United States
Environmental Protection
Agency
Office of Research and
Development
Washington DC 20460
EPA/540/R-95/521
August 1995
&EPA
Field Analytical Screening
Program: PCB Method
Innovative Technology
Evaluation Report
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
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EPA/540/R-95/521
August 1995
FIELD ANALYTICAL SCREENING PROGRAM: PCB
METHOD
INNOVATIVE TECHNOLOGY EVALUATION REPORT
NATIONAL RISK MANAGEMENT RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
NATIONAL EXPOSURE RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
LAS VEGAS, NEVADA 89193
Printed on Recycled Paper
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Notice
The information in this document has been funded wholly or in part by the U.S. Environmental Protection
Agency (EPA) in partial fulfillment of Contract No. 68-CO-0047, Work Assignment No. 0-40, to PRC
Environmental Management, Inc. It has been subject to the Agency's peer and administrative review, and it
has been approved for publication as an EPA document. The opinions, findings, and conclusions expressed
herein are those of the contractor and not necessarily those of the EPA or other cooperating agencies.
Mention of company or product names is not to be construed as an endorsement by the agency.
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Foreword
The U.S. Environmental Protection Agency is charged by Congress with protecting the Nation's land,
air, and water resources. Under a mandate of national environmental laws, the Agency strives to formulate and
implement actions leading to a compatible balance between human activities and the ability of natural systems
to support and nurture life. To meet this mandate, EPA's research program is providing data and technical
support for solving environmental problems today and building a science knowledge base necessary to manage
our ecological resources wisely, understand how pollutants affect our health, and prevent or reduce environmental
risks in the future.
The National Risk Management Research Laboratory is the Agency's center for investigation of
technological and management approaches for reducing risks from threats to human health and the environment.
The focus of the Laboratory's research program is on methods for the prevention and control of pollution to air,
land, water and subsurface resources; protection of water quality in public water systems ; remediation of
contaminated sites and ground water; and prevention and control of indoor air pollution. The goal of this research
effort is to catalyze development and implementation of innovative, cost-effective environmental technologies;
develop scientific and engineering information needed by EPA to support regulatory and policy decisions; and
provide technical support and information transfer to ensure effective implementation of environmental
regulations and strategies.
This publication has been produced as part of the Laboratory's strategic long-term research plan. It is
published and made available by EPA's Office of Research and Development to assist the user community and
to link researchers with their clients.
E. Timothy Oppelt, Director
National Risk Management Research Laboratory
111
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Abstract
This innovative technology evaluation report (ITER) presents information on the demonstration of the
U.S. Environmental Protection Agency (EPA) Region 7 Superfund Field Analytical Screening Program (FASP)
method for determining polychlorinated biphenyl (PCB) contamination in soil. This method was demonstrated in
Kansas City, Kansas, in August 1992.
The FASP PCB Method was developed by the EPA Superfund Branch for use at Superfund sites. The method uses
a gas chromatograph (GC) equipped with a megabore capillary column and an electron capture detector (ECD). Gas
chromatography is an EPA-approved method for determining PCB concentrations in soil, water, and waste samples.
The FASP PCB Method is an abbreviated, modified version of approved methods. Soil samples require extraction
before GC analysis. To remove matrix interferences, a sulfuric acid cleanup step is used during the FASP PCB
Method.
The FASP PCB Method was found to be field-portable only in a mobile laboratory, must be done in a temperature-
controlled environment, and requires a skilled chemist for operation. The detection limit reported by this method for
is 0.4 part per million for soil samples. PRC used linear regression and inferential statistics to compare the method's
data to that from the confirmatory laboratory. When the data sets were evaluated, the FASP PCB Method's results
were statistically the same as the confirmatory laboratory. This method can produce Level 3 data. This method can
also identify individual PCB isomers.
This report was submitted in partial fulfilment of contract 68-CO-0047 by PRC Environmental Management, Inc.,
under the sponsorship of the U.S. Environmental Protection Agency. This report covers a period from January
1992, to August 31, 1992, and work was completed as of February 1, 1993.
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Table of Contents
Section
Page
Notice i i
Foreword i i i
Abstract iv
List of Figures vi i
List of Tables vi i
List of Abbreviations and Acronyms Vl"
Acknowledgments x
1 Executive Summary 1
2 Introduction 3
Document Purpose 3
EPA's SITE Program and MMTP: An Overview 3
The Role of Monitoring and Measurement Technologies 3
Defining the Process 3
Components of a Demonstration 4
Demonstration Purpose, Goals, and Objectives 4
3 Predemonstration Activities 6
Identification of Developers 6
Site Selection - 6
Selection of Confirmatory Laboratory and Method : 7
Operator Training ~7
Sampling and Analysis ~7
4 Demonstration Design and Description 8
Sample Collection ,., 8
Quality Assurance Project Plan 9
Statistical Analysis of Results 10
Field Analysis Operations 12
5 Confirmatory Analysis Results , 13
Confirmatory Laboratory Procedures •.. 13
Soil Sample Holding Times -... 13
Soil Sample Extraction :.. 13
Initial and Continuing Calibrations •... 14
Sample Analysis :.. 14
Detection Limits :.. 14
Quality Control Procedures 15
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of
Confirmation of Analytical ..,.,,,,.,,,, 15
Column Confirmation ,,,,,,,...,. 15
Gas Chromatographic Confirmation 15
Reporting 15
Aroclors by the Confirmatory Laboratory 18
Quality of Confirmatory Laboratory 16
Accyracy ...........,.,.....,,., 18
Precision 16
Completeness , ,,. 17
of Qualified for Analysis .................. ..,....,..,..,. 17
6 EPA. Super-fund; Field Analytical Program PCB ,.,,...... 18
Theory of and Background Information ...,...,., 18
...,...,.,.,,.,,..... 13
Performance Factors ........,...,..,.,......,.,.,....,..,.,...,,...,..„....... 21
Limits and 21
Matrix ....,,,.......,.......,, 22
Throughput ,.,,,,.,,,,,,,..,,.,,„ 23
Linear 23
Drift ,,. 23
....,,,...,,,.,,..,,...,.... ........,.,.,..,.,.,..». 23
Irttramethod ,. . , 28
Comparison of to Confirmatory ..................................... 30
, .,.,.,..,,,...,... 30'
Precision ........,.,,.,.«,,,,, , 34
7 ..........,.,,.,.,.. 36
8 . , ,, 37
vt
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List of Figures
Page
6-1 . Confirmatory Data vs. FASP PCB Data .............................................. 34
List of Tables
Table Page
6-1 Aroclor Specificity Test Resu s [[[ 25
6-2 Statistical Analysis of the Aroclor Specificity Test Result ............................... 27
6-3 Matrix Spike and Matrix Spike Duplicate Result ..................................... 30
6-4 Laboratory and Field Duplicate Same Results ...................................... 31
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List of Abbreviations and Acronyms
AICO Abandoned Indian Creek Outfall
Allied-Signal Allied-Signal, Inc.
CCAL continuing calibration
CLP Contract Laboratory Program
CMS corrective measures study
CRQL contract-required quantitation limit
DOE Department of Energy
DQO data quality objective
ECD electron capture detector
EPA U.S. Environmental Protection Agency
ERA Environmental Research Associates
FASP Field Analytical Screening Program
GC gaschromatograph
HSP health and safety plan
ICAL initial calibration
ID inside diameter
IDW investigation-derived waste
ITER Innovative Technology Evaluation Report
KCP Kansas City Plant
L liter
|jg/L micrograms per liter
pL microliter
tjg/kg micrograms per kilogram
mg/kg milligrams per kilogram
mL milliliter
mm millimeter
MMTP Monitoring and Measurement Technologies Program
MS mass spectrometer
NERL-LV National Exposure Research Laboratory-Las Vegas
NRMRL National Risk Management Research Laboratory
ORD Office of Research and Development
OSWER Office of Solid Waste and Emergency Response
PCB polychlorinated biphenyl
PE performance evaluation
PRC PRC Environmental Management, Inc.
QA/QC quality assurance/quality control
QAPP quality assurance project plan
r2 coefficient of determination
RCRA Resource Conservation and Recovery Act
RFI RCRA facility investigation
RPD relative percent difference
SARA Superfund Amendments and Reauthorization Act of 1986
VIII
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List of Abbreviations and Acronyms (Continued)
SITE Superfund Innovative Technology Evaluation
SOP standard operating procedures
SOW statement of work
TCL target compound list
TIC tentatively identified compounds
TPM technical project manager
U V ultraviolet
IX
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Acknowledgments
This demonstration and the subsequent preparation of this report required the services of numerous personnel from the
U.S. Environmental Protection Agency, National Exposure Research Laboratory (Las Vegas, Nevada); U.S.
Environmental Protection Agency, Region 7 (Kansas City, Kansas); the U.S. Department of Energy Kansas City Plant
(Kansas City, Missouri); Allied-Signal, Inc. (Kansas City, Missouri); and PRC Environmental Management, Inc. (Kansas
City, Kansas; Cincinnati, Ohio; and Chicago, Illinois). The cooperation and efforts of these organizations and personnel
are gratefully acknowledged.
Additional information concerning the demonstration described in this report can be obtained by contacting Mr. Lary Jack,
the U.S. Environmental Protection Agency, National Exposure Research Laboratory , technical project manager, at (702)
798-2373 or Mr. Eric Hess, the PRC Environmental Management project manager, at (913) 573-1822.
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Section 1
Executive Summary
This innovative technology evaluation report (ITER)
presents information on the demonstration and evaluation
of a field screening method for determining
polychlorinated biphenyl (PCB) contamination in soil.
PRC Environmental Management, Inc. (PRC), conducted
the demonstration under contract with the U.S.
Environmental Protection Agency (EPA) Superfund
Innovative Technology Evaluation (SITE) Program.
Specifically, this demonstration was conducted under the
Monitoring and Measurement Technologies Program
(MMTP) of the SITE Program, which is administered by
the EPA National Exposure Research Laboratory, Las
Vegas (NERL-LV).
The method selected for this demonstration and
evaluation was a modified version of the Field Analytical
Screening Program (FASP) method developed for the
Field Investigation Team contract, which is part of the
Superfund program. The method uses a field gas
chromatograph (GC) and an extraction process that is
similar to that of a conventional fixed laboratory. In
August 1992, the method was demonstrated and evaluated
at a site in Kansas City, Missouri. It was demonstrated in
conjunction with the demonstrations and evaluations of
three other field screening technologies for PCBs in soil:
the Clor-N-Soil PCB Test Kit and L2000 PCB/Chlonde
Analyzer, both of which are manufactured by the Dexsil
Corporation; and the EnviroGard PCB Test, which is
manufactured by Millipore, Inc. Separate ITERs have
been prepared on the evaluations of these technologies and
are available. These ITERs are entitled "Innovative
Technology Evaluation Report on the Dexsil Corporation's
Demonstration of the Clor-N-Soil PCB Test Kit and L2000
PCB/Chloride Analyzer" and "Innovative Technology
Evaluation Report on the Demonstration of the Millipore,
Inc., EnviroGard PCB Test. "
The FASP PCB Method is designed to quickly
provide quantitative results for PCB concentrations in soil
samples. It uses gas chromatography, which is an
EPA-approved method for determining PCB
concentrations in soil samples. In fact, the FASP PCB
Method is a modified version of EPA SW-846 Manual
Method 8000. The method determines results for PCB
concentrations, in the micrograms per kilogram (jig/kg)
range, by using a GC equipped with an electron capture
detector (ECD). Chromatograrns produced by the GC and
BCD for each sample are compared to the chromatograms
from Aroclor standards.
The instrumentation and equipment required for the
FASP PCB Method are not highly portable. However,
when they are mounted in a mobile laboratory trailer, the
method can be operated on or near most sites relatively
easily. Use of this method requires electricity, and
Aroclor standards require refrigeration. An exhaust hood
and carrier gases are also needed. For the method to
produce reliable results, it must be operated by a trained
and experienced operator.
The initial purchase cost of the instrumentation and
equipment is relatively high. The three major pieces of
equipment used in this demonstration cost $23,214.
Similar equipment can be rented for $1,500 to
$2,500 per month. Additional accessory equipment,
reagents, and glassware needed to extract, prepare, and
analyze soil samples during the demonstration cost an
additional $5,000. This cost includes nondisposable
glassware and laboratory equipment, in addition to
disposable items. During this demonstration, 400 Sam-pie
extractions and injections were conducted.
The detection limit for the method is reported to be
400 ,ug/kg. During the demonstration, however, PRC
found that the method can often achieve a detection limit
as low as 100 ,wg/kg. The highest number of samples
analyzed in an 8-hour day was 21; the average number
analyzed per 8-hour day was 15.
The method is susceptible to interferences from some
compounds, other than PCBs, that are sometimes found in
soil samples. Common interferants include phthalates,
sulfur, halogenated solvents, and halogenated pesticides.
In some cases in which these interferants are present,
higher detection limits must be used for PCBs. It is also
difficult, at times, for the operator to correctly identify and
quantify mixtures of more than one Aroclor. Correct
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identification of Aroclors depends largely on the judgment
and experience of the operator.
To assess this method's precision, PRC evaluated its
performance on the analysis of field and laboratory
duplicate samples. PRC used the data from the duplicate
analyses to establish precision control limits. The FASP
PCB Method analysis showed 34 sample pairs in which
both a sample and its duplicate had positive results. The
data from these 34 pairs had a mean relative percent
difference (RPD) of 34 percent and a standard deviation of
29. During this evaluation, precision control limits were
established by adding two times the standard deviation to
the mean for the upper control limit and using zero for the
lower control limit. Therefore, the control limits were set
at 0 and 92 percent. All of the RPDs for the duplicate
sample pairs fell within the control limits. Therefore, the
precision of the method (100 percent) was considered
acceptable.
PRC used a regression analysis approach to evaluate
the accuracy of the FASP PCB Method. The regression
analysis was based on 76 matched pairs of positive sample
results, and it defined a coefficient of determination (r2)
factor of 0.86, indicating that there was a strong
relationship between the two sets of data. It defined a
regression line with a y-intercept of 3.57 milligrams per
kilogram (mg/kg) and a slope of 1.09. This indicates that
the method is accurate. No correction is needed for the
FASP PCB Method data, as it is not statistically different
from the confirmatory data. The Wilcoxon Signed Ranks
Test was used to verify these results. It indicated, at a 95
percent confidence level, that the data from the FASP PCB
Method was not significantly different from those of the
conlirmatory laboratory. The accuracy of the FASP PCB
Method data was verified.
PRC also used the Dunnett's Test to evaluate the
precision of the FASP PCB Method. This test indicated
that the FASP PCB Method and the confirmatory
laboratory may not have achieved identical precision.
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Section 2
Introduction
Document Purpose
This ITER summarizes the procedures used to
demonstrate the FASP PCB Method, discusses the results
of the demonstration, and evaluates the effectiveness and
possible uses of the FASP PCB method at various
hazardous waste sites. The main goal of the
demonstration was to evaluate the technology and to
provide Superfund decisionmakers with information on its
performance and cost effectiveness for possible use in
future site characterization or cleanup projects.
EPA SITE Program and MMTP: An Overview
When the Superfund Amendments and
Reauthorization Act of 1986 (SARA) took effect, it was
widely recognized that new and better methods were
needed to attack the environmental cleanup problem.
Therefore, EPA developed the SITE Program to fulfill a
requirement of SARA that EPA address the potential of
alternative or innovative technologies. EPA gave joint
responsibiity for this program to its Office of Solid Waste
and Emergency Response (OSWER) and the Office of
Research and Development (ORD). The SITE Program
includes four component programs:
* Demonstration Program (for remediation
technologies)
* Emerging Technology Program
* Meawsuring and Monitoring Technologies
Program (MMTP)
* Technology Transfer Program
The largest part of the SITE Program involves the
treatment technologies and is administered by ORD
National Risk Management Research Laboratory
(NRMRL) in Cincinnati, Ohio. However, the MMTP
component is administered by NERL-LV. MMTP
involves monitoring and measurement technologies that (1)
identify, quantity, or monitor changes in contaminants
occurring at hazardous waste sites, or (2) are used to
characterize a site.
MMTP seeks to identify and demonstrate innovative
technologies that may provide a less expensive, better,
faster, or safer means of completing this monitoring or
characterization. Managers of hazardous waste sites are
often reluctant to use any method, other than conventional
ones, to generate critical data on the nature and extent of
contamination. Courts generally recognize data generated
by conventional laboratory methods; still, there is a need
to generate data more cost-effectively. Therefore, EPA
must identify innovative approaches and, through
verifiable testing of the technologies under the SITE
Program, ensure that the innovative technologies are
equivalent to, or better than, traditional technologies.
The Role of Monitoring and Measurement
Technologies
Effective measurement and monitoring technologies
are needed to accurately assess the degree of
contamination; to provide data and information to
determine the effects of those contaminants on public
health and the environment; to supply data for selection of
the most appropriate remedial action; and to monitor the
success or failure of a selected remedy. Therefore,
MMTP is broadly concerned with evaluating screening
(including remote sensing), monitoring, and analytical
technologies for all media.
Candidate technologies may come from within the
federal government or from the private sector. Through
the program, developers are provided with the opportunity
to rigorously evaluate the performance of their
technologies. Finally, distributing the results and
recommending those evaluations enhances the market for
the technologies.
Defining the Process
EPA begins the innovative technology demonstration
process by canvassing its 10 regional offices (with input by
OSWER and ORD) to determine their needs.
Concurrently, classes of technologies are identified. An
ideal match is made when there is a clear need by EPA's
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regions and a reasonable number of innovative
technologies that can address that need. The
demonstrations are designed to judge each technology
against existing standards and against each other. "
The demonstration is designed to provide detailed
quality assurance and quality control (QA/QC) procedures
to ensure that a potential user can evaluate the precision,
accuracy, representativeness, completeness, and
comparability of data derived from the innovative
technology. In addition, the necessary steps and activities
associated with operating the innovative technology are
described. Cost data, which are critical to any
environmental activity, are generated during the
demonstration and allow a potential user to make
economic comparisons. Finally, information on practical
matters such as operator training requirements, detection
levels, and ease of operation is reported. Therefore, the
demonstration report and other informational materials
produced by MMTP provide a real-world comparison of
that technology to traditional technologies. With access to
cost and performance data, in addition to "how to"
information, users can more comfortably determine
whether, and to what degree, a new technology meets their
needs.
Components of a Demonstration
After a decision has been made to demonstrate
technologies to meet a particular EPA need, the MMTP
performs several activities. First, MMTP identifies
potential participants and determines whether they are
interested in participating. Each developer is advised of
the general nature of the particular demonstration and is
provided with information common to all MMTP
demonstrations. Information is sought from each
developer about its technology to ensure that the
technology meets the parameters of the demonstration.
After evaluation of the information, all respondents are
informed of whether they have been accepted for the
demonstration. While participants are being identified,
potential sites are also identified, and basic site
information is obtained. These activities complete the
initial component of an MMTP demonstration.
The next component, and probably the most
important, is the development of plans that describe how
various aspects of the demonstration will be conducted. A
major part of EPA's responsibility is the development of
a demonstration plan, a quality assurance project plan
(QAPP), and a health and safety plan (HSP). Although
EPA pays for, and has the primary responsibility for,
these plans, each is developed with input from all of the
demonstration's participants. The plans define how
activities will be conducted and how the technologies will
be evaluated. MMTP also provides each developer with
site information and, often, predemonstration samples so
that the developer can maximize the field performance of
its innovative technology. Typically, the developers train
demonstration personnel to ensure that those operating a
technology have been adequately trained. This also
ensures that potential users have valid information on
training requirements and the types of operators who
typically use a technology successfully.
The field demonstration is the shortest part of the
process. During the field demonstration, data are obtained
on cost, technical effectiveness (compared to standard
methods), and limiting factors. In addition, standardized
field methods are developed, and daily logs of activities
and observations (including photos or videotape) are
produced. EPA is also responsible for the comparative,
conventional method analytical costs and the disposal of
any wastes generated by the field demonstration.
The final component of an MMTP demonstration
consists of reporting the results and ensuring distribution
of demonstration information. The main product of the
demonstration is an 1TER, which is reviewed by peers and
distributed as part of the technology transfer responsibility
of MMTP. The ITER fully documents the procedures
used during the field demonstration, QA/QC results, the
field demonstration results, and conclusions. A separate
QA/QC data package is also made available for those
interested in evaluating the demonstration in greater depth.
Two-page Technical Briefs are prepared to summarize the
demonstration results and to ensure rapid and wide
distribution of the information.
Each developer is responsible for providing the
equipment or technology product to be demonstrated, its
own mobilization costs, and the training of
EPA-designated operators. MMTP does not provide any
funds to developers for costs associated with preparation
of equipment for demonstration or for development, and
it does not cover the costs that developers incur to
demonstrate their products.
Demonstration Purpose, Goals,
and Objectives
For this demonstration, the FASP PCB Method was
evaluated for its accuracy and precision in detecting high
and low levels of PCBs in soil samples, and the effects, if
any, of matrix interferences on the technology. The
accuracy and precision of the method were statistically
compared to the accuracy and precision attained in a
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conventional, fixed laboratory by using standard EPA evaluated qualitatively for the length of time required for
analytical methods. The FASP PCB Method was also analysis, ease of use, portability, and operating cost.
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Section 3
Predemonstration Activities
Several predemonstration activities were conducted by
NERL-LV, PRC, and the other demonstration participants.
These activities included identifying developers, selecting
the demonstration site, selecting the confirmatory
laboratory and analytical method, conducting operator
training, and conducting predemonstration sampling and
analysis. This section summarizes these activities and
presents the findings and results of the predemonstration
sampling and analysis.
Identification of Developers
NERL-LV identified the FASP PCB Method as a
technology showing promise for use in PCB field
screening. After a review of available data on this
technology, NERL-LV concluded that it warranted
evaluation under MMTP.
Site Selection
The following criteria were used to select a haz-
ardous waste site suitable for the demonstration:
* Wide range of PCB contamination
* Thorough characterization and documentation of
contaminant concentrations (Thorough site
background information was needed so that a
demonstration sampling plan could be designed
with a high degree of confidence that the desired
range of PCB concentrations would be present in
samples).
* Accessible to the degree that demonstration
activities could be conducted without interfering
with other planned site activities
Based on these criteria, the Abandoned Indian Creek
Outfall (AICO) site at the U.S. Department of Energy
(DOE) Kansas City Plant (KCP) was selected as the
location of this demonstration. The soil at the AICO site
is contaminated with a wide range of PCB concen-trations.
PCB levels range from not detected, at a detection limit of
0.16 mg/kg, to 9,680 mg/kg. DOE has conducted
numerous investigations at the site, including a Resource
Conservation and Recovery Act (RCRA) facility
investigation (RFI) and corrective measures study (CMS)
in 1989 (U.S. DOE 1989). PCB concentrations at the
AICO site are well documented, which enabled PRC to
collect samples having a wide range of PCB
concentrations.
The DOE KCP is located about 20 miles south of
downtown Kansas City, Missouri, at the northeast corner
of Troost Avenue and 95th Street. The facility is owned
by the federal government and operated by Allied-Signal,
Inc. (Allied-Signal), for DOE. Since 1949, the plant has
been used to manufacture nonnuclear components for
nuclear weapons systems. The facility occupies more than
300 acres and includes three main buildings and numerous
outbuildings with over 3 million square feet under roof.
Land around the plant is occupied mainly by suburban
residential and commercial developments (U.S. DOE
1989).
The AICO site is located immediately south of the
DOE KCP between 95th Street and Bannister Road. The
site is located in a former channel of Indian Creek and is
the former location of a storm water outfall (Outfall 002),
which discharged from KCP into the creek. In the early
1970s, Indian Creek was rerouted as part of a flood
protection project and the construction of Bannister Road.
When the creek was rerouted, the storm water outfall was
also rerouted by extending a box culvert from the former
outfall to the new creek channel. The outfall now
discharges into Indian Creek about 500 feet south of the
AICO site. The former creek channel in the AICO area
was covered with about 10 feet of fill
(U.S. DOE 1989).
PCBs comprise the only significant contaminant at the
site. Before this demonstration, samples from
12 borings were analyzed for priority pollutants other than
PCBs. Only one of these borings contained non-PCB
priority pollutants. This boring was found to contain
several base-neutral organics, including anthracene,
fluoranthene, pyrene, and chrysene. PRC believes that
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this sample included a piece of asphalt from the material
used to fill the old creek channel and that the presence of
these compounds did not result from DOE KCP discharges
through Outfall 002 (U.S. DOE 1989).
According to logbooks recorded by Allied-Signal
when boreholes were drilled during investigation of the
AICO site, the former Indian Creek channel is overlain by
7 to 15 feet of till material composed mainly of mottled
clays. Shale and limestone fragments, wood, asphalt, and
concrete slag up to 4 feet wide are found in the fill
material. Near the surface, up to 20 percent of the fill is
composed of organic matter, such as roots, peat, and wood
(U.S. DOE 1989).
Sediments overlying bedrock consist of moist clayey
silt that is soft, dark brown to gray, homogenous, and of
medium to high plasticity, with traces of fine sand. This
material varies from 7 to 15 feet deep, and appears to have
low permeability. The aquifer of concern beneath the
AICO site is the shallow groundwater lying just above
bedrock (U.S. DOE 1989).
Selection of Confirmatory Laboratory and
Method
EPA Region 7 Laboratory personnel selected one
laboratory participating in the Contract Laboratory
Program to perform the confirmatory analysis of samples
for this demonstration. All samples were analyzed by
using the method described in the 1990 CLP statement of
work (SOW) for analyzing PCBs and pesticides. The EPA
Region 7 Laboratory conducted a Level II data review of
the confirmatory laboratory's data.
Operator Training
Before the demonstration, the operator of the FASP
PCB Method was trained in the use of the technology.
This training included a review of operating procedures
and instructions provided by the lead chemist for this
demonstration.
Sampling and Analysis
In May 1992, PRC prepared a predemonstration
sampling plan (PRC 1992a) and on July 14 1992, PRC
collected predemonstration soil samples from areas at the
AICO site that had previously been identified as containing
high, medium, low, and nondetected concentrations of
PCBs. These samples were split into replicates. One
replicate of each sample was analyzed by using the FASP
PCB Method, and the confirmatory laboratory analyzed
one replicate of each sample by using standard EPA
analytical methods. This sampling allowed potential
matrix effects or interferences to be evaluated before the
demonstration. The main finding from predemonstration
sampling was that the soil at the AICO site was more
clayey than expected, thereby making it difficult to
homogenize the samples (see Section 4).
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Section 4
Demonstration Design and Description
This section describes the sample collection
procedures and the experimental design used to evaluate
the FASP PCB Method. This section summarizes key
elements of the QAPP (PRC 1992b), field analysis
operations, and data management activities.
Sample Collection
For the demonstration, PRC collected 112 soil
samples and 32 field duplicate samples from the AICO
site. Each sample was thoroughly homogenized and then
split into six replicate samples. One replicate from each
sample was submitted to the confirmatory laboratory for
analysis by using the 1990 CLP SOW method. At the
request of the EPA technical project manager (TPM), a
second replicate was submitted to NERL-LV for separate
analysis, although the data generated by NERL-LV was
not used in this demonstration. A third replicate was
analyzed in the field by the FASP PCB Method. The
remaining replicates were analyzed in the field by using
the three other technologies, described in separate ITERs.
PRC collected samples by using a drill rig to reach
areas of the AICO site that, based on data from past
investigations, exhibited a wide range of PCB
concentrations. PRC collected all samples by using the
sample collection and homogenization procedures specified
in the sampling plan (PRC 1992b). All PRC field
activities conformed with requirements in the HSP
prepared for this demonstration (PRC 1992b).
Samples were collected from areas known to exhibit
PCB concentrations ranging from not detected (at a
detection limit of 0.16 mg/kg) to 9,680 mg/kg. Most of
the samples were collected from areas that had been
identified as containing PCBs at concentrations ranging
from nondetected to 100 mg/kg, for two reasons. First,
this range encompasses typical regulatory thresholds for
PCBs, such as the 10-mg/kg level for cleanups in
unrestricted access areas and the 50-mg/kg level for
cleanups in industrial areas. Second, most field screening
technologies are designed for operation in this range.
PRC collected twenty samples from areas that had
been identified as containing PCBs at concentrations
ranging from 100 to 1,000 mg/kg, and from 1,000 to
10,000 mg/kg. These samples were analyzed to evaluate
the abilities of the field screening technologies to monitor
PCBs in higher concentrations. After col-lection, soil
samples were placed in plastic bags and thoroughly
homogenized. Samples were then split and placed in
sample containers. Samples to be submitted for
confirmatory laboratory analysis were placed in 8-ounce
wide-mouth glass jars with Teflon-lined lids. Samples for
submittal to NERL-LV and for analysis by the
field-screening technologies were placed in 4-ounce
wide-mouth glass jars with Teflon-lined lids.
PRC monitored homogenization of the samples by
adding a small amount of powdered uranine, which is the
sodium salt of fluorescein dye (fluorescein), to each soil
sample. Homogenization was then performed. PRC then
examined each sample under an ultraviolet (UV) lamp in
a portable darkroom. Because fluorescein fluoresces
under UV light, PRC was able to ensure that
homogenization was complete. While that sample was
under the UV light, PRC sliced each sample in a minimum
of five different places and examined each slice for
fluorescence. If any of the slices did not contain evenly
distributed signs of fluorescence, homogenization of the
sample continued, and the examination process was
repeated. PRC found that of small amounts of fluorescein
did not interfere with sample analysis for any of the
field-screening technologies or for the confirmatory
laboratory.
After PRC received confirmatory laboratory results,
it used the results from samples and their respective field
duplicate samples to statistically determine whether the
homogenization efforts were successful. Because the
duplicate samples were collected as splits, the expected
difference between a sample and its duplicate was zero.
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This is based on the assumption that there was perfect
homogenization and that there was no difference intro-
duced by analytical error. Using a matched pair Student's
t-test enabled PRC to determine whether the mean of the
differences between the samples and their duplicates was
significantly different from zero at a
95 percent confidence level. The matched pair Student's
t-test showed that this mean was not significantly different.
Therefore, though the results of a few pairs of samples and
duplicates appear to indicate that their homogenization
could have been better, the homo-genization technique
used was highly effective overall.
To apply the matched pair Student's t-test, it was
necessary to have a normally distributed data population.
The differences between confirmatory labora-
tory samples and their respective duplicates were
statistically evaluated and found to be normally distributed.
Two data point outliers were noted in the frequency plot.
Samples 91 and 102, respectively, were the low and high
outliers. However, the Student's paired t-test was found
acceptable even when the outliers were included in the
data set. The statistical analysis indicates that the
homogenization was acceptable but, even at a 95 percent
confidence level, a few anomalous duplicate results can
exist in a data set without significantly affecting the
analysis. For example, one pair of samples with high
RPDs relative to the population's mean RPD is masked
and does not affect the overall assessment. Therefore,
even with a statistical assessment that indicates overall
effective sample homogenization, it is possible that some
of the samples in the demonstration were poorly
homogenized. The analysis of such data could produce
limited cases of inaccurate data. Therefore, PRC collected
and analyzed a large number of samples to prevent any
anomalous samples from affecting the overall results.
Quality Assurance Project Plan
To ensure that all activities associated with this
demonstration met demonstration objectives, PRC
prepared a QAPP (PRC 1992b). The QAPP, which was
incorporated into the demonstration plan, defined project
objectives, how those objectives would be achieved, data
quality objectives (DQO), and the steps taken to ensure
that these objectives were achieved. All demonstration
participants were given the opportunity to contribute to the
development of the QAPP; all participants ultimately
agreed to its content.
The main purpose of the QAPP was to outline steps
to be taken to ensure that data resulting from the
demonstration was of known quality and that a sufficient
number of critical measurements were taken. Based on
the NERL-LV SOW, this demonstration is considered a
Category II project. The QAPP addressed the key
elements required for Category II projects prepared in
accordance with guidelines in the EPA booklet Preparing
Perfect Project Plans (1989) and the Interim Guidelines
and Specifications for Preparing Quality Assurance
Project Plans (U.S. EPA 1983).
For sound conclusions to be drawn concerning the
field-screening technology, the data obtained during the
demonstration needed to be of known quality. For all
monitoring and measurement activities conducted for EPA,
the agency requires that DQOs establish the basis of the
way in which the data will be used. DQOs must include
at least five indicators of data quality: represen-tativeness,
completeness, comparability, accuracy, and precision.
The following paragraphs discuss these indicators in
greater detail. The success of the demonstration required
that DQOs be met by the confirmatory laboratory. Some
DQOs for the con-firmatory laboratory were indicated in
the CLP 1990 SOW, and others were derived from data
generated during use of the method. It was critical that the
confirmatory laboratory analyses be sound and within CLP
1990 SOW method specifications so that the data that the
method generated could be compared to that obtained by
the technologies. High-quality, well-documented
confirmatory results were essential to making this
comparison.
Representativeness refers to the degree to which the
data accurately and precisely represent the condition or
characteristic of the parameter that is represented by the
data (U.S. EPA 1983). In this demonstration, PRC
ensured representativeness by (1) executing a consistent
sample collection, homogenization, and handling program,
and (2) using each technology at its optimum capability to
provide results that represented the most accurate and
precise measurements that it was capable of achieving.
Completeness refers to the amount of data collected
from a measurement process compared to the amount that
was expected (U.S. EPA 1983). For this demonstration,
completeness refers to the proportion of valid, acceptable
data generated by using each of the tecochnologies and the
confirmatory laboratory. During the demonstration, the
completeness objective for each technology was 90
percent, which was achieved.
Comparability refers to the confidence with which one
data set can be compared to another (U.S. EPA 1983).
The main focus of this demonstration was to compare data
generated by the FASP PCB Method and the other
technologies with confirmatory laboratory results by using
the experimental design and statistical methods discussed
in the QAPP. Additional QC for comparability was
achieved by (1) analyzing QC samples, blanks, and
Aroclor standards, and (2) adhering to standard EPA
analytical methods and standard operating procedures
(SOP) for.preparing samples and operating instruments.
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Accuracy refers to the difference between the sam-ple
result and the reference or true value for the sample.
Bias, a measure of the departure from complete accuracy,
can be caused by instrument calibration,
loss of analyte in the sample extraction process, inter-
ferences, and systematic contamination or carryover of
analyte from one sample to the next. During this
demonstration, PRC assessed accuracy by using the
statistical comparisons detailed in the QAPP.
Precision refers to the degree of mutual agreement
among individual measurements and provides an estimate
of random error. For this demonstration, PRC measured
precision by comparing the RPDs of samples and their
duplicates with control limits established through the
statistical methods detailed in the QAPP.
The main objective of the demonstration was to
evaluate the efficiencies of the FASP PCB Method in
determining PCB contamination in soil. This evaluation
included defining the precision, accuracy, cost, and range
of usefulness for the technology. This objective also
included determining the DQOs that the technology was
capable of achieving. A secondary objective was to
evaluate the specificity of the technology to different
Aroclors.
Accuracy and precision were the most important
quantitative factors evaluated, particularly for PCB
concentrations near 10 mg/kg, a common cleanup goal. A
significant part of PRC's statistical evaluation was to
evaluate these factors. The cost of using the field-
screening technology was another important quantitative
factor. Cost items include expendable supplies,
nonexpendable equipment, labor, and disposal of
investigation-derived waste (IDW). These costs were
tracked during the demonstration. Although batch analysis
of samples can have major effects on per sample costs, the
number of samples collected for this demonstration were
within the range of a normal site investigation.
Many analytical techniques can have significant
operator effects, in which individual differences in
technique have a significant effect on the numerical
results. To reduce the potential impact of measurement
variation, PRC used one operator for the field- screening
technology, and accepted that the error introduced by
operator effect would not be distinguishable from error
inherent in the field- screening technology. This policy
was selected because it approximates ordinary field
conditions, in which only one screening method is
typically used.
All analytical methods have a specific usable range
with lower and upper limits. The usable range for the
field-screening technology was determined by comparing
results from the technology with those from the
confirmatory laboratory. PRC then used statistical
analysis of these results to identify the contaminant range
in which results from the technology were comparable to
the confirmatory laboratory result.
The Aroclor expected to be found at the AICO site
was Aroclor 1242, which is a common PCB. However,
there are other common Aroclors. In the planning stages
of this demonstration, interest was shown in the
cross-reactivity between Aroclors for the technology. To
assess this factor, PRC evaluated cross-reactivity for the
technology by using matrix spikes for each of the seven
Aroclors (1016, 1221, 1232, 1242, 1248, 1254, and 1260)
typically analyzed by using standard EPA analytical
methods. This information was then used to determine the
sensitivities of the technology to each Aroclor.
Statistical Analysis of Results
This demonstration required comparisons of various
groups of data. Sample results from the technology were
statistically compared with duplicate sample results and
other QA/QC sample results. These are called
intramethod comparisons. The sample results were also
statistically compared with the results from the
confirmatory laboratory, which were considered as
accurate and precise as possible. Finally, in some cases,
the precision of a technology was statistically compared
with the precision of the confirmatory laboratory method.
All of the statistical tests used for this demonstration
were stipulated in the demonstration plan, which all
demonstration participants approved in advance of data
collection. The demonstration plan also stipulated that all
sample pairs that included a nondetect result would be
removed from data sets. PRC believed that the variance
introduced by eliminating these data pairs would be less
than or equal to the variance introduced by giving an
arbitrary value to nondetect results.
In cases in which field duplicate samples were
collected, the demonstration plan stated that the results of
the two duplicates would be averaged and that this average
would be used in subsequent statistical analysis. PRC
followed this guideline. In this way, samples were not
unduly weighted in the statistical analyses.
The intramethod comparisons involved a statistical
analysis of RPDs. First, the RPDs of the results for each
sample pair, in which both the sample and its duplicate
were found to contain PCBs, were determined. The
following equation was used:
(4-1)
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RPD =
where
(R,
100
RPD = relative percent difference.
R, = initial result.
Rd = duplicate result.
The RPDs were then compared with upper and lower
control limits. Because the technology being demonstrated
was also being assessed, the control limits used were
calculated from data provided during this investigation.
To determine these control limits, PRC calculated the
standard deviation of the RPDs for the technology. This
standard deviation was then multiplied by two and added
to its respective mean RPDs. This established the upper
control limit for the technology. Because an RPD of zero
would indicate that the duplicate samples matched their
respective samples perfectly, zero was used as the lower
control limit. This resulted in a large range of acceptable
values. Because duplicate analyses seldom match
perfectly, even for established technologies, all samples
that fell within the control limits were considered
acceptable. PRC determined that, if at least 95 percent of
the duplicate samples fell within these control limits, the
precision of the technology was acceptable.
Data from the field screening technology was
compared with the confirmatory laboratory data to
determine the accuracy of the technology. For the FASP
PCB Method, two statistical methods were used: linear
regression analysis and the Wilcoxon Signed Ranks Test.
PRC calculated the linear regression by using the
method of least squares. Calculating linear regression in
this way makes it possible to determine whether two sets
of data are reasonably related and, if so, how closely.
Calculation of linear regression is expressed as an
equation that can be visually expressed as a line. Three
factors are determined during calculations of linear
regression: the y-intercept, the slope of the line, and the
correlation coefficient. Before a technology's accuracy
could be considered acceptable, all three of these factors
must have had acceptable values.
The r2 expresses the mathematical relationship
between two data sets. If the r2 is 1, the two data sets are
closely related. Lower r2 values indicate less of a
relationship. Because of the nature of environmental
samples, r2 values between 0.80 and 1 were considered
acceptable for this demonstration.
If an r* below 0.80 was found, the data was reviewed
to determine whether any particular results were skewing
the r2. Skewing of the \ can be caused by the greater
accuracy of technologies in analyzing samples in one range
than in analyzing samples in another range. In particular,
samples with either very high or very low levels of
contamination often skew the results. For this
demonstration, an examination of regression residuals
(Draper and Smith 1981) technique was used to identify
outliers that might have skewed the results. In fact, the
computer program used to calculate the linear regression
identified most of the outliers. After outliers were
identified, they were removed, and linear regression
recalculated.
If the corrected data set resulted in an r2 between 0.80
and 1, the regression line's y-intercept and slope were
examined to determine how closely the two data sets
matched. A slope of 1 and a y-intercept of zero would
indicate that the results of the technology perfectly
matched those of the confirmatory laboratory.
Theoretically, the farther the slope and y-intercept differ
from these expected values, the less accurate the
technology. Still, a slope or y-intercept can differ slightly
from their expected values without that difference being
statistically significant. To determine whether such
differences were statistically significant, PRC used the
normal deviate test statistic. This test statistic calculates
a value that is compared to a table. The value at the 95
percent confidence level was used for the comparison.
If an r2 between 0.80 and 1 was not found, the
method's data was considered inaccurate. If an r2 be-
tween 0.80 and 1 was found but the normal deviate test
statistic indicated that either the y-intercept or the slope
differed significantly from its expected result-the
technology was found to be inaccurate; however, in this
case, results from the technology could be mathematically
corrected if 10 to 20 percent of the samples were sent to
a confirmatory laboratory. Analysis of a percentage of the
samples by a confirmatory laboratory would provide a
basis for determining a correction factor. Only in cases in
which the r2, the y-intercept, and the slope were all found
to be acceptable did PRC determine that the technology
was accurate.
The Wilcoxon Signed Ranks Test is a nonparametric
method of comparing matched pairs of data. It can be
used to evaluate whether two sets of data are significantly
different. The test requires no assumption regarding the
population distribution of the two sets of data being
evaluated other than that the distributions will occur
identically. That is, when one data point deviates, its
respective point in the other set of data will deviate
similarly. Because the only deviation expected during the
demonstration was a difference in the concentrations
reported by each technology, the two sets of data were
expected to deviate in the same way.
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The calculation performed in the Wilcoxon Signed
Ranks Test uses the number of samples analyzed and a
ranking of the number that results when a sample's result
obtained by using one analytical method is subtracted from
the corresponding result obtained by using another
method. The rankings can be compared to predetermined
values on a standard Wilcoxon distribution table, which
indicates whether, overall, the two methods have produced
similar results.
Although the linear regression analysis and the
Wilcoxon Signed Ranks Test perform similar types of
comparisons, they are based on different assumptions. By
running both tests on the data, PRC was able to determine
whether either test's assumptions were violated and, if so,
whether the statistical results were affected.
Finally, PRC used Dunnett's Test to statistically
compare the intermethod precision of the method with the
the precision of the confirmatory laboratory. This test was
used to assess whether the precision of the technology and
that of the confirmatory laboratory were statistically
equivalent. PRC first determined the mean RPD for all
samples and their respective duplicates analyzed by the
confirmatory laboratory. It then statistically compared this
mean RPD with the RPDs of each duplicate pair analyzed
by each of the technologies. The Dunnett's Test results in
a single statistical value that indicates the degree of
certainty that the precision of the two methods is the same.
In other words, a 90 per-cent value indicates that one can
be 90 percent sure the precision is the same. During this
demonstration, values of 95 percent or better indicated that
the precisions were statistically the same.
Results below 95 percent do not indicate that the
precision of the technology was not acceptable, only that
it may be different from the precision of the confirmatory
laboratory. In particular, Dunnett's Test has no way of
determining whether any difference between the two data
sets was caused by the precision of a technology's data
being greater than that of the confirmatory laboratory.
Field Analysis Operations
The field analysis portion of the demonstration was
performed in a rented 28-foot trailer. Electricity was
supplied for the equipment, refrigerators, and air
conditioners. Space within the trailer was divided to
provide an area for each technology, storage of samples,
and storage of sample collection equipment. All
equipment, field supplies, reagents, and office supplies
needed for the demonstration were moved into the trailer
during the weekend before the start of the demonstration.
All analytical equipment was powered up and checked to
ensure that it was operable. All problems found were
corrected.
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Section 5
Confirmatory Analysis Results
All samples collected during this demonstration were
submitted to the EPA Region 7 Laboratory for analysis
under its CLP. The data supplied by the CLP laboratory
is discussed in more detail in the following subsections.
Confirmatory Laboratory Procedures
The samples collected during the demonstration were
sent to the EPA Region 7 Laboratory, where they were
assigned EPA activity number DSX06. The samples were
then shipped to the confirmatory laboratory for analysis by
the 1990 CLP SOW method. This method requires that
organochlorine pesticides and PCBs be analyzed by using
a GC equipped with an BCD.
EPA Region 7 Laboratory personnel conducted a
Level II data review of the results provided by the
confirmatory laboratory. This data review involved
evaluating reported values and specific QC criteria. A
Level II data review does not include an evaluation of the
raw data or a check of calculated sample values. The
confirmatory laboratory reviewed the raw data and
checked the calculations before submitting the data
package to EPA. PRC was not able to review the raw
data generated from the analysis of samples. However,
PRC reviewed EPA's comments generated by the Level II
data review.
The following subsections discuss specific procedures
used to identify and quantity PCBs by using the CLP 1990
SOW method. Most of these procedures involved
requirements established to guarantee the quality of the
data generated.
All of the confirmatory laboratory results used to
assess the FASP PCB Method are presented in tables in
Section 6.
Soil Sample Holding Times
The 1990 CLP SOW method requires that all soil
sample extractions be completed within 7 days of receipt
of the laboratory's validated sample. The analysis of soil
samples must be completed within 40 days of receipt of
the validated sample. The holding time requirements for
the samples collected during this demonstration were met.
Soil Sample Extraction
PRC extracted soil samples in accordance with the
procedures outlined in the 1990 CLP SOW method for
organochlorine pesticides and PCBs. This procedure
involves placing 30 grams of soil into a beaker and adding
60 grams of purified sodium sulfate. This mixture is
thoroughly mixed to a grainy texture. One hundred
milliliters (mL) of a 50:50 ratio mixture of acetone and
methylene chloride are then added to the beaker.
Pesticides and PCBs are extracted into the organic solvent
with the aid of a sonic disrupter. This sonic disrupter
bombards the soil with sonic waves, which facilitates the
transfer of pesticides and PCBs into the organic solvent.
The organic solvent is vacuum-filtered through filter paper
to separate it from the soil particles. Sonication is
repeated twice with
100 mL of the acetone and methylene chloride mixture.
The organic solvent is filtered and combined in a vacuum
flask.
After filtration, the solvent is transferred to a
Kudema-Danish apparatus. The Kuderna-Danish
apparatus is placed in a hot water bath, and the organic
solvent is concentrated. After it has been concentrated,
the solvent is transferred from the acetone and methylene
chloride mixture into hexane by using a nitrogen
evaporation system. The soil sample extract, now in
hexane, is concentrated to a known volume by using this
system. The soil sample extract is taken through a
florisil solid-phase extraction column to remove any polar
compounds from the extract. The soil sample extract is
diluted to 10 mL with hexane and is transferred to a test
tube to await sample analysis.
Initial and Continuing Calibrations
The 1990 CLP SOW method for analyzing PCBs
involves an initial calibration (ICAL) for PCBs which
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consists of analyzing one concentration of each of the
seven Aroclors listed in the Target Compound List (TCL).
The ICAL is used to determine peaks to identify Aroclors
and to determine factors to quantify PCBs in samples.
The ICAL is performed before sample analysis begins.
PCBs cause multipeak patterns when analyzed by using
gas chromatography. For each Aroclor, three to five
peaks are chosen to monitor retention time shift and to
determine factors used for quantitation.
Continuing calibrations (CCAL) are performed by
analyzing instrument blanks and performance evaluation
(PE) mixture standards. The retention times and
calibration factors determined during the ICAL are
monitored through CCALs. The CCAL standard is
typically a mid-level pesticide standard; however, because
PCBs were the compounds of interest, an Aroclor was
used as the CCAL standard for analyzing these samples.
The retention times were monitored by evaluating the
amount of retention time shift from the PCB CCAL
standard as compared to the PCB ICAL standard. The
retention time window was defined as ± 0.07 minutes for
each peak identified in thelCAL. According to the 1990
CLP SOW method, when a peak of an Aroclor falls
outside of its window, a new ICAL must be conducted.
During the analysis of samples for this demonstration, the
retention times of the peaks chosen for monitoring during
the CCAL never exceeded the windows established for
them in the ICAL.
Calibration factors were monitored in accordance with
the 1990 CLP SOW method and were acceptable, as the
CCAL calibration factor never exceeded 25 per-cent.
After an ICAL has been performed, sample analysis
begins. Sample analysis usually begins by analyzing a
method blank to verify that it meets the 1990 CLP SOW
method requirements. After this, sample analysis may
continue for 12 hours. After every 12 hour period, a
CCAL standard must be analyzed. Sample analysis may
continue as long as CCAL standards meet the 1990 CLP
SOW method requirements.
Sample Analysis
PCBs are identified in samples by matching peak
patterns found after analyzing the sample with those found
in Aroclor standards. Because of the way in which the
PCBs were manufactured or because of the effects of
weathering, peak patterns may not match exactly. When
the patterns do not match, the analyst must choose the
Aroclor that most closely matches the peak pattern present
in the sample. For this reason, identification of peak
pattern depends largely on the experience and
interpretation of the analyst.
PCBs are quantified by measuring the response of the
peaks in the sample to those same peaks identified in the
ICAL standard. The reported results of this calculation
are based on dry weights, as required by the 1990 CLP
SOW method. Because the screening technologies all
reported wet weight results, PRC converted the results
reported by the confirmatory laboratory from dry to wet
weights to account for any loss of sample weight caused
by drying.
Sample extracts frequently exceed the calibration
range determined during the ICAL. When they do so,
they must be diluted to obtain peaks that fall within the
linear range of the instrument. For PCBs, this linear
range is detined as 16 times the response of the Aroclor
standards analyzed during the ICAL. After a sample has
been diluted to within the linear range, it is analyzed
again. When appropriate, dilutions were performed on the
samples for this demonstration.
Detection Limits
During the ICAL, one concentration of each Aroclor
was analyzed. The concentration of each Aroclor standard
should correspond to the Contract-Required Quantitation
Limit (CRQL) when corrected for the sample extraction
concentration factors. The concentration used for Aroclor
1221 was 200 /tg/kg; the level used for the other six
Aroclors was 100 /tg/kg. This corresponds to soil sample
detection limits of
67 /tg/kg for Aroclor 1221 and 33 /tg/kg for the other
Aroclors .
Because of 1990 CLP SOW method requirements,
these detection limits are based on samples that have no
moisture content. Because almost all soil samples contain
moisture, the detection limits stated in the preceding
paragraph are raised to correct for the percent moisture
present in the soil sample. However, PRC did not correct
the detection limits to account for the percent moisture
present in the samples, because the CRQLs were listed in
/tg/kg, and the detection limits of the FASP PCB Method
was listed in mg/kg. Even when corrected to account for
percent moisture, the CRQLs would be significantly below
the detection limits for the technology.
Quality Control Procedures
As required in the 1990 CLP SOW method, the
confirmatory laboratory used numerous QC measures
including analysis of resolution standard mixes, method
blanks, and instrument blanks; all requirements were met
for this demonstration.
Also, surrogate standards were added to all standards,
method blanks, matrix spikes, and soil samples analyzed
by using the 1990 CLP SOW method. The percent
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recovery of each surrogate was calculated and compared
with the advisory control limits of 60 to 150 percent in the
1990 CLP SOW. No corrective action is needed when
surrogate recoveries fall outside of the advisory control
limits. However, the surrogate recoveries are reported
with the other QC data. During this demonstration, 12
soil samples and field duplicate samples from the
confirmatory laboratory analysis were outside the advisory
control limits for surrogate recoveries.
During the demonstration, 46 samples and their
respective duplicate samples required dilution to obtain
peaks that were witbin the linear range required by the
1990 CLP SOW; however, the dilutions decreased the
amount of the surrogate standards that were injected onto
the GC, resulting in nondetection of the surrogates in the
samples. PRC was not able to obtain information
regarding actual surrogate standard recovery for each of
the samples analyzed by the confirmatory laboratory.
However, comments from the EPA Level II data review
indicated that 88 of the samples and their respective
duplicate samples resulted in acceptable surrogate
recovery data.
The 1990 CLP SOW requires that matrix spikes and
matrix spike duplicate samples be prepared with six
organochlorine pesticides and analyzed with each batch of
samples. Because the demonstration was only concerned
with PCB results, the matrix spike results were not
reported.
Confirmation of Analytical Results
The 1990 CLP SOW also requires that all positive
sample results be confirmed. There are two methods of
conmming sample results. The. first, required in all cases,
is to reanalyze the sample by using a second GC column.
If concentrations identified this way are sufficiently high,
the second method, reanalyzing the sample by using a GC
mass spectrometer (MS), must also be used.
Second Column Confirmation
As required, all samples that were found to contain
PCBS during analysis of the first column were analyzed on
the second column. In all cases, the presence of PCBs
were confiiimed. Second column confirmations were
required for 122 samples.
The 1990 CLP SOW states that results from the two
columns should be within 25 percent of each other. When
this requirement is not met, the result for that sample must
be coded to indicate that the results are estimated. For the
analysis of the samples from this demonstration, 17 sample
results were above the 25 per-cent requirement of the 1990
CLP SOW. These results were J-coded to indicate that the
results were estimated but were not validated by approved
QC procedures. Finally, following the 1990 CLP SOW
method required when values obtained from the analysis
of a sample on two columns were different, the reported
value was the lower of the two values. This requirement
was followed for the samples from this demonstration.
Gas Chromatographic Mass Spectrometer
Confirmation
The 1990 CLP SOW requires that, when pesticides or
PCBs are present in samples at sufficient quantities, they
be confirmed by GC and MS analysis. Twenty samples
from this demonstration contained sufficient quantities of
PCBs to require GC and MS confirmation. These samples
were compared to Aroclor standards. None of the 20
samples was confirmed through GC and MS analysis.
Lack of GC and MS confirmation is not uncommon for
Aroclors, because they are a mixture of congeners, and
the GC and MS analysis is better suited to identifying
individual congeners . Because all 20 sam-ples were
confirmed on the second GC column, the lack of GC and
MS confirmation was determined to be insignificant during
the EPA Level II data review. Therefore, these samples
were not coded.
Data Reporting
The data report PRC received from the EPA Region
7 Laboratory included a standard EPA Region 7 Analysis
Request Report. PCBs were the only compounds
reported. Results were reported on a dry weight basis, as
required in the 1990 CLP SOW. PRC obtained data, from
the confirmatory laboratory, on the percentage of solids in
the sample and used these data to convert the results to
wet weight. This conversion was required, because the
data were to be compared with data obtained by the FASP
PCB Method which reported concentrations on the basis
of wet soil weight. PRC also converted the confirmatory
laboratory results from ^tg/kg to mg/kg.
The results reported by the confirmatory laboratory
contained three different codes. Every result was coded
with a "V," indicating that the data had been reviewed and
reported correctly. Some data were coded with a "K,"
indicating either (1) that the actual PCB concentration in
the sample was less than the reported value, or (2) that
PCBs were not found in the sample. The third code used
was a "J" code, which indicated that the data was
estimated but not validated by approved QC procedures.
Twenty-nine of the 146 total samples submitted for
analysis were J-coded.
Aroclors Reported by the Confirmatory
Laboratory
According to RF1 and CMS results from April
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1989, Aroclor 1242 was the only Aroclor believed to be
present at the AICO site. Most of the samples analyzed
by the confirmatory laboratory were found to contain
either Aroclor 1242 or Aroclor 1248, however, the
confirmatory laboratory found three additional Aroclors in
the samples collected during the demonstration.
Seventy-three samples were found to contain only Aroclor
1242, and 33 samples were found to contain only Aroclor
1248. Sixteen samples were found to contain mixtures of
two of the four Aroclors found. The predominant mixture
consisted of Aroclor 1242 and Aroclor 1248. Seven
samples were found to contain this mixture. Four samples
were found to contain a mixture of Aroclor 1242 and
Aroclor 1260. Three samples were found to contain a
mixture of Aroclor 1248 and Aroclor 1260. Two samples
were found to contain a mixture of Aroclor 1242 and
Aroclor 1254.
In all, 122 soil samples submitted to the confirmatory
laboratory for this demonstration were found to contain
detectable levels of PCBs. Twenty-four samples were
reported as not containing PCBs at concentrations above
the CRQLs.
Data Quality Assessment of Confirmatory
Laboratory Data
This subsection discusses the accuracy, precision, and
completeness of the confirmatory laboratory data.
Accuracy
Accuracy for the confirmatory laboratory was
assessed through the use of PE samples containing a
known quantity of Aroclor 1242, and purchased from
Environmental Research Associates (ERA). For each PE
sample, ERA supplied data sheets which included the true
concentration and an acceptance range for the sample.
The acceptance range was based on the 95 per-cent
confidence interval taken from data generated by ERA and
EPA interlaboratory studies.
The two PE samples contained different
concentrations-one low and one high. These samples
were extracted and analyzed in exactly the same manner
as were the other soil samples. The confirmatory
laboratory knew that the samples were PE samples but did
not know the true concentrations and acceptance ranges of
the samples. The true concentration of sample
047-4024-114 (the high-level sample) was 110 mg/kg, with
an acceptance range of 41 to 150 mg/kg. The result
reported for this sample by the confirmatory laboratory
was 67 mg/kg of Aroclor 1242, which was within the
acceptance range. The percent recovery of this sample by
the confirmatory laboratory was 61 per-cent. The true
value concentration of sample 047-4024-113 (the low-level
sample) was 32.7 mg/kg, with an acceptance range of 12
to 43 mg/kg. The result reported by the confirmatory
laboratory for this sample was 15 mg/kg, which was
within the acceptance range. The percent recovery of this
sample by the confirmatory laboratory was 46 percent.
Based on the results of the PE samples, the accuracy of the
confirmatory laboratory was acceptable.
Precision
Precision for the confirmatory laboratory results was
determined by evaluating field duplicate sample results.
Other types of data typically used to measure precision
were not available. Laboratory duplicate samples were
not required by the 1990 CLP SOW. Two other types of
data commonly used to measure precision-matrix spike
and matrix spike duplicate RPDs-were also unavailable,
because matrix spike compounds required by the 1990
CLP SOW method are pesticide compounds, not PCBs.
PRC used the evaluation of field duplicate sample
results to assess the precision of the analytical method.
Precision can be evaluated by determining the RPDs for
sample results and their respective field duplicate sample
results. The RPDs for the 32 field duplicates and their
respective samples averaged 31.8 percent, but this
included two pairs of samples with extremely dissimilar
results. Sample 102 had a result of 293 mg/kg, whereas
its duplicate, Sample 102D, had a result of 1.77 mg/kg.
The RPD for the sample pair was calculated as
197.6 percent. Also, Sample 97 had a result of
1.23 mg/kg, whereas its duplicate had a result of
0.285 mg/kg. The RPD for Samples 97 and 97D was
124.8 percent. However, the other RPDs had much lower
percentages. Without these two samples, the mean RPD
fell from 31.8 to 20 percent. Overall, these data show
excellent agreement between the samples and their
respective field duplicates, indicating a high degree of
precision by the confirmatory laboratory. The mean RPD
also indicated that the method used to homogenize the
samples before splitting them for analysis was highly
effective.
Completeness
This demonstration resulted in the collection of
112 samples, 32 field duplicate samples, and two PE
samples. Results were obtained for all of these samples.
Of the 146 total samples analyzed by the confirmatory
laboratory, 29 were J-coded. The EPA Region 7 Lab-
oratory defines the J-code as data estimated but not
validated by approved QC procedures. Based on the
definition of completeness stated in the QAPP (PRC
1992b), these 29 samples cannot be considered complete.
Because of this, completeness for the samples analyzed by
the confirmatory laboratory was 80 percent, which is
below the completeness objective of 90 percent.
However, PRC and NERL-LV determined that the J-coded
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data were acceptable. For this reason, the actual
completeness of data used was 100 percent.
Use of Qualified Data for Statistical Analysis
As noted, 20 percent of the confirmatory laboratory
results were reported as data not validated by approved
QC procedures. The EPA Level II data review indicated
that these J-coded data were not valid, because they had
failed at least one of the two QA/QC criteria specified in
the 1990 CLP SOW.
Twelve samples were determined to be invalid,
because one of the two surrogate compound recoveries
was outside of the advisory control limits. In all cases, the
second surrogate recovery was within the advisory control
limit. The remaining 17 samples were considered invalid,
because results from the two GC columns used for sample
quantitation differed by more than 25 percent.
Neither of these QA/QC problems was considered
serious enough to preclude the use of J-coded data for this
demonstration. The surrogate recovery control limits are
for advisory purposes only, and no corrective action was
required for the surrogate recoveries that were outside of
this range. High percent differences between the sample
results analyzed on the two GC columns is a frequent
problem in analyzing samples with very complex
chromatograms. In all cases, the reported value was the
lower of the two, reducing the effect of interferants on the
results.
As discussed in the QAPP (PRC 1992b), a rejection
of a large percentage of data would increase the apparent
variation between the confirmatory laboratory data and the
data from the technologies. This apparent variation would
be of a magnitude similar to that introduced by using the
data. For these reasons, PRC, after consulting with
NERL-LV, chose to use the J-coded data regardless of the
determination by the EPA Region 7 Laboratory that the
results were invalid under approved QC procedures.
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Section 6
EPA Superfund: Field Analytical Screening Program PCB Method
This section discusses the FASP PCB Method,
including background information, operational
characteristics, performance factors, a data quality
assessment, and a comparison of its results with those of
the confnmatory laboratory. Observations made by the
operator are presented throughout this section.
Theory of Operation and Background
Information
The FASP PCB Method is designed to provide quick
and accurate results for PCB concentrations in soil
samples. PCB concentrations are reported in fig/kg. This
method was developed as part of the Field Investigation
Team contract administered by the EPA Region 7
Superfund program.
The FASP PCB Method uses a GC equipped with an
BCD to identify and quantify PCBs. Gas chromatography
is used in EPA SW-846 Manual Method 8000, an
EPA-approved method for determining PCB
concentrations in soil samples. The FASP PCB Method
is an abbreviated version of this method. Soil samples
must be extracted before analysis begins. First, 5 grams
of a soil sample are placed into an extraction vial. For
removal of the water from the soil sample, 10 grams of
anhydrous sodium sulfate are added to the extraction vial
and thoroughly mixed with the soil. Twenty mL of
pesticide-grade hexane are added to the extraction vial,
which is then mixed with a vortex mixer for 2 minutes.
The extraction vial is allowed to sit so that the soil and
sodium sulfate mixture separates from the hexane extract.
A part of the hexane extract is transferred to a test tube.
One to 2 mL of concentrated sulruric acid is added to the
test tube, where it is mixed with the hexane extract. The
hexane and sulfuric acid mixture is allowed to sit for 10
minutes so that they can separate. This step is used to
remove potential interferences from the resulting soil
sample extract.
Next, the GC must undergo an ICAL. The ICAL
involves analyzing standards containing three different
concentrations of seven Aroclors. Peak patterns are
observed, and retention time windows are determined for
three to five peaks in each Aroclor. Calibration factors
for each Aroclor are calculated and evaluated. When an
acceptable ICAL has been completed, analysis of soil
sample extracts may begin.
Analysis begins with the injection of microliter
amounts of the soil sample extract into a GC equipped
with a megabore capillary column. The GC megabore
capillary column effluent is directed through an ECD.
Sample chromatograms are compared to PCB standard
chromatograms to identify and quantify Aroclors. Peak
patterns and retention times from the chromatograms are
used to identify PCBs in the soil sample extract. Peak
patterns are used to identify and quantify PCBs in the soil
sample extract.
Chromatograms for standards and samples can be
plotted on a strip chart, an integrator, or a data system.
Samples analyzed during the demonstration were plotted
on a data system. The data system plotted
chromatograms, measured retention times of peaks,
calculated peak areas and peak heights, stored
chromatographic data on floppy disks, and manipulated
data for baseline correction. The data generated were
transferred to a spreadsheet program for the evaluation of
standards and samples.
Daily CCALs are performed for four of the seven
Aroclors. CCALS are used to monitor the performance of
the GC. Acceptable CCALs must be performed before
sample analysis can continue. When unacceptable CCALs
occur, a new ICAL must be performed before sample
analysis can continue.
Operational Characteristics
Because they are large, the instruments and equipment
required for the FASP PCB Method are not very portable.
The instruments used for this demonstration included (1)
a Shimadzu GC-14A equipped with an ECD, (2) a
Shimadzu AOC-14 auto-sampler, (3) a Shimadzu CR-4AX
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equipped with an BCD, (2) a Shimadzu AOC-14 auto-
sampler, (3) a Shimadzu CR-4AX data system, and
(4) a COMPAQ SLT/286 laptop computer. The GC
with the auto sampler was 18 by 24 by 42 inches and
weighed about 100 pounds. The data system was 18 by
24 by 12 inches and weighed 25 pounds. Laboratory
equipment needed for sample preparation and analysis
included: (1) one cylinder of Nitrogen gas, (2) a GC
Column: DB-608, 30 meter, 0.53 millimeter (mm) ID,
or equivalent, (3) 10, 50, and 100 fj.L micropipettes,
(4) 10, 25, 50, 100, and 500 PL micro syringes, (5) 1,
5, and 10 mL glass volumetric pipettes, (6) 2 to 10 mL
repipettors with Teflon liners, (7) 10, 50, and 100 mL
volumetric flasks made of glass and with ground-glass
stoppers, (8) 2 mL glass vials with Teflon-lined caps for
storing stock standards, (9) 2 mL autosampler vials with
Teflon-lined cap, (10) a bubble flow meter used, used to
check the GC column flows, (11) 4-fluid-ounce standard
bottles with Teflon-lined screw cap for calibration
standard storage, (12) Pasteur pipets: 5.75- and 9-inch
size Pasteur pipettes made of disposable glass,
(13) 40mL extraction vials with Teflon-lined screw caps,
(14) 13 mm by 100 mm test tubes with Teflon-lined
screw caps, (15) stainless-steel spatulas, (16) a top
loader balance with 0.01 gram accuracy, (17) a high
speed vortex mixer, (18) a digital timer capable of
timing up to 99 minutes, (19) both large and small pipet
Bulbs to fit the volumetric and Pasteur pipets,
(20) labels, (21) markers, (22) polypropylene or latex
gloves, (23) safety glasses, (24) laboratory coats or
protective clothing, (25) a refrigerator or ice chest for
standards and samples, (26) a hood to remove solvent
fumes from work area, and (27) floppy disks for data
storage.
The standard reagents used for sample extraction
and analysis are pesticide-grade hexane; granular,
pesticide-grade sodium sulfate; concentrated sulfuric
acid; powdered sodium bicarbonate (for acid spills); and
Aroclor standards of 96 percent purity or greater.
The FASP PCB Method must be performed indoors
to protect the analytical equipment from moisture and
temperature extremes. Most of the other equipment and
reagents also require this protection. During this
demonstration, this method was performed in a trailer.
Another logistical requirement was electricity.
Electricity was provided to the trailer through a
temporary power pole. An alternative source of
electricity may be used, such as a gasoline-powered
generator. A generator allows the analytical equipment
to be operated at even the most remotely located
PCB-contaminated sites. The FASP PCB Method
requires using a hood to evacuate solvent and acid fumes
from the work area. The hood may be vented directly
outdoors or through a charcoal trap in which the harmful
fumes are trapped. Regular maintenance of the charcoal
trap is required to ensure that it is operating correctly.
A flammable solvent storage cabinet is recommended for
storing solvents safely. A refrigerator is needed for
storing the Aroclor standards. The refrigerator used for
this demonstration was 3.5 cubic feet in size. Carrier
gases are required for gas chromatography. These gases
may be purchased before arrival at the site, or
agreements for delivering the carrier gases to the site
may be made with local carrier gas suppliers. The work
space required for the setup of analytical equipment is
12 square feet. Another 8 square feet of space is needed
to perform the sample extraction and preparation.
Storage space is also needed for the equipment, reagents,
and glassware.
Soil samples should be refrigerated until sample
analysis. However, they should not be stored with
Aroclor standards, which should be stored in a second
refrigerator. The refrigerator is recommended for
storing samples overnight or until it is determined which
of the samples will be transported to a formal laboratory
for further analysis.
A minimum of 6 months of experience in using a
GC and a minimum of 1 month of experience in
analyzing PCBs is required to effectively use the FASP
PCB Method. The operator noted that the method is
relatively easy to run with some prior GC experience
and that any person with a basic knowledge of analytical
chemistry can be expected to quickly learn the method
and techniques. PRC tested the FASP PCB Method by
using the equipment from its mobile laboratories. The
ruggedness of PRC's equipment has been proven. This
equipment has been transported and used in Hawaii,
California, Arizona, Montana, Kansas, Missouri, Iowa,
Wisconsin, Illinois, Michigan, and Ohio. No problems
have been observed in the instrumentation.
In addition to the GC, the operator used an
autosampler that automatically injected equal amounts of
sample extracts into the GC's column. Using the
autosampler analysis can occur even when the analyst is
not present. In addition, the autosampler ensures that
the correct amount of extract is used for each analysis.
Maintenance of the GC and other equipment is essential
to ensure quick and accurate PCB results in the field.
Because of the rigors of working in the field, the
equipment should be on site and operating correctly at
least 1 to 2 days before sample collection begins. This
lead time allows any needed maintenance to be
performed before sample collection begins. Routine
maintenance includes carrier gas changes, injector port
septum changes, and column conditioning. Nonroutine
maintenance may include column changes or electronic
board replacement. Agreements with equipment
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suppliers for overnight delivery of replacement parts,
and in-the-field servicing by equipment service
representatives may be required to provide all of the
necessary maintenance.
PRC evaluated instrument reliability by monitoring
the equipment's ability to maintain its calibration. An
ICAL was performed at the start of the demonstration.
The instrument calibration was monitored daily through
CCALs by using the mid-level concentrations for four
Aroclor standards. Three to five peaks were identified
in the mid-level Aroclor standards to monitor CCALs.
The height of these peaks in the ICAL were compared
with the height of these peaks in subsequent CCALs.
The heights of these peaks were compared by calculating
their RPDs. An RPD value of less than or equal to
25 percent is required to continue sample analysis.
CCAL RPD checks were performed on four Aroclors:
1016, 1242, 1254, and 1260.
During the 17 days of the demonstration, 16 CCALs
were performed. The first 14 CCALs analyzed were
determined acceptable. On the 15th day, the CCAL for
Aroclor 1260 was above the 25-percent RPD criterion.
Corrective action was taken to determine the cause of the
calibration failure. It was determined that the septum
needed replacement. The total number of sample and
standard injections performed on the GC before the 15th
day was greater than 400. This is an extremely high
number of analyses without a septum change. The
septum was changed, and another set of CCAL standards
was analyzed. The CCAL RPD values for the reanalysis
were less than 25 percent. Sample analysis was
continued. On the 16th day, a CCAL was performed
after sample analysis was completed. The RPD values
for this final CCAL were less than 25 percent and
considered acceptable.
The retention times of specific Aroclor peaks were
also monitored through the CCALs. The retention times
of these peaks shifted throughout the demonstration.
The windows were adjusted to maintain accurate
retention time windows for these peaks. Thii adjustment
was made by using the CCAL PCB peaks as the mean of
the window, and the absolute retention time windows
stated in the FASP PCB Method were applied to this
mean. Another reliability factor evaluated was the
consistency of the data system to properly draw a
baseline for standards and samples. Overall, the data
system was consistent in its baseline determinations.
However, because of numerous interference peaks in
the samples, numerous chromatograms had to be
reprocessed to correct the baseline. The operator of this
method was able to redraw the baselines of these
samples to more correctly simulate the baseline of the
standards.
The FASP PCB Method uses three chemicals to
remove potential interferants from samples and to extract
the PCBs. Hexane, a flammable solvent that can be
absorbed through the skin, is used to extract PCBs from
samples and to dilute standard solutions. Sodium
sulfate, which can irritate the skin and eyes, is used to
bind to the water in soil samples. Sulfuric acid, which
can burn the skin, was used to remove possible
interferences from soil sample extracts. While using any
of these chemicals, personnel should wear chem-
ical-resistant clothing, gloves, and safety glasses. Fire
extinguishers, safety equipment, and an adequate source
of water should be available in case the acid comes into
contact with the skin. Eyewash solutions should also be
available.
The BCD contains nickel-63, which is a radioactive
material. The amount of radioactive material in the
BCD is minimal, and it is stored in a sealed container.
The container must be checked for possible leakage
twice each year. Leakage of the radioactive material of
above federally-regulated limits requires immediate
attention. The manufacturer of the material must be
contacted to determine the appropriate action.
Mr. Ramarao Rayavarapu, an employee of PRC,
was the operator chosen to analyze samples by using the
FASP PCB Method. Mr. Rayavarapu earned a B.S.
degree in civil engineering in 1983 from Andhra
University in India. Mr. Rayavarapu also earned an
M.S. in environmental engineering in 1990 from the
University of Missouri. While at PRC, Mr. Rayavarapu
has conducted RCRA facility inspections, compliance
evaluation inspections, and field sampling and oversight
work. Before joining PRC, he was involved in
designing industrial and municipal waste treatment
systems. Mr. Rayavarapu has more than 5 years of
experience in designing these types of systems. His
experience also includes using several types of wet
chemical analytical methods. The lead chemist for the
demonstration trained Mr. Rayavarapu in using the
FASP PCB Method. This training included 1 week of
hands-on work using and maintaining the GC. Training
also included specific procedures required for the
extraction, preparation, and analysis of samples.
Mr. Rayavarapu analyzed all soil samples collected
during the predemonstration activities using the FASP
PCB Method. Mr. Rayavarapu's training culminated
with the analysis of two PE samples to determine
whether he could produce acceptable results by using this
method. Mr. Rayavarapu completed the PE samples
with acceptable results. After analyzing these samples,
Mr. Rayavarapu noted that he felt comfortable using the
method.
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The analytical instrumentation used to analyze soil
samples during this demonstration was purchased
through a Shimadzu sales representative. The total cost
of the analytical equipment was $23,214. This cost
includes the GC equipped with an BCD, the
autosampler, the data system, all equipment required for
set-up of the GC, and installation. Costs per component
were $13,149 for the GC, $3,865 for the autosampler,
and $6,200 for the data system. Similar analytical
equipment can be purchased from other analytical
equipment manufacturers. The costs are expected to be
comparable to the Shimadzu prices. Analytical
equipment can also be rented from numerous companies.
The costs for renting comparable equipment range from
$1,500 to $2,500 per month. Most rental companies
require a minimum rental period, but this may be
negotiable. Rental rates sometimes include delivery and
set-up. Many companies also offer rent-to-own or
lease-to-own options for analytical equipment.
The reagents and equipment needed to perform the
extraction, preparation, and analysis of soil samples by
using the FASP PCB Method are estimated to cost
$5,000. This demonstration required over 400 sample
extractions and injections. These 400 sample extractions
include initial sample analysis, subsequent sample
dilutions, and QA/QC samples. These supplies may be
purchased from numerous analytical supply companies.
Waste disposal is another operating cost. During
this demonstration the waste generated filled a 55-gallon
barrel. The appropriate way to dispose of this waste is
through an approved PCB incinerator facility. Disposing
of one barrel of this waste is estimated to cost $1,000.
Performance Factors
The following subsections describe the FASP PCB
Method's performance factors, including its detection
limits and sensitivity, sample throughput, linear range,
specificty, and drift.
Detection Limits and Sensitivity
The sensitivity of the FASP PCB Method depends
on the detection limit of the BCD. For most methods
that use this sort of instrument, the detection limit is
defined as the minimum amount of a compound that will
give a response that is greater than three times the noise
level of the instrument. The BCD is so sensitive that it
almost always detects something in its environment; this
level of detection is termed "noise level." During the
demonstration, the noise level of the instrument's
detection limit was not evaluated. However, PRC noted
that the responses of all of the low-concentration
Aroclor standards were significantly above three times
the noise level for the instrument.
The detection limit of the FASP PCB Method was
stated to be 0.4 mg/kg for soil samples. This detection
limit was based on the low-concentration Aroclor
standards used to calibrate the GC, and the dilution
factors used to extract and prepare samples. The low-
concentration standard for all seven Aroclors was
100 /ig/kg. No further dilution or concentration of the
sample was performed during the extraction process.
The detection limit is calculated by dividing the number
of liters (L) of solvent (.02 L) by the number of grams
of soil (5 grams), and multiplying this number by the
concentration of the low Aroclor standard (100 ^g/kg).
This results in the detection limit of 0.4 mg/kg.
The BCD is used to detect organochlorine pesticides
and PCBs in soil and water samples by using standard
EPA-approved methods. The BCD is sensitive to
halogenated compounds, especially chlorine. PCBs
contain an appreciable amount of chlorine, making the
BCD a sensitive detector for analyzing PCBs.
The range and attenuation of the GC were set to
provide 100 percent, full-scale deflection for high-
concentration Aroclor standards. This means that the
heights of the peaks for these standards were set to reach
the top of the chromatographs. The low-concentration
Aroclor standards exhibited 10 percent of a full-scale
deflection. This means that the peaks reached 10 percent
of the distance to the top of the chromatogram. When
the samples were analyzed, numerous samples exhibited
responses that fell below 10 percent of full-scale
deflections. That is, the responses of these samples were
below the responses of the low-concentration Aroclor
standards. This indicated that the BCD detected levels
of PCBs below the low-concentration Aroclor standard
of 100 jig/kg. This means that the GC was detecting
levels of PCBs below the calculated detection limit.
Of the 146 total samples analyzed during this
demonstration, 17 exhibited PCB patterns below the
10 percent deflection. The concentrations of these
samples was reported as containing PCBs below
0.4 mg/kg. These values were below the stated
detection limit of the FASP PCB Method and were
J-coded to indicate that the reported results were
estimated. From this information, it appears that the
detection limit of the FASP PCB Method may actually
be lower than 0.4 mg/kg.
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Sample Matrix Effects
Sample matrices were less than ideal, because most
of the samples consisted of clay, which caused problems
with extraction and analysis. The first set of soil
samples extracted was not prepared properly. During
the extraction process, anhydrous sodium sulfate was ad-
ded to these soil samples to remove water from them.
The mixture of soil and anhydrous sodium sulfate must
be thoroughly mixed to a fine granular texture. Because
the operator failed to thoroughly mix the first set of soil
samples extracted, there were many large lumps of soil.
The PRC lead chemist instructed the operator on how to
thoroughly mix the samples. The first set of extractions
was then discarded and these samples were reextracted.
The operator extracted a second set of soii samples by
using the directions provided by the PRC lead chemist.
The lead chemist evaluated the mixing process and found
it to be acceptable.
Because of the nature of the soils, a fine granular
texture could not be achieved for all samples extracted.
The operator was instructed to perform the mixing as
thoroughly as possible in a reasonable amount of time.
Although some samples still exhibited small lumps of
soil, this was not viewed as a major problem, because
the vortex mixer was able to break these small lumps
apart.
The GC analyses of some of the soil samples
showed large interference peaks in their chromatograms.
About 85 percent of the samples analyzed exhibited these
interference peaks. The interference peaks consisted of
three peaks. These peaks eluted at retention times of
4.9, 9.8, and 14.4 minutes. The 4.9~minute peak eluted
before any of the Aroclors. The 9.8-minute peak eluted
in the middle of the Aroclor 1016, 1232, 1242, and
1248 peak patterns, and at the beginning of the Aroclor
1254 peak pattern. The 14.4~minute peak eluted at the
end of the Aroclor 1016, 1232, 1242, and 1248 peak
patterns; in the middle of the Aroclor 1254 peak
pattern; and at the beginning of the Aroclor 1260 peak
pattern. The source of the interference peaks was
determined to be from the samples and not from any
type of laboratory-induced contamination. These inter-
ference peaks were not found in any of the reagent
blanks analyzed with the GC.
The interference peaks in the chromatograms ranged
in size from less than a 100 percent, full-scale deflection
to many times above a 100 percent, full-scale deflection.
The interference peak that eluted at 14.4 minutes was
found in more chromatograms, and appeared to contain
a higher concentration, than the other two interference
peaks.
Three soil samples showing interference peaks were
sent to the EPA Region 7 Laboratory for an EPA
SW-846 Method 8270 analysis to determine the identity
of the compounds causing the interference peaks. The
three samples sent for Method 8270 analysis were
samples 026, 052, and 054. No Method 8270 analytes
were identified. The laboratory also performed a library
search for tentatively identified compounds (TIC). The
results of the TICS showed only low concentrations of
chlorinated biphenyl congeners, polynuclear aromatic
hydrocarbons, and hydrocarbons. These TIC
compounds did not appear to match the' interference
peaks for the three samples analyzed by the FASP PCB
Method, because (1) the PCBs identified through the
TIC search had already been detected by the FASP PCB
Method, and (2) because polynuclear aromatic
hydrocarbons and other hydrocarbons do not exhibit
responses when analyzed with an ECD.
PRC originally theorized that the interference peaks
in the samples analyzed by the FASP PCB Method were
phthalates. During the predemonstration activities,
Dexsil analyzed the predemonstration samples by using
a GC and MS. Dexsil tentatively identified
buty 1-2-methyl propyl phthalate in some of the
predemonstration samples. A subsequent library search
indicated a 70 percent probability that this compound
would also be present in the demonstration samples.
A review of the predemonstration chromatograms
generated by the FASP PCB Method showed that the
14.4-minute interference peak found in the
demonstration samples was also present in the
predemonstration samples. An assumption was made
that the phthalate found by Dexsil was causing this peak.
The EPA Region 7 Laboratory's TIC search did not
indicate the presence of any phthalates. Therefore, the
compounds causing these interference peaks cannot be
positively identified. The interference peaks did not
prevent PCBs in the soil samples from being identified
and quantified, because PCBs consist of many resolved
peaks, which elute throughout a relatively wide area of
the chromatogram. The interference peaks masked part
of some of the Aroclor peak patterns. However, enough
of the patterns were unaffected to allow PRC to identify
and quantify PCBs.
Another sample matrix effect was the high levels of
PCBs found in many of the samples. Any sample that
was analyzed and found to contain levels of PCBs above
a full-scale deflection of 100 percent required dilution.
Of the 146 samples analyzed during the demonstration,
48 required dilution, which is 33 percent. To avoid
contaminating the ECD by injecting large amounts of
PCBs into the GC, PRC diluted any samples suspected
of containing high levels of PCBs before sample
22
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analysis. PRC used two methods that helped the
operator determine samples that potentially contained
high levels of PCBs First, those samples with highly-
colored organic sample extract were diluted before
sample analysis. Second, highly-colored sulfuric acid
layers were also diluted before sample analysis.
However, the operator noted that this visual observation
did not always correctly indicate high PCB con-
centrations. Samples that were found to contain no
PCBs in the diluted sample extract were reanalyzed at a
more concentrated sample extract solution until either a
positive result was obtained or the 20-mL sample extract
solution was analyzed.
Sample Throughput
The FASP PCB Method uses an autosampler to
increase the number of samples that can be analyzed in
1 day. The autosampler allows samples to be analyzed
24 hours a day. After it is loaded with samples, the
autosampler can be operated without an operator present.
The FASP PCB Method claimed that the analysis of up
to 20 samples per day could be completed. During this
demonstration, the most samples analyzed in 1 day by
using the FASP PCB Method was 21. The average
number of samples analyzed in 1 day was 15 samples.
Linear Range
The linear range of the BCD was not established
during the demonstration. PRC established the linear
range of the analysis for PCBs by analyzing the three
concentrations for each Aroclor standard during the
ICAL. The three concentrations used during the ICAL
ranged from 100 to 1,000 jig/kg. These concentrations
correspond with PCB concentrations ranging from 0.4 to
4 mg/kg in the soil samples.
Based on the ICAL Aroclor standard concentrations,
any sample that exceeded a PCB concentration
above 4 mg/kg required dilution. As discussed
previously, 48 samples collected during this
demonstration re-quired dilution to obtain Aroclor peaks
within the linear range of the calibration. Twenty-three
of the samples required a 1: 10 dilution; 12 required a
1: 100 dilution; 11 required a 1: 1,000 dilution; and
2 required a 1: 10,000 dilution. These dilutions were
used to obtain the sample results.
The linear range for the FASP PCB Method is
comparable to the linear ranges used in formal lab-
oratory analysis. Although this range is very narrow, as
indicated by the high number of dilutions, it may be
extended upward if the response of the BCD to higher
levels of PCBs meets the ICAL. This is a suggested
improvement for the FASP PCB Method.
Drift
Drift is a measurement of an instrument's variability
in quantifying a known amount of a standard. The drift
associated with the FASP PCB Method was evaluated
through daily CCALs. For sample analysis to continue,
the CCALs were required to meet specific criteria. The
responses exhibited by the CCALs were compared with
those exhibited by the ICAL. As discussed previously,
all but one of the CCALs were found to be acceptable.
The reason for the unacceptable CCAL was that the GC
injection port septa had worn out. The GC septa was
replaced, and a new CCAL was performed. The new
CCAL was found to be acceptable, and sample analysis
continued. Replacement of GC injection port septa is a
normal maintenance requirement for GC analysis. The
performance during this demonstration, of more than
400 injections before the septa required replacement
indicates that the instrument was not highly susceptible
to drift. GC septa replacement is typically done after
100 injections.
Drift of Aroclor retention times was also monitored
through CCALs. During the analysis of samples, PRC
noticed that the retention times of the Aroclors were
shifting. These shifts were small, but they exceeded the
acceptable retention time ranges calculated during the
ICAL. Shifting of retention times was also observed in
the sample chromatograms. PRC compensated for the
shifting of retention times by establishing new acceptable
retention time ranges. The retention times of the
Aroclor peaks for the CCALs were used.
Specificity
Most of the interferences associated with analyzing
PCBs by using the FASP PCB Method are attributed to
phthalates and sulfur. Phthalates and sulfur produce
large, late-eluting peaks, which partially or totally mask
PCB patterns. These interferants are found in many
environmental samples. Phthalates are also common
laboratory contaminants and can be found in many of the
plastic materials used in some extraction processes.
Using organic solvents to extract PCBs from samples
will also extract the phthalates from these plastics. For
this reason, plastic materials should not be used in any
stage of sample storage, extraction, or analysis.
Interferences may be introduced through other
means, such as carrier-gas contamination, carryover
from extremely contaminated samples, and sample
matrix interferences. Potential for carrier-gas contamin-
ation is reduced by using ultra-high, purity-grade gases.
The use of carrier gas filters also helps to eliminate these
problems. The analysis of highly contaminated samples,
followed by the analysis of less contaminated samples,
23
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frequently results in sample carryover contamination.
During this demonstration, PRC reduced sample
carryover contamination by using disposable glassware.
Glassware was replaced after the extraction and analysis
of each sample. To reduce contamination of the GC and
BCD, PRC analyzed those samples believed to be highly
contaminated after the analysis of those believed to be
less contaminated. The use of solvent washes added to
the GC after the analysis of highly contaminated samples
also reduced the amount of sample carryover
contamination.
Sample matrix interferences are more difficult to
eliminate. Extensive sample cleanup may be required to
determine the amount of PCBs in these samples.
Common sample matrix interferants present in
environmental samples include phthalates, sulfur,
halogenated solvents, halogenated pesticides, polar
halogenated compounds, and chlorinated paraffins.
Although this section discusses a simple cleanup, such
may not eliminate all sources of matrix interferences that
may be found in environmental samples. For these
samples, alternative methods of identifying and
quantifying PCBs may be needed. This may include
using different peaks for identification and quantitation.
In samples in which interferences totally mask the PCB
pattern, higher detection limits may need to be reported.
Another source of matrix interference that may be
found in samples consists of high PCB concentrations.
High concentrations of one Aroclor may prevent the
identification or quantitation of other Aroclors. PCBs
are mixtures of chlorinated biphenyls. There are
209 congeners of chlorinated biphenyls, differentiated by
the number and position of chlorine atoms on the
biphenyl compound. PCBs were manufactured as
mixtures of chlorinated biphenyls called Aroclors.
These Aroclors differ in the percentage of chlorine
present. The number nomenclature associated with the
Aroclors refers to the percent chlorination. Each
Aroclor contains five to 100 different congeners of the
chlorinated biphenyl group. This large number of
congeners results in many resolved peaks when the
Aroclor is analyzed by using an BCD. Each Aroclor
exhibits a characteristic peak pattern when analyzed by
an ECD. Although the peak pattern of each Aroclor is
characteristic, many of the Aroclors exhibit similar peak
patterns. Aroclors 1016, 1221, 1232, 1242, and 1248 all
exhibit similar peak patterns. These Aroclors contain
many of the same peaks when analyzed by using the GC
and ECD, but the major differences between these
Aroclors is the peak response ratio. When a sample is
found to contain one of these Aroclors, the peak
responses are evaluated to determine which of the
Aroclors that the sample peak pattern most resembles.
If any one of these five Aroclors is found in a
sample, identifying and quantifying the other four
Aroclors within this group is nearly impossible. When
this occurs, the FASP PCB Method will report results
for only the Aroclor that is found. The other four
Aroclors will not be reported. Aroclors 1254 and
1260 do not present this problem. The peak patterns of
these two Aroclors elute in a different region of the
chromatogram and can be discerned from Aroclors
1016, 1221, 1232, 1242, and 1248. Aroclor 1254 and
1260 can be identified and quantified when present in a
sample containing the other five Aroclois. Aroclor
1254 can also be identified and quantified in samples
containing Aroclor 1260 and vice versa.
For many reasons, Aroclor peak patterns may not
exactly match those of Aroclor standards. This may be
because (1) different manufacturing batches of a specific
Aroclor may not have exactly the same ratio of
chlorinated biphenyls as the standards, (2) Aroclors can
be physically weathered in the environment, and
(3) sample interferences may affect the peak pattern.
During this SITE demonstration, PRC measured the
specificity of the FASP PCB Method to each of the
seven Aroclors. Seven soil samples were spiked with
known amounts of each Aroclor. Each sample was
spiked with a different Aroclor. First, each sample was
divided into four aliquots. All four aliquots were then
spiked with an Aroclor at a concentration of about
10 mg/kg. This concentration was chosen, because it is
a common cleanup goal at PCB-contaminated sites.
Table 6-1 shows the results of the Aroclor specificity
test.
The Aroclor-spiked samples were identified with
nine-digit, alpha-numeric identification numbers. The
first three digits of this code refer to the soil sample
number. The next four digits, "ARSP," are an
abbreviation of the words "Aroclor spike.' The next
digit is a letter, A through G, referring to a code used to
identity the Aroclor that was used to spike the sample.
The last digit is a number, 1 through 4, referring to the
aliquot of the sample. To ensure that the results of the
assessment were unbiased by operator effects, the
operator did not know which Aroclor was used for
spiking or the concentration used for spiking.
At the time at which the Aroclor spikes were
prepared, the concentrations of the PCBs in the soil
samples were not known. Initial indications from the
FASP PCB Method were available, but the results had
not been finalized. All but two of the samples
chosen for the Aroclor specificity test were found to
24
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6-1.
Sample
No,
003ARSPA1
003ARSPA2
003ARSPA3
003ARSPA4
012ARSPB1
012ARSPB2
012ARSPB3
012ARSPB4
021ARSPC1
021ARSPC2
021ARSPC3
021ARSPC4
034ARSPD1
034ARSPD2
034ARSPD3
034ARSPD4
040ARSPE1
040ARSPE2
040ARSPE3
040ARSPE4
058ARSPF1
058ARSPF2
058ARSPF3
058ARSPF4
077ARSPG1
Q77AR8PG2
077ARSPG3
077ARSPG4
Soil Sample
Result.
(mg/kg)
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NO
ND
ND
ND
ND
4.8
4.6
4.6
4.8
0.58
0,58
0,58
0,58
ND
ND
ND
ND
Aroclor
Spike
A.R1221
AR1221
AR1221
AR1221
AR1280
AR1280
AR1280
AR1280
AR1232
AR1232
AR1232
AR1232
AR1254
AR1254
AR1254
AR1254
AR1242
AR1242
AR1242
AR1242
AR1248
AR1248
AR1248
AR1248
AR1016
AR1018
AR1016
AR1016
Spike Amount
(mg/kg)
9.86
9.71
9.87
9,73
10.00
9,98
10.02
9,98
9,78
9.94
10.06
10.10
9.75
9.96
10.02
9.84
9,92
9,98
9,92
9,75
9.77
9,94
9,71
9,94
9.90
9.94
9,98
9,84
Spiked Sample
Result
{mg/kg)
3.83
3,75
3,59
4.13
6.40
7,24
9.30
8.80
30,30
3,60
3,60
2.70
6.80
5.20
5,01
5.14
18.4
12,3
14.6
7.80
4,43
5.40
4.50
5,70
3.40
4,80
4,80
4.30
Percent
Recovery
(%)
39
39
37
42
64
73
93
88
34
38
36
27
88
52
50
52
139
73
101
33
39
48
48
52
34
48
48
44
Note:
ND Not detected above the 0.4 mg/kg limit
25
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contain less than 0.4 mg/kg of the Aroclor used for the
spike, as determined by the FASP PCB Method.
Sample 077 was spiked with Aroclor 1016. The
unspiked soil sample result (1016) reported by the FASP
PCB Method was less than 0.4 mg/kg of any Aroclor.
The amount of Aroclor 1016 found in the four spiked
aliquots ranged from 3.4 to 4.8 mg/kg. Therefore, the
percent recoveries obtained for the Aroclor 1016-spiked
samples ranged from 34 to 48 percent. From the
Aroclor specificity test results, PRC determined that a
sample containing 10 mg/kg of Aroclor 1016 can be
detected with the FASP PCB Method, but less than half
of the amount of the Aroclor spiked into the sample can
be detected.
Sample 058 was spiked with Aroclor 1248. The
unspiked soil sample result (1248) reported by the FASP
PCB Method was 0.58 mg/kg. The amount of Aroclor
1248 found in the four spiked aliquots ranged from
3.9 to 5.1 mg/kg. Therefore, the percent recoveries
obtained for the Aroclor 1248-spiked samples ranged
from 39 to 52 percent. From these Aroclor specificity
10 mg/kg of Aroclor 1248 can be detected with the
FASP PCB Method, but less than 60 percent of the
amount of the Aroclor spiked into the sample can be
detected.
Sample 040 was spiked with Aroclor 1242. The
unspiked soil sample result (1242) reported by the FASP
PCB Method was 4.6 mg/kg. The amount of Aroclor
1242 found in the four spiked aliquots ranged from
7.8 to 18.4 mg/kg. The percent recoveries obtained for
the Aroclor 1242-spiked samples ranged from 33 to
139 percent. From these specificity test results, PRC
determined that a sample containing 10 mg/kg of
Aroclor 1242 can be detected with the FASP PCB
Method. However, the four reported results varied
widely. It is believed that the relatively high
concentration of Aroclor 1242 in the soil sample affected
the outcome of the specificity test.
Sample 034 was spiked with Aroclor 1254. The
unspiked soil sample result (1254) reported by the FASP
PCB Method was less than 0.4 mg/kg The amount of
Aroclor 1254 found in the four spiked aliquots ranged
from 5.0 to 6.6 mg/kg. Therefore, the percent
recoveries obtained for the Aroclor 1254-spiked samples
ranged from 50 to 68 percent. From these results, PRC
determined that a sample containing 10 mg/kg of
Aroclor 1254 can be detected with the FASP PCB
Method. However, during this specificity test, all of the
reported results for this Aroclor were below 7 mg/kg.
One possible explanation for this low recovery is that
FASP PCB Method found this sample to contain
22.9 mg/kg of Aroclor 1242. This high concentration of
Aroclor 1242 may have affected the results of the
Aroclor specificity test for Aroclor 1254.
Sample 021 was spiked with Aroclor 1232. The
unspiked soil sample result (1232) reported by the FASP
PCB Method was less than 0.4 mg/kg. The amount of
Aroclor 1232 found in the four spiked aliquots ranged
from 2.7 to 3.6 mg/kg. The percent recoveries obtained
for these samples ranged from 27 to 36 percent. From
the Aroclor specificity test results, PRC determined that
a sample containing 10 mg/kg of Aroclor 1232 can be
detected with the FASP PCB Method. However, during
this specificity test, all of the reported results for this
Aroclor were below 4 mg/kg, which is a 40 percent
recovery.
Sample 012 was spiked with Aroclor 1260. The
unspiked soil sample result (1260) reported by the FASP
PCB Method was less than 0.4 mg/kg. The amount of
Aroclor 1260 found in the four spiked aliquots ranged
from 6.4 to 9.3 mglkg. Therefore, the percent
recoveries obtained for these samples ranged from 64 to
93 percent. From the Aroclor specificity test results,
PRC determined that a sample containing 10 mg/kg of
Aroclor 1260 can be detected with the FASP PCB
Method. However, during this specificity test, all of the
reported results for this Aroclor were below 10 mg/kg,
which is less than a 100 percent recovery.
Sample 003 was spiked with Aroclor 1221. The
unspiked soil sample result (1221) reported by the FASP
PCB Method was less than 0.4 mg/kg. The amount of
Aroclor 1221 found in the four spiked aliquots ranged
from 3.6 to 4.1 mg/kg. Therefore, the percent
recoveries obtained for the Aroclor 1221-spiked aliquots
ranged from 37 to 42 percent. From the Aroclor
specificity test results, PRC determined that a sample
containing 10 mg/kg of Aroclor 1221 can be detected
with the FASP PCB Method. However, during this
specificity test, all of the reported results were below
5 mg/kg, which is a 50 percent recovery.
Table 6-2 shows some statistics used to assess the
results of the Aroclor specificity test. The statistics detail
the mean percent recoveries and standard deviations of
the Aroclor spikes in terms of percentages and
concentrations.
Another measure of specificity is the ability of an
operator to correctly identify Aroclors. The FASP PCB
Method uses one column to determine the Aroclor,
which is usually sufficient to provide a positive
identification, because Aroclors are multiple-component
compounds, which exhibit multiple characteristic peak
26
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TABLE 6-2. STATISTICAL ANALYSIS OF THE AROCLOR SPECIFICITY TEST RESULTS.
Sample No.
003ARSPA1-4
012ARSPB1-4
021ARSPC1-4
034ARSPDI-4
040ARSPE1-4
058ARSPF1-4
077ARSPG1-4
Aroclor
Spike
AR1221
AR1260
AR1232
AR1 254
AR1 242
AR1 248
AR1016
Mean Percent
Recovery
(%l
39.3
79.5
33.3
55.5
87.8
46.3
43.0
Mean
Recovery
(mg/kg)
3.8
2.1
3.3
5.5
8.7
4.43
4.3
Standard
Deviation
Recovery
(%)
2.1
13.4
4.3
8.4
44.3
5.44
6.22
Standard
Deviation
Recovery
(mg/kg)
0.23
1Jk
0.42
0.74
4,43
0,64
0.62
patterns when analyzed by the GC and BCD. The
characteristic peak patterns give the operator more
identification information than single-component
compounds. Therefore, it is possible for an experienced
operator to correctly identify and quantify PCBs in most
soil samples without needing second column con-
firmation.
PRC evaluated the chromatograms of samples from
the demonstration to determine the particular Aroclor
present in each sample. The chromatograms were
complex and presented some identification problems.
The presence of interferants in the samples presented
some problems in identifying Aroclors during this
demonstration, but these problems were overcome. In
some samples, other problems also affected the
identification of Aroclors.
One problem was that some samples contained more
than one Aroclor. The operator of the FASP PCB
Method was initially unaware of this. The presence of
two Aroclors in the samples was observed only after a
review of the data by the PRC lead chemist. Six
samples analyzed by using the FASP PCB Method were
found to contain Aroclor 1242 and Aroclor 1260. These
samples were 040, 047, 047D. 053, 068, and
078. Because the operator of the FASP PCB Method
overlooked the presence of Aroclor 1260 in these
samples, their chromatograms were misinterpreted,
resulting in incorrect results. The interpretation of PCB
chromatograms is a very complex and interpretive
procedure, and the chromatograms for these samples
were particularly difficult to interpret. It is believed
that, if the operator of the FASP PCB Method had been
more experienced in interpreting PCB chromatograms,
the Aroclor 1260 in the samples would have been
identified.
Another Aroclor pattern recognition problem
observed during the demonstration was disagreement
between the FASP PCB Method and confirmatory
laboratory Aroclor identifications for numerous samples
did not agree. The demonstration resulted in the analysis
of 146 total samples, consisting of 112 samples, 32 field
duplicate samples, and 2 PE samples. Of these samples,
101 were determined to contain PCBs by both the FASP
PCB Method and the confirmatory laboratory.
The FASP PCB Method identified three different
Aroclors in the demonstration. Two samples were found
to contain Aroclor 1232, 13 samples were found to
contain Aroclor 1248, and 86 samples were found to
contain Aroclor 1242. Most of the samples analyzed by
the confirmatory laboratory were identified as containing
either Aroclor 1242 or Aroclor 1248. Seventy-three
samples were identified as containing only Aroclor
1242, and 33 samples were identified as containing only
Aroclor 1248. The confirmatory laboratory identified
sixteen samples as containing a mix of two Aroclors.
The predominant mix consisted of Aroclor 1242 and
Aroclor 1248. The were found to contain this mix.
Four samples were identified as containing a mix of
Aroclor 1242 and Aroclor 1260. Three samples were
found to contain a mix of Aroclor 1248 and Aroclor
1260. Two samples were found to contain a mix of
Aroclor 1242 and Aroclor 1254.
Of the 122 samples found to contain PCBs by the
confirmatory laboratory, only 101 were found to contain
PCBs by the FASP PCB Method. Of the 101 samples
determined by both the FASP PCB Method and the
27
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confirmatory laboratory to contain PCBs, the two
methods identified different Aroclors in 29 samples.
Intramethod Assessment
Reagent blank samples were prepared by taking
reagents through all extraction, cleanup, and reaction
steps of the analysis. Reagent blanks were prepared with
each batch of 20 samples. Ten reagent blanks were
prepared and analyzed during the demonstration. No
PCBs were detected in any of the blanks, at levels above
the detection limit of 0.4 mg/kg. The reagent blanks had
no large broad peaks present in their chromatograms.
These results indicate that no laboratory-induced
contamination was present.
For this demonstration, completeness refers to the
proportion of valid, acceptable data generated by using
the FASP PCB Method. Seventeen of the results from
the samples were reported as below the EPA Superfund
FASP PCB method's detection limit. The results from
these samples were coded with a'T to indicate that the
reported concentrations were below the detection limit.
These points were used in the statistical evaluation of the
method This was consistent with the use of coded data
for the other technologies. Completeness for the
samples analyzed by the FASP PCB Method during the
demonstration was 100 percent.
Surrogate standards are used to determine the
extraction efficiency of the FASP PCB Method.
Surrogates are added to all standards, blanks, samples,
and matrix spikes performed. The surrogate standard
used for the FASP PCB Method is decachloro-biphenyl.
Decachloro-biphenyl is a PCB; however, it is not a
major PCB peak in any of the seven Aroclors analyzed
by using standard EPA-approved methods. Surrogate
standards evaluated were taken from the original sample
extracts. When samples with high PCB concentrations
were analyzed, dilutions were often needed. No
surrogate recovery was calculated for samples that
required dilution. Because of the dilution, the original
sample extract could not be analyzed. In all, 187 sur-
rogate recovery values were obtained. The average
surrogate recovery was 109 percent. The standard
deviation of the surrogate recovery was 4 percent.
Under guidelines outlined in the EPA SW-846 Manual
Method 8000, control limits for surrogate standards are
defined as f 3 standard deviations from the mean. For
the surrogate standards analyzed during this
demonstration, the calculated control limits are from
97 to 121 percent recovery. Two of the 187 surrogate
standard recoveries were outside of these control limits.
The surrogate standard control limits determined during
the demonstration were very narrow. This indicates that
the extraction and analysis efficiencies of the method
were very good, as determined from the surrogate
recoveries. However, these control limits appear too
narrow for use during most projects. The FASP PCB
Method lists control limits of 50 to 150 percent. These
limits may be more reasonable for use on most projects
than the limits determined from this demonstration.
None of the surrogate standard recoveries during this
demonstration exceeded these more typical control
limits.
Intramethod accuracy for the FASP PCB Method
was assessed through the use of PE samples and matrix
spike and matrix spike duplicate samples. Intel-method
accuracy was also determined by comparing the results
of the method with those of the confiiatory laboratory.
During the demonstration, two PE samples were
analyzed by the FASP PCB Method. These samples
were extracted and analyzed in exactly the same manner
as were all other soil samples. The operator knew that
the samples were PE samples but did not know their true
values or their ranges. The true result for sample
047-4024-114 (the high-level sample) was 110 mg/kg,
with an acceptance range of 41 to 150 mg/kg. The
quantitative result for the PE sample, determined by the
FASP PCB Method, was 112 mg/kg. This is only
2 mg/kg above the true value and is well within the
acceptance range of the PE sample. The percent
recovery of this analysis was 102 percent. The true
result for sample 047-4024-113 (the low-level sample)
was 32.7 mg/kg. It had an acceptance range of 12 to
43 mg/kg. The result for the PE sample, when analyzed
by the FASP PCB Method, was 20.3 mg/kg. This value
is well within the acceptance range. The percent
recovery of this analysis was 62 percent.
Matrix spike samples, prepared by adding a known
quantity of PCB Aroclor 1242 to an actual sample, were
used to evaluate the extraction and analysis efficiency of
the technology. They were also used to determine
accuracy. Matrix spike samples were prepared by
adding a known quantity of PCBs to a sample. The PCB
used for the matrix spike samples was Aroclor
1242. Enough of a concentrated Aroclor 1242 standard
was added to a 10-gram soil sample to produce a matrix
spike concentration of 2 mg/kg. The spiked sample was
also duplicated to produce a matrix spike duplicate
sample. Six matrix spike samples and six matrix spike
duplicate samples were extracted and analyzed by using
the FASP PCB Method. The recoveries for these
samples ranged from 0 to 214 percent. Two of the six
soil samples used as matrix spikes contained PCBs at
concentrations of 6.1 and 10.4 mg/kg. Though these are
low concentrations of PCBs, they are significant when
compared to the 2 mg/kg concentration used to spike the
samples. Therefore, these original PCB concentrations
28
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may have affected the matrix spike recoveries observed.
In the case of Sample 102, which contained 10.4 mg/kg
of PCBs before being spiked, one of the two percent
recovery values obtained was 0 percent. Using this
result in the statistical evaluation of these data would
have significantly widened the range of acceptable
recoveries. For this reason, this value was not used in
the statistical evaluation. The other 11 results were used
for the statistical evaluation. The average recovery for
these sample results was 122 percent, or 2.44 mg/kg.
The standard deviation was 48 percent, or 0.96 mg/kg.
Based on these data, control limits for matrix spike
recovery samples were established. Under guidelines
outlined in the EPA SW-846 Manual Method 8000, con-
trol limits can be established as ± 2 standard deviations
from the mean percent recovery. For the matrix spike
samples analyzed during this demonstration, the
calculated control limits are from 26 to 218 percent
recovery. All matrix spike samples analyzed-except
Sample 102-fell within these control limits.
PRC assessed precision for this method by
comparing the two results obtained. For this
demonstration, three types of precision data were
generated: data from laboratory duplicate samples, data
from field duplicate samples, and data from matrix spike
duplicate samples. Table 6-3 provides matrix spike
duplicate results. Table 6-4 presents laboratory and
field duplicate sample results.
Laboratory duplicate samples are two analyses
performed on a single sample delivered to a laboratory.
Originally, laboratory duplicate samples were to be
analyzed with each set of 20 samples submitted for
analysis. However, additional laboratory duplicates
were analyzed for the purpose of evaluating whether the
homogenization of the samples was complete. In all,
14 pairs of laboratory duplicate samples and their
respective soil samples were analyzed by using the FASP
PCB Method. The initial analyses of the duplicate
samples ranged from 0.14 to 1,790 mg/kg. When the
analysis was duplicated, the results ranged from 0.07 to
2,030 mg/kg. Field duplicate samples were also
analyzed during this demonstration. Field duplicates are
two samples collected together but brought to the
laboratory with separate sample numbers. PRC
collected 32 field duplicate samples during this
demonstration. Each sample and its duplicate was
analyzed by each technology and by the confirmatory
laboratory.
Typically, field and laboratory duplicate samples are
used to determine problems with collection and analysis,
not problems with the technology. The laboratory
duplicates would be compared to a window of acceptable
values; if one fell outside that window, the laboratory
would take corrective action. Field duplicates would be
used to (1) ensure that samples were not being
contaminated during sample collection, and (2) set
boundaries of variance resulting from heterogeneity
inherent in soil.
However, PRC was tasked not with determining the
precision of those collecting the samples or of the
laboratory, but with determining the precision of the
technology. To do this, PRC attempted to control any
factor, other than those inherent in the technology, that
might contribute to a difference between a sample and its
duplicate. To control the problems usually detected by
laboratory duplicates, PRC used only one operator for
the technology. PRC assumed that any variance in that
operator's laboratory techniques would be the same for
each sample and, therefore, statistically insignificant, as
discussed in Section 4. For the field duplicates, PRC put
each sample through a homogenization process designed
to ensure that there was little difference between the
contamination in a sample and its duplicate.
Confirmatory laboratory data on the field duplicates and
their respective soil samples indicate that, overall, this
technique worked as discussed in Section 4. The
homogenization appears to have been incomplete in only
a very few samples.
The 46 duplicate pairs were used together to
evaluate intramethod precision. Even the best
technology that determines results quantitatively cannot
reproduce its results every time. PRC established
control limits to determine whether the difference
between a result from a duplicate and the result from its
respective sample was reasonable. To establish the
control limits, PRC removed all sample pairs that did not
produce two positive results from the data population.
The RPD for each sample pair was then calculated, and
the mean RPD and population standard deviation were
determined. The lower control limit was set at zero,
indicating the results from a duplicate and its sample
matched perfectly. The upper control limit was set by
multiplying the standard deviation by two and adding the
product to the mean RPD. The RPD of each sample
pair was then compared to these control limits. Each
was expected to fall within them. If greater than 95 per-
cent fell within this range, the technology's precision
was considered adequate. If fewer than 95 percent of
them fell within this range, the data were reviewed; if no
explanation was found, the technology's precision was
considered inadequate.
The FASP PCB Method detected PCBs in both the
sample and its duplicate in 34 of the 46 sample pairs.
The data from these 34 pairs had a mean RPD of 34 per-
cent and a standard deviation of 29. Therefore, the
RPDs for the duplicate pairs fell within the control
29
-------
TABLE 6-3. MATRIX SPIKE AND MATRIX SPIKE DUPLICATE RESULTS.
Sample No.
047-4024-003
047-4024-026
047-4024-042
047-4024-062
047-4024-086
047-4024-102
Soil Sample
Result
(mg/kg)
ND
0.43
0.73
6.1
0.43
10.4
Matrix Spike
Amount
(mg/kg)
2
2
2
2
2
2
Matrix Spike
Recovery
(%)
73
168
89
175
114
0
Matrix Spike
Duplicate
Recovery
(%)
86
156
93
214
121
51
Relative
Percent
Difference
(%)
16
7
4
20
6
200
Note:
ND Not detected above the 0.4 mg/kg detection limit.
limits. Therefore, the technology's precision was
considered acceptable.
Matrix spike duplicate samples were used to further
evaluate the precision of this method. The matrix spike
duplicate results were compared to the matrix spike
results for this precision evaluation. Precision of the
matrix spike duplicate samples was evaluated through the
RPD of the matrix spike result compared to the matrix
spike duplicate result. RPD values for the six sets of
matrix spike samples ranged from 4 to 200 percent. The
RPD results for Sample 102 were removed from the
precision evaluation. As discussed previously, the RPD
from this matrix spike sample and its duplicate may have
been affected by the original amount of PCB in the
sample. Including it hi the statistical analysis would
have skewed the acceptable range for the RPDs. The
RPDs for the remaining five matrix spike samples and
then- duplicates ranged from 4 to 20 percent. The mean
RPD for these samples was 11 percent, and the standard
deviation was 7 percent. Using an upper control limit of
two times the standard deviation resulted in an upper
control limit of 25 percent. All RPD values for the
matrix spike duplicate samples—except that of Sample
102—fell within this range.
Comparison of Results to Confirmatory
Results
The following subsections compare the accuracy and
precision of the data from analyses conducted by using
both the FASP PCB Method and the confirmatory
laboratory. The results from the confirmatory
laboratory are considered accurate, and its precision is
considered acceptable. Table 6-5 and Figure 6-1 sum-
marize the results.
Accuracy
To measure the accuracy of the FASP PCB Method,
PRC compared the data from this method with the data
from the confirmatory laboratory by using linear
regression techniques and the Wilcoxon Signed Ranks
Test (detailed in Section 4). Linear regression produces
a coefficient of determination, also called an r2, which
defines whether a relationship exists between two sets of
data. The best relationship possible would be expressed
as an r2 of 1.0. For this demonstration, 1 values of
0.80 to 1.0 were considered acceptable.
If a relationship exists, linear regression also defines
an equation that shows the relationship between the two
sets of results. That equation can be expressed as a line
on a graph. This line represents where the results of one
set of data would be expected if the other set of data was
given. Because the results from the technology and the
results from the confirmatory laboratory were expected
to match, that line should have a slope of 1 and a
y-intercept of zero.
PRC used a normal deviate test statistic to determine
whether either the slope or the y-intercept varied, at a
two-tailed 95 percent confidence level, from those
expected. If the slope or y-intercept of the regression
line varied greatly, the two sets of data were considered
comparable but not the same. That is, the technology's
data were not accurate, but there was a relationship
between the technology's data and the confirmatory
laboratory's data. This relationship would enable PRC
30
-------
TABLE 6-4. LABORATORY AND FIELD DUPLICATE SAMPLE RESULTS.
Sample No,
047-4024-004 LD
047-4024-012 LD
047-4024-01 3 LD
047-4024-014 LD
047-4024-01 5 FD
047-4024-01 5 LD
047-4024-016 LD
047-4024-017 LD
047-4024-01 8 LD
047-4024-019 LD
047-4024-022 FD
047-4024-024 FD
047-4024-028 FD
047-4024-033 LD
047-4024-035 FD
047-4024-037 FD
047-4024-042 FD
047-4024-043 FD
047-4024-048 FD
047-4024-047 FD
047-4024-048 LD
047-4024-050 FD
047-40244)80 FD
Soil
Sample
Result
(mg/kg)
2,8
ND
0.18J
0.33J
19,0
19.0
737
2,3
163
8.9
ND
ND
0.17J
5.1
ND
ND
0.73
25,3
ND
ND
ND
1,3
1,5
Duplicate
Sample
Result
(mg/kg)
7,2
ND
0.38J
0.24J
8,9
14,2
818
2,0
188
12,9
ND
ND
0.1 5J
7.1
ND
ND
0,78
28.7
ND
ND
ND
2,5
1.6
i- i i
r >* i,
1
Mple No.
T " " ~
c 1 * 4024-083 FD
NA
71
32
72
29
10
14
14
37
NA
NA
13
33
NA
NA
7
13
NA
NA
NA
63
6
047-4024-083 LD
047-4024-089 FD
047-4024-071 FD
047-4024-081 FD
047-4024-082 FD
047-4024-083 FD
047-4024-084 FD
047-4024-085 FD
047-4024-085 LD
047-4024-088 FD
047-4024-087 FD
047-4024-088 FD
047-4024-090 FD
047-4024-091 FD
047-4024-092 FD
047-4024-095 FD
047-4024-097 FD
047-4024-098 FD
047-4024-1 00 FD
047-4024-101 LD
047-4024-1 02 FD
047-4024-109 FD
Soil
Sample
Result
{mg/kg)
0,27J
0.27J
ND
ND
0,75
ND
0.24J
8.1
501
501
0.43
0.20J
1.6
0,81
1790
0,50
35.9
0.14J
2,4
889
2.3
10,3
ND
Duplicate
Saropte
Result
(mg/kg)
0.11J
0.29J
ND
ND
0,40
ND
0.22J
3,2
488
449
1,0
0.1 9J
1.6
0,84
2030
0.19
47.5
0.07J
1.9
1 ,000
1,9
12.6
ND
Relative
Percent
Difference
84
7
NA
. NA
61
NA
9
87
7
11
80
5
0'
4
13
90
28
87
23
40
19
20
NA
Notes:
FD Field duplicate
J Reported amount is below detection limit.
LD Laboratory duplicate
NA Not analyzed
ND Not detected above the 0.4 mg/kg detection limit
to correct the technology's results mathematically if a
specified number of samples were sent to a confirmatory
laboratory.
All three of these linear regression factors-the
slope, the y-intercept, and the r2 factor-had to be
considered acceptable before a technology would be
considered accurate.
The linear regression for the FASP PCB Method
was based on results from 81 samples. The other results
indicated that noPCBs were detected at levels above the
31
-------
TABLE 6-5. COMPARISON OF DATA OBTAINED BY FASP PCB METHOD AND
CONFIRMATORY LABORATORY.
Sample
No.
001
002
003
004
005
006
007
008
009
010
011
012
013
014
015
01 5D
016
017
018
019
020
021
022
0220
023
024
024D
025
026
027
028
028D
029
030
031
032
FASP PCB
Method
0.40 mglkga
5.98
1.27
ND
2.77
1.80
0.37J
0.1 2J
3.27
2.37
1.13
1.05
ND
0.1 8J
ND
19.0
8.89
737
2.32
163
8.90
ND
ND
ND
ND
18.2
ND
ND
12.8
0.43
ND
0.1 7J
0.1 5J
ND
1 .0!
0.1 4J
18.9
Confirmatory
Laboratory
0.033 mg/kga
0.593
1.50
0.114
6.71 J
1.37
0.679
0.552
2.00
1.30J
0.1 7J
1.1 5J
ND
1.13
0.18
9.13
9.84
2,110
2.55
45.4
6.70
0.07J
0.063
0.535
0.718
20.8
0.055
0.049
11.7
1.96
0.057
0.216
0.224J
0.229J
1.15
0.263
47.6
Difference
5.39
-0.23
NA
-3.94
0.43
-0.31
-0.43
1.27
1.07
0.96
-0.10
NA
-0.95
NA
9.87
-0.95
-1373
-0.23
118
2.20
NA
NA
NA
NA
-2.6
NA
NA
1.1
-1.53
NA
-0.05
-0.07
NA
-0.014
-0.12
-28.7
Relative
Percent
Difference
164
16.6
NA
83.1
27.1
58.9
130
48.2
58.3
147
9.1
NA
145
NA
70.2
10.1
96.5
9.4
113
28.2
NA
NA
NA
NA
13.3
NA
NA
9.0
128
NA
23.8
39.6
NA
13.0
61 .0
86.3
Sample
No,
033
034
035
ID35D
036
037
037D
038
039
040
041
042
042D
043
043D
044
045
046
046D
047
047D
048
049
050
0500
051
052
053
054
055
056
057
058
059
060
060D
FASP PCB
Method
0.40 mg/kga
5.10
22.9
ND
ND
5890
ND
ND
1210
0.53
4.63
ND
0.73
0.78
25.3
28.7
0.1 6J
ND
ND
ND
ND
ND
ND
ND
1.29
2.52
ND
1.99
1.20
1.04
2.32
0.52
ND
0.58
9.59
1.47
1.55
Confirmatory
Laboratory
0.033 mglkga
6.00J
34.0
ND
ND
816
0.055J
0.040J
1030J
0.676
4.25
ND
0.517
0.462J
1.69J
1.74
0.592J
ND
ND
ND
0.094J
0.098J
ND
ND
3.60
4.41
ND
4.21
0.958
0.51 6J
2.40
0.505
ND
0.681
7.86
0.624J
0.577
Difference
-0.90
-11.1
NA
NA
5074
NA
NA
180
-0.15
.38
NA
0.21
0.32
23.6
27.0
0.43
NA
NA
NA
NA
NA
NA
NA
-2.31
-1.89
NA
-2.22
0.24
0.52
-0.08
0.02
NA
-0.10
1.73
0.85
0.97
Relative
Percent
Difference
16.2
39.0
NA
NA
151
NA
NA
16.1
24.2
8.7
NA
34.2
51.2
175
177
115
NA
NA
NA
NA
NA
NA
NA
94.5
54.5
NA
71.6
22.4
67.4
3.2
2.9
NA
16.0
19.8
80.8
91.5
32
-------
TABLE 6-5 (Continued). COMPARISON OF DATA OBTAINED BY FASP PCB METHOD AND
CONFIRMATORY LABORATORY.
Sample
No,
061
082
083
083D
064
085
088
06?
068
089
069D
070
071
07 1D
072
073
074
075
076
077
078
079
080
081
081 D
082
082D
083
083D
084
084D
085
FASP PCB
Method
0.40 mg/kga
745
6,12
0.27J
0.11J
94,4
3,39
2,59
NO
0.26J
NO
ND
ND
ND
ND
ND
42,9
9,50
15.8
38,3
ND
2.25
81.1
2.00
0.75
0.40
ND
ND
0.24J
0.22J
8,09
3,15
501
Confirmatory
Laboratory
0.033 mg/kga
580'
2.35
0.092J
0.154J
19.0
3,08
1 .98
0.081
0.504J
ND
ND
ND
0.052J
ND
0.035J
15.8
13.3
23,0
48.7
ND
2.27
42.8
3.77
0.687
0.450
ND
0.244
0,484
0.413
1.16
1 .08
428
Difference
185
3,77
0.18
-0.04
75.4
0.31
0.61
NA
-0.24
NA
NA
NA
NA
NA
NA
27,1
-3,8
-7.2
-8.4
NA
-0.02
38.3
-1.77
0.06
-0.05
NA
NA
43.24
-0.19
6.93
2,07
73
Relative
Percent
Difference
24.9
89.2
98.3
33.3
133
9.6
28,7
NA
83,9
NA
NA
NA
NA
NA
NA
92,3
33,3
37.1
19,8
NA
0.7
61.8
61.4
Sample
No,
085D
086
086D
087
087D
088
088D
089
090
090D
091
091 D
092
092D
093
094
095
095D
098
097
097D
098
098D
8.8 1 099
11.8 1 100
NA
NA
67,4
61 ,0
150
97.9
15.7
100D
101
102
102D
103
104
105
FASP PCB
Method
0.40 mg/kg9
488
0.43
1 .04
0.20J
0.1 9J
1.59
1.58
48,8
0,81
0.84
1790
2030
0,50
0.1 9J
ND
0.42
35,9
47,5
ND
0.1 4J
0.07J
2.41
1.85
ND
669
1000
2,33
10,3
12,6
207
12.4
ND
Confirmatory
Laboratory
0.033 trig/kg3
465
1,42
1 .25
0,078
ND
2,70
1 .77
45.0
1.01
1.40
1630
1704
1.21
ND
0,295
0.362J
17.5
31.2
0.059J
1 .23
0.285
1.17
0.825
ND
177
187
1.21
293
1.77
40,3
7.66
0.210
Difference
3
-0,99
-0.21
0,12 '
NA
-1.11
-0.19
1.6
-0.20
-0.56
160
326
43,71
NA
NA
0.06
18,4
16.3
NA
-1.09
0.22
1.24
1.03
NA
492
833
1,12
-283
10,8
167
4,7
NA
Relative
Percent
Difference
0,8
107
18.3
NA
NA
51 .7
11,3
3.5
22.0
50.0
9.2
17,5
83,0
NA
NA
14,8
88,9
414
NA
159
121
69.3
76.6
NA
116
143
83,3
188
151
135
47,3
NA
33
-------
TABLE 6-5 (Continued). COMPARISON OF DATA OBTAINED BY FASP PCB METHOD AND
CONFIRMATORY LABORATORY.
Sample
No.
106
107
1 08
1 09
109D
FASP PCB
Method
0.40 mg/kg*
0,71
89,3
1.41
ND
NO
Confirmatory
Laboratory
0.033 mg/kg*
2.50
14, 1J
3.84J
ND
NO
Difference
-1.79
55,2
-2.43
NA
NA
I
Relative
Percent
Difference;
112
Sample
No.
110
}.
132 1111
92,6
NA
NA
112
113
1 1 4
FASP PCB
Method
0,40 mg/kg*
ND
ND
1 77
20,3
112
Confirmatory i >
Labor a' / i i
0,033 n } »
NO NA "i
ND NA NA
315 -138 58,1
14.9 5,4 30.7
86.3 45,7 51,3
Notes:
J
NA
ND
Detection limit.
Reported amount is below detection limit or not valid by approved QC procedures.
Not analyzed.
PCBs not detected above the detection limit.
FIGURE 6-1. CONFIRMATORY DATA VS. FASP
PCB DATA
detection limit. The r2 value for the regression was
0.31, indicating that there was no relationship between
the FASP PCB Method's results and those from the
confirmatory laboratory. However, an analysis of
regression residuals identified that the r2 was greatly
influenced by Samples 16, 36, 38, 91, and 100. All of
these samples show high levels of contamination. PRC
removed these five sample results as outliers and
recalculated the linear regression. The second analysis,
calculated on the remaining 76 sample results, defined an
r2 factor of 0.86, indicating a relationship between the
two sets of data. It defined a regression line with a
y-intercept of 3.57 mg/kg and a slope of 1.09. The
normal deviate test statistic indicated that these results
are not statistically different from those expected. This
means that linear regression of me FASP PCB Method's
results, after the outliers had been removed, produced an
acceptable r2, slope, and y-intercept. Therefore, it is
accurate. No correction of the method's data would be
needed. The FASP PCB Method's results can be
expected to be similar to those of a confirmatory
laboratory.
The Wilcoxon Signed Ranks Test was used to verify
these results, It indicated, at a 95 percent confidence
level, that the data from the FASP PCB Method were
not significantly different than data from the
confirmatory laboratory. This also indicates that the
EPA Superfund FASP Method's data are accurate.
Precision
To compare the precision of the FASP PCB
Method's results to the precision of the confirmatory
laboratory's results, PRC performed a Dunnett's Test on
the RPDs determined from the field duplicates and their
respective soil samples. The Dunnett's Test determines
the probability that the data sets on which it is based are
the same. If the RPDs from the confirmatory laboratory
and those from the technology are the same, it can be
assumed that the precisions are also similar. The
Dunnett's Test results in a percentage. For this
demonstration, probabilities above 95 percent indicate
that the precision of the technology and that of the
confirmatory laboratory were considered the same.
Lower probabilities indicate that one cannot be sure that
the precisions are the same. However, this does not
mean that the technology's precision is worse than that
34
-------
of the confirmatory laboratory, only that there was a confirmatory laboratory's data, a probability of 91.0
greater probability that they were different. percent resulted. This indicates that the FASP PCB
Method's precision and the confirmatory laboratory's
When the Dunnett's Test compared the RPDs be- precision may not be the same.
tween the FASP PCB Method's data and the
35
-------
Section 7
Applications Assessment
The FASP PCB Method produces accurate and
precise quantitative results. It is capable of identifying
each specific Aroclor and is not affected by interferants
under most circumstances. The method produces very
few false positive or negative results. It is relatively
portable and can be set up at most hazardous waste sites.
However, the necessary equipment must be operated
indoors, and electricity and refrigeration are required.
One to 2 days may be required for equipment set-up and
calibration before analysis of samples can begin.
The FASP PCB Method requires the one-time
purchase of analytical equipment. After this equipment
has been purchased, the method is less expensive than
formal laboratory analysis, and is capable of providing
higher sample throughput and quicker turnaround time
than formal laboratories. The method can produce high-
quality data within 1 to a few hours of sample collection.
The method is similar to standard EPA analytical
methods used by formal laboratories. For this reason,
experienced, highly trained personnel are required to
operate it. The linear range of the method is not as great
as that of other PCB field-screening technologies, and
dilutions must be used to produce quantitative results for
samples with high concentrations of PCBs.
The results of the Aroclor specificity test indicated
that the FASP PCB Method is capable of accurately and
precisely quantifying different Aroclors.
The FASP PCB Method would be useful at any
PCB-contaminated site at which quantitative results were
needed quickly. The method would be particularly
useful in characterizing large potentially contaminated
areas in which false positives could significantly affect
the costs of a project. The method is also particularly
useful at sites at which the presence of interferants is
known or suspected or at which the Aroclors of concern
are not positively known.
36
-------
Section 8
References
Draper, N. R., and H. Smith. 1981. Applied Regression Analyses. John Wiley & Sons, Inc. New York. 2nd ed.
Environmental Protection Agency (EPA). 1983. "Interim Guidelines and Specifications for Preparing Quality
Assurance Project Plans."" EPA/600/4-83/004.
— 1989. "Preparing Perfect Project Plans" U.S. Environmental Protection Agency. Cincinnati, OH.
EPA/600/9-89/087.
—. 1990. Contract Laboratory Program. Statement of Work.
Pearson, E.S., and H.O. Hartley. 1976. Biometrika Tables for Statisticians. Charles Griffin and Company, Ltd.
Third edition with corrections.
PRC Environmental Management, Inc. (PRC). 1992a. "SITE Demonstration: EnSys, Inc., Immtmosystems, and
Dexsil Corporation, PCB Field Kits, Pre-Demonstration Sampling Plan.""May.
— 1992b. "Final Demonstration Plan and Quality Assurance Plan for Demonstration of PCB Immunoassay and
Field Screening Technologies."" July 24.
Systat, Inc. 1990. SYSTAT/SYGRAPH Software for DOS. Evanston, Illinois.
U.S. Department of Energy. 1989. "RCRA Facility Investigation and Corrective Measures Study for the Abandoned
Indian Creek Outfall. " Albuquerque Operations Office, Environment and Health Division, Environmental
Programs Branch, Kansas City Plant.
37
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