anticipation
of variability in achievement of MDLs between different methodologies and analytical
laboratories.
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EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
DQO Stage III - Design Data Collection Program
Stage III of the DQO process identifies the specific methods by which data of acceptable
quality and quantity are obtained.
Task Objective: to obtain defensible analytical data that provides quantification of fuel oil #2
and/or its constituents of indoor air in selected flood-damaged homes in Grand Forks, ND.
Decisions: The following decisions must be made in order to meet the task objective.
• Determine the appropriate volume of air that must be pumped across the charcoal and
thermal desorption tubes to allow for adequate mass of samples to be collected onto the
tubes in order to meet project-specific MDLs.
• Determine the appropriate analytical methodologies required to provide sufficient
quantitative data for end use.
• Evaluate analytical results to determine which of the analytical methods used for this
screening-level risk assessment may be used if screening of large numbers of residences is
required in the future.
There are two phases for data collection:
• Collection of field data at the residences of Grand Forks, ND.
• Collection of laboratory data analyzed from samples collected in the field.
Collection of Field Data: Certain information can only be collected at the residential homes, but
its integration for final data evaluation is important. The following data will be collected in the
field:
• Information collected during interviews with residents and visual and olfactory observations
by the field team.
• Measurement of temperature in the location where samples are collected.
• Measurement of humidity in the location where samples are collected.
• Measurement of volatile organics taken in the location where samples are collected using a
photoionziation detector (PID).
It is important for final evaluations of risk to have a record of humidity and temperature
conditions in the homes. If differences in these parameters are observed among residences,
final data users may determine that analytical results must be normalized to achieve
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EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
comparable evaluations. Likewise, documentation of observations of visual and olfactory
evidence of residual fuel oil contamination by the sampling team will provide qualitative data for
final risk evaluation.
Because this investigation is meant to perform a screening-level risk assessment on a sub-
population of affected residents, it is desirable to integrate a number of methodologies that may
identify the presence of heating oil in indoor air and evaluate the comparability of results. The
relative accuracy and precision of results along with cost-effectiveness and speed of analysis
should be weighed if future analyses in the Grand Forks area are required. Three methods
have been chosen.
The first of these methods is a PID measurement taken in the location where samples on
charcoal and thermal desorption media are collected. The PID will measure the quantity of
volatile organics present in the indoor air.
Collection of Laboratory Data: The remaining two methods planned for quantification of fuel oil
in indoor air will be determined at commercial laboratories.
• Quantification of btenzene, toluene, ethylbenzene, xylenes (BTEX) and total petroleum
hydrocarbons (TPH) as fuel oil #2 via GC/FID.
• Quantification of BTEX, TPH (as undecane), total volatile organic compounds (TVOCs) and
tentatively identified compounds (TICs) via TD-GC/MS.
GC/FID: GC/FID is a reliable method for screening the analytes of interest. In addition,
quantification of BTEX and TPH (as fuel oil) can be performed on a large number of homes
because it is more cost-effective than TD-GC/MS. However, achievement of project-specific
detection limits within the stipulated air volume (300 L) is not certain for benzene.
TD-GC/MS: This method was chosen because thermal desorption allows for achievement of
project-specific MDLs within the stipulated air volume (15-24 L). Additionally, the mass
spectrometer enables the quantification of 72 calibration volatile organic compounds and the
tentative identification of additional compounds that may exist in the residences. It is of interest
to this project to eliminate potential sources other than heating oil that may be present in the
residences.
An inter-instrument comparison of results for TD-GC/MS versus GC/FID will be performed to
evaluate sensitivity and selectivity of each method.
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EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
B. MEASUREMENT AND DATA ACQUISITION
B1 SAMPLING PROCESS DESIGN
Treatment groups: For this investigation, the City of Grand Forks has been selected as
the target study area. Residential homes impacted by fuel oil spilled during flooding exist along
the Red River corridor including Fargo, ND, Wapeton, ND and rural areas extending to the
Canadian border. It is believed that fuel oil-damaged homes in Grand Forks are likely to be
representative of homes impacted in other areas and that exposures and possible hazards
associated with homes in Grand Forks may be extrapolated to other areas of interest.
The exposure questionnaire (Appendix E1) administered to residents known or
suspected of having fuel oil contamination will serve as a primary tool for targeting homes for
indoor air monitoring. Homes will be broken into groups based upon residents response on the
exposure questionnaire (step 1). The objective will be to preferentially sample homes at the
high end of the spectrum of possible exposures, although homes of lesser reported importance
will also be sampled. Whether an individual home is indeed at the high end of the exposure
spectrum will only be determined by the final analytical data collected following successful
sampling.
Three site teams of two individuals each will be designated for the sampling effort.
Appointments will be established which will allow placement of sampling tubes and air pumps
followed by collection of these sampling devices following approximately 5 hours of air
sampling. Portable communication devices (eg. cellular telephones or VHF radios) will be used
by each team to remain in contact with homeowners and other sampling teams.
Sample Location: All samples will be taken in the basements of homes since it is here
where the largest concentrations of heating oil are expected to exist. Air pumps will be placed
in the center of the room at breathing zone height (between 4-6 feet above the floor) during air
sampling.
Table 2 provides an example sampling schedule for residences in the City of Grand
Forks. The finalized sampling schedule will be establish after all volunteer residents have been
contacted and appointments for sampling confirmed.
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EPA R6 North Dakota Flood Rasponaa—QAPP for Hydrocarbon monitoring FRP-ESF #10
Table 2: Proposed schedule for sampling indoor air of homes in Grand Forks for fuel oil related hydrocarbons.
TIME
Friday
Saturday
Sunday
Monday
Team A
Team B
TeamC
Team A
Team B
Team C
Team A
Team B
Team C
Team A
Team B
Team C
8:00 AM
Drop (12)
Drop (13)
Drop (14)
Drop (23)
Drop (24)
Drop (25)
Drop (34)
Drop (35)
Drop (36)
.30
9:00 AM
Drop (1)
Drop (2)
Drop (3)
:30
Drop (15)
Drop (16)
Drop (17)
Drop (26)
Drop (27)
Drop (28)
Drop (37)
Drop (38)
Drop (39)
10:00 AM
:30
Drop (4)
Drop (5)
Drop (6)
11:00 AM
Drop (18)
Drop (19)
Drop (20)
Drop (29)
Drop (30)
Drop (31)
Drop (40)
Drop (41)
:30
Dup
Dup
Dup
12:00 PM
Drop (7)
Drop (8)
Drop (9)
:30
Dup
Drop (21)
Drop (22)
Drop (32)
Drop (33)
1:00 PM
30
Drop (10)
Drop (11)
Pickup (12)
Pickup (13)
Pickup (14)
Pickup (23)
Pickup (24)
Pickup (25)
Pickup (34)
Pickup (35)
Pickup (36)
2:00 PM
:30
Pickup (1)
Pickup (2)
Pickup (3)
3:00 PM
Pickup (15)
Pickup (16)
Pickup (17)
Pickup (26)
Pickup (27)
Pickup (28)
Pickup (37)
Pickup (38)
Pickup (39)
:30
4:00 PM
Pickup (4)
Pickup (5)
Pickup (6)
:30
Pickup (18)
Pickup (19)
Pickup (20)
Pickup (29)
Pickup (30)
Pickup (31)
Pickup (40)
Pickup (41)
5:00 PM
:30
Pickup (7)
Pickup (8)
Pickup (9)
6:00 PM
Pickup (21)
Pickup (22)
Pickup (32)
Pickup (33)
:30
7:00 PM
Pickup (10)
Pickup (11)
:30
8:00 PM
:30
9:00 PM
I
14
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EPA R8 North Dakota Flood Response—QAFP for Hydrocarbon monitoring FRP-ESF #10
Sample size and characteristics: For this study, a target number of 41 residences will
be sampled using charcoal and thermal desorption tubes and personal air monitoring pumps.
Residences will be categorized based upon questionnaire responses into one of four possible
groups. These groups will include: 1) homes where respondents report a strong odor of fuel oil
(20 homes); 2) homes where odors from fuel oil are moderate or intermittent (7 homes); 3)
homes where odors are no longer detectable by the resident (7 homes); and 4) control homes
where fuel oil is used for heat but which were not impacted by the flooding during the spring of
1997 (7 homes). Because these sampling locations are dependent upon resident responses
and participation, actual sampling stratification and locations may differ slightly from the above
proposal. Professional judgement will be applied for determination of final sampling
stratification and locations.
B2 SAMPLING METHODS REQUIREMENTS
The proposed sampling consists of the collection of approximately 41 samples and the
required QA/QC (10-20%) samples including appropriate background samples collected in
residential areas unaffected by the flooding. Samples of indoor air will be collected directly
onto charcoal and thermal desorption tubes using standard personal air pumps with known air
flow rate. Samples will be collected for approximately 5 hours in each home as necessary to
assure attainment of analytical method detection limits required for risk-based decision making.
Sample locations within the residential area of Grand Forks will be determined by
analysis of a questionnaire to be administered prior to field sampling. Test and control
residences will be stratified based upon responses to questions asked on the questionnaire.
QA/QC samples will consist of field blanks, duplicate samples, blind QC standards and
background samples collected within randomly selected residences who use fuel oil heating
systems within unaffected areas. The following descriptions of the QC samples, planned for
collection or submittal, are provided below.
Field blank - One field blank will be collected each day of sampling. Because sampling is
planned to extend over 4 days, 4 field blanks will be collected for each type of analysis (GC/FID
and TD-GC/MS) and submitted for analysis. A field blank is collected by opening and closing
the tube caps in the field. No air is pumped across the tubes.
Field duplicates - One field duplicate will be collected for every 10 investigative samples
obtained. Since 41 investigative samples are planned, 5 field duplicates will be collected for
each type of analysis (GC/FID and TD-GC/MS) and submitted for analysis.
Blind Standard - One blind standard will be collected for approximately every 20 investigative
samples obtained. Two blind standards will be prepared during the investigation and submitted
for analysis. One blind standard will be submitted to each of the two laboratories to evaluate
accuracy of analysis. The blind standard will contain known masses of BTEX and fuel oil #2.
15
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EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
Surrogate Standards - Surrogate standards are chemicals that are similar to analytes of
interest, but are not expected to be found in the environment (e.g. fluorinated or deuterated
compounds) that will be flash spiked onto the thermal desorption tubes prior to delivery to the
field. These standards are used to evaluate system performance by reporting percent
recoveries of surrogates.
Every reasonable effort will be made to adhere strictly to specified SOPs and laboratory
guidelines. Where deviation from SOPs is unavoidable, documentation of the deviation and its
potential impact on the outcome of the data collection effort will be recorded. Detailed field
notes will record information pertinent to each sample collection and specific characteristics of
the residence being sampled. Appendix E2 presents the SOP for field sampling procedures.
These field notes will be indexed and made available for review following sample collection.
Sampling methods:A variety of sampling devices were evaluated for their applicability for
fuel oil analysis of grab samples, including: SUMMA® canisters, Tedlar® bags, charcoal and
thermal desorption tubes. Although accurate results (results within 20% of known values) for
grab air samples using SUMMA® canisters and Tedlar® bags are well-documented for light,
volatile hydrocarbons, these sampling systems are unproven for heavier diesel range organics
(DROs) such as fuel oil. Therefore, the sampling devices chosen for this class of organic
compounds are absorption via charcoal and thermal desorption tubes. Collection of DROs
onto carbon tubes requires a known volume of air be pumped across the tubes to allow
absorption of hydrocarbons onto the media. The appropriate volumetric flow rate of air requires
that the total collection time be approximately 5 hours per sample.
Sample Identification: The following protocol details the procedures for identification of
investigative and QC samples. All samples will have the following format:
GF-H-C-001
GF-H-C-001-D
GF-H-TD-001
GF-H-TD-001-FB
Each portion of the sample ID provides a separate piece of information.
First Section: Project Location
GF - Grand Forks
Second Section: Project Name
H - Hydrocarbon Project
Third Section: Sampling Media
C- Charcoal Tube
TD - Thermal Desorption Tube
16
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EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
Fourth Section: Residential Location Number
001 - Residence #1
002 - Residence #2
041 - Residence #41
Fifth Section: QC Sample Identification
None- First tube collected
D - Duplicate tube
FB- Field blank
B3 Sampling, Handling and Custody Requirement
Documentation of sample collection, handling, and shipment will include completion of
chain-of-custody forms in the field, use of field maps and field forms, and entry of data into a
field logbook. A chain-of-custody form shall accompany every shipment of samples to the
analytical laboratory. The purpose of the chain-of-custody form is to establish the
documentation necessary to trace possession from the time of collection to final disposal.
The chain-of-custody form will have the following information:
• Project number
• Sampler's signature
• Date and time of sample collection
• Sample identification number
• Analytical parameters
The shipping forms or transmittal memo from EPA will describe:
• Number of containers
• Date and time of sample shipments
The labs will enter the following information upon receipt:
• Name of person receiving the sample
• Date of sample receipt
• Sample condition
• Temperature of samples upon receipt at the laboratory
All corrections to the chain-of-custody record will be marked out with a single line,
initialed and dated by the person making the corrections. Each chain-of-custody form will
include signatures of the appropriate individuals indicated on the form. The originals will
accompany the samples to the laboratory, and copies documenting each custody change will
be recorded and kept on file.
17
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EPA R8 North Dakota Flood R»spon««-niDn „
Pon»e—QAPP for Hydrocarbon monitor
-------
EPA R8 North Dakota Flood Response—OAPP for ,
1 *-QAPP for Hydrocarbon monitoring FRP-ESF #10
B5 Quality Control Requirements
The project team organization ensures attainment of QA objectives by:
• Assigning responsibility for performing work according to specifications
• Providing oversight of quality-related activities for verification of conformance with
specifications
• Defining the relationships between management and personnel performing
quality-related work Corrective Action
The Project Manager will prepare a summary of quality-related activities and problems.
This summary will be forwarded to EPA for inclusion in the project file. If deficiencies in the
program are identified, the Project Manager will identify recommendations for corrective
action
Communications. Lines of communication between project personnel and project
management staff will be appropriate to enable timely response to events that have the
potential to affect data quality. Project personnel will be provided with a project contact list that
includes telephone numbers for both routine communications and emergency notifications.
Copies of all written communications and written summaries of all substantive telephone
conversations will be placed in a permanent project file maintained by the EPA Project
Manager.
Communications will also entail ensuring that information on sample collection,
transportation, analysis, and storage; data acquisition, analysis, and reporting; personnel
assignments and activities; and other information pertinent to the project are
distributed to potentially affected personnel in a timely manner. Changes in procedures,
equipment, personnel, or other program elements as a result of an accident or emergency that
have the potential to affect data quality or achievement of overall program objectives will be
communicated to the Project Manager in writing in a timely manner.
Laboratory Responsibilities. The laboratory and its staff will have the responsibility for
processing all samples submitted according to the specific protocols for sample custody,
holding times, analysis, reporting, and associated laboratory QA/QC. Laboratory spikes,
duplicates, etc. will be performed.
B7 INSTRUMENT CALIBRATION and FREQUENCY
Air pumps and PID detectors will be tested and calibrated prior to then following the
sample collection field exercise. See Appendices E3 and E4 for calibration procedures.
Digital thermometers and hygrometers do not require calibration everyday of use. Ihese
instruments are calibrated by the manufacturer.
19
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EPA R8 North Dakota Flood Raaponae—QAPP for Hydrocarbon monitoring FRP-ESF #10
SOPs will identify requirements needed to be met by the laboratories to meet adequate
instrument calibration frequency, and QA/QC for raw data and reports.
C. ASSESSMENT OVERSIGHT
C1 ASSESSMENTS and RESPONSE ACTIONS
The EPA Scientific Support Coordinator will be on-site to oversee and inspect sampling
activities.
D. DATA VALIDATION and USABILITY
D1 DATA REVIEW, VALIDATION and VERIFICATION REQUIREMENTS
Data validation will consist of a) establishing an absolute range, acceptance limits
(screening criteria), and appropriate statistics for each data parameter, b) describing methods
for determining the disposition of suspect data, and c) documenting final disposition of invalid
or qualified data.
Direct comparison of individual residential sampling and analytical results with
toxicological benchmark criteria will be used to estimate the likelihood of health effects due to
inhalation of hydrocarbons at each residence.
if feasible, based upon sampling success, a one-tailed t-test will be used to compare
the four groups (flood-damaged homes reported to have severe, moderate and low odor and
control homes) (a two-tailed t-test is not used since any change in concentration of indoor fuel
oil hydrocarbon concentrations is expected to be one direction above background levels as per
EPA Risk Assessment Guidance). If there is statistical probability of a < 0.05 for flood
damaged residences being higher than reference areas, then reject the null hypothesis and
conclude that significant difference exists between the two groups for a particular
toxicologically-based benchmark concentration . Therefore, potential exposure of humans to
this indoor air concentration of fuel oil hydrocarbons would not be able to be screened out.
Conversely, if a > 0.05 for all hydrocarbon contaminant combinations in a study that is
reasonably well conducted with fairly homogeneous concentrations (i.e., no "hot-spots"), then
the null hypothesis is accepted and exposure via the inhalation route is not consequential and
is able to be screened out with no further evaluation being justifiable.
OA for data reduction and validation will ensure that the screening criteria are
comprehensive, unambiguous, reasonable, and internally consistent; and that data validation
activities are properly documented. Data discrepancy reports should be prepared describing
any data problems observed and any data correction activities undertaken.
20
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EPA R8 North Dakota Flood Response—QAPP Cor Hydrocarbon monitoring FRP-ESF #10
All data records should be cataloged and stored in their original form. Calibration
adjustments and adjustments to reduce data to standard conditions for comparability will be
clearly documented, and raw data clearly distinguished from "corrected" data (i.e., data to
which calibration and standardization adjustments have been applied).
Raw data and adjustments will be entered into a computer database and/or spreadsheet
for correction, statistical analysis, manipulation, formatting, and summarizing to reduce the
potential for human error. All data will be placed into MS Windows-based software such as MS
Office Access version 2.0 and Excel version 5.0, or newer.
D2 VALIDATION and VERIFICATION METHODS
Data reporting consists of communicating summarized data in a final form. OA for
reporting consists of measures intended to avoid or detect human error and to correct identified
errors. Such methods include specification of standard reporting formats and contents of
measures to reduce data transcription errors. Data will undergo peer review by qualified
reviewers capable of evaluating reasonableness of the data for the scientific design.
Reports: A report of all the summary study design characteristics, sample collections
and analyses, data quality and results shall be presented by the analytical laboratories. Simple
statistical tests of group treatment differences should be performed and presented as
discussed above and will be conducted by EPA. All raw data and summary results of both data
and summary statistics (means, standard deviations, ranges, etc.) should be tabulated by the
laboratories. Results should be interpreted to qualitatively estimate the relative frequency of
occurrence of toxicologic effects above reference levels. Study reports should be available
within 14 days of receipt of acceptable laboratory results and reports.
Data will be reviewed by project managers, EPA and State epidemiologists, and by a
peer review team (CDC/NIOSH) to assess data quality in accordance with DURA (1992) for this
Federal Response Plan site.
OA records and project files will be maintained in accordance with standard project
procedures. All QA records, logbooks, sample data forms, raw data summaries, and the like
will be maintained until written directions for their disposal are provided.
D3 RECONCILIATION with DQOs
The project team will review any results which fall outside the DQOs and decide (per
DURA 1992 and RAGS 1992) the extent of useability of results for risk assessment.
21
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EPA R8 North Dakota Flood Response—QAPP for Hydrocarbon monitoring FRP-ESF #10
REFERENCES:
EPA. 1992. DURA Data Useability for Risk Assessment.
EPA. 1992. RAGS Risk Assessment Guidance for Superfund.
EPA. 1994. Requirements for Quality Assurance Project Plans for Environemntal Data
Operations, Draft Interim Final QA/R-5 August, 1994.
EPA. 1994. Guidance for the Data Quality Objectives Process QA/G-4 September, 1994.
22
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Appendix E1: Exposure Questionnaire
-------
Appendix E1: Exposure Questionnaire:
QUESTIONNAIRE FOR SURVEY OF GRAND FORKS HOMES
The U.S. Environmental Protection Agency is conducting a survey
to investigate the extent of heating oil spills in homes impacted by
the recent flood along the Red River.
QUESTIONS:
Phone (Day): Phone (Eve):
Name:
Address:
How many people currently live in your home?
What are the ages and sex of the people living in your
house?
I #21 M/F I I #3) M/fl I #4)M/F
#S)M/F| | #6) M / F | | #7) M / F [ |#8)M/F
Is anyone in your home currently pregnant or nursing?
YES - Nursing _ NO
YES - Pregnant
Did you have a fuel oil spill in your home during the flood?
_ YES --—(go to question 4)
_ NO —(go to question 6)
4. Please rate the immediately post-flood odor from the oil
inside your house according to one of the following
categories:
No Odor
Low (occasional odor, but not a bother)
-------
_ Moderate (frequent unpleasant odor, but no other effects)
Severe (odor plus irritation of eyes, lungs, etc.)
5. Please rate the current odor from the oil inside your house
according to one of the following categories:
No odor remains
Low (occasional odor, but not a bother)
Moderate (frequent unpleasant odor, but no other effects)
Severe (odor plus irritation of eyes, lungs, etc.)
6. EPA will be collecting samples in the Grand Forks area in the near future.
If asked, would you permit an air sample to be collected from inside
your home? This would require a sampling team placing an air
monitoring unit in your home, and returning approximately 3-4 hours
later to retrieve it.
YES —(go to Question 7)
NO Thank you for participating
EPA is planning on sampling in late February, early March. If your home is
selected, what day and time would be most convenient for you?
Monday AM/PM Friday AM/PM
Tuesday AM / PM Saturday AM IPM
Wednesday AM / PM Sunday AM / PM
Thursday AM I PM
OTHER NOTES OR COMMENTS
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Appendix E2: Standard Operating Procedures for Air Sampling
-------
Standard Operating Procedures
for Indoor Air Sampling for Fuel Oil #2 at Homes in Grand Forks
using Personal Air Pumps and Sampling Tubes (Charcoal and Thermal Desorption)
1.0 Purpose
The protocols prescribed in this standard operating procedure (SOP) document the step-by-step
procedures for implementing the indoor air sampling program for selected homes in Grand Forks, ND for
the eventual quantification of heating oil present. There are two phases to this sampling program: 1) Set-
up and installation of personal air pumps and sampling tubes; and 2) Pick-up of sampling equipment and
tubes.
Sampling of fuel oil #2 in air samples will collected on two different sampling tubes: charcoal and
multi-bed thermal desorption tubes. Additionally a reading using a hand-held photoionization detector
(PID) will be taken at every home where quantification of fuel oil #2 is planned (approximately 41
homes). The objective of this procedure is to evaluate whether the PID can effectively quantify human
health risk levels of fuel oil concentrations inside affected homes.
2.0 Calibration of Field Equipment and Instrumentation
2.1 Personal Air Pumps: The personal air pumps must be calibrated twice daily, once before
using the pumps to collected air samples and immediately following completion of
sampling. The calibration procedures are detailed in another SOP.
2.2 PhotoioniTation Detector: The PID must be calibrated twice daily, once before any
readings are taken in the homes and at the end of the day after the last reading has been
taken. The calibration procedures are detailed in another SOP.
3.0 Set-up and Installation of Sampling Equipment
3.1 Equipment Set-up: The team leader will set up the sampling equipment in the basement of
selected homes.
3.1.1 The calibrated pumps should be placed in the breathing zone (approximately 4-6
feet above the floor).
3.1.2 Using an indelible marker (eg. Sharpie), mark on the sampling tube the date and
time the sampling begins. Also label the tube with the sample ID. See Section B2
of the quality assurance project plan (QAPP) for the procedures for identifying
samples.
3.13 The charcoal tube will be placed into the low volume air pump. Note the arrows
on the tube. This indicates the direction that the tube should be loaded. The
arrows identify the direction of air flow across the tube.
3.1.4
The thermal desorption tube will be placed into the very low volume air pump.
-------
Note the arrow on the tube. This indicates the direction that the tube should be
loaded. The arrows identify the direction of air flow across the tube.
3.1.5 Set the flow rate for the low volume pump (charcoal tube) at lL/min. Turn on the
air pump and note the time in the logbook the sampling was begun.
3.1.6 Set the flow rate for the very low volume pump (thermal desoiption tube) at 70
mL/min. Turn on the air pump and note the time in the field logbook the sampling
was begun.
3.2 Preliminary Observations: While one team member is setting up the sampling equipment,
the second team member will make notes and observations as detailed on the attached
sample logbook page.
4.0 Pick-up of Sampling Equipment
4.1 Equipment Pick-up: One member of the Pick-up Team will take down the sampling
equipment.
4.1.1 Turn off the low volume air pump (charcoal tube) and note the time in the field
logbook sampling was stopped.
4.1.2 Turn off the very low volume air pump (thermal desorption tube) and note in the
field logbook the time sampling was stopped.
4.1.3 Remove the charcoal and thermal desorption tubes from the air pumps.
4.1.4 Calibrate both the low volume and very low volume air pumps before leaving the
sampling location.
4.1.5 Note samples IDs on chain-of-custody forms and prepare for submission to
analytical labs.
4.2 Final Field Observations: While one team member is taking down the sampling
equipment, the second team member will make notes and observations as detailed on the
attached sample logbook page.
-------
Resident ID#:
Page of
Field Logbook Page for Indoor Air Sampling Using
Charcoal and Thermal Desorption Tubes
Project: Grand Forks - Hydrocarbon Date Sampled:
Team Members:
Resident Name:
Phone Number
Address:
Interview Questions/Observations:
1) Do you and/or any other residents smoke inside the house? Yes No
If yes, what is the combined estimate the residents smoke indoors (packs/week)?
2) What type of heating did you use prior to the flood (% of each type)?
Fuel Oil Furnace Natural Gas Fireplace/Wood Stove
Electric Other (list)__
3) What type of heating do you use now (post-flood) (% of each type)?
Fuel Oil Furnace Natural Gas Fireplace/Wood Stove
Electric Other (list)
4) Have you done any cleanup of the oil? If so, what type?
5) How much time do you spend in the basement?
6) Basement Composition:
7) Notes:
Risk/Grand Forks/SAPP-QAPP/Logbook Page.doc
-------
Resident ID#: Page of
Drop-Off Sampling Information:
Pre-calibration by:
VLV Pump Serial #: Time:
LV Pump Serial #: Time:_
Sample ID# charcoal tube:
TD tube:
Flow rates (L/min): VLV: LV:
Time Sampling Begun:
PID Reading (ppm):
Temperature (° F/C):
Relative Humidity (%):
Notes:
Visual observations of heating oil sources or other sources of volatile compounds
(gas cans, smoking, cooking,)
Hydrocarbon staining
Approximate coverage: Floor Walls Ceiling
Are gas cans or gas powered equipment visible?
Are paint or solvent containers visible? (circle which are present)
Olfactory observation of heating oil or other sources (gas, smoke, cooking)
Fuel Oil Odor: Smoke Odor:
Severe (3) Severe (3)
Moderate (2) Moderate (2)
Slight (1) Slight (1)
None observed (0) None observed (0)
Gasoline/Paint or Solvent Odor: Oily/Greasy Cooking Odor:
Severe (3) Severe (3)
Moderate (2) Moderate (2)
Slight (1) Slight (1)
None observed (0) None observed (0)
Risk/Grand Forks/SAPP-QAPP/Logbook Page.doc
-2-
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Resident ID#:
Page of
Pick-up Sampling Information:
Post-calibration by:
VLV Pump Serial #: Time:
LV Pump Serial #:_ Time:
Flow rates (L/min): VLV: LV:
Time Sampling Ended:
Total Air Volume:
PID Reading (ppm):__
Temperature (° F/C):
Relative Humidity (%):
Notes:
Does the pump/sampling equipment appear disturbed? No Yes
If yes, describe
Visual observations of heating oil sources or other sources of volatile compounds
(gas cans, smoking, cooking,)
Hydrocarbon staining
Approximate coverage: Floor Walls Ceiling
Are gas cans or gas powered equipment visible?
Are paint or solvent containers visible? (circle which are present)
Olfactory observation of heating oil or other sources (gas, smoke, cooking)
Fuel Oil Odor: Smoke Odor:
Severe (3) Severe (3)
Moderate (2) Moderate (2)
Slight (1) Slight (1)
None observed (0) None observed (0)
Gasoline/Paint or Solvent Odor: Oily/Greasy Cooking Odor:
Severe (3) Severe (3)
Moderate (2) Moderate (2)
Slight (1) Slight (1)
None observed (0) None observed (0)
Risk/Grand Forks/SAPP-QAPP/Logbook Page.doc
-3-
-------
ADDITIONAL NOTES FOR THIS RESIDENCE:
Risk/Grand Forks/SAPP-QAPP/Logbook Page, doc
-------
Resident ID#:
Page of
USE THIS PAGE ONLY FOR DUPLICATE SAMPLES
Drop Off Information:
VLV Pump Serial
LV Pump Serial #:
Flow rates (L/min): VLV
Pre-calibration by:
Time:
Time:
LV:
Sample ID# charcoal tube:_
TDtube:
Time Sampling Begun
PID Reading (ppm):
Temperature (° F/C):
Relative Humidity (%):_
Proximity to Primary Sampler
Notes:
Pick-up Information:
VLV Pump Serial #:
LV Pump Serial #:
Flow rates (L/min): VLV:_
Time Sampling Ended:
Total Air Volume:
PID Reading (ppm):
Temperature (° F/C):
Relative Humidity (%):
Notes:
Post-calibration by:
Time:
Time:
LV:
Does the pump/sampling equipment appear disturbed?
If yes, describe
No
Yes
Risk/Grand Forks/SAPP-QAPP/Logbook Page.doc
-5-
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Designation: D 3686 - 89
Standard Practice for
Sampling Atmospheres to Collect Organic Compound Vapors
(Activated Charcoal Tube Adsorption Method)1
This standard is issued under ihe fixed designation D 3686; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last ^approval. A
superscript epsilon («) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This practice covers a method for the sampling of
atmospheres for determining the presence of certain organic
vapors by means of adsorption on activated charcoal using a
charcoal tube and a small portable sampling pump worn by a
worker. A list of some of the organic chemical vapors that
can be sampled by this practice is provided in Annex Al.
This list is presented as a guide and should not be considered
as absolute or complete.
1.2 This practice does not cover any method of sampling
that requires special impregnation of activated charcoal or
other adsorption media.
1.3 This standard may involve hazardous materials, oper-
ations, and equipment. This standard does not purport to
address all of the safety problems associated with its use. It is
the responsibility of the user of this standard to establish
appropriate safely and health practices and determine the
applicability of regulatory limitations prior to use. A specific
safety precaution is given in 9.4.
2. Referenced Documents
2.1 ASTM Standards:
D 1356 Terminology Relating to Atmospheric Sampling
and Analysis2
D 3687 Practice for Analysis of Organic Compound Va-
pors Collected by the Activated Charcoal Tube Adsorp-
tion Method2
2.2 NIOSH Standard:
CDC-99-74-45 Documentation of NIOSH Validation
Tests3
HSM-99-71-31 Personnel Sampler Pump for Charcoal
Tubes; Final Report3
2.3 OSHA Standard:
CFR 1910 General Industrial OSH A Safety and Health
Standard4
3. Terminology
3.1 For definitions of terms used in this method, refer to
Terminology D 1356.
1 This practice is under the jurisdiction of ASTM Comniillcr 0-22 on
Sampling and Analysis of Atmospheres, and is the direct responsibility of
Subcommittee D22.04 on Analysis of Workplace Atmospheres.
Current edition approved May 26. 19X9. Published July 1989. Originalh
published as D 3686 - 78. Last previous edition D 3686 - 84.
2 Annual Book vl'ASTM Standards. Vol 11.03.
s Available from the U.S. Department of Commerce. National Technical
Information Service. Port Royal Road. Springfield. VA 22It)I.
"* Available from Superintendent of Documents. U.S. Government Printing
Office, Washington. DC 30401.
3.2 Activated charcoal refers to properly conditioned
coconut-shell charcoal.
4. Summary of Practice
4.! Air samples are collected for organic vapor analysis by
aspirating air at a known rate through sampling tubes
containing activated charcoal, which adsorbs the vapors.
4.2 Instructions are given to enable the laboratory person-
nel to assemble charcoal tubes suitable for sampling purposes.
4.3 Instructions are given for calibration of the low
flow-rate sampling pumps required in this practice.
4.4 Information on the correct use of sampling devices is
presented.
4.5 Practice D 3687 describes a practice for the analysis of
these samples.
5. Significance and Use
5.1 Promulgations by the Federal Occupational Safety
and Health Administration (OSHA) in 29 CFR 1910.1000
designate that certain organic compounds must not be
present in workplace atmospheres at concentrations above
specific values.
5.2 This practice, when used in conjunction with Practice
D 3687, will provide the needed accuracy and precision in
the determination of airborne time-weighted average concen-
trations of many of the organic chemicals given in 29 CFR
1910.1000, CDC-99-74-45 and HSM-99-71-31.
5.3 A partial list of chemicals for which this method is
applicable is given in Annex Al, along with their OSHA
Permissible Exposure Limits.
6. Interferences
6.1 Water mist and vapor can interfere with the collection
of organic compound vapors. Humidity greater than 60 %
can reduce the adsorptive capacity of activated charcoal to
50 % for some chemicals (l).3 Presence of condensed water
droplets in the sample tube will indicate a suspect sample.
7. Apparatus
7.1 Charcoal Tube:
7.1.1 A sampling tube consists of a length of glass tubing
containing two sections of activated charcoal which arc held
in place by nonadsorbant material and sealed ai each cud.
7.1.1.1 Sampling tubes are commercially available. The
tubes range in size from 100/50 to 800/400 mg, which means
the lubes are divided into two sections with the front section
1 The boldface numbers in parentheses refer to the list of references at the end
of this standard.
200
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# D 3686
Direction of Airflow
Plug of
Glass Wool
100mg 20/40-Mesh
Activated Charcoal
Glass Tube
4mm ID
6mm OD
70mm Long
Flame-Sealed Ends
2mm Urerhane Foam
50mg 20/40-Mesh
Activated Charcoal
FIG. 1 Activated Charcoal Adsorption Sampling Tube
ontaining 100 to 800 mg of activated charcoal and the back
ection containing 50 to 400 mg of activated charcoal. The
00/50-mg tube ((2, 3, 4) and Fig. I) which is the one most
requentlv used, consists of a glass tube, 70-mm long. 6-mrti
>uts\dc diameter, 4-mm inside diameteT, and contains two
ections of 20/40 mesh-activated charcoal but separated by a
!-mm section of urethane foam. The front section of 100 mg
s retained by a plug of glass wool, and the back section of 50
ng is retained by either a second 2-mm portion of urethane
oam or a plug of glass wool. Both ends of the tube are
lame-sealed.
Note I—Ureihane foam is known to adsorb cenain pesticides (5),
which this practice is contraindicated.
7.1.1.2 When it is desirable to sample highly volatile
ompounds for extended periods, or at a high volume flow
ate, a larger device capable of efficient collection can be
'sed, provided the proportions of the tube and its charcoal
ontents are scaled similarly to the base dimensions, to
'rovide nominally the same linear flow rate and contact time
'ith the charcoal bed.
7.1.2 The back portion of the sampler tube, which may
ontain between 25 and 100 % of the mass of activated char-
°al present in the front section, adsorbs vapors thai peric-
yte the front section and serves as a warning that break-
hrough may have occurred. (Annex AI gives recommended
Maximum lube loading information for many chemicals.)
7.1.2.1 Should analysis of the back portion show it to
Ontain more (fian 20 % of" (fie total amount of vapor coi-
ned (or 25 % of the amount found in the front section), the
fissibilitv exists that solvent vapor penetrated both sections
charcoal, and the sample must be considered suspect,
^hese percentages apply to 100/50-mg tubes. For other sire
Ubcs having disproportionate amounts of charcoal in the
<*ont and back sections, the percentages used to indicate
'pteniial breakthrough must be adjusted to take into account
Afferent ratios of charcoal. If results from the analysis of
Aspect samples are used to calculate vapor concentrations,
he results must be reported as equal to or greater than the
-alculated concentrations. In such cases, the test must be
ePeated for confirmation of vapor concentration.
Note 2—Reportings from suspect samples would have significance
Jhen health standards are clearly exceeded and the amoiinl by which
ire exceeded is academic. (See V.5-)
7,1.3 jhe adsorptive capacity and desorption efficiency of
'Herent batches of activated charcoal may vary. Commer-
"'a' lubes, if used, should be purchased from the same batch
and in sufficient number to provide sampling capacity for a
definite period of time. Care must be taken to have enough
tubes from (he same hatch for a given study.
7.1.3.1 The desorption efficiency and contamination level
of a batch of tubes should be determined, following the
procedure outlined in Practice D 3687 for activated charcoal.
A random selection of at least five charcoal tubes from a
specified lot should be taken for these checks.
7.1.4 Pressure drop across the sampling tube should be
less than 25 mm Hg (3.3 kPa) at a flow rate of 1000 mL/min
and less than 4.6 mm Hg (0.61 kPa) at a flow rate of 200
mL/min.
7.1.5 Charcoal sampling tubes prepared in accoitiance
with this practice and with sealed glass ends may be stored
indefinitely.
7.2 Sampling Pumps:
7.2.1 Any pump whose flow rate can be accurately
determined and be set at the desired sampling rate is suitable.
Primarily though, this practice is intended for use with small
personal sampling pumps.
7.22 Pumps having stable low flow rates (10 to. 200
mL/min) are preferable for long period sampling (up to 8 h)
or when the concentration of organic vapors is expected to
be high. Reduced sample volumes will prevent exceeding the
adsorptive capacity of the charcoal tubes. (Suggested flow
rates and sampling times are given in Annex A1 for
anticipated concentration ranges. Sample volumes are also
discussed in 9.5.)
7.2.3 Pumps are available that will provide stable flow
rates between ±5 %. Pumps should be calibrated before and
after sampling. If possible, flow rates should be checked
during the course of the sampling procedure.
7.2.4 All sampling pumps must be. carefully calibrated
with the charcoal tube device in the proper sampling posi-
tion. (See Annex A2 for calibration procedure.)
8. Reagents
8.1 Activated Coconut-Shell Charcoal— Prior to being
used to make sampling devices the charcoal should be heated
in an inert gas to 600°C and held there for I h. Commercially
available coconut charcoal (20/40 mesh) has been found to
have adequate adsorption capacity. Other charcoals can be
used for special applications.
9. Sampling with Activated Charcoal Samplers
9.1 Calibration of the Sampling System—Calibrate the
sampling system, including pump, flow regulator, tubing to
->AI
-------
Cfe D 3686
be used, and a representative charcoal tube (or an equivalent
induced resistance) with a primary or calibrated secondary
flow-rate standard to ±5%.
9.1.1 A primary standard practice is given for the calibra-
tion of low flow-rat? pumps in Annex A2 and Fig. A2.1.
9.2 Break open both ends of the charcoal tube to be used
for sampling, ensuring that each opening is at least one half
the inside diameter of the tube.
9.3Insert the charcoal tube into the sampling line, placing
the back-up section nearest to the pump. At no time should
there be any tubing ahead of the sampling tubes.
9.4 For a breathing zone sample, fasten the sampling
pump to the worker, and attach the sampling tube as close to
the worker's breathing zone as possible. Position the tube in
a vertical position to avoid channeling of air through the
adsorber sections.
Note 3: Warning—Assure that the presence of the sampling equip-
ment is not a safety hazard to the worker.
9.4.1 Turn on the pump and adjust the flow rate to the
recommended sampling rate.
9.4.2 Record the flow rate and starting time or, depending
on the make of pump used, the register reading.
9.5 Sampling Volumes—The minimum sample volume
will be governed by the detection limit of the analytical
method, and the maximum sample volume will be deter-
mined by either the adsorptive capacity of the charcoal or
limitations of the pump battery.
9.5.1 One method of calculating required sample volumes
is to determine first the concentration range, over which it is
important to report an exact number, for example from 0.2
to 2 times the permissible exposure concentration, and then
calculate the sample volumes as follows:
Minimum sample volume,
minimum detection limit, mg
0.2 x permissible exposure limil,mg/m3
Maximum sample volume, m3
tube capacity for vapors, mg
2 x permissible exposure limit, mg/m3
9.5.2 Select a sampling rate that, in the sampling time
desired, will result in a sample volume between the min-
imum and maximum calculated in 9.5.1.
9.5.2.1 Generally a long sampling time at a low flow rate
is preferable to short-term high-volume sampling. This is
consistent with the fact that most health standards are based
on 8-h/day time-weighted averages of exposure concentra-
tions.
9.5.2.2 A sample flow rate of less than 10 mL/min,
however, should not be used. Calculations based upon
diffusion coefficients for several representative compounds
indicate that sampling at less than 10 mL/min may not give
accurate results.6
9.5.2.3 Approximate sample volumes and sample times
are given in Annex A1.
9.5.3 When spot checks are being made of an environment,
a sample volume of 10 L is adequate for determining vapor
concentrations in accordance with exposure guidelines.
* Heitbrink, W. A., "Diffusion Effects Under Low Flow Conditions," American
Industrial Hygiene Association Journal, Vol 44, No. 6, 1983, pp. 453-462.
9.6 At the end of the sampling period recheck the flow
rate, turn off the pump, and record all pertinent information:
time, register reading, and if pertinent, temperature, baro-
metric pressure, and relative humidity.
9.6.1 Seal the charcoal tube with the plastic caps provided.
9.6.2 Label the tube with the appropriate information to
identify it.
9.7 At least one charcoal sampling tube should be pre-
sented for analysis as a field blank with every 10 or 15
samples, or for each specific inspection or field study.
9.7.1 Break the sealed ends oftthe tube and cap it with the
plastic caps. Do not draw air through the tube, but in all
other ways treat it as an air sample.
9.7.2 The purpose of the field blank is to assure that if the
sampling tubes adsorb vapors extraneous to the sampling
atmosphere, the presence of the contaminant will be detected.
9.7.3 Results from the field blanks shall not be used to
correct sample results. If a field blank shows contamination,
the samples taken during the test must be assumed to be
contaminated.
9.8 Calculation of Sample Volume:
9.8.1 For sample pumps with llow-rate meters:
Sample volume, mL = /x t ^ "\J~jT x
where:
/ = flow rate sampled, mL/min,
l = sample time, min,
P, = pressure during calibration of sampling pump (mm Hg
or kPa)
P2 = pressure of air sampled (mm Hg or kPa)
T, - temperature during calibration of sampling pump (K),
and
7% = temperature of air sampled (K).
9.8.2 For sample pumps with counters:
Sample volume, mL
{R2 - R,) x V />, 298
/ X 760 X T, + 273
where:
R2 = final counter reading,
/?, = beginning counter reading.
V = volume, (i) mL-count (1)
Pt = barometric pressure, mm Hg,
T, = temperature, °C, and
V = total sample volume, mL.
10. Handling and Shipping of Samples Collected on Char-
coal Sampling Tubes
10.1 There is a paucity of information on the possible fate
of the many different chemical species that can be collected
in activated charcoal and the variety of conditions to which
these samples may be exposed. Good practice suggests the
following:7
7 Two recent studies that present information peninent to this section ate:
Saalwaechter, A. T., el al. "Performance Testing of the NIOSH Charcoal Tube
Technique for the Determination of Air Concentration*«f Organic Vapors."
American Industrial Hygiene Association Journal, Vol JMt No. 9. September
1977, pp. 476-486.
Hill, R- H., Jr., et al, "Gas Chromatographic Determination of Vinyl Chloride in
Air Samples Collected on Charcoal," Analytical Chemistry. Vol 48, No. 9.
August 1976, pp. 1395-1398.
202
-------
# 0 3686
. 1 Samples should be capped securely and identified
.2 Samples collected in charcoal tubes should not be
i warm places or exposed to direct sunlight.
.3 Samples or highly vaporous or low-boiling mate-
uch as vinyl chloride, should be stored and transported
ice.
1.4 At present there are no published test data on the
of conditions in aircraft cargo holds on capped
es. The preferred procedure is to carry the samples on
1-5 Samples should be shipped as soon as possible,
1 under refrigeration until they are analyzed, and
zed if possible within 5 working days.
10.1.6 Migration or equilibration of the sampled materia!
within the sampling tube during prolonged or adverse storage
or handling could be interpreted as break-through. This can
be prevented by separating the front and back sections
immediately after sampling, by having each section in a
separate tube and capping them separately.
10.1.7 In some situations, circumstances and facilities
may permit making up calibration standards at the facility
where the study is being made and submitting these stand-
ards as quality control checks. (See Practice D 3687 for
recommended procedure for making up standards.)
10.1.8 Bulk solvent samples should never be shipped or
stored with the collected air samples.
ANNEXES
(Mandatory Information)
A1. INFORMATION OF SOME ORGANIC COMPOUND VAPORS THAT CAN BE COLLECTED ON COCONUT-SHELL CHARCOAL
(100/50 mg tubes)
Substance PEL
Ppm-mg/m3'*
Recommended Sampling
Rate, mL/min to Detect Ap-
proximately 15 to 200 X of
PEL in Time Given 8
2h
4h
8h
Recommended
Maximum
Tube Load-
ing, mg°
Approximate
Desorption Ef-
ficiency X e
Eluent
GC Column F
CVT<
>e. 1000-2400
40-70
'coM, 2-4.8
"I acetate, 100-525
Tiyl acetate, 125-650
y alcohol, 100-360
¦ne, 10-31.3
'I chloride. 1-5
>«ne. 1000-2200
«y ethanol, 50-240
yt acetate. 150-710
"tyl acetate. 200-950
u'yl acetate. 200-950
alcohol, 100-300
utyl alcohol, 150-450
utyl alcohol. 100-300
9'ycidyl ether. 50-270
-Sutyl toluene. 10-60
^or, 2-12.5
disulfide, 20-60
>n tetrachloride. 10-65
obenzene. 75-350
otwomomethane 200-1050
olorm. 50-240
>ne. 50-245
>he*ane, 300-1050
>hexanol. 50-200
lhexanone, 50-200
Jliexene, 300-1015
'tone alcohol. 50-240
rt|orobenzene S0-300
"chloroe thane. 100-405
10
50
200
50
50
50
100
10
100
50
50
50
100
50
50
100
100
200
200
200
50
25
100
50
25
100
100
25
100
50
50
25
100
25
25
25
100
200
c
50
25
25
25
50
25
25
50
50
100
100
100
25
10
50
25
10
50
50
10
50
25
25
c
9
86 ± 10
cs2
3
0.082
25
2.7
0.072
50
<0.4
89 ± 5
CSj + 5 X 2-propanol
2
0.11
10
15
86*5
CS2
4
0.051
10
15.5
91 + 10
CSj
4
0.071
10
10
CSj + 5 X 2-propanol
2
0.077
50
96
CSj,
1
0.060
200
<0.4
90+ 5
CSj
2
0.096
c
4
CSj
1
0.058
25
99 ± 5
methylene chloride +
5X methanol
2
0.060
10
15
95
CSj
4
0.069
10
15
91 ± 5
CSj
4
0.054
10
12.5
94 + 5
CSj
4
0.091
25
10.5
88+5
CSj + 1 X 2-propanol
2
0.065
10
6
93 t 5
CS2 + 1 X 2-propanol
2
0.066
to
5
90 + 5
CSj + 1 X 2-propanol
2
0.075
25
11.5
86+10
CS2
0 074
25
2.5
100+
CSj
2
0.067
50
13.4
98 + 5
CS3 + 1 X methanol
2
0.074
50
95
benzene
8
0.059
50
7.5
97 + 5
CSs
1
0.092
10
15.5
90 + 5
CSj
2
0.056
c
9.3
94 ± 5
CSj
2
0.061
25
11
96 + 5
CSj
1
0.057
10
11
100+
CSj
2
0.059
c
6.3
100+
CSs
3
0.066
25
25
c
10
99 + 5
CS2 + 5 % 2-propanol
2
0080
13
78 + 5
CSj
2
0.062
100+
CS2
3
0.073
25
10
12
77 + 10
CS2 + 5 X 2-propanol
2
0.101
15
85 + 5
CSj
6
0.067
10
7 5
100+
CSj
2
0.057
203
-------
# D 3686
A1 Continued
Substance PEL
ppm-mg/m5'*
Recommended Sampling
Rate. mL/mln to Detect
Approximately 15 to 200 X
ol PEL in Time Given *
Recommended
Maximum
Tube Load-
Approximate
Desorption El-
Eluent
GC Column'
CV,C
2h
4h
Bh
ing. mg
25
10
c
5.1
100+
CS,
2
0.052
100
50
25
13
91 ± 5
CS,
1
0.054
25
10
c
75 + 15
CS,
2
0064
50
25
10
19
74+ 10
CS,
4
0.062
25
10
c
12.5
89 + 5
CS,
4
0.058
200
100
50
<5
95 + 5
CS*
4
0.054
c
c
c
2.6
77 ± 10
CS, + 1 X 2-butanol
2
0.065
200
100
50
16
100+
CS,
2
0.041
100
50
25
7.1
83+5
isopropanol
2
0.054
50
25
10
<5.5
93 ± 5
CS, + 1 X methanol
2
0.086
10
c
c
7.5
98 ±5
ethyl acetate
3
0.053
50
25
10
4.8
80 ± 10
CS;
1
0.074
100
50
25
<10.7
93 ± 5
CS,
2
0.077
100
50
25
12
95+5
cs,
6
0.079
100
50
25
22.5
90 ± 5
tetrahydroturan
2
0080
10
c
c
12.5
96 ± 5
CS,
6
0.056
10
c
c
11
94 ± 5
cs,
1
0.062
50
25
10
16.5
90 ± 5
CS,
4
0.056
50
25
10
10
99+5
CS, + 5 X 2-propanol
2
0.065
50
25
10
14
92 ±5
CS,
4
0.065
50
25
10
10.5
84 ± 10
CS, + 1 X 2-propanol
2
0.073
25
10
c
13
85 ± 5
CSj
4
0.067
25
10
c
5.6
94 ± 5
CS2 + 1 X 2-butanol
2
0.064
100
50
25
10.5
80 £ 10
CS,
2
0.067
100
50
25
4.8
79 ± 5
CS, + 1 X methanol
2
0.071
25
10
c
7
88 ± 5
CS,
1
0.055
200
100
50
<1.5
00 ±10
CS,
4
0.066
10
c
c
11.5
78 ± 10
hexane
3
0.06
50
25
10
7.5
80+10
CS, + 1 X methanol
2
0 061
50
25
10
2.0
79 ± 10
CS,
2
0.053
100
50
25
10
97 + 5
methylene chloride + 5 X
2
0.068
methanol
100
50
25
5
76 ± 10
CS,
4
0.068
25
10
c
18
98+
CS,
6
0.054
10
c
c
95 t 5
CS,
1
0.052
50
25
10
9.5
89+10
CS,
2
0.072
200
100
50
57
99 ± 5
CS, + 5 X 2-propanol
2
0.080
100
50
25
21
91 ± 5
CS,
2
0054
10
c
c
9.3
95 ± 5
CS,
1
0.073
100
50
25
14.8
88 ± 5
CS,
7
0.051
10
c
c
15
93 ± 5
CS,
1
0 060
10
c
c
9
96 + 5
CS,
1
0055
25
10
c
88 ± 5
CS,
2
0.063
50
25
10
29
95 ± 5
CS,
e
0.052
10
c
c
12 3
96 + 5
OS,
6
0.052
200
200
0.6
90 ± 5
CS,
2
0070
100
50
25
12.5
97 ± 5
CS,
2
0.057
50
25
10
14 5
93 ± 5
CS,
4
0056
50
25
10
9
87 ± 5
CS2 + 1 X 2-propanol
2
0.075
50
25
10
5
97 ± 5
CS,
2
0056
25
10
c
2
9015
CS,
3
0.085
200
100
50
<7.3
70+ 10
cs,
0.059
10
c
c
13
96± 5
CS,
7
0.05?
100
50
25
18
87 ±5
CS,
2
0.057
10
c
c
19.5
100+
CS,
2
0.069
10
c
c
26
96 + 5
CS,
2
0.054
25
10
c
7.5
92 ± 5
CS,
3
0.055
100
50
25
5
96 ± 5
CS,
6
0.057
100
50
25
21
96 ± 5
CS,
6
0.082
10
c
c
20
100+
CS,
5
0.07
50
25
10
13
96 ± 5
CS,
7
0.055
100
50
25
17
85 ± 10
CS,
2
0058
l^-OicNaroethylene. 200-790
p-Ooxjne. 100-360
Dipropylene glycol methyl ether.
100-600
2-Ettiaxyethyl acetate. 100-500
Etnyt acetate. 400-1400
Ethyl acrylate, 25-100
Ethyl alcohol. 1000-1885
Ethyl benzene. 100-435
Ethyl bromide. 200-890
Ethyl butyl ketone. 50-230
Ethyl ether 400-1210
Ethyl formate. 100-300
Ethylene bromide. 20-155
Ethylene dichkxWe. 50-202.5
Gtyodol 50-150
Heptane. 500-2000
Hexane, 500-1600
isoamyt acetate, 100-525
ttoamyl alcohol. 100-360
laobutyl acetate. 150-700
hobutyl alcohol, 100-305
Isopropyl acetate, 250-950
Isopropyl alcohol 400-985
Isopropyl glycidyl ether. 50-240
Mesityl oxide, 25-100
Methyl acetate. 200-610
Methyl acrylate. 10-35
MethyW. 1000-3110
Methyl amyl Ketone. 100-465
Methyl butyl Ketone, 100-410
Methyl cettosotve. 25-80
Methyl cetosoive acetate,
25-120
Methyl chloroform, 350-1900
Methyl cyclohexane, 500-2000
Methyt ethyt ketone. 200-590
Methyl Isotoutyl carbinol, 25-105
a-Metfty< styrene. 100-480
Methylene cMoride, 500-1740
Naphtha (ooal tar). 100-400
"-octane, 600-2350
Pentane, 1000-2950
2-Pentenone, 200-700
Parchloroethylene. 100-680
Petroleum distillates. 500-2000
Phenyl ethet vapor, 1-7
Phenyl glycidyl ether, 10-59
"•Propyl acetate. 200-840
"-Propyl alcohol. 200-490
Propylene dichloride, 75-350
Propylene oxide. 100-240
Pyridine, 5-15
Stoddard solvent. 500-2950
Styrene (monomer), 100-425
1 -1.1,2-Tetrachloro-2,2-dinuoro-
•thane. 500-4170
' .1,2-Tetrachtoro-1,2-difluoro-
•Ihane, 500-4170
Tetrahydroluran, 200-590
' -1,2-T richtoroethane, 10-55
Trichkxoethylene. 100-535
'•1.2-Trichk*o-1.2.2-tnthjoroethane.
1000-7660
Turpentine. 100-560
toluene. 100-480
204
-------
lib D 3686
A1 Continued
* Substances—The list does not contain all compounds for which the method is applicable. It lists only those lor which reliable data could be obtained. PEL-t-eoerai
Permissible Exposure Limits, as given in the Federal Register, June 1974, and updated May 1976. These values, which may be either ceiling limits or 8-h/day average
exposure limits, depending on the compound, are presented to give guidance in selecting sampling rates and times. These values are subject to change by the Federal
Occupational Safety and Health Administration.
" Recommended Sampling Rate—The suggested sampling rates for the different sampling periods are sufficient to provide a tube loading of at least 0.01 mg when
concentrations are 15 % of the PEL., but win not exceed the recommended tube loading when atmosphere are 200 % of the PEL. These figures are based on the 100-mg
coconut-shed charcoal tubes described in this practice.
c Sample rates of less than 10 mL/min are not recommended. Shorter sampling periods are required.
" Recommended Maximum Tube Loading—These values are conservative, to allow for high humidity or the presence of other substances which reduce the normal tube
capacity.
E Approximate Desorption Efficiency—These Figures are given only as guides for carrying out system calibrations. Actual desorption efficiencies should always be
determined at the time of analysis, and any significant deviation should be regarded as a possible indication of a systematic error in the analytical technique. The figure given
for desorption efficiency is an average figure. The desorption efficiency for a compound will vary with the amount: in most cases, the desorption efficiency will be lower for
reduced tube loadings.
f Gas Chromatographic Columns—key:
1—20-ft x 1/8 in: ss packed with 10 X FFAP on Chromosorb W AW
2—10-ft x 1/8 in: ss packed with 10 X FFAP on Chromosorb W AW
3—4-ft x 1/4 in: ss packed with 60/80 Porapak Q
4—10-fl x 1/8 in: ss packed with 5 X FFAP on Supelcoport
5—6-ft x 1/4 in: ss packed with 60/80 Porapak Q
6—10-ft x 1/8 in: ss packed with 10% OV-101 on Supelcoport
7—6-ft x 1/8 in: ss packed with 1.5 % OV-101 on Chromosorb W AW
8—6-ft x 1/4 in: Glass column packed with 5 X OV-17 on Supelcoport
0 CVT—Coefficient of variation (that is, relative standard deviation) of the total (net) error in the method (including variability of the pump).
CVr - (CV^ef + cvs! + CVV2
where:
* coefficient of variation of a single future assay including error in the desorption efficiency factor Of.
CVS = coefficient of variation due to sampling errors (not including variable of the pump) along with variability in true desorption efficiency from tube-to-tube, ana
¦» coefficient of variation due to pump [CVP m 0.O5 assumed).
Acknowledgements: The information in this table comes from NIOSH Standards Completion Program." We gratefully acknowledge NIOSH's contribution to this table,
making available previously unpublished CVT data, and we acknowledge having used summaries of SCP data prepared by MDA Scientific. Inc., Park Ridge, IL, SKC
Corp.. Eighty-Four, PA, and Supelco, Inc.. Betefonte. PA.
'Taylor, D. G„ Kupel, R. E., and Bryant, J. M., "Documentation of NIOSH
Validation Tests," DHEW (NIOSH). Pub. No. 77-185. Available from National
Technical Information Service, Springfield, VA 22161 (PB274-248).
A2. METHOD FOR CALIBRATION OF SMALL VOLUME AIR PUMPS
A2.1 Using a buret that approximately represents a 1-min
sampling volume, assemble the apparatus as shown in Fig.
^2.1 using any good soap bubble solution as a source of the
film. Make sure all connections are tight.
A2.1.] It is advisable to check the volume of burets used
0r calibrating sampling pumps by weighing the volume of
*ater contained in the buret and calculating the true volume.
^2.1.2 Make sure the batteries of the pump are charged.
. ^^.2 prime the surface of the cylinder with bubble solu-
hon by drawing repeated films up the tube until a single film
travels to the desired mark.
A2.3 With a stop watch, time the travel of a single film
from an initial zero mark to a selected volume mark. Note
the time and repeat this procedure at least three times.
A2.4 Calculate the sampling rate of the pump, correcting
the air voiume to 25°C and 760 mm Hg (101.3 kPa), using
the ambient barometric pressure.
A2.5 Replace the charcoal tube sampler with another one
selected at random, and repeat the calibration sequence.
A2.5.1 Sampling tubes should consistently meet the pres-
sure drop criterion given in 7.1.4.
205
-------
D 3686
Tubing
^ d
500
fW
\
Trap
Soap Bubble
Meter
(Inverted Buret)
Beaker
Soap Solution
ii
ft
1
Activated
Charcoal
Sampling
Tube
7
rers
Personnel
Sampling Pump
Manometer
FIG. A2.1 Calibration Setup (or Personnel Sampling Pump with Activated Charcoal Sampling Tube
REFERENCES
1) "Second NIOSH Solid Sorbents Roundtable," Ed. E. V. Ballou.
1976, NIOSH Publication No. 76-193.
2) White, L. D., Taylor, D. G., Mauer, P. A.. an
-------
Appendix E3: Standard Operating Procedures for Calibration of Low Volume and Very
Low Volume Personal Air Monitoring Pumps
-------
Section 3
Theory of Operation
1. Primary Airflow Standard
To be a primary standard, all values must be absolute and-measured as
absolute. A primary standard airflow measurement Is a volume divided by a.
time interval as performed by the Control Unit of the Calibrator. The volume,
V, is a measured volume of space between two infrared sensors. The time is
that interval needed for a soap film bubble to traverse between the two sensors
which bound the volume. Therefore, V/t, the volume per unit of time, becomes
the airflow and is prime because all measurements are basic.. .volume and time.
In today's technology, time is measured by an electronic clock whose accuracy
exceeds that of volume measurements by orders of magnitude, hence, the con-
trol accuracy volume resides solely with volume measurements.
2. Bubble Generation and measurement
a) The Cilibrator consists of two elements, the Flow Cell Assembly and
the Control Unit (base). The function of the Flow Cell Assembly is to generate
a clean consistent bubble which traverses up the flow tube. Measurement of the
traverse time is done by infrared sensor pairs which are mounted at the bottom
and the top of the Sensor Block. The volume bound by these sensors is speci-
fically adjusted to a volume standard by allowing the upper sensor blocks to
move in unison so as to enable this calibration to be set accurately to a primary
volume standard. A seconds function of the sensor block provides the Interfacing
code to define the cell volume as well as sensitivity adjustments for the optical
sensor systems.
b) As tl?e bubble traverses between the sensors, first one and then the
second, sensors are tripped thereby providing the tme for the bubble
traverse. This timing information is sent to the micro processor of the control
base which in turn provides the crystal control time base for the system. The
timing information along with the volumeinformation are then sent to the micro
processor which in turn does the necessary mathematical calculations which allow the
flow to be displayed directly on the LCD readout. In order to insure the highest
accuracy possible, a Delete and Average function are provided on the Control Unit.
The Delete allows for subtracting out an obvious malformed bubble and the average
allows the user to obtain average information without pencil or paper. A printer
interface allows connection of a Printer Module so that hard copy can be produced.
-------
Section 4
Operating Procedures
1. Initial Set-up
This covers all steps necessary to bring the Cilibrator into
operating status. This includes charging, cell mounting, installing
soap solution, connecting the printer (optional) and connecting the
sampling source.
A) Charging the Cilibrator for Operation
1. Prior to operation, plug the 120V charger into the wail and
connect to the Charging Jack on the right side of the Control
Unit. The unit's Charging LEO will light indicating that the unit
is charging properly. Allow to charge for II hours prior to
operation.
B) Mounting the Flow Cell Assembly
1. Select the Flow Cell Assembly to cover the flow range
required.
2. The bottom of the Flow Cell Assembly employs a quick mount
feature. The base of the Flow Cell Assembly is positioned onto
the mounting plate of the Control Unit.
3. Engage the pin of the cell assembly base into the mounting
plate of the Control Unit (NOTE: When cell is properly engaged,,
the base of the cell will be flush to the mounting plate and the
cell label will face the 3'oclock position - As observed from the
top).
4. Grasp the bottom cell chamber and rotate clockwise until It
clicks in. (CAUTION: Always engage £ disengage the cell by
grasping and rotating only the bottom cell chamber.) The cell
assembly label will now face forward (6 o'clock position).
5. Insert the Control Unit's connector plug into the Jack
located at the back of the sensor block.
C) Adding the Cilibrator Soap Solution
1. Remove the Seal Tubing from the upper outlet boss of the
upper cell. Fill dispenser bottle with soap solution. Using the
rubber tubing as a funnel, add soap solution from the dispenser.
2. The amount of soap needed can be determined by depressing the
Bubble Initiate button and holding it in the lower position. Con-
tinue to add only enough soap solution until the bottom of the
ring generator is immersed In the solution.
Do Not Overfill!
3. After filling Is completed, the rubber Seal Tubing may be
removed completely. Recap soap solution for later use.
NOTE: If Flow Cell Assembly Is not going to be used for a pro-
longed period of time, reinstall the rubber tubing between the
-------
inlet and outlet bosses. This will prevent evaporation from
occurring which may cause the solution's concentrations to alter.
D) Printer Connection (if applicable)
1. Connect printer cable to Printer Jack connector on The left
side of the Control Unit. Be sure to properly match up connectors
before connecting.
E) Connect the Sampler
1. Connect the air sampler to be calibrated to the upper outlet
boss of the Flow Cell Assembly. An auxiliary liquid trap between
sampler and flow cell Is recommended to prevent moisture carry
over into the sampler during continuous calibration periods.
2. Operation
A) Conditioning the Flow Tube
1. Turn on the sampler . Depress the Bubble Initiate Button
several times to wet the inner walls of the flow tube. Vou will
not be able to initiate a timing bubble without first "Priming"
the flow tube. The operator will develop a feel for bubble
generation with practice.
S) Power Up
2. After the Flow Tube walls have been "primed", turn on the Power
switch of the Cilibrator Control Unit (base) and the Printer
Module if one is being used. Wait approximately 10 seconds while
the system runs through it's check sequence. The Run LED will
light at this time as well as a Lo Battery-indication and a series
of S dashes displayed on the LCD Readout. Do not operate the
Cilibrator until the Run LED signal extinguishes. Ready operation
is indicated by a series of 4 dashes.
C) Bubble Generation
1. For optimum bubble generation, depress the Bubble Generator
button and hold to initiate 1 bubble up the flow tube. Release
the button to initiate a second bubble up the flow tube. This will
be the standard procedure to making clean, consistent bubbles at
High and Medium flow ranges. At Low flow ranges depressing the
button once will generate a clean bubble.
2. As the bubble rises up the tube, It will initiate the timing
sequence as it passes the lower sensor (the Run LED will light)
and culminate the timing sequence upon passing the upper sensors
(the Run LED will extinguish). The timing information is then
transmitted to the control unit which will perform all the
necessary mathematics. A flow reading will appear on the LCD
display.
-------
Appendix E4: Standard Operating Procedures for Calibration of Field Photoionization
Detector
-------
[NSTRUMENT RENTRL 11) :8fl r'-SM-S'ibU »*tB i4^uo inu.uiu r .u^
SECTION 111
Routine Maintenance
The routine maintenance of the 580B involves the calibration of the instrument, the cleaning of the lamp window, and
he maintaining of charge on the battery. The following pages give instructions for routine mainten&cc. Figure 3.1 illustrates
he detector assembly.
5.1 LAMP INSERTION AND REMOVAL
M.l REMOVAL
MOTE: The 580B must be off while removing the lamp.
In order to remove the lamp the four screws which hold the case top and bottom together must first be loosened. TJie
;&sc bottom should be placed flat on the tabic and the top placed on its side next to the bottom.
The high voltage power supply is removed next by loosening the thumb screws on each side and then pulling the power
.upply towards the rear of the instrument (see figure 3.1). The lamp may now be removed by loosening the lamp nut.
1.1.2 INSERTION
Insertion of the lamp is accomplished by performing the above tasks in the reverse order. The lamp should be placed
flat against the o-ring and the lamp nut fastened down in order to create a proper seal. The high voltage power supply should
hen be inserted and the thumb nuts fastened down. There are three pins protruding from the high voltage power supply which
should fit snugly into connectors located beneath the detector. The lamp spring (mounted m the center of the high voltage
jower supply) should make contact with the lamp ring.
».1.J LAMP CLEANING
On occasion the lamp should be removed for cleaning. Cleaning of the lamp is accomplished by cleaning: the lens surface,
>f the UV lamp. This is accomplished by using the aluminum oxide scouring powder provided with the 580B.
The orocedure for cleaning the lamp is as follows. First place a small amount of aluminum ox.de scourmg powder on
¦he 1^ or rtw iTv lamp NwTgenily scour this lens with a soft tissue or cloth. Scour the lens in a rotary type motion. After
during the lens nrfro gently blow the remaining powder from the lens. Uns WIlh ft dcan msuc
o remove the last traces of cleaning powder. The lamp » now able to be mser.ed ,nto the detctor.
5.2 CALIBRATION
NOTE: Chapter four should be read before calibrating the 580B in order to gain a better understanding of the concepts behind
calibration of the S80D.
¦rn. r .. . ¦ . • , • f -alihration as it relates to different lamps. One of the parameters in the Parameters
> newlompTimcdthc 58011 must * Thi, i. .r« ev»if ,b. ne»H«np .he new
iiiut . \ u .l tnn \i TKit ie Hue to the fact that each lamp will have a slightly diiterent sensitivity.
i, u rPp.?;e„,;»...»* .r m
Hie use of the 580B should be directed to Thermo Environmental s Application Laboratory.
The 580B is quite simple to calibrate. A source of "zero air" and -span gas" are all that is needed to calibrate the 580B.
3-1
-------
.NSTRUMhNI KtNIHL
ine zero air is introduced to the 580B in order to determine the "background" signal. The concentration of the span gas
ii then selected. The span gas is finally introduced to the S80B. The instrument makes all of the necessary calculations (in-
cluding linearization) to arrive at a "calibration constant." When in the Run mode the signal is multiplied by the calibration
constant in order to arrive at the current PPM.
SPAN PPM
CALIBRATION CONSTANT » —
SPAN ZERO SIGNAL
PPM = (SPAN SIGNAL - ZERO SIGNAL) CALIBRATION CONSTANT
NOTE : The PPM Is then multiplied by the RESPONSE FACTOR before being displayed. Chapter four explains the use of
response factors when calibrating.
Section 2.4.6 gives a detailed explanation of which buttons to press in order to calibrate the 580B. The now chart at the
back of this manual may also be helpful!.
3.3 CHARGE
When there is a flashing "B" in the lower left corner of the display (while in the run mode) the battery is low. The battery
Is recharged by pluging the charger into the RUN/CHARGE plug at the rear of the 5BOB. The instrument runs while it is
charging. The charger has an LED which indicates the amount of current being drawn. The LED gets brighter as more current
is drawn. The LED can therefore be used as a rough indication of the charge on the battery.
3-3
-------
Ht INS I KUMhN 1 KtNIHL i U *- f-\3 04-S ^du httf ' y» 14:U4 N0.U14 K . U<4
2.4.5 LAMP SELECTION
The 580B will display:
LAMP
>n the top line. The bottom line will alternate every two seconds between:
"RESET" TO CHG
md the currently selected lamp setting and its associated serial number.
i.e.
ll.SeV 000000
Dy pressing the RESET switch, the S80B will display;
+ /lOeV -/Ilev
on the bottom line. Pressing the + /INC switch will select the 10.0 eV lamp. Pressing the -/CRSR switch will select the 11,8eV
lamp. In either case the 580B will then allow editing of the lamp serial number. The display will show:
SERIAL f 000000
"RESET"WHEN DONE
The + / INC switch will Increment the number above the cursor and the - /CRSR switch will move Ihc cursor. Pressintlhe
RESET switch will return operation to the original lamp screen.
2.4.6 RESPONSE FACTOR SETTING
The current Response Factor setting will be displayed on the top line of the display. The Response Factor may be changed
by simultaneously pressing the RESET switch with either the +/INC switch to increment the digit above the cursor or the
— /CRSR switch to move the cursor.
The response factor is used to equate the response of one organic vapor with that of the calibration gas. The current
reading is allways multiplied by the response factor in order to obtain the displayed concentration. A response factor of one
will not change the displayed concentration.
2.4.7 CALIBRATION
The 580B will display:
"RESET" TO
CALIBRATE
The calibration mode may be entered by pressing the RESET switch.
The 580U will display:
RESTORE BACKUP
+ & YES
The previous calibration information in ay bp restored by pressini lilf tfINC T!}f Till {Nn return to the previous
tcreeh. if the backup is not desired, by pressing the - /INC switch the calibration ratine will continue! WdUplayUii iw:
ZERO GAS
RESET WHEN READY
2-5
-------
Appendix E5: Standard Operating Procedures for GC/FID Analysis
-------
HYDROCARBONS. BP 36 - 126 °C
METHOD: 1500
ISSUED: 2/15/84
OSHA, NIOSH, ACGIH: Table 2 PROPERTIES: Table 1
COMPOUNDS: benzene n-heptane n-octane
(Synonyms cyclohexane n-hexane n-pentane
in Table 1) cyclohexene methylcyclohexane toluene
SAMPLING MEASUREMENT
SAMPLER: SOLID SORBENT TUBE
TECHNIQUE: GAS CHROMATOGRAPHY. FID
(coconut shell charcoal,
100 mg/50 mg)
ANALYTES: hydrocarbons listed above
FLOW RATE. VOLUME: Table 3
DESORPTION: 1 mL CS2; stand 30 min
SHIPMENT: no special precautions
INJECTION VOLUME: 5 yL
SAMPLE STABILITY: at least 2 weeks
TEMPERATURE-INJECTION: 250 °C
-DETECTOR: 250 °C
BLANKS: 2 to 10 field blanks per set
-COLUMN: see step 11
BULK SAMPLE: desirable, 1 to 10 mL; ship in
CARRIER GAS: N2 or He, 25 mL/min
separate containers from samples
COLUMN: glass, 3.0 m x 2 mm, 201 SP-2100 on
80/100 mesh Supelcoport
ACCURACY
CALIBRATION: analytes in CS2
RANGE STUDIED,
BIAS and OVERALL PRECISION (sr): Table 3
RANGE AND PRECISION (sr): Table 4
ESTIMATED LOD: 0.001 to 0.01 mg per sanple
with capillary column [1]
APPLICABILITY: This method is intended for determining the OSHA-regulated hydrocarbons
included within the boiling point range of n-pentane through n-octane. It may be used for
simultaneous measurements; however, interactions between analytes may reduce breakthrough
volumes and change desorption efficiencies.
INTERFERENCES: At high humidity, breakthrough volumes may be reduced by as much as 501. Other
volatile organic solvents, e.g., alcohols, ketones, ethers, and halogenated hydrocarbons, are
likely interferences. If interference is suspected, use a more polar column or change column
tenoerature.
OTHER METHODS: This method is based on and supercedes Methods P&CAM .127, benzene and toluene
[2]; S28, cyclohexane [3]; S82, cyclohexene [3]; S89, heptane [3]; S90, hexane [3]; S94,
methyl cyclohexane [3]; S311, benzene [4]; S343, toluene [4]; S378, octane [4]; and S379,
pentane [4], For benzene or toluene in complex mixture of alkanes (£Cjq), Method 1501
(aromatic hydrocarbons) is more selective.
FORMULA: Table 1
M.W.: Table 1
2/15/84
Preceding page blank
1500-1
afcs'
-------
HYDROCARBONS. BP 36-126 °C
METHOD: 1500
EQUIPMENT:
1. Sampler: glass tube, 7 cm long, 6 mn OD, 4 mm ID,
flame-sealed ends, containing two sections of
activated (600 °C) coconut shell charcoal (front
= 100 mg, back - 50 mg) separated by a 2-tm urethane
foam plug. A silylated glass wool plug precedes the
front section, and a 3-mm urethane foam plug follows
the back section. Pressure drop across the tube at
1 L/min airflow must be less than 3.4 kPa. Tubes
are conroercially available.
2. Personal sampling punp, 0.01 to 0.2 L/min, with
flexible connecting tubing.
3. Gas chromatograph, FID, integrator and column
(page 1500-1).
4. Vials, glass, 1-mL, with PTFE-lined caps.
5. Pipet, 1-mL, with pipet bulb.
6. Syringes, 5-, 10-, 25- and 100-pL.
7. Volumetric flasks, 10-ibL
SPECIAL PRECAUTIONS: Carbon disulfide is toxic and extremely flammable (flash point = -30 °C) •
tjenzene is a suspect carcinogen. Prepare samples and standards in a well-ventilated hood.
SAMPLING:
1. Calibrate each personal sampling pump with a representative sampler in line.
2. Break the ends of the sampler immediately before sampling. Attach sampler to personal
sampling pump with flexible tubing.
3. Sample at an accurately known flow rate between 0.01 and 0.2 L/min (0.01 to 0.05 L/min for
n-pentane) for a total sample size as shown in Table 3.
4. Cap the samplers with plastic (not rubber) caps and pack securely for shipment.
SAMPLE PREPARATION:
5. Place the front and back sorbent sections of the sampler tube in separate vials. Discard
the glass wool and foam plugs.
6. Add 1.0 mL eluent to each vial. Attach crimp cap to each vial inmediately.
7. Allow to stand at least 30 tnin with occasional agitation.
CALIBRATION AND QUALITY CONTROL:
8. Calibrate daily with at least five working standards over the appropriate range (ca. 0.01
to 10 mg analyte per sample; see Table 4).
a. Add known amounts of analyte to eluent in 10-«iL volunetric flasks and dilute to the mark.
b. Analyze together with samples and blanks (steps 11, 12 and 13).
c. Prepare calibration graph (peak area of analyte vs. mg analyte).
9. Determine desorption efficiency (0E) at least once for each batch of charcoal used for
sampling in the calibration range (step 8). Prepare three tubes at each of five levels
plus three media blanks.
a. Remove and discard back sorbent section of a media blank sampler.
b. Inject a known amount of analyte directly onto front sorbent section with a microliter
syringe.
REAGENTS:
1. Eluent: Carbon disulfide*,
chromatographic quality with
(optional) suitable internal
standard.
^.Analytes, reagent grade.*
2. Nitrogen or helium, purified.
A. Hydrogen, prepurified.
Air, filtered.
*See Special Precautions.
2/15/84
1500-2
-------
1ETH00: 1500
HYDROCARBONS. BP 36-126 °C
c. Cap the tube. Allow to stand overnight.
d. Oesorb (steps 5 through 7) and analyze together with working standards (steps 11, 12
and 13).
e. Prepare a graph of DE vs. mg analyte recovered.
10. Analyze three quality control blind spikes and three analyst spikes to instire that the
calibration graph and DE graph are in control. Check for possible contamination during
shipment of field samples by comparing results from field blanks and media blanks.
CASUREMENT:
11. Set gas chromatograph according to manufacturer's recommendations and to conditions given
on page 1500-1. Select appropriate column temperature:
Approximate Retention Time (min). at Indicated Column Temperature
Substance
40 "C
70 "C
8
•
O
Proqrammed3
n-pentane
2.2
1.2
1.8
solvent (CS2)
3.0
1.6
2.4
n-hexane
5.1
2.2
3.5
benzene''
7.7
3.2
4.5
cyclohexane*3
8.4
3.4
4.7
cyclohexene
9.5
3.8
4.9
n-heptane
12
4.3
5.4
methylcyclohexane
14
5.2
2.2
5.9
toluene
17
6.5
2.6
6.5
n-octane
19
8.7
3.2
7.1
^Temperature program: 50 °C for 2 min, then 15 °C/min to 150 #C, 2- Wf/10, report breakthrough and possible sample loss.
15. Calculate concentration, C, of analyte in the air volume sampled, V (L):
_ (Uf V-w.
V
2/15/84
1500-3
247
-------
HYDROCARBONS. BP 36-126 "C
METHOD: 1500
EVALUATION OF METHOD:
Precisions and biases (Table 3) were determined by analyzing generated atmospheres containing
one-half, one, and two times the OSHA standard. Generated concentrations were independently
verified. Breakthrough capacities were determined in dry air. Storage stability was not
assessed. Measurement precisions (Table 4) were determined by spiking sairpling media with
amounts corresponding to one-half, one, and two times the OSHA Standard for nominal air
volumes. Desorption efficiencies for spiked samplers containing only one compound exceeded
751. Reference [12] provides more specific information.
REFERENCES:
[1] User check, UBTL, NIOSH Sequence #4213-1 (unpublished, January 31, 1984).
[2] NIOSH Manual of Analytical Methods, 2nd. ed., V. 1, PSCAM 127 U.S. Department of Health,
Education, and Welfare, Publ. (NIOSH) 77-157-A (1977).
[3] NIOSH Manual of Analytical Methods, 2nd. ed., V. 2, S28, S82, S89, S90, S94, U.S.
Department of Health, Education, and Welfare, Publ. (NIOSH) 77-157—8 (1977).
[4] NIOSH Manual of Analytical Methods, 2nd. ed-, V. 3., S311, S343, S378, S379, U.S.
Department of Health, Education, and Welfare, Publ. (NIOSH) 77—157—C (1977).
[5] R- 0. Driesbach, "Physical Properties of Chemical Compounds"; Advances in Chemistry
Series, No. 15; American Chemical Society, Washington (1955).
[6] R- 0. Driesbach, "Physical Properties of Chemical Compounds - II"; Advances in Chemistry
Series, No. 22; American Chemical Society, Washington (1959).
[7] Code of Federal Regulations; Title 29 (Labor), Parts 1900 to 1910; U.S. Government
Printing Office, Washington, (1980); 29 CFR 1910.1000.
[8] Update Criteria and Reconmendations for a Revised Benzene Standard, U.S. Department of
Health, Education, and Welfare, (August 1976).
[9] Criteria for a Recommended Standard... .Occupational Exposure to Alkanes (C5-C8), U.S.
Department of Health, Education, and Welfare, Publ. (NIOSH) 77-151 (1977).
; 103 Criteria for a Recommended Standard Occupational Exposure to Toluene, U.S. Department
of Health, Education, and Welfare, Publ. (NIOSH) 73-11023 (1973).
' 11J TLVs—Threshold Limit Values for Chemical Substances and physical Agents in the Work
Environment with Intended Changes for 1983-84. ACGIH, Cincinnati, OH (1983).
;i2] Documentation of the NIOSH Validation Tests, S28, S82, S89, S90, S94, S311, S343, S378,
S379, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-185 (1977).
ETHOD REVISED BY: R. Alan Lunsford, Ph.D., and Julie R. Okenfuss; based on results of NIOSH
Contract CDC-99-74-45.
2/15/84
1500-4
2.L?
-------
HFTHOO: 1500
Table 1. Synonyms, formula, molecular weignt, properties.
HYDROCARBONS. BP 36-126 °C
Mane
Synonyms
benzene3
CAS #71-43-2
cyclohexane3
CAS #110-82-7
hexahydrobenzene
hexamethylene
cyclohexene3
CAS #110-83-8
tetrahydrobenzene
n-heptane*3
CAS #142-82-5
n-hexane15
CAS #110-54-3
methylcyclohexane3
CAS #108-87-2
n-octane^
CAS #111-65-9
n-pentane^
CAS #109-66-0
toluene3
CAS #108-88-3
methylbenzene
Empirical ular
itructure Formula Weight
o
C6"6
^12
^"lO
C6"14
C7H14
AA/
O
AAA/ cqHj8
AA C5H12
Holec- Boiling Vapor Pressure Density
Point 3 25 °C 3 20 °C
o
AAA C7H16 100.21
CC) Coin Hq) (kPa) (g/ml)
78.11 80.1
84.16 80.7
98.4
114.23 125.7
95.2 12.7 0.879
97.6 13.0 0.779
82-15 83.0 88.8 11.8 0.811
45.8 6.1 0.684
86.18 68.7 151.3 20.2 0.659
98.19 100.9 46.3 6.2 0.769
14.0 1.9 0.703
72.15 36.1 512.5 68.3 0.626
92.14 110.6 28.4 3.8 0.867
^properties from [5],
^Properties from [6].
2/15/84
1500-5
-------
uvnPOCARBQNS. BP 36-126 T
NPTMrW
Table 2. Permissible exposure limits, ppm [7-11],
Substance
benzene*
cyclohexane
cyclohexene
n-heptane
n_hexanea
methylcyclohexane
n-octane
n-pentane
toluene
OSHA
TWA
10
300
300
500
500
500
500
1000
200
C Peak
25
5(P
300 500b
NIOSH
TWA
85 440
100 510
75
120
100
385
610
200c
ACGIH
TLV STEL
10
300
300
400
50
400
300
600
100
25
375
500
500
375
750
150 (skin)
a-fhe aCGIH recommendation for other hexane isomers is: TLV 500, STEL 1000.
bflaxinium duration 10 min in 8 hr.
cio-min sample.
*ACGIH: suspect carcinogen
mg/m3
per ppm
g OTP
3.19
3.44
3.36
4.10
3.52
4.01
4.67
2.95
3.77
Table 3. Sampling flowrate*, volime, capacity, range, overall bias and
precision [2-4, 12].
Substance
benzene
cyclohexane
cyclohexene
n-heptane
n-hexane
methy1 eye1ohexane
n-octane
n-pentane
toluene
Flowrate
(L/min)
SO. 20
SO. 20
SO. 20
SO. 20
SO. 20
SO. 20
SO. 20
SO. 05
SO. 20
Samp!inq
Volime (l)
VOL-MOM VOL-MAXb
2C
2.5
5
4
4
4
4
2
2C
30
5
7
4
4
4
4
2
8
Breakthrough
Volume at
Concentration
(L)
>45
7.6
10.4
6.1
5.9
6.1
6.5
3.1
11.9
Minimum recommended flow is 0.01 L/min.
^Approximately two-thirds the breakthrough volume.
c10-min sample.
^Corrected value, calculated from data in [12],
(mg/m3)
149.1
1650
2002
4060
3679
3941
4612
5640
2294
Range
at
VOL-NOM
(mg/m3)
41.5
510
510
968
877
940
1050
1476
548
Overall
165
2010
2030
4060
3679
3941
4403
6190
2190
Bias
(X)
0.8
5.4
9.0
-6.5
-3.8
5.5
-5.2
-9.7
3.8
Precision
(sr)
0.059
0.060d
0.073
0.056
0.062
0.052
0.060
0.055
0.052
2/15/84
1500-6
170
-------
mpthOO: 1500
HYDROCARBONS. BP 36-126 °C
Table neasurement range, precision, and chromatographic conditions [2-4,12].
Co! iron Parameters'5
Measurement4
Carrier
Dia-
Range Precision
Gas
Flow
t
Length
meter
Substance
(mg)
(sr)
(ml/mi n)
(°C)
{m)
(mm)
Packi
benzene
0.09-0.35
0.036
h2
50
115
0.9
3.2
A
cyclohexane
1.3 - 5.3d
0.024
n2
50
210
1.2
6.4
8
cyclohexene
2.4 - 9.7d
0.021
*2
50
205
1.2
6.4
B
n_heptane
4.08-16.3
0.016
He
30
80
3.0
3.2
C
n-hexane
3.56-14.5
0.014
He
30
52
6.1
3.2
D
methy 1 cy c 1 ohexane
3.98-16.1
0.012
He
30
55
6.1
3.2
0
n_octane
4.75-18.9
0.009
He
30
52
6.1
3.2
D
n-pentane
2.98-11.8
0.014
He
30
52
6.1
3.2
D
toluene
1.13-4.51
0.011
n2
50
155
0.9
3.2
B
amjection volume, 5.0 yL; desorption volume, 1.0 tnL, except cyclohexane and cyclohexene,
0.5 mL.
bAll columns stainless steel. Diameter is outside dimension.
CA, 50/80 mesh Porapak P; B, 50/80 mesh Porapak Q; C, 101 0V-101 on 100/120 mesh
Supelcoport; 0, 10X FFAP on 80/100 mesh Chranosorb U AW-DMCS.
dcorrected value, calculated from data in [12].
2/15/84
1500-7
271
-------
2 72-
-------
Designation: D 3687 - 89
Standard Practice for
Analysis of Organic Compound Vapors Collected by the
Activated Charcoal Tube Adsorption Method1
This standard is issued under the fixed designation D 3687; the number immediately following the designation indicates the year of
original adoption or. in :hc case of revision, the \ear of last revision. A number in parentheses indicates the year of last reapproval. A
\u|x:rM.npi epsilon l»i indicates an editorial change since the last revision or reapproval.
Scope
l. I This practice covers the applications of methods for
; desorption and gas chromatographic determination of
^ariic vapors that have been adsorbed from air in sampling
bes packed with activated charcoal.
1.2 This practice is complementary to Practice D 3686.
1.3 This practice is applicable for analysis of samples
ken from workplace or other atmospheres, provided that
c contaminant has been found amenable to collection on
arcoal tubes and gas chromatographic analysis. A partial
t of organic compounds for which this method is appli-
ble is given in the appropriate Annex, in Practice D 3686.
1.4 Components of multicomponent samples may mutu-
!y interfere during analysis. Methods to resolve interfer-
ices are given in Section 6.
1.5 This standard may involve hazardous materials, oper-
ions, and equipment. This standard does not purport to
fdress all of the safety problems associated with its use. Jt is
c responsibility of the user of this standard to establish
ypropriatc safety and health practices and determine the
iplicabi/ity of regulatory limitations prior to use. Specific
ecautions are given in 8.1.4.2 and Annex Al.
Referenced Documents
2.1 ASTM Standards:
D1356 Terminology Relating to Atmospheric Sampling
and Analysis*
D3686 Practice for Sampling Atmospheres to Collect
Organic Compound Vapors (Activated Charcoal Tube
Adsorption Melhod)-
E 355 Praclicc for Gas Chromatography Terms and
Relationships^
2.2 NJOSIi Standards:
CDC-99-74-45 Documentation of NIOSH Validation
Tests4
Manual of Analytical Methods, 2nd Ed.4
2.3 OSllA Standard:
' This practice is under |bc jurisdiction of ASTM Committee D-22 on
ampling and Analysis of Atmospheres, and is the direct responsibility of
ubcommntecs D 22.04 on Analysis of Workplace Atmospheres.
Current edition approved May 2h. I Wf Published July 19X9. Originallv
ublishcd .is 1) 3(iX7 - 7K. I.ast previous edition D 1(>K7 - X4.
- Arwij,/! nj IS i\t Sluhdtmh. Vol 11.03
1 .inniul II,hA „l AS I'M Stii>iihiril\, Vol 14.01.
4 Available Iruin the I'.S. !X'p.it 1 men! ol Commerce. National Technical
Information Service. Port Koyal Road. Springfield. VA 22161.
29 CFR 1910 General and Industrial OSHA Saiety and
Health Standard5
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this practice, refer to
Definitions D 1356, and E 355.
3.1.2 retention time (RT)—time to elute a specific chem-
ical from a chromatographic column, for a specific carrier
gas flow rate, measured from the time the chemical is
injected into the gas stream to when it appears al the
detector.
3.1.3 relative retention time (RRT)—a ratio of RTs' for
two chemicals for the same chromatographic column and
carrier gas flow rate, where the denominator represents a
reference chemical.
4. Summary of Practice
4.1 Organic vapors, which have been collected on acti-
vated charcoal and eluted therefrom with carbon disulfide or
other appropriate desorbent, are determined by gas-liquid
chromatography, using a flame ionization detector and other
appropriate detectors.
4.2 Interferences resulting from the analytes having sim-
ilar retention times during gas-liquid chromatography are
resolved by improving the resolution or separation, such as
by changing the chromatographic column or operating
parameters, or by fractionating the sample by solvent extrac-
tion.
4.3 Peaks are identified using techniques such as GC/MS
and dual column chromatography,
5. Significance and Use
5.1 Promulgations by the Federal Occupational Safety
and Health Administration (OSHA) in 29 CFR 1910 desig-
nate that certain organic compounds must not be present in
workplace atmospheres at concentrations above specified
values.
5.2 This practice, when used in conjunction with Practice
D 3686, will promote needed accuracy and precision in the
determination of airborne concentrations of many of the
organic chemicals given in 29 CFR 1910, CDC-99-74-45,
and the Manual of Analytical Methods. It can be used to
determine worker exposures to these chemicals, provided
appropriate sampling periods are used.
5.3 A partial list of chemicals for which this method is
"¦ Available liom Superintendent of Documents. U.S Government Printing
OlliiC. Washington. DC 211402
207
-------
Q) D 3687
applicable is given in the appropriate Annex of Practice
D 3686, along with their OSHa Permissible Exposure
Limits.
6. Interferences
6.1 Any gas chromatographic separation that involves a
mixture of polar and nonpolar compounds is confronted
with serious problems due to peak supcrimposition. In many
industrial operations, both nonpolar compounds, such as
mixed aliphatic petroleum hydrocarbons, and polar sub-
stances. such as aromatic hydrocarbons, amines, oxygenated
compounds and sometimes lialogenated compounds, may be
used and found in the workplace atmosphere. It is rarely the
case that a single organic solvent vapor may be expected in a
workplace atmosphere where organic solvents are being used.
6.2 Such interferences are frequently resolved by changing
the type of column, length of column, or operating condi-
tions. to improve resolution of separation of compounds.
6.3 General approaches which can be followed are given
below:
6.3 1 Generally unknown samples are analyzed using at
least two columns of different polarity.
6.3.2 As a general guide to practice, nonpolar substrates,
such as the silicones, tend to separate according to the boiling
points of the compounds, whereas polar column separations
are influenced more by the polarity of the compounds.
6.3.3 A single wide bore capillary column can replace
several specialized packed columns and provide better
sample resolution in significantly less time. Application of
these columns minimizes operational changes required to
achieve peak resolution.
6.4 Selective solvent stripping techniques have been used
successfully to make clean and fast separations of polar,
nonpolar and oxygenated compounds. A general guideline is
given in Annex A1 and detailed procedures are given in Refs
(1) and (2).6
7. Apparatus
7.. Gas Chromatagraph (GC). having a flame ionization
detector and either an isothermally controlled or tempera-
ture programmed heating oven.
7.2 A variety of packed and capillary columns are suit-
able. Two suitable packed columns are a 10 ft stainless steel
column, '/h inch ID packed with 10 % free fatty acid phase
(FFAP) substrate on 80/100 mesh acid washed Chromosorb
W7 and a nonpolar column containing 10 % methyl silicone
substrate on the same support material in a similar column
as given above. Alternatively, 35 % diphenyl. 65 % dimethyl
polysiloxane-- and Carbowax 20 Mx wide bore capillary
columns (0.53 and 0.75 mm) may be used in place of the
packed columns. These columns are available in 30 and 60
m lengths.
7.3 Microsyrinxc.s, two or more lO-fiL volume.
7.4 17uls, 5-mL serum.N
TFE-lluorocarbon.
fitted with caps lined with
* The boldface numbers in parentheses refer 10 the list of references at the end
of this standard.
7 "Chromosort) W." a trademark of the Johns-Manvillc Products Corp.. or
equivalent has been found satisfactory for this purpose.
" "Carbowax." a trademark of the Union Carbide Co.. or equivalent has been
found satisfactory for this purpose.
8. Calibration
8.1 Preparation of Gas Chronwtogmph:
8.1.1 Install the selected column.
8.1.2 Check the system for leaks as prescribed b\ uC
manufacturer.
8.1.3 Select a carrier gas flow compatible with the deicctor
and column selected lor the separation.
8.1.4 Calibrate the chromatographic column to determine
the relative retention times (RRTs") ot the various com-
pounds ill interest.
8.1.4.1 Select a reference solvent which will serve as a
benchmark.
8.1.4.2 Prepare a 0.05 % solution of this solvent (volume/
volume) in chromatographic grade carbon disulfide (CS2).
When kept in a properly closed container (see 7.4) and
refrigerated when not in use, some solutions will keep for
several weeks (3).
Note 1: Warning—Carbon disulfide is loxic and explosive, as are
many of the organic compounds to be analyzed. Work with these
chemicals must be done in a properly operating laboratory hood.
8.1.4.3 Into a clean 10-pL syringe draw 2 nL of CS2. Draw
the CS, into the barrel of the syringe until the air bubble
appears at the 1-nL mark. Check the nominal volume of
CSv, it should be about 2 pL. If it is not, repeat the process
until the proper volume is present.
8.1.4.4 Draw 2 p.L of 0.05 % benzene (or other reference
chemical)'0 in CS2 into the syringe and then into the barrel
in accordance with 8.1.4.3. The barrel should now contain 2
pL of CS2> a small bubble of air, and 2 pL of 0.05 % solution
of benzene in CS2.
Note 2—Two microlitres of an 0.05 % v/v solution of any solute in
a solvent will contain, in micrograms, the numerical equivalent of the
density of the solute. For example. 2 pL of an 0.05 % solution of
benzene contains 0.879 ng of benzene. The practical density of benzene
is 0.879 at 25°C.
8.1.4.5 Inject the contents of the syringe into the gas-
chromatographic column. (See 8.1.4.3, 8.1.4.4. and 8.1.4.5
describing the solvent-flush technique referred to in this
practice.) Start the chart recorder and mark the starting point
on the strip chart. Injection by means of a GC autosampler »s
acceptable in most cases.
8.1.4.6 Permit the benzene to be eluted from the column,
so as to form a complete chromatogram.
8.1.4.7 The time between the injection of benzene onto
the chromatographic column and peak maximum is the
retention time (RT) for benzene.
8.1.4.8 Retention times may be determined manually b>
observing the time required for a compound to pass through
the chromatographic column using a stop watch or by mea-
suring the distance from the starting point to peak maximum
shown on the strip chart. Alternatively an electronic integra-
tor may be used to deteimine RT.s'. Most modern gas chro-
matographs are equipped with electronic integrators that can
' A. H. Thomas Catalog No. S569-E 10 or equivalent has been fo«»c
satisfactory.
<» Benzene ,s used .n this practice as the reference chemical for the purposes,
illustration, but a less iomc chemical such us ,0|ucnc aiuU1 K. usct,
208
-------
D 3687
accurately measure RT.s' within a hundredth of a minute.
K. 1.4.S) For the same conditions of operation (carrier gas-
flow rate, column temperature, column characteristics) the
RT may be considered a constant.
8.1.4.10 It is an excellent practice to maintain a con-
tinuing record of RTs' for the reference compound in a
laboratory log. This log record should include the date, the
concentration and volume of the reference compound, the
operating conditions of the gas chromatograph, the carrier
gas flow rate, the recorder constants, and the degree of signal
attenuation. It should also include the flow rate of air and
hydrogen to the detector flame.
8.1.4.11 Prepare 0.05% solutions (or other concentra-
tions) of organic solvents of interest and develop a set of
RTs' for them. It is preferable to run more than one analysis
for each solvent.
8.1.4.12 Record both the RT and the detector response.
For general analytical usage these data provide a quick
means of ascertaining crude concentration levels. (When
TABLE 1 Relative Retention Times (RRTs') (or a Group of
Common Organic Compounds
Note—Column: 20-lt. 1 e-m outside diameter, stainless steel column (20 m)
packed with 10 Carbowax on 80/100 mesh Chromosorb W. Oven Isothermal at
95°C
(All data relative to the Retention Time ol Benzene = 1.000 RRTs' are a
mean ol three or more determinations.)
compound
Ardour
Amyl acetate
Isoaniyi acetate
Benzene
Buianoi
Isobutanol
2-Butanone (MEK)
Butyl acetate
Isobutyl acetate
Carbon tetrachloride
Cellosolve
Cellosolve acetate
Chloroform
Ethanol
Ethyl acetate
Ethyl benzene
Ethylene chloride
Methyl acetate
Methanol
Methylene chloride
Methyl isobutyl ketone
Pentanol
Perchloroethylene
Propanol
Isopropanol
Propyl acetate
Isopropyl acetate
Styrene
Toluene
T ricliloroethylene
Trimethyl benzene
1.1.1-Trichloroethane
m Xylene
o- Xylene
p-Xylene
precise information is necessary, fresh standards are run to
prepare a standard curve.)
8.1.4.13 Using the RT of the reference compound as the
denominator and the RT of the solute as the numerator,
calculate the relative retention time (RRT). This parameter
is a constant for a given set of operating conditions. It may be
used for rapid and accurate qualitative analysis when there is
no reason to believe that there are peak superimpositions. A
separate laboratory log for RRTs' should be developed and
maintained, using at least two columns of different polarities.
(A list of such values is given in Table 1, for example only.) A
gas chromatograph interfaced with a mass spectrometer
provides the most positive means of peak identification.
8.1.4.14 It is good practice to ascertain periodically the
relative standard deviation of this parameter for all solutes of
interest.
8.1.5 The quantitative response of a GC detector may be
determined by the peak height measurement or peak area
integration using an electronic integrator or a Data System.
A detailed description of these techniques can be found in
Practice E 355.
8.2 For any compound of interest a set of standards
should be prepared in the eluent to be used for the samples
(usually CS2). The concentration levels of the standards
should be such as to embrace the concentration of the
unknown quantity.
8.2.1 At least the standard solutions should be prepared.
8.2.2 At least three runs of each standard should be-done.
8.2.3 When there is initial variability in the' detector
response ol standards, so that the calculated relative standard
deviation or the mean is greater than a value considered
acceptable by the analyst (generally, this should not.exceed
5 'c for a good chromatographic system), a series of at least
live points should be run and at least five peaks per point
measured. Outliers should be eliminated by the application
of statistical methods (4). If the variability does not comply
with the performance criteria described in this paragraph,
check the stability system (flow, temperature, column, etc)
before proceeding further.
8.2.4 A fresh set of standards should be prepared for each
analytical scries. Generally standards kept in properly closed
vials, sealed with TFE-fluorocarbon lined screw caps, will
keep for at least a week if refrigerated (5). Standards kept in
containers capped by glass stoppers will not keep longer than
a day and should be discarded after that time.
8.2.5 This practice does not recommend the use of small,
standard-taper centrifuge tubes, sealed with standard taper
stoppers, for preparation of either standards or samples.
Carbon disulfide (CS;) is highly volatile and will be lost from
such vials. No attempt should be made to replace the
evaporated loss by addition of CS2 to a fixed volume line in
such a container.
8.3 Desorplion efficiencies for organic compounds trapped
on activated charcoal must he determined for each batch of
charcoal or charcoal samplers. For purpose of reference,
reported desorption efficiencies for a number of organic
compounds are given in the appropriate Anne\ of Practice
D 36X6.
8.3.1 Open a charcoal sampling tube of the same lot used
for collecting the samples.
8.3.2 Inject a known amount (2 to 20 jtL/100 mg charcoal)
Mean RRr _ . Standard
Deviation
Deviation. %
0.676
0014
2 1
2 156
0 047
2.18
2.228
0 107
4 8
1.000
2.945
0.155
5.3
2.146
0.935
43.6
0.930
0.085
9 14
1.739
0026
15
1.37
0.74
0.014
1.9
5.27
6.51
1.298
0.03
2.3
1.078
0.001
0 1
0.812
0.027
3.3
2.183
0.002
0.1
1.408
Q.33
23.4
0.639
0.015
2.4
1.020
0.028
2.7
0.875
0.005
0.57
1.382
0.009
0.7
5.11
1.335
0019
1.4
1.659
0.018
11
1.033
0.0099
1 0
1 16
0 028
2 4
0.828
0 017
2.1
4 467
0.270
60
1.505
0016
1 06
1.162
0.03
26
3.72
0 78
2 309
0.107
4 6
2964
0058
1 96
2.315
0.04
1 7
209
-------
® D 3687
of one or more solvents below the surface of and directly
onto the activated charcoal, and cap the tube immediately. It
is useful to chill the sampling tube during this operation, or
to have chilled the capped tube and contents immediately
prior to its being charged with solvent, since the heat of
adsorption may be sufficient to volatilize some of the material
and to cause loss. The amount injected should approximate
realistically that quantity which would be found in 10 L of
air containing the exposure limit designated in 29 CFR 1910.
8.3.3 Tubes should be prepared for each of the following
amounts: 0.5, 1.0, and 2.0 times the amount determined in
8.3.2.
8.3.4 Let the tubes stand at room temperature for a
minimum of 8 h.
8.3.5 Treat these charcoal tubes exactly as described in
Section 9 of this practice, eluting the chemical with CS-. (or
other appropriate eluent) and analyzing the eluate for its
contents.
8.3.6 The percentage of chemical recovered from the
charcoal (calculated by dividing the quantity recovered by
the quantity applied, times 100) is the desorption efficiency.
The datum obtained for the analyte of concern should be
corrected by using the decimal fraction of the determined
desorption (elution) efficiency.
8.3.7 When the desorption efficiency of a chemical is less
than 75 %, an alternative sampling and analytical method
should be considered.
9. Procedure
Note 3: Warning—Perform in a properly ventilated fume hood.
9.1 Prepare a set of empty vials by placing appropriate
labels on them, indicating the identification number and
designating whether they will contain the front (F) of the
sampler or the back-up (B) portion.
9.2 Remove the plastic caps from the sampling tubes, or
score and break the tubes just above the plug.
9.3 Remove the plug of glass wool which holds the front
portion of charcoal in place and transfer the charcoal to the
appropriate vial and close the vial. (A crochet hook is a
convenient device for removing the plugs from the samplers,
or a hook can be fashioned from a fine (18 to 20-gage) steel
wire or a 3-in. (76-mm) No. 20 hypodermic needle.)
9.4 Repeat the same procedure for the back-up portion.
9.5 Continue this process until all of the samples have
been transferred appropriately to vials.
9.6 Fit a 1-mL hypodermic syringe with a 3 or4-in. (76 or
100-mm) No. 20 or No. 22 hypodermic needle.
9.7 With this syringe transfer 1 mL of CS2 to each of the
vials, taking care to cap them securely after the CS2 has been
added."
9.8 From time to time agitate the samples. Let the elution
process continue for at least 30 min. A longer period of time
is desirable (3). (Some methods given in the reference in
2.2.2 require up to 4 h.)
9.9 Using the solvent-flush technique described in 8.1.4.3,
'' The 1-mL volume of CS2 is used when analyzing 150-mj; iharioal lubes II
larger charcoal tubes are being anal\zed. a proportionately larger volume of CS,
should be used.
8.1.4.4. and 8.1.4.3, accomplish the chromatography of the
samples.
Noti 4. Caution—Bclorc beginning any analytical program, place a
Iresh septum into the injection port ol the chrnmatograph. As a niaitcr
ol good practice, replace the septum daily or when necessary. Septum
failure is the most frequent cause of inconsistent detector response for a
given standard or sample.
9.10 Repeat the analysis at least three times.
9.11 The volume parameters specified in 8.1.4.3, 8.1.4.4,
and 8.1.4.5 should be maintained. Two microlitres of sample,
followed by 2 nL of solvent-flush in the microsyringe, have
been found practical and completely adequate for all needs
by at least one compliance laboratory (5).
9.12 After the analytical series has been accomplished, the
reference solvent should be run as a performance standard.
(See 8.1.4.)
9.13 Data reduction, either by peak height, area, or mass
measurement, may now be performed.
10. Calculation
10.1 Determination of ji£ per Sample:
10.1.1 The actual concentration, in micrograms of analyte
per millilitre of sample solution, can be taken from a
standard curve plotted on linear paper, where peak height (or
peak area or mass) is plotted as the ordinate and concentra-
tion in micrograms per 1 mL of CS2 as the abscissa. If the
instrumental response is known to be linear (from the
performance of the standards) a single concentration level
may be chosen as a calculation constant, if desired.
10.1.2 From the standard curve, determine the micro-
grams of analyte standard equivalent to the peak area (or
height) from a particular compound. When 1 mL of CS; has
been used for desorption, no volume corrections are needed;
the standard curve is based on ng/mL CS2 and the volume of
the sample injected is identical to the volume of the standard
injected.
10.1.3 Ascertain whether the field blank has been contam-
inated. If the blank has been contaminated, the sampling
series must be held suspect. (Sec appropriate paragraph of
Practice D 3686.)
10.1.4 The total microgram amount found in the sample
is corrected for desorption efficiency and laboratory blank as
follows:
Jig. corrected = H8 in sample - (ig in blank
desorption efficiency
Sum quantities for front and back-up sections.
10.1.5 If the back-up section contains more than 25 % of
that of the front section, discard the sample as unreliable (see
7.1.2.2 of Practice D 3686).
Note 5—A break-through to the back-up section of 25 % of that of
the front section usually suggests that some of the contaminant in the
sampled air was not retained by the charcoal, and the calculated
airborne concentration results will be lower than the actual concentra-
tions. In cases where the calculated airborne concentrations exceed the
health standard, despite break-through, it is meaningful and proper to
report the results as greater than the calculated value.
10.2 Determination of Air Concentration:
10.2.1 Correct air volume of the sample to standard
temperature and pressure (see appropriate paragraph of
Practice D 3686).
210
-------
# D 3687
) 2-2 If the criteria for a proper sample have been met.
ul^te the concentration of solvent vapor in a cubic metre
ir as follows:
Total analyte (pg/sample) _ jjg _ mg
Sampled air volume (L/sample) L m3
0 2-3 If '• 's desired to convert this value to parts per
1 io*1 (v/v) in air.
mg/m3
ppm — 24.4 x mo|ecu|ar weight of solvent
11. Precision and Bias
11.1 Precision and bias in this type of analytical proce-
dure are dependent upon the precision and bias of the
analytical procedure for each solvent analyte of concern, and
the precision and bias of the sampling process.
11.2 When the errors involving determination of
desorption efficiency, sampling, analysis, and pump calibra-
tion arc combined, the state of the art indicated a relative
precision of ± 15 % at the 95 % confidence, level for most
solvent vapors.
ANNEX
(Mandatory Information)
Al. SELECTIVE SOLVENT-STRIPPING TECHNIQUES
\1 1 Organic compounds are soluble, or react with a
mt>er of solvents in a selective manner. Advantage of these
enomena may be taken in the analysis or solvent systems
Cs2 when there is peak overlap (1).
M 2 The following criteria are generally useful:
AI 2 1 Certain amines and amides are water soluble.
methylformamide is rapidly extracted from CS2 with one
lSh of laboratory grade water (5).
A 2 2 Oxygenated hydrocarbons such as esters, ketones,
-ohols and ethers are extracted by a solution consisting of
bv volume of concentrated sulfuric acid and one of
iPcLhonc acid (85 %)¦ A volume of 0.5 to I mL of this
F Qiinicient to effect a quantitative extraction of an
vvoenatcd hydrocarbon compound from CS; (I).
A| 1 Dimcthvl sulfate will extract nitrated aromatic
compound from a mixture of aromatics and alkyl hydro-
carbon solvents in CS2.
Note Al.I: Warning—Dimethyl sulfate is a suspected carcinogen
and is extremely corrosive.
A 1.2.4 A saturated solution of sodium metabisulfite will
extract selectively acetone and methyl ethyl ketone from a
mixture of oxygenated and other carbon compounds in CS2
with one wash.
A 1.2.5 A 10% solution of hydroxylamine hydrochloride
will extract selectively acetone, methyl ethyl ketone, isobutyl
ketone, methyl propyl ketone and methyl butyl ketone from
solution in CS2 in three separate washes.
A 1.3 The usual semimicrochemical techniques and pre-
cautions should be taken when such manipulations of the
CS2 cluatc arc undertaken, and cognizance should be taken
of the fact that CS; is highly volatile.
REFERENCES
I) Levadic. 11. and MacAskill. S. M„ "Analysis of Organic Solvents
Taken on Charcoal Tube Samplers by a Simplified Technique
Analytical Chemistry, Vol 48. No. 1. 1976, pp. 76-78.
12) Levadie, B.. and MacAskill, S. M., addendum to Ref (1). Vol 48,
No. II. p. 1656.
(3) White, I. D., Taylor, D. G.. Mauer, P. A., and Kupel. R. E., "A
Convenient Optimized Method for the Analysis of Selected Solvent
Vapors in Industrial Atmosphere," American Industrial Hygiene
Association Journal. Vol 31, 1970, p. 225.
(4) Dean, R. B.. and Dixon. W. J., "Simplified Statistics for Small
Numbers of Observations," Analytical Chemistry, Vol 23, 1951,
pp. 636-638.
(5) Levadie, B., Vermont Division of Occupational Health Labora-
tory, Personal Communication on File at ASTM Headquarters,
July 1976.
The American Society lor Testing end Materials takes no position respectma the vahit
with any item mentioned in this standard. Users oI litis standard are exoresslv , T* palent nghls asserted ,n connection
patent rights, and the risk ot infringement ol such rights, are entirely their own responsibly ""™"0" "* V3W"Y °'any such
This standard is sub/eel to revision at any time by the responsible lechmrai ^
it not revised, either reapproved or withdrawn. Your comments are inviled either lor rwMnn rev,ewed every Uve years and
and should be addressed to ASTM Headquarters. You, comn^mZTrec^ecJ^TrZ!i *s stan,3a>d or,or addiuona, standards
technical committee, which you may attend. „ you tee, c^Z™,r^TaZV,'"***««*
views known to the ASTM Corrmttm on Standards, 1916 Race St., Philadelphia, pa 19103 ^ y0° shovtd make your
2N
-------
Appendix E6: Standard Operating Procedures for TD-GC/MS Analysis
-------
Standard Operating Procedures
for the Analytical Determination of
Benzene, Toluene, Ethylbenzene, Xylenes and Total Petroleum Hydrocarbons
using Gas Chromatography/Mass Spectrometry
1.0 Applicability
The protocols prescribed in this standard operating procedure (SOP) are based upon EPA Method TO-1
and NIOSH Method 2549 and have been altered slightly to identify compounds of interest and to tighten
the quality control (QC) associated with the method to meet project-specific requirements. Deviations
from the prescribed method are noted in this SOP. This SOP is not meant to take the place of original
methods, therefore, the details of the GC/MS analysis as presented in EPA TO-1 are required for this
analysis. EPA Method TO-1 and NIOSH Method 2549 are attached. EPA Method TO-1 and NIOSH
Method 2549 have been used for the characterization of environments containing mixtures of volatile
organic compounds (VOCs). The sampling has been conducted using multi-bed thermal desorption
tubes.
2.0 Interferences
2.1 In situations where high levels of humidity may be present on the sample, some of the
polar volatile compounds may not be efficiently collected on the internal trap of the
thermal desorber.
23. Compounds which coelute on the chromatographic column may present an interference in
the identification of each compound. By appropriate use of background subtraction, the
mass spectrometrist may be able to obtain more representative spectra of each compound
and provide a tentative identification.
23 Contamination of the thermal desorption tubes is a common problem encountered with
this method. For this reason, all tubes will be pre-heated/purged to remove potential
residual contamination present on purchased tubes.
3.0 Equipment/Instrumentation
3.1 Sample tubes: The multi-bed sorbent tubes containing tenax, carbosieve and carbopack
sorbents. (Manufactured by Dynatherm.)
3.2 Gas Chromatograph/Mass Spectrometer with Thermal Desorption System (GC/MS-TDV
The GC will have an initial oven temperature of 40 °C, ramped for 30 minutes to a final
oven temperature of280 °C. Mass Spectrometer capable of scanning 30-440 m/z region
with a scan rate of 1 scan/second. Equipped with a computerized data system for
instrument control, data acquisition, data processing and data storage.
-------
4.0 Reagents
4.1 Helium, high purity
4.2 Organic compounds of interest for mass spectral verification (benzene, toluene,
ethylbenzene, xylenes, undecane, hexane, fuel oil #2 and full list of SW-846 8260 volatile
organic compounds (VOCs)).
43 Solvents (99+% purity; low benzene; chromatographic grade) for preparing spiking
solutions, liquid calibration standards (eg. carbon disulfide).
5.0 Standards
5.1 Liquid Standards: Prepare stock solutions by adding known amounts of analytes to 10-mL
volumetric flasks containing high purity solvent (carbon disulfide). Solvents are chosen
based on solubility for the analytes of interest and ability to be chromatographically
separated. Highly volatile compounds should be dissolved in a less volatile solvent.
Carbon disulfide is a good general purpose solvent, but will interfere with early-eluting
compounds. For this reason, the instrument must be programmed so the carbon disulfide
solvent is not displayed on the chromatography.
5.2 Tube Spiking: Fit Dynatherm attachment for flash preparation of calibration standards,
performance evaluation standard spikes and surrogate spikes onto thermal desorption
tubes. Attach clean thermal desorption tubes to the attachment so that the flow direction is
the same as for sampling. Take an aliquot of the standard solution (liquid standards 0.1 to
2 |iL) and flash onto a thermal desorption tube. Remove tube and submit for field
investigation or analyze by thermal desorption using the same conditions as for field
samples.
6.0 Holding Times and Storage
6.1 Thermal desorption tubes must be analyzed within 14 days of sampling.
6.2 Thermal desorption tubes may be transported from the field at ambient temperatures. If
long-term storage is required at the laboratory, the tubes must be stored at -10 °C. This
will not be the case for this project because turn-around-time will be 10 days from receipt
of the samples at the laboratory.
7.0 Reporting Limits
-------
For this project, the required reporting limits are also referred to as the method detection limits. The
method detection limit (MDL) is a statistically defined value. The procedure for determination of the
MDL is prescribed in the 40 Code of Federal Regulation (CFR), Chapter 1, Part 136, Appendix B. In
summary, a standard for each analyte of interest is prepared with a concentration approximately the
estimated limit of detection for the instrument. Seven replicates of this standard are prepared. A blank
and 7 replicates are analyzed and a statistical evaluation is performed. The MDL is the value described
by 3 standard deviations of the mean concentration for the seven replicates. The complete procedure for
MDL determination is attached to this SOP.
The required project-specific reporting/method detection limits are presented in Table 1. A range of
detection limits, acceptable for end use, were established in anticipation of variability in achievement of
MDLs between different methodologies and analytical laboratories.
Table 1: Project Target Detection Limits
Target Detection Limits
Parameter
Low
Hi|
gfa
|ig/m3
ppbv
Hg/m3
ppbv
Benzene
0.2
0.06
5
1.6
Toluene
10
2.7
50
13
Ethylbenzene
50
12
100
23
Xylenes
10
2.3
50
11
TPH (based on
undecane)
20
3
«•*
8.0 Instrument Set-up
8.1 The GC column will be fused silica bonded phased and have dimensions of 0.31 mm ID
and 30 m in length. The GC temperature program will have an initial oven temperature of
40 °C, ramped for 30 minutes to a final oven temperature of 280 °C.
8.2 Helium purge flows and carrier gas flows are set at approximately 10 mL/min and 1 -2
mL/min, respectively.
8 J The MS and data system are set according to manufacturer's instructions. Electron impact
ionization (70 eV) and an electron multiplier gain of approximately 5 x 104 should be
employed.
9.0 Instrument Calibration
9.1 Instrument Tuning and Mass Standardization: Instrument tuning and mass standardization
-------
of the MS system is performed according to manufacturer's instructions.
Perfluorotributylamine is generally used for this purpose. The material is introduced
directly into the ion source. The instrumental parameters (e.g. lens volatages, resolution,
etc.) should be adjusted to give acceptable resolution and peak shape as well as the relative
ion abundances shown in Table 2.
Table 2: Suggested Performance Criteria for Relative Ion Abundances
M/E
% Relative Abundance
51
1.8 ±0.5
69
100
100
12.0 ±1.5
119
12.0 ±1.5
131
35.0 ±3.5
169
3.0 ±0.4
219
24.0 ± 2.5
264
3.7 ±0.4
314
0.25 ± 0.1
If these approximate relative abundance cannot be achieved, the ion source may require
cleaning according to manufacturer's instructions. In the event that the user's instrument
cannot achieve these relative ion abundances, but is otherwise operating properly, the user
may adopt another set of relative abundances as performance criteria. These alternate
values must be repeatable on a day-to-day basis.
9.2 Initial Calibration: An acceptable initial calibration must be performed prior to the
analysis of any investigative samples. The following steps must be successfully
performed before analyzing any investigative samples.
9.2.1 Perform an initial calibration of the instrument using a range of 5 concentration
levels and including the following compounds: benzene, toluene, ethylbenzene,
xylenes, undecane, hexane, fuel oil #2 and the 72 SW-846 8260 VOCs. The
concentration levels should be graduated along the linear range of the instrument
for the compounds of interest and will begin with the minimum requested detection
limit described in the Quality Assurance Project Plan (QAPP) and in Section 6.0 of
this SOP. Introduction standards into the GC/MS system will be accomplished by
thermal desorption of standards spiked onto thermal desorption tubes.
9.2.2 Data from calibration standards are used to calculate a response factor for each
component of interest. Determination of the response factor (area/nanogram
injected) from the linear least squares fit of a plot of nanograms injected versus
area (for the characteristic ion). A relative standard deviation (RSD) will be
calculated using the 5 levels of each analyte. The RSD must not exceed 20% for
any of the compounds of interest. Alternatively, a calibration curve of area versus
concentration (in nanograms) may be constructed. The linear regression of this
-------
curve must result in a correlation coefficient, r > 0.995.
RSD = cr x 100%
x
Where cr — standard deviation of the 5 response factors for each analyte
x = average response factor for the 5 levels of each analyte
9.23 If substantial nonlinearity is present in the calibration curve, a nonlinear least
squares fit (quadratic) should be employed. This process involves fitting the data
to the following equation:
Y = A + BX + CX2
Where Y = peak area
X = quantity of analyte, nanograms
A,B, C = coefficients in the equation
9.2.4 Data processing for instrument calibration also involves determination of retention
times and integrated characteristic ion intensities for each of the compounds of
interest. Additionally, for at least one chromatographic run, the individual
spectra should be inspected and compared to reference spectral to ensure proper
instrumental performance.
93 Continuing Calibration: Investigative samples may be analyzed on days subsequent from
the successful initial calibration. However, the instrument must be evaluated prior to each
analytical batch to confirm that conditions have not altered significantly. The following
steps must be successfully performed prior to the analysis of any investigative samples.
93.1 Tune the mass spectrometer according Section 8.1 of this SOP.
93.2 Analyze a continuing calibration verification (CCV). The CCV is typically the
mid-range concentration standard containing all compounds of interest used for the
initial calibration standard. The percent drift (% D) for each analyte may not
exceed 20%.
% D = A^B x 100%
B
Where A = Observed concentration value of the analyte
B = Theoretical value of the analyte.
10.0 Sample Preparation
10.1 Allow the sample tubes to equilibrate to room temperature prior to analysis. The long-
-------
term storage caps must remain securely in place.
10.2 Analyze the "humidity test" sampler first to determine if humidity was high during
sampling.
10.3 If high humidity is observed, dry purge the tubes with purified helium at 50 to 100
mL/min for a maximum of 3 L and at ambient temperature prior to analysis. Note this
procedure in the analytical logbook and include this information in the case narrative
provided with the analytical results.
11.0 Sample Analysis
11.1 Analyze at least one instrument blank prior to analyzing any investigative samples to
ensure that the TD-GC/MS system produces a clean chromatographic background. Also,
analyze an instrument blank after analysis of heavily concentrated samples to prevent any
carryover in the system. If carry over is observed, perform instrument blanks until the
contamination is flushed from the thermal desorption system.
11.2 Place the sampler (thermal desorption tube) onto the termal dersorber. Desorbinthe
reverse direction to the sampling flow.
11.3 Quantification of target analytes is general performed by 1) qualitatively determining the
presence or absence of each compound of interest on the basis of a set of characterisitic
ion and the retention time using a reverse-search software routine; 2) quantification of
each identified component by integrating the intensityof a characterisitc ion and compring
the value to that of the calibration standard; and 3) tentative identification of other
components observed using a NIST library search software routine. Compounds not
included in the calibration will be considered tentatively identified compounds (TICs) if
the quality of match is 50 or greater.
11.4 Based upon estimated TD sample loading (determined by analysis of target analytes via
GC/FID), samples will be split by flow regulation to achieve optimum GC column loading
and optimal MS performance.
11.5 TVOC concentration will be estimated as the sum of calibrated VOC concentrations plus
the sum of TICs, estimated as toluene. Additional TVOC concentration will be reported
for calibrated VOC plus TOC as hexane and then as undecane.
11.6 TPH (as fuel oil #2) concentrations will be estimated as the sum of total peak response
over the elution period (retention time) for fuel oil #2.
11.7 BTEX and other EPA 8260 listed VOC concentration will be calculated based on a point-
to-point or best-fit through zero curve of the five point calibration standards.
-------
12.0 Quality Control
12.1 Analyze a minimum of one instrument blank per analytical batch. Perform additional
instrument blanks as necessary to eliminate carryover between analyses. The instrument
blanks must be free of target analyte contamination. If target compounds are detected in
the instrument blank, perform another instrument blank analysis.
12.2 Analyze surrogate recoveries on each investigative and QC sample. The surrogate
compound will be either a fluorinated or deuterated compound. Historical data for typical
surrogate recoveries will be established by the laboratory prior to submission of
investigative samples. Because TD tubes are one-time analyses only, surrogate recoveries
outside laboratory-established acceptance limits cannot be re-evaluated. Surrogate
recoveries outside the acceptance limits will serve as indicators for potential problems in
sampling and analysis.
L3.0 References
EPA. 1984. Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient
Air. 600/4-84-041.
EPA. 1986. Test Methods for Evaluation of Solid Waste, Physical/Chemical Methods SW-846,3rd
Edition plus updates.
EPA. 1995. Title 40 Code of Federal Regulations, Chapter I, Part 136, Appendix B pp 882-884.
NIOSH. 1996. NIOSH Manual of Analytical Methods: Method 2549.
-------
METHOD TO!
Revision 1.0
April, 1984
METHOD FOR THE DETERMINATION OF VOLATILE ORGANIC COMPOUNDS
IN AMBIENT AIR USING TENAX® ADSORPTION AND
GAS CHRQMATOGRAPHY/MASS SPECTROMETRY (GC/MS)
Scope
1.1 The document describes a generalized protocol for collection
and determination of certain volatile organic compounds
which can be captured on Tenax® GC (poly(2,6-Diphenyl
phenylene oxide)) and determined by thermal desorption
6C/MS techniques. Specific approaches using these techniques
are described in the literature (1-3).
1.2 This protocol is designed to allow some flexibility in order
to accommodate procedures currently in use. However, such
flexibility also results in placement of considerable
responsibility with the user to document that such procedures
give acceptable results {i.e. documentation of method performance
within each laboratory situation is required). Types of
documentation required are described elsewhere in this method.
1.3 Compounds which can be determined by this method are nonpolar
organics having boiling points in the range of approximately
80° - 200°C. However, not all compounds falling into this
category can be determined. Table 1 gives a listing of
compounds for which the method has been used. Other compounds
may yield satisfactory results but validation by the individual
user is required.
Applicable Documents
2.1 ASTM Standards:
D1356 Definitions of Terms Related to Atmospheric Sampling
and Analysis.
E355 Reconmended Practice for Gas Chromatography Terms and
Relationships.
-------
TO!-2
2.3 Other documents:
Existing procedures (1-3).
U.S. EPA Technical Assistance Document (4).
Summary of Protocol
3.1 Ambient air is drawn through a cartridge containing tl-2
grams of Tenax and certain volatile organic compounds are
trapped on the resin while highly volatile organic compounds
and most inorganic atmospheric constituents pass through the
cartridge. The cartridge is then transferred to the
laboratory and analyzed.
3.2 For analysis the cartridge is placed in a heated chamber and
purged with an inert gas. The inert gas transfers the
volatile organic compounds from the cartridge onto a cold trap
and subsequently onto the front of the GC column which is held
at low temperature (e.g. - 70°C). The GC column temperature is
then increased (temperature programmed) and the components
eluting from the column are identified and quantified by mass
spectrometry. Component identification is normally accomplished,
using a library search routine, on the basis of the GC retention
time and mass spectral characteristics. Less sophistacated
detectors (e.g. electron capture or flame ionization) may be
used for certain applications but their suitability for a given
application must be verified by the user.
3.3 Due to the complexity of ambient air samples only high resolution
(i.e. capillary) GC techniques are considered to be acceptable
in this protocol.
Si gni fi cance
4.1 Volatile organic compounds are emitted into the atmosphere from
a variety of sources including industrial and commercial
facilities, hazardous waste storage facilities, etc. Many of
these compounds are toxic; hence knowledge of the levels of
-------
T01-3
such materials in the ambient atmosphere is required in order
to determine human health impacts.
4.2 Conventional air monitoring methods (e.g. for workspace
monitoring) have relied on carbon adsorption approaches with
subsequent solvent desorption. Such techniques allow
subsequent injection of only a small portion, typically 1-5%
of the sample onto the GC system. However, typical
ambient air concentrations of these compounds require a more
sensitive approach. The thermal desorption process, wherein
the entire sample is introduced into the analytical (GC/MS)
system fulfills this need for enhanced sensitivity.
5. Definitions
Definitions used in this document and any user prepared SOPs should
be consistent with ASTM D1356(6). All abbreviations and symbols
are defined with this document at the point of use.
6. INTERFERENCES
6.1 Only compounds having a similar mass spectrum and GC retention
time compared to the compound of interest will interfere in
the method. The most commonly encountered interferences are
structural isomers.
6.2 Contamination of the Tenax cartridge with the compound(s)
of interest is a commonly encountered problem in the method.
The user must be extremely careful in the preparation, storage,
and handling of the cartridges throughout the entire sampling
and analysis process to minimize this problem.
7. Apparatus
7.1 Gas Chromatograph/Mass Spectrometry system - should be capable
of subambient temperature programming. Unit mass resolution
or better up to 800 amu. Capable of scanning 30-440 anu region
every 0.5-1 second. Equipped with data system for instrument
control as well as data acquisition, processing and storage.
-------
T01-4
7.2 Thermal Desorption Unit - Designed to accommodate Tenax
cartridges in use. See Figure 2a or b.
7.3 Sampling System - Capable of accurately and precisely
drawing an air flow of 10-500 ml/minute through the Tenax
cartridge. (See Figure 3a or b.)
7.4 Vacuum oven - connected to water aspirator vacuum supply.
7.5 Stopwatch
7.6 Pyrex disks - for drying Tenax.
7.7 Glass jar - Capped with Teflon-lined screw cap. For
storage of purified Tenax.
7.8 Powder funnel - for delivery of Tenax into cartridges.
7.9 Culture tubes - to hold individual glass Tenax cartridges.
7.10 Friction top can (paint can) - to hold clean Tenax cartridges.
7.11 Filter holder - stainless steel or aluminum (to accommodate
1 inch diameter filter). Other sizes may be used if desired,
(optional)
7.12 Thermometer - to record ambient temperature.
7.13 Barometer (optional).
7.14 Dilution bottle - Two-liter with septum cap for standards
preparation.
7.15 Teflon stirbar - 1 inch long.
7.16 Gas-tight glass syringes with stainless steel needles -
10-500 ul for standard injection onto GC/MS system..
7.17 Liquid microliter syringes - 5.50 nL for injecting neat
liquid standards into dilution bottle.
7.18 Oven - 60 + 5°C for equilibrating dilution flasks.
7.19 Magnetic stirrer.
7.20 Heating mantel.
7.21 Variac
7.22 Soxhlet extraction apparatus and glass thimbles - for purifying
Tenax.
7.23 Infrared lamp - for drying Tenax.
7.24 GC column - SE-30 or alternative coating, glass capillary or
fused silica.
-------
T01-5
7.25 Psychrometer - to determine ambient relative humidity,
(optional).
Reagents and Materials
8.1 Empty Tenax cartridges - glass or stainless steel (See
Figure la or b).
8.2 Tenax 60/80 mesh (2,6-diphenylphenylene oxide polymer).
8.3 Glasswool - silanized.
8.4 Acetone - Pesticide quality or equivalent.
8.5 Methanol - Pesticide quality, or equivalent.
8.6 Pentane - Pesticide quality or equivalent.
8.7 Helium - Ultra pure, compressed gas. (99.9999X)
8.8 Nitrogen - Ultra pure, compressed gas. (99.9999%)
8.9 Liquid nitrogen.
8.10 Polyester gloves - for handling glass Tenax cartridges.
8.11 Glass Fiber Filter - one inch diameter, to fit in filter holder,
(optional)
8.12 Perfluorotributylamine (FC-43).
8*13 Chemical Standards - Neat compounds of interest. Highest
purity available.
8.14 Granular activated charcoal - for preventing contamination of
Tenax cartridges during storage.
Cartridge Construction and Preparation
9.1 Cartridge Design
9.1.1 Several cartridge designs have been reported in the
literature (1-3). The most common (1) is shown in
Figure la. This design minimizes contact of the
sample with metal surfaces, which can lead to
decomposition in certain cases. However, a
disadvantage of this design is the need to rigorously
avoid contamination of the outside portion of the
cartridge since the entire surface is subjected to the
purge gas stream during the desorption porcess.
-------
TO!-6
Clean polyester gloves must be worn at all times
when handling such cartridges and exposure of the
open cartridge to ambient air must be minimized.
9.1.2 A second common type of design (3) is shown in
Figure lb. While this design uses a metal (stainless
steel) construction, it eliminates the need to avoid
direct contact with the exterior surface since only
the interior of the cartridge is purged.
9.1.3 The thermal desorption module and sampling system
must be selected to be compatible with the particular
cartridge design chosen. Typical module designs
are shown in Figures 2a and b. These designs are
suitable for the cartridge designs shown in Figures
la and lb, respectively.
9.2 Tenax Purification
9.2.1 Prior to use the Tenax resin is subjected to a
series of solvent extraction and thermal treatment
steps. The operation should be conducted in an area
where levels of volatile organic compounds (other than
the extraction solvents used) are minimized.
9.2.2 All glassware used in Tenax purification as well as
cartridge materials should be thoroughly cleaned by
water rinsing followed by an acetone rinse and dried
in an oven at 250°C.
9.2.3 Bulk Tenax is placed in a glass extraction thimble
and held in place with a plug of clean glasswool.
The resin is then placed in the soxhlet extraction
apparatus and extracted sequentially with methanol
and then pentane for 16-24 hours (each solvent) at
approximately 6 cycles/hour. Glasswool for cartidge
preparation should be cleaned in the same manner as
Tenax.
9.2.4 The extracted Tenax is immediately placed in an open
glass dish and heated under an infrared lamp for two
-------
TO!-8
9.3.4 After the four hour heating period the cartridges
are allowed to cool. Cartridges of the type shown
in Figure la are immediately placed (without cooling)
in clean culture tubes having Teflon-lined screw caps
with a glasswool cushion at both the top and the bottom.
Each tube should be shaken to ensure that the cartridge
is held firmly in place. Cartridges of the type shown
in Figure lb are allowed to cool to room temperature under
inert gas purge and are then closed with stainless steel
plugs.
9.3.5 The cartridges are labeled and placed in a tightly
sealed metal can (e.g. paint can or similar friction
top container). For cartridges of the type shown
in Figure la the culture tube, not the cartridge^s
labeled.
9.3.6 Cartridges should be used for sampling within 2 weeks
after preparation and analyzed within two weeks after
sampling. If possible the cartridges should be stored
at -20°C in a clean freezer (i.e. no solvent extracts
or other sources of volatile organics contained in the
freezer).
10. Sampling
10.1 Flow rate and Total Volume Selection
10.1.1 Each compound has a characteristic retention volume
(liters of air per gram of adsorbent) which must not
be exceeded. Since the retention volume is a function
of temperature, and possibly other sampling variables,
one must include an adequate margin of safety to
ensure good collection efficiency. Some considerations
and guidance in this regard are provided in a recent
report (5). Approximate breakthrough volumes at 38*C
(100°F) in liters/gram of Tenax are provided in Table 1.
These retention volume data are supplied only as rough
guidance and are subject to considerable variability,
depending on cartridge design as well as sampling
parameters and atmospheric conditions.
-------
TO!-7
hours in a hood. Care must be exercised to avoid
over heating of the Tenax by the infrared lamp.
The Tenax is then placed in a vacuum oven (evacuated
using a water aspirator) without heating for one hour.
An inert gas (helium or nitrogen) purge of 2-3
ml/minute is used to aid in the removal of solvent
vapors. The oven temperature is then increased to
110°C, maintaining inert gas flow and held for one
hour. The oven temperature control is then shut
off and the oven is allowed to cool to room temperature.
Prior to opening the oven, the oven is slightly
pressurized with nitrogen to prevent contamination
with ambient air. The Tenax is removed from the oven
and sieved through a 40/60 mesh sieve (acetone rinsed
and oven dried) into a clean glass vessel. If the Tenax
is not to be used imnediately for cartridge preparation
it should be stored in a clean glass jar having a
Teflon-lined screw cap and placed in a desiccator.
9.3 Cartridge Preparation and Pretreatment
9.3.1 All cartridge materials are pre-cleaned as described
in Section 9.2.2. If the glass cartridge design shown
in Figure la is employed all handling should be
conducted wearing polyester gloves.
9.3.2 The cartridge is packed by placing a 0.5-lcm glass-
wool plug in the base of the cartridge and then
filling the cartridge to within approximately 1 cm
of the top. A 0.5-lcm glasswool plug is placed in
the top of the cartridge.
9.3.3 The cartridges are then thermally conditioned by
heating for four hours at 270°C under an inert gas
(helium) purge (100 - 200 ml/min).
-------
where
T01-10
B is the calculated linear flow velocity in
centimeters per minute.
r is the internal radius of the cartridge in
centimeters.
If B is greater than 500 centimeters per minute
either the total sample volume (VMAX) should be
reduced or the sample flow rate (QMAX) should be
reduced by increasing the collection time. If B is
less than 50 centimeters per minute the sampling rate
(QMAX) should be increased by reducing the sampling
time. The total sample value (VMAX) cannot be
increased due to component breakthrough.
10.1.4 The flow rate calculated as described above defines
the maximum flow rate allowed. In general, one should
collect additional samples in parallel, for the same
time period but at lower flow rates. This practice
yields a measure of quality control and is further
discussed in the literature (5). In general, flow
rates 2 to 4 fold lower than the maximum flow rate
should be employed for the parallel samples. In
all cases a constant flow rate should be achieved
for each cartridge since accurate integration of the
analyte concentration requires chat the flow be
constant over the sampling period.
0.2 Sample Collection
10.2.1 Collection of an accurately known volume of air
is critical to the accuracy of the results. For
this reason the use of mass flow controllers,
rather than conventional needle valves or orifices
is highly recommended, especially at low flow
velocities (e.g. less than 100 milliliters/minute).
Figure 3a illustrates a sampling system utilizing
mass flow controllers. This system readily allows
for collection of parallel samples. Figures 3b
shows a commercially available system based on
•>nn>4ia waluo flnu rnnt.rol 1 ers.
-------
T01-9
10.1.2 To calculate the maximum total volume of air which
can be sampled use the following equation:
Vmax = VbxM
1.5
where
VMAX 1S calculated maximum total volume in liters.
Vfo is the breakthrough volume for the least retained
compound of interest (Table 1) in liters per gram
of Tenax.
W is the weight of Tenax in the cartridge, in grams.
1.5 is a dimensionless safety factor to allow for
variability in atmospheric conditions. This factor
is appropriate for temperatures in the range of
25-30°C. If higher temperatures are encountered the
factor should be increased (i.e. maximum total volume
decreased).
10.1.3 To calculate maximum flow rate use the following
equation:
Qmax - * 1000
where
QMAX 1S t'ie calculated maximum flow rate in mi 11 i-
leters per minute,
t is the desired sampling time in minutes. Times
greater than 24 hours (1440 minutes) generally
are unsuitable because the flow rate required
is too low to be accurately maintained.
10.1.4 The maximum flow rate Qmax should yield a linear flow
velocity of 50-500 cm/minute. Calculate the linear
velocity corresponding to the maximinn flow rate
using the following equation:
-------
T01-12
pressure, relative humidity, dry gas meter reading
(if applicable) flow rate, rotameter reading (if
applicable), cartridge number and
-------
TOT-11
10.2.2 Prior to sample collection insure that the sampling
flow rate has been calibrated over a range including
the rate to be used for sampling, with a "dummy"
Tenax cartridge in place. Generally calibration
is accomplished using a soap bubble flow meter
or calibrated wet test meter. The flow calibration
device is connected to the flow exit, assuming
the entire flow system is sealed. ASTM Method
D3686 describes an appropriate calibration scheme,
not requiring a sealed flow system downstream
of the pump.
10.2.3 The flow rate should be checked before and after
each sample collection. If the sampling interval
exceeds four hours the flow rate should be checked
at an intermediate point during sampling as well.
In general, a rotameter should be included, as
showed in Figure 3b, to allow observation of the
sampling flow rate without disrupting the sampling
process.
10.2.4 To collect an air sample the cartridges are removed
from the sealed container just prior to initiation
of the collection process. If glass cartridges
(Figure la) are employed they must be handled
only with polyester gloves and should not contact
any other surfaces.
10.2.5 A particulate filter and holder are placed on
the inlet to the cartridges and the exit end
of the cartridge is connected to the sampling
apparatus. In many sampling situations the use
of a filter is not necessary if only the total
concentration of a component is desired. Glass
cartridges of the type shown in Figure la are
connected using teflon ferrules and Swagelok
(stainless steel or teflon) fittings. Start the
pump and record the following parameters on an
appropriate data sheet (Figure 4): data, sampling
location, time, ambient temperature, barometric
-------
T01-13
where
Vm = Total volume sampled in liters at measured
temperature and pressure.
T2 = Stop time.
T] = Start time.
T = Sampling time = 1% - Tj, minutes
10.2.10 The total volume (Vs) at standard conditions,
25°C and 760 mmHg, is calculated from the
following equation:
V = v x 298
vs vm x 760x 273 + tA
where
= Average barometric pressure, mmHg
^ = Average ambient temperature, °C.
GC/MS Analysis
11.1 Instrument Set-up
11.1.1 Considerable variation from one laboratory to
another is expected in terms of instrument configurati
Therefore each laboratory must be responsible
for verifying that their particular system yields
satisfactory results. Section 14 discusses specific
performance criteria which should be met.
11.1.2 A block diagram of the typical GC/MS system
required for analysis of Tenax cartridges is
depicted in Figure 5. The operation of such
devices is described in 11.2.4. The thermal
desorption module must be designed to accommodate
the particular cartridge configuration. Exposure
of the sample to metal surfaces should be
minimized and only stainless steel, or nickel metal
surfaces should be employed.
-------
T01-14
The volume of tubing and fittings leading from
the cartridge to the GC column must be minimized
and all areas must be well-swept by helium carrier
gas.
11.1.3 The GC column inlet should be capable of being
cooled to -70°C and subsequently increased rapidly
to approximately 30°C. This can be most readily
accomplished using a GC equipped with subambient
cooling capability (liquid nitrogen) although
other approaches such as manually cooling the
inlet of the column in liquid nitrogen may be
acceptable.
11.1.4 The specific GC column and temperature program
employed will be dependent on the specific compounds
of interest. Appropriate conditions are described
in the literature (1-3). In general a nonpolar
stationary phase (e.g. SE-30, OV-1) temperature
programmed from 30°C to 200°C at 8°/minute will
be suitable. Fused silica bonded phase columns
are preferable to glass columns since they are
more rugged and can be inserted directly into
the MS ion source, thereby eliminating the need
for a GC/MS transfer line.
11.1.5 Capillary column dimensions of 0.3 mm ID and 50
meters long are generally appropriate although
shorter lengths may be sufficient in many cases.
11.1.6 Prior to instrument calibration or sample analysis
the GC/MS system is assembled as shown in Figure
5. Helium purge flows (through the cartridge)
and carrier flow are set at approximately 10 ml/
minute and 1-2 ml/minute respectively. If applicable,
the -injector sweep flow is set at 2-4 ml/minute.
-------
T01-15
11.1.7 Once the column and other system components are
assembled and the various flows established the
column temperature is increased to 250°C for
approximately four hours (or overnight if desired)
to condition the column.
11.1.8 The MS and data system are set according to the
manufacturer's instructions. Electron impact
ionization (70eV) and an electron multiplier gain
of approximately 5 x 104 should be employed.
Once the entire 6C/MS system has been setup the
system is calibrated as described in Section 11.2.
The user should prepare a detailed standard
operating procedure (SOP) describing this process
for the particular instrument being used.
11.2 Instrument Calibration
11.2.1 Tuning and mass standarization of the MS system
is performed according to manufacturer's instructions
and relevant information from the user prepared
SOP. Perfluorotributylamine should generally
be employed for this purpose. The material
is introduced directly into the ion source
through a molecular leak. The instrumental
parameters (e.g. lens voltages, resolution,
etc.) should be adjusted to give the relative
ion abundances shown in Table 2 as well as
acceptable resolution and peak shape. If
these approximate relative abundances cannot
be achieved, the ion source may require cleaning
according to manufacturer's instructions.
In the event that the user's instrument cannot
achieve these relative ion abundances, but
is otherwise operating properly, the user
may adopt another set of relative abundances
as performance criteria.
-------
T01-16
However, these alternate values must be repeatable
on a day-to-day basis.
11.2.2 After the mass standarization and tuning process
as been completed and the appropriate values
ntered into the data system the user should
hen calibrate the entire system by introducing
nown quantities of the standard components
f interest into the system. Three alternate
rocedures may be employed for the calibration
rocess including 1) direct syringe injection
if dilute vapor phase standards, prepared
n a dilution bottle, onto the GC column, 2)
injection of dilute vapor phase standards
into a carrier gas stream directed through the
Tenax cartridge, and 3) introduction of permeation
>r diffusion tube standards onto a Tenax cartridge.
The standards preparation procedures for each
)f these approaches are described in Section
13. The following paragraphs describe the
instrument calibration process for each of
these approaches.
11.2.3 If the instrument is to be calibrated by direct
injection of a gaseous standard, a standard
is prepared in a dilution bottle as described
in Section 13.1. The GC colunm is cooled
to -70°C (or, alternately, a portion of the
column inlet is manually cooled with liquid
nitrogen). The MS and data system is set
up for acquisition as described in the relevant
user SOP. The ionization filament should be turned
off during the initial 2-3 minutes of the run to
allow oxygen and other highly volatile components
to elute. An appropriate volume (less than 1 ml)
of the gaseous standard is injected onto the GC
system using an accurately calibrated gas tight syringe.
-------
TO!-17
The system clock is started and the column is
naintained at -70°C (or liquid nitrogen inlet cooling)
for 2 minutes. The column temperature is rapidly
increased to the desired initial temperature (e.g. 30°C).
The temperature program is started at a consistent
time (e.g. four minutes) after injection. Simultaneously
the ionization filament is turned on and data acquisition
is initiated. After the last component of interest has
eluted acquisiton is terminated and the data is processed
as described in Section 11.2.5. The standard injection
process is repeated using different standard volumes as
desired.
11.2.4 If the system is to be calibrated by analysis of
spiked Tenax cartridges a set of cartridges is
prepared as described in Sections 13.2 or 13.3.
Prior to analysis the cartridges are stored as
described in Section 9.3. If glass cartridges (Figure la)
are employed care must be taken to avoid direct
contact, as described earlier. The GC column is
cooled to -70°C, the collection loop is immersed in
liquid nitrogen and the desorption module is
maintained at 250°C. The inlet valve is placed in the
desorb mode and the standard cartridge is placed in
the desorption module, making certain that no leakage
of purge gas occurs. The cartridge is purged
for 10 minutes and then the inlet valve is placed in
the inject mode and the liquid nitrogen source removed
from the collection trap. The GC column is maintained
at -70°C for two minutes and subsequent steps are as
described in 11.2.3. After the process is complete the
cartridge is removed from the desorption module and
stored for subsequent use as described in Section 9.3.
-------
T01-18
11.2.5 Data processing for instrument calibration involves
determining retention times, and integrated characteristic
ion intensities for each of the compounds of interest.
In addition, for at least one chromatographic run,the
individual mass spectra should be inspected and
compared to reference spectra to ensure proper
instrumental performance. Since the steps involved
in data processing are highly instrument specific, the
user should prepare a SOP describing the process for
individual use. Overall performance criteria for
instrument calibration are provided in Section 14. If
these criteria are not achieved the user should refine
the instrumental parameters and/or operating
procedures to meet these criteria.
11.3 Sample Analysis
11.3.1 The sample analysis process is identical to that
described in Section 11.2.4 for the analysis of standard
Tenax cartridges.
11.3.2 Data processing for sample data generally involves
1) qualitatively determining the presence or absence
of each component of interest on the basis of a set
of characteristic ions and the retention time using
a reverses-search software routine, 2) quantification
of each identified component by integrating the intensity
of a characteristic ion and comparing the value to
that of the calibration standard, and 3) tentative
identification of other components observed using a
forward (library) search software routine. As for
other user specific processes, a SOP should be prepared
describing the specific operations for each individual
laboratory.
-------
T01-19
Calculations
12.1 Calibration Response Factors
12.1.1 Data from calibration standards is used to calculate
a response factor for each component of interest.
Ideally the process involves analysis of at least
three calibration levels of each component during a
given day and determination of the response
factor (area/nanogram injected) from the linear
least squares fit of a plot of nanograms injected
versus area (for the characteristic ion).
In general quantities of component greater
than 1000 nanograms should not be injected
because of column overloading and/or MS response
nonlinearity.
12.1.2 In practice the daily routine may not always
allow analysis of three such calibration standards.
In this situation calibration data from consecutive
days may be pooled to yield a response factor»
provided that analysis of replicate standards
of the same concentration are shown to agree
within 20X on the consecutive days. One standard
concentrationi near the midpoint of the analytical
range of interest, should be chosen for injection
every day to determine day-to-day response
reproducibility.
12.1.3 If substantial nonlinearity is present in
the calibration curve a nonlinear least squares
fit (e.g. quadratic) should be employed.
This process involves fitting the data to
the following equation:
Y= A + BX + CX2
where
Y = peak area
X = quantity of component, nanograms
A,Bt and C are coefficients in the equation
-------
TO!-20
12.2 Analyte Concentrations
12.2.1 Analyte quantities on a sample cartridge are calculated
from the following equation:
whp rp
YA = A + BXft + CXa
Ya is the area of the analyte characteristic ion for
the sample cartridge.
Xa is the calculated quantity of analyte on the sample
cartridge, in nanograms.
A,B, and C are the coefficients calculated from the
calibration curve described in Section 12.1.3.
12.2.2 If instrumental response is essentially linear over the
concentration range of interest a linear equation
(00 in the equation above) can oe employed.
12.2.3 Concentration of analyte in the original air sample is
calculated from the following equation:
where
C^ is the calculated concentration of analyte in
nanograms per liter.
V$ and are as previously defined in Section
10.2.10 and 12.2.1, respectively.
13. Standard Preparation
13.1 Direct Injection
13.1.1 This process involves preparation of a dilution
bottle containing the desired concentrations
of compounds of interest for direct injection
onto the GC/MS system.
-------
TOT-22
13.1.6 The bottle is placed in a 60°C oven for at
least 30 minutes prior to removal of a vapor
phase standard.
13.1.7 To withdraw a standard for GC/MS injection
the bottle is removed from the oven and stirred
for 10-15 seconds. A suitable gas-tight microber
syring warmed to 60°C, is inserted through
the septum cap and pumped three times slowly.
The appropriate volume of sample (approximately 251
larger than the desired injection volume) is drawn
into the syringe and the volume is adjusted to the
exact value desired and then immediately injected
over a 5-10 seconds period onto the GC/MS system as
described in Section 11.2.3.
13.2 Preparation of Spiked Cartridges by Vapor Phase Injection
13.2.1 This process involves preparation of a dilution
bottle containing the desired concentrations
of the compound(s) of interest as described
in 13.1 and injecting the desired volume of
vapor into a flowing inert gas stream directed
through a clean Tenax cartridge.
13.2.2 A helium purge system is assembled wherein
the helium flow 20-30 ml/minute, is passed
through a stainless steel Tee fitted with
a septum injector. The clean Tenax cartridge
is connected downstream of the tee using
appropriate Swagelok fittings. Once the cartridge
is placed in the flowing gas stream the appropriate
volume vapor standard, in the dilution bottle,
is injected through the septum as described in
13.1.6. The syringe is flushed several times
by alternately filling the syringe with carrier
gas and displacing the contents into the flow
stream, without removing the syringe from the septum.
Carrier flow is maintain through the cartridge for
approximately 5 minutes after injection.
-------
T01-21
13.1.2 Fifteen three-millimeter diameter glass beads
and a one-inch Teflon stirbar are placed in a
clean two-liter glass septum capped bottle and
the exact volume is determined by weighing the
bottle before and after filling with deionized water.
The bottle is then rinsed with acetone and dried at 200°C.
13.1.3 The amount of each standard to be injected into the
vessel is calculated from the desired injection quantity
and volume using the following equation:
WT s«Lx VB
Vi
where
Wy is the total quantity of analyte to be injected
into the bottle in milligrams
Wj is the desired weight of analyte to. be injected
onto the 6C/MS system or spiked cartridge in
nanograms
Vj is the desired GC/MS or cartridge injection
volume (should not exceed 500) in microliters.
Vg is total volume of dilution bottle determined
in 13.1.1, in liters.
13.1.4 The volume of the neat standard to be injected
into the dilution bottle is determined using
the following equation:
UT
"t -4-
where
Vj is the total volume of neat liquid to be injected
in microliters.
d is the density of the neat standard in grams per
milliliter.
-------
TO!-23
13.3 Preparation of Spiked Traps Using Permeation or Diffusion
tubes
13.3.1 A flowing stream of inert gas containing known
amounts of each compound of interest is generated
according to ASTM Method 03609(6). Note that
a method of accuracy maintaining temperature
within + 0.1°C is required and the system
generally must be equilibrated for at least
48 hours before use.
13.3.2 An accurately known volume of the standard
gas stream (usually 0.1-1 liter) is drawn
through a clean lenax cartridge using the
sampling system described in Section 10.2.1,
or a similar system. However, if mass flow
controllers are employed they must be calibrated
for the carrier gas used in Section 13.3.1
(usually nitrogen). Use of air as the carrier
gas for permeation systems is not recommended,
unless the compounds of interest are known
to be highly stable in air:
13.3.3 The spiked cartridges are then stored or inroediatel.
analyzed as in Section 11.2.4.
Performance Criteria and Quality Assurance
This section sunroarizes quality assurance (QA) measures and
provides guidance concerning performance criteria which should be
achieved within each laboratory. In many cases the specific
QA procedures have been described within the appropriate section
describing the particular activity (e.g. parallel sampling).
-------
TO!-24
14.1 Standard Opreating Procedures (SOPs)
14.1.1 Each user should generate SOPs describing the
following activities as they are performed
in their laboratory:
1) assembly, calibration, and operation of
the sampling system,
2) preparation, handling and storage of Tenax
cartridges,
3) assembly and operation of GC/MS system including
the thermal desorption apparatus and data
system, and
4) all aspects of data recording and processing.
14.1.2 SOPs should provide specific stepwise instructions
and should be readily available to, and understood
by the 1aboratdry personnel conducti ng the
work.
14.2 Tenax Cartridge Preparation
14.2.1 Each batch of Tenax cartridges prepared (as
described in Section 9) should be checked for
contamination by analyzing one cartridge irimediately
after preparation. While analysis can be accomplished
by GC/MS, many laboratories may chose to use
GC/FIO due to logistical and cost considerations.
14.2.2 Analysis by GC/FID is accomplished as described
for GC/MS (Section 11) except for use of FID
detection.
-------
T01-25
14.2.3 While acceptance criteria can vary depending
on the components of interest, at a minimum
the clean cartridge should be demonstrated
to contain less than one fourth of the minimum
level of interest for each component. For
most compounds the blank level should be less
than 10 nanograms per cartridge in order to
be acceptable. More rigid criteria may be
adopted, if necessary, within a specific laboratory
If a cartridge does not meet these acceptance
criteria the entire lot should be rejected.
T4«.3 Simple Cbl lection
14.3.1 During each sampling event at least one clean
cartridge will accompany the samples to the
field and back to the laboratory, without being
used for sampling, to serve as a field blank.
The average amount of material found on the
field blank cartridge may be subtracted from
the amount found on the actual samples. However,
if the blank level is greater than 25X of the
sample amount, data for that component must
be identified as suspect.
14.3.2 During each sampling event at least one set
of parallel samples (two or more samples collected
simultaneously) will be collected, preferably
at different flow rates as described in Section
10.1. If agreement between parallel samples
is not generally within +25% the user should
collect parallel samples on a much more frequent
basis (perhaps for all sampling points). If
a trend of lower apparent concentrations with
increasing flow rate is observed for a set
-------
TO!-26
of parallel samples one should consider using
a reduced flow rate and longer sampling interval
if possible. If this practice does not improve
the reproducibility further evaluation of the
method performance for the compound of interest
may be required.
14.3.3 Backup cartridges (two cartridges in series)
should be collected with each sampling event.
Backup cartridges should contain less than
20t of the amount of components of interest
found in the front cartridges, or be equivalent
to the blank cartridge level, whichever is
greater. The frequency of use of backup cartridges
should be increased if increased flow rate
is shown to yield reduced component levels
for parallel sampling. This practice will
help to identify problems arising from breakthrough
of the component of interest during sampling.
14.4 GC/MS Analysis
14.4.1 Performance criteria for MS tuning and mass
calibration have been discussed in Section
11.2 and Table 2. Additional criteria may
be used by the laboratory if desired. The
following sections provide performance guidance
and suggested criteria for determining the
acceptability of the GC/MS system.
14.4.2 Chromatographic efficiency should be evaluated
using spiked Tenax cartridges since this practice
tests the entire system. In general a reference
compound such as perf1uorotoluene should be
spiked onto a cartridge at the 100 nanogram
level as described in Section 13.2 or 13.3.
The cartridge is then analyzed by GC/MS as
-------
T01-27
described in Section 11.4. The perfluorotoluene (or
other reference compound) peak is then plotted on an
expanded time scale so that its width at 10% of the
peak can be calculated, as shown in Figure 6. The
width of the peak at 10X height should not exceed
10 seconds. More stringent criteria may be required
for certain applications. The assymmetry factor
(See Figure 6) should be between 0.8 and 2.0. The
assymmetry factor for any polar or reactive compounds
should be determined using the process described above.
IT peaks are observed that exceed the peak width or
assymmetry factor criteria above, one should inspect
the entire system to determine if* unswept zones or
cold spots are present rn any of the fittings and'
is necessary. Some laboratories may chose
to evaluate column performance separately by
direct injection of a test mixture onto the
GC column. Suitable schemes for column evaluation
have been reported in the literature (7).
Such schemes cannot be conducted by placing
the substances onto Tenax because many of
the compounds (e.g. acids, bases, alcohols)
contained in the test mix are not retained,
or degrade, on Yenax.
14.4.3 The system detection limit for each component
is calculated from the data obtained for
calibration standards. The detection limit
is defined as
DL s A + 3.3S
-------
TO!-28
where
DL is the calculated detection limit in
nanograms injected.
A is the intercept calculated in Section
12.1.1 or 12.1.3.
S is the standard deviation of replicate
determinations of the lowest level standard
(at least three sucn aeterm nations are
required.
In general the detection limit should be 20
nanograms or less and for many applications
detection limits of 1-5 nanograms may be required.
The lowest level standard should yield a signal
to noise ratio.from the total ion current response,
of approximately 5.
14.4.4 The relative standard deviation for replicate
analyses of cartridges spiked at approximately
10 times the detection limit should be 20%
or less. Day to day relative standard deviation
should be 25X or less.
14.4.5 A useful performance evaluation step is the
use of an internal standard to track system
performance. This is accomplished by spiking
each cartridge, including blank, sample, and
calibration cartridges with approximately 100
nanograms of a compound not generally present
in ambient air (e.g. perfluorotoluene). The
integrated ion intensity for this compound
helps to identify problems with a specific
sample. In general the user should calculate
the standard deviation of the internal standard
response for a given set of samples analyzed
under identical tuning and calibration conditions.
Any sample giving a value greater than + 2
standard deviations from the mean (calculated
-------
T01-29
excluding that particular sample) should be
identified as suspect. Any marked change in
internal standard response may indicate a need
for instrument recalfbration.
-------
TO!-30
REFERENCES
1. Krost, K. J., Pellizzari, E. D., Walburn, S. G., and Hubbard, S. A.,
"Collection and Analysis of Hazardous Organic Emissions",
Analytical Chemistry, 54, 810-817, 1982.
2- Pellizzari, E. 0. and Bunch, J. E., "Ambient Air Carcinogenic Vapors-
Improved Sampling and Analytical Techniques and Field Studies",
EPA-600/2-79-081, U.S. Environmental Protection Agency, Research
Triangle Park, North Carolina, 1979.
3. Kebbekus, B. B. and Bozzelli, J. W., "Collection and Analysis of
Selected Volatile Organic Compounds in Ambient Air", Proc. Air
Pollution Control Assoc., Paper No. 82-65.2. Air Poll. Control
Assoc., Pittsburgh, Pennsylvania, 1982.
4. Riggin, R. M., "Technical Assistance Document for Sampling and
Analysis of Toxic Organic Compounds in Ambient Air", EPA-600/
4-83-027, U.S. Environmental Protection Agency, Research Triangle
Park, North Carolina, 1983.
5. Walling, J. F., Berkley, R. E., Swanson, D. H., and Toth, F. J.
"Sampling Air for Gaseous Organic Chemical-Applications to Tenax",
EPA-600/7-54-82-059, U.S. Environmental Protection Agency, Research
Triangle Park, North Carolina, 1982.
6. Annual Book of ASTM Standards, Part 11.03, "Atmospheric Analysis",
American Society for Testing and Material, Philadelphia,
Pennsylvania.
7. Grob, K., Jr., Grob, G.,~and Grob, K., "Comprehensive Standardized
Quality Test for Glass Capillary Columns", J. Chromatog., 156,
1-20, 1978.
-------
TO!-31
TABLE 1. RETENTION VOLUME ESTIMATES FOR COMPOUNDS ON TENAX
ESTIMATED RETENTION VOLUME AT
COMPOUND 100°F (38°C)-LITERS/GRAM
Benzene 19
Toluene 97
Ethyl Benzene 200
Xylene(s) -v 200
Cumene 440
n-Heptane 20
1-Heptene 40
Chloroform 8
Carbon Tetrachloride 8
1,2-Dichloroethane 10
1»1,1-Trichloroethane 6
Tetrichloroethylene 80
Trichloroethylene 20
1.2-Dichloropropane 30
1.3-Dichloropropane 90
Chlorobenzene 150
Bromoform 100
Ethylene Dibromide 60
Bromobenzene 300
-------
T01-32
TABLE 2. SUGGESTED PERFORMANCE CRITERIA FOR RELATIVE
ION ABUNDANCES FROM FC-43 MASS CALIBRATION
% RELATIVE
M/E
ABUNDANCE
51
1.8 + 0.5
69
100
100
12.0 + 1.5
119
12.0 + 1.5
131
35.0 + 3.5
169
3.0 + 0.4
219
24.0 + 2.5
264
3.7 + 0.4
314
0.25 + 0.
-------
TOT-33
Tenax
~1 J5 Grams (6 cm Bed Depth)
Glau Wool Plugs
(0.5 cm Long)
Glass Cartridge
(13.5 mm OD x
100 mm Long)
.(a) Glass Cartridge
-•«.i ¦»»
1/2" to
1/8"
Reducing
Union
1/8" End Cap
Metal Cartridge
(12.7 mm OD x
100 mm Long)
1/2"
Swageiok
Fitting
Tenax
~1.5 Grams (7 cm Bed Depth)
(b) Metal Cartridge
FIGURE 1. TENAX CARTRIDGE DESIGNS
-------
TO!-34
Latch for
Compression
Seal
Cavity for-
Tmu
Cartridge
Effluent to
6-Port Valve
ToGC/MS
Uquld
Nitrogen
Coolant
(a) Glass Cartridges (Compression Fit)
ToGC/MS
Vent
oa>
Swagaiok
End Fittings
Carrier
Gas
Liquid
Nitrogen
Coolant
(b) Metal Cartridges (Swagaiok Fittings)
FIGURE 2. TENAX CARTRIDGE DESORPTION MODULES
-------
T01-35
Couplings
to Connect
Tenax
Cartridges
Mats Flow
Controllers
Oilless
Pump
Vent
(a) Man Flow Control
Rotometer
Vent
Dry
Test
Meter
Pump
Needle
Valve
(b) Needle Valve Control
FIGURE 3. TYPICAL SAMPLING SYSTEM CONFIGURATIONS
-------
TO! — 36
SAMPLING DATA SHEET
(One Sample Per Data Sheet)
OJECT:
TE:
DATE{S) SAMPLED:
ICATION:
TIME PERIOD SAMPLED:
OPERATOR:
ISTRUMENT MODEL NO:
MP SERIAL NO:
LHPLIWG DATA
CALIBRATED BY:
Sample Number:
Start Time:
Stop Time:
Time
Dry Gas
Meter
Reading
Rotameter
Reading
Flow
Rate,*Q
ml /Mi n
Ambient
Temperature
°C
Barometric
Pressure,
mmHg
Relative
Humidity, t
Coinnents
Total Volume Data**
vm ~ (Final - Initial) Dry Gas Meter Reading, or-
= Qi + Q2 + Q3--Qn
1
TOOO x (Sampling Time in Minutes)
Liters
Liters
* Flowrate from rotameter or soap bubble calibrator
(specify which).
** Use data from dry gas meter if available.
FIGURE 4. EXAMPLE SAMPLING DATA SHEET
-------
TOl-37
Purge
Gas
Therm*)
Desorption
Chamber
6-Port High-Temperature
Valve
Capillary
Gat
Chromatograph
Mass
Spectrometer
Heated
Blocks
^Vent
Freeze Out Loop
Carrier
Gas
Liquid
Nitrogen
Coolant
FIGURE 5. BLOCK DIAGRAM OF ANALYTICAL SYSTEM
-------
TO!-38
E
Asymmetry Factor " —
Ad
Example Calculation:
Paak Height» DE -100 mm
10% Paak H tight - BD - 10 mm
Paak Width at 10% Paak H tight - AC - 23 mm
AB ¦ 11 mm
BC • 12 mm
Therefore: Asymmetry Factor
FIGURE 6. PEAK ASYMMETRY CALCULATION
-------
Pt. 136, App. B
appendix B to Part 136—Definition
and Procedure for the Deter-
mination of the Method Detec-
tion Limit—Revision 1.11
Definition
The method detection limit (MDL) is de-
fined as the minimum concentration of a
substance that can be measured and reported
with 99% confidence that the analyte con-
centration is greater than zero and is deter-
mined from analysis of a sample in a given
matrix containing the analyte.
Scope and Application
This procedure is designed for applicability
to a wide variety of sample types ranging
from reagent (blank) water containing
analyte to wastewater containing analyte.
The MDL. for an analytical procedure may
vary as a function of sample type. The proce-
dure requires a complete, specific, and well
defined analytical method. It is essential
that all sample processing steps of the ana-
lytical method be included In the determina-
tion of the method detection limit.
The MDL obtained by this procedure is
used to judge the significance of a single
measurement of a future sample.
The MDL procedure was designed for appli-
cability to a broad variety of physical and
chemical methods. To accomplish this, the
procedure was made device- or instrument-
independent.
Procedure
1. Make an estimate of the detection limit
using one of the following:
(a) The concentration value that cor-
responds to an instrument signal/noise in the
range of 2.5 to 5.
(b) The concentration equivalent of three
times the standard deviation of replicate in-
strumental measurements of the analyte in
reagent water.
(c) That region of the standard curve where
there is a significant change in sensitivity.
I.e., a break in the slope of the standard
curve.
(d) Instrumental limitations.
It is recognized that the experience of the
analyst is important to this process. How-
ever, the analyst must include the above
considerations in the initial estimate of the
detection limit.
2. Prepare reagent (blank) water that is as
free of analyte as possible. Reagent or inter-
ference free water is defined as a water sam-
ple in which analyte and interferent con-
centrations are not detected at the method
detection limit of each analyte of interest.
Interferences are defined as systematic er-
rors in the measured analytical signal of an
established procedure caused by the presence
of interfering species (interferent). The
interferent concentration is presupposed to
40 CFR Ch. I (7-1-95 Ec
be normally distributed in represent
samples of a given matrix.
3. (a) If the MDL is to be determined
agent (blank) water, prepare a labor.,
standard (analyte in reagent water) at aJ
centration which is at least equal to
the same concentration range aa the
mated method detection limit. (Recotni
between l and 5 times the estimated m<
detection limit.) Proceed to Step 4.
(b) If the MDL is to be determined In
other sample matrix, analyze the sample
the measured level of the analyte is in
recommended range of one to five times
estimated detection limit, proceed to StejS
If the measured level of analyte is ijj
than the estimated detection limit, addj
known amount of analyte to bring the le'
of analyte between one and five times the
timated detection limit.
IX the measured level of analyte Is
than five times the estimated detect
limit, there are two options.
(1) Obtain another sample with a 1<
level of analyte in the same matrix If
sible.
(2) The sample may be used as is for dot
mining the method detection limit if
analyte level does not exceed 10 times
MDL of the analyte in reagent water,
variance of the analytical method changes
the analyte concentration increases from LhsJ
MDL, hence the MDL determined un<
these circumstances may not truly refli
method variance at lower analyte concent
tions.
4. (a) Take a minimum of seven aliquots of]
the sample to be used to calculate the meth-1
od detection limit and process each through,
the entire analytical method. Make all com-jj
putations according to the defined method^
with final results in the method reporting;
units. If a blank measurement is required to:
calculate the measured level of anaiyte. ob-^
tain a separate blank measurement for each ]
sample aliquot analyzed. The average blank
measurement is subtracted from the respec-
tive sample measurements.
(b) It may be economically and technically
desirable to evalup ^e the estimated method
detection limit before proceeding with 4a.
This will: (1) Prevent repeating this entire
procedure when the costs of analyses are
high and (2) Insure that the procedure 1«
being conducted at the correct concentra-
tion. It is quite possible that an inflated
MDL will be calculated from data obtained
at many times the real MDL even though the
level of analyte is less than five times the
calculated method detection limit. To insure
that the estimate of the method detection
limit is a good estimate, it is necessary to
determine that a lower concentration of
analyte will not result in a significantly
lower method detection limit. Take two
aliquots of the sample to be used to calculate
the method detection limit and process each
tonfal Pri
gh the entire
irements aa
aate these datt
If these me
jle is In dosirc
t of the MD!
quota and proce-
nts for calculat:
U these mt
aple is not in
f MDL. obtain r
either 4a or 4
i. Calculate the
.rlatl on (S) of t:
» follows.
m
^wb«re:
Tr 1=1 to n. are
final methor
> from the n t
to the sum c
S_ (a) Compute
MDL
where:
MDL = the me
Vu- - .»•» =
prlate for a
standard de-
grees of free
B ~ standard
analyses
(b) The 95% .
for the MDL d'
oordlng to the
from percenti)<
trees of freedor
LCL = 0.64 M:
OCL. = 2.20 M
where: LCL
upper 95'/.
baaed on se
1. Optional
the reaaonabl.
MDL and subs-
(a) If this is
MDL based or
lated in Step
In Step 6, spik
MDL and pr<
•tarting with
(b) If this is
the MDL cak
rent MDL ca
vioua MDL c
ratio. The F-r
In* the larger
the other intc
-------
2 Ch. I (7-1-95 Edrttoffl^HLvtroomental Protection Agency
-ibuted in representative!
matrix.
is to be determined in r»-|
.er. prepare a laboratory!
n reagent water) at a con-1
s at least equal to or Inl
ration range as the estl-J
sction limit. (Recommend;
nes the estimated method
oceed to Step 4.
3 to be determined in an.
ix. analyze the sample, u
1 of the analyte is in the
e of one to five times the J
n limit, proceed to Step 4. i
level of analyte is lea;
,d detection limit, add 41
analyte to bring the level
one and five times the ea-
limit.
level of analyte is greater
the estimated detection
0 options.
ber sample with a lower
! the same matrix if pos
iay be used as is for deter-
3d detection limit if the
1 not exceed 10 times the
-te in reagent water. The
llytical method changes an
ltration increases from the
MDL determined under
._es may not truly reflect
t lower analyte concentra-
^irnum of seven allquots of *
aed to calculate the meth- :
and process each through
^aJ method. Make all com-
og to the defined method
in tbe method reporting
5 eftsurement I9 required to *
sured level of analyte. ob-
anfc measurement for each
J^lyzed- The average blank
ubtracted from the respec-
irementa.
onomically and technically
iate the estimated method
ictore proceeding with 4a.
vent repeating this entire
tbe costs of analyses are
ire thxt the procedure Is
at the correct concentra-
possible that an inflated
ajated from data obtained
. real MDL even though the
s less than five times the
i detection limit. To Insure
e of tie method detection
stiinate. it is necessary to
lower concentration of
result in a significantly
election limit. Take two
-nple to be used to calculate
tion limit and process each
¦ through the entire method, including blank
Eujeasuramenta « de»crlbod above In 4a.
i Evaluate these data:
these measurements indicate the
"i| sample is in desirable range for determina-
nt tion MDL, take five additional
Pt. 136, App. B
puted F-ratlo is then compared with the F-
ratlo found In the table which ia 3.05 as fol-
lows: if S3a/S*»<3.05. then compute the pooled
standard deviation by the following equa-
tion:
V tion 01
t, £ ^liquota and proceed. Use all seven meaaure-
Pv jaents for calculation of the MDL.
fS. (2) If these measurements indicate the
^ ~ gsznple is not in correct range, re estimate
the MDL. obtain new sample as in 3 and re-
peat either 4a or 4b.
5. Calculate the variance (S*) and standard
deviation (S) of the replicate measurements,
as follows:
Spooled"
6si +&S
12
s2 = -
n —1
=1S
i.(s*y
where:
Xi; 1=1 to n. are the analytical results in the
final method reporting units obtained
from the n sample aliquote and Z refers
to the sum of the X values from 1=1 to n.
6. (a) Compute the MDL as follows:
MDL = tta.1,1^ - a**) (S)
where:
MDL = the method detection limit
t{».t,]_ - sn = the students' t value appro
priate for a 99% confidence level and a
standard deviation estimate with n-1 de-
greea of freedom. See Table.
S = standard deviation of the replicate
analyses.
(b) The 95% confidence interval estimates
for the MDL derived in 6a are computed ac-
cording to the following equations derived
from percentiles of the chi square over de-
grees of freedom distribution (xVdQ.
LCL = 0.64 MDL
UCL = 2.20 MDL
where: LCL and UCL are the lower and
upper 95% confidence limits respectively
baaed on seven allquots.
7. Optional iterative procedure to verify
the reaaonableness of the estimate of the
MDL and subsequent MDL determinations.
(a) If this is the initial attempt to compute
MDL baaed on the estimate of MDL formu-
lated in Step 1, take the MDL aa calculated
In Step 6, spike the matrix at this calculated
MDL and proceed through the procedure
starting with Step 4.
(b) If this is the second or later iteration of
the MDL calculation, use S* from the cur-
rent MDL calculation and S* from the pre-
vious MDL calculation to compute the F-
ratio. The F-ratio is calculated by substitut-
ing the larger S* into the numerator SJA and
the other into the denominator SV The com-
if S2VS2»>3.05, re spike at the most recent
calculated MDL and process the samples
through the procedure starting with Step
4. If the most recent calculated MDL
does not permit qualitative identifica-
tion when samples are spiked at that
level, report the MDL as a concentration
between the current and previous MDL
which permits qualitative identification.
(c) Use the R, ¦ ¦ as calculated in 7b to
compute the final MDL according to the fol-
lowing equation:
MDL=2.681 'K ¦ -•>
where 2.681 is equal to tot =»«).
(d) The 95% confidence limits for MDL de-
rived in 7c are computed according to the
following equations derived from precentiles
of the chi squared over degrees of freedom
distribution.
LCL =0.72 MDL
UCL=1.65 MDL
where LCL and UCL are the lower and upper
95% confidence limits respectively baaed on
14 allquots.
Tables of Students' t Values at the 99
Percent Confidence Level
Nuntotr of raphcalet
9
10 ,
11
16
21
26
31
61
Degrees
o< free-
U-i. *»)
dom (n-1)
6
3.143
7
2.996
B
2-896
9
2.621
10
2.764
15
2X02
20
2.528
25
2.465
30
2.457
60
2-3T*
00
2,326
Reporting
The analytical method used must be spe-
cifically identified by number or title aid the
MDL for each analyte expressed in the ap-
propriate method reporting units. If the ana-
lytical method permits options which affect
the method detection limit, these conditions
must be specified with the MDL value. The
sample matrix used to determine the MDL
must also be identified with MDL value. Re-
port the mean analyte level with the MDL
and indicate if the MDL procedure was iter-
883
-------
Pt. 136, App. C
ated. If a laboratory standard or a sample
that contained a known amount analyte was
used for this determination, also report the
mean recovery.
If the level of analyte in the sample was
below the determined MDL or exceeds 10
times the MDL of the analyte in reagent
water, do not report a value for the MDL.
[49 FR 43430. Oct. 26. 1984; 50 FR 694. 696. Jan
4. 1985. as amended at 51 FR 23703, June 30
1986]
appendix c to Part 136—inductively
Coupled Plasma—atomic Emission
Spectrometry Method for Trace
Element analysis of Water and
Wastes method 200.7
1. Scope and Application
1.1 This method may be used for the de-
termination of dissolved, suspended, or total
elements in drinking water, surface water,
and domestic and industrial wastewaters.
1.2 Dissolved elements are determined in
filtered anil acidified samples. Appropriate
steps must be taken in all analyses to ensure
that potential interferences are taken into
account. This is especially true when dis-
solved solids exceed 1500 mg/L. (See Section
5.)
1.3 Total elements are determined after
appropriate digestion procedures are per-
formed. Since digestion techniques increase
the dissolved solids content of the samples,
appropriate steps must be taken to correct
for potential interference effects. (See Sec-
tion 5.)
1.4 Table 1 lists elements for which this
method applies along with recommended
wavelengths and typical estimated instru-
mental detection limits using conventional
pneumatic nebulization. Actual working de-
tection limits are sample dependent and as
the sample matrix varies, these concentra-
tions may also vary. In time, other elements
may be added as more information becomes
available and as required
1.5 Because of the differences between
various makes and models of satisfactory in-
struments. no detailed instrumental operat-
ing instructi.ons can be provided. Instead, the
analyst is referred to the instruction pro-
vided by the manufacturer of the particular
instrument.
2. Summary o! Method
2.1 The method describes a technique for
the simultaneous or sequential multielement
determination of trace elements in solution.
The basis of the method is the measurement
of atomic emission by an optical
spectroscopic technique. Samples are
nebulized and the aerosol that is produced is
transported to the plasma torch where exci-
tation occurs. Characteristic atomic-line
emission spectra are produced by a radio-fre-
40 CFR Ch. I (7-1-95 Edition)
quency inductively coupled plasma (ICP).
The spectra are dispersed by a grating spec-
trometer and the intensities of the lines are
monitored by photomultiplier tubes. The
photocurrents from the photomultiplier
tubes are processed and controlled by a com-
puter system. A background correction tech-
nique is required to compensate for variable
background contribution to the determina-
tion of trace elements. Background must be
measured adjacent to analyte lines on sam-
ples during analysis. The position selected
for the background intensity measurement,
on either or both sides of the analytical line,
will be determined by the complexity of the
spectrum adjacent to the analyte line. The
Position used must be free of spectral inter-
ference and reflect the same change in back-
ground intensity as occurs at the analyte
wavelength measured. Background correc-
tion is not required in cases of line broaden-
ing where a background correction measure-
ment would actually degrade the analytical
result. The possibility of additional inter-
ferences named in 5.1 (and tests for their
presence as described in 5.2) should also be
recognized and appropriate correctioni
made.
3. Definitions
3.1 Dissolved—Those elements which will
Pass through a 0.45 jim membrane filter.
3.2 Suspended—Those elements which are
retained by a 0.45 nm membrane filter.
3.3 Total—The concentration determined
on an unfiltered sample following vigorous
digestion (Section 9.3), or the sum of the dis-
solved plus suspended concentrations. (Sec-
tion 9.1 plus 9.2).
3.4 Total recoverable—The concentration
determined on an unfiltered sample follow-
ing treatment with hot. dilute mineral acid
(Section 9.4).
3.5 Instrumental detection limit—The con-
centration equivalent to a signal, due to the
analyte, which is equal to three times the
standard deviation of a series of ten replicate
measurements of a reagent blank signal at
the same wavelength.
3.6 Sensitivity—The slope of the analytical
curve, i.e. functional relationship betw .-en
emission intensity and concentration.
3.7 Instrument check standard—A multiele-
ment standard of known concentrations pre-
pared by the analyst to monitor and verity
instniment performance on a daily basis.
(See 7.6.1)
3.8 Interference check sample—A solution
containing both interfering and analyte
elemelts of known concentration that can be
used to verify background and interelement
correction factors. (See 7.6.2.)
3.9 Quality control sample—A solution ob-
tained from an outside source having known,
concentration values to be used to verify the
calibration standards. (See 7.6.3)
Environrr
3.10 Ca,
known st>
lyst for c
pre para tic
3.11 Li>
tion rangi
remains li
3.12 Rec
distilled u
trix as t
through t
7.5.2)
3.13 Co
deionized
HNOj and
3.14 Mt
standard .
of the ur
known air
4.1 The
reagent u
precisely
compound
health ha
sore to t!
the lowes
available,
maintain:
OSHA rei
dling of t)
od. A refe
sheets she
personnel
Additions
are avalla
aad 14.*) fQj.
5.1 Sev.
may contr
mination
summarize
5.1.1 Sp
egorized a
another e
molecular
tribution
phenomer.
from Btra
high cone
these effec.
a compute
quiring th
the interf
may requl
length. Tfc
ally be cor
tion adjac
tlon. user
instrumen
slblllty of
interferes
occur in a
channel ir.
-------
Appendix E7: Map of Sampling Areas
-------
MAY, 1997
*VC wg
THIS MAP IS COMPUTER ORAWN
DY THE CITY OP GRAND fORKS
CNC/NCCRINO OCPARTMCNT
DRAFT Sampling Locations
(Sampling locations are plotted as Drop number on Table
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