United States
Environmental Protection
Agency
Office of Research and
Development
Washington DC 20460
EPA/540/R-95/517
August 1995
EnviroGard PCB Test Kit,
Millipore,
Innovative
Evaluation
Inc.
Technology
Report
-------
CONTACT
Jeanette Van Emon and Steve Rock are the EPA contacts for this report. Jeanette Van Emon is presently
with the new Characterization Research Division (formerly the Environmental Monitoring Systems
Laboratory) in Las Vegas, NV, which is under the direction of the National Exposure Research Laboratory
with headquarters in Research Triangle Park, NC.
Steve Rock is presently with the new Land Remediation and Pollution Control Division (formerly the Risk
Reduction Engineering Laboratory) in the newly organized National Risk Management Research Laboratory
in Cincinnati, OH.
-------
EPA/540/R-95/517
August 1995
ENVIROGARD PCB TEST KIT, MILLIPORE, INC.
INNOVATIVE TECHNOLOGY EVALUATION REPORT
NATIONAL RISK MANAGEMENT RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAlL PROTECTION AGENCY
CINCINNATI, OHIO 45268
NATIONAL EXPOSURE RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
LAS VEGAS, NEVADA 39193
Printed on Recycled Paper
-------
Notice
The information in this document has been funded wholly or in part by the U.S. Envkonmental Protection
Agency (EPA) in partial fulfillment of Contract No. 68-CO-0047, Work Assignment No. 0-40, to PRC
Envkonmental 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.
11
-------
I.
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 mandat
;, 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 pollitants affect our health, and prevent or reduce environmental
risks in the future.
The National Risk Management Researdh 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 oh 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.
i. Timothy Oppelt, Director
Tational Risk Management Research Laboratory
m
-------
Abstract
This report describes the demonstration and evaluation of an immunoassay field screening technology designed to
determine polychlorinated biphenyl (PCB) contamination hi soil. The immunoassay technology was the EnviroGard
PCB Test developed by Millipore, Inc. The technology was demonstrated in Kansas City, Missouri, in August 1992,
by PRC Environmental Management, Inc. (PRC), under contract to the Environmental Protection Agency's (EPA)
Environmental Monitoring Systems Laboratory-Las Vegas (EMSL-LV).
The principal objective of the demonstration was to evaluate the technology for accuracy and precision at detecting
high and low levels of PCB in soil samples by comparing their results to those attained by a confirmatory laboratory
using standard EPA analytical methods. The technology also was qualitatively evaluated for the length of time
required for analysis, ease of use, portability, and operating cost. Accuracy was also assessed through analysis of
performance evaluation (PE) samples, and precision was further assessed by comparing the results obtained on
duplicate samples. A secondary objective of the demonstration was to evaluate the specificity of the technology. The
evaluation of specificity was performed by examining any problems due to naturally occurring matrix effects,
site-specific matrix effects, Aroclor sensitivity, and chemical cross reactivity. Information on specificity was gathered
from the developer, from the analysis of demonstration samples, and from a specificity study performed during the
demonstration.
This report was submitted in fulfillment of contract No. 68-CO-0047 by PRC, under sponsorship of the EPA. This
report covers a period from February 10, 1992, to August 31, 1992, and work was completed as of February 28,
1993.
IV
-------
Table of Contents
Section
Notice
Foreword
Abstract
List of Figures
ListofTables
List of Exhibits
List of Abbreviations and Acronyms
Acknowledgments
1 Executive Summary
2 Introduction J. ......
EPA's SITE Program and MMTP: An Overview
The Role of Monitoring and Measurement Technologies
Defining the Process ,
Components of a Demonstration
Demonstration, Purpose, Goals, and Objectives ..'...
3 Predemonstration Activities
Identification of Developers
Site Selection
Selection of Confirmatory Laboratory and Method
Operator Training
Sampling and Analysis
Demonstration Design and Description ..
Sample Collection
Quality Assurance Project Plan
Experimental Design
Statistical Analysis of Results
Field Analysis Operations
Confirmatory Analysis Results
Confirmatory Laboratory Procedures
Soil Sample Holding Times
Soil Sample Extraction
Initial and Continuing Calibrations
Sample Analysis
Detection Limits
Quality Control Procedures
. iii
. iv
. vii
. vii
.,vii
viii
. ix
1 -f
. 1
. 3
. 3
. 3
. 3
. 4
. 4
. 6
. 6
. 6
. 7
. 7
. 7
. 8
. 8
. 9
10
10
13
14
14
14
14
15
15
15
16
-------
Table of Contents (Continued)
Section
Confirmation of Analytical Results 16
Second Column Confirmation 16
Gas Chromatographic and Mass Spectrometer Confirmation 16
Data Reporting 17
Arociors Reported by the Confirmatory Laboratory 17
Data Quality Assessment of Confirmatory Laboratory Data 17
Accuracy 17
Precision ' 17
Completeness 18
Use of Qualified Data for Statistical Analysis 18
6 Millipore EnviroGard PCB Test 19
Theory of Operation and Background Information 19
Operational Characteristics 19
Performance Factors 22
Detection Limits and Sensitivity 22
Sample Matrix Effects : 23
Sample Throughput 23
Drift 23
Specificity 24
Intramethod Assessment 26
Comparison of Results to Confirmatory Laboratory Results 28
Accuracy 28
Precision 32
Quantitative Evaluation 32
Theory of Operation and Background Information 32
Operational Characteristics 32
Performance Factors 32
Specificity 35
Intramethod Assessment 37
Comparison of Results to Confirmatory Laboratory Results 39
7 Applications Assessment 41
8 References 42
VI
-------
i
List of Figures
Figure
6-1 Assessment of Semiquantitative EnviroGard PCB Test Data
6-2 Assessment of Quantitative EnviroGard PCB Test Data
Page
31
35
List
i
j
Table
f Tables
6-1 Semiquantitative Results for the Aroclor Specifbity Test .".'.' ........
6-2 Semiquantitative Results for Laboratory and Field Duplicate Samples
6-3 Comparison of Semiquantitative Data for EnviroGard PCB Test and Confirmatory Laboratory
6-4 Comparison of Quantitative Data for EnviroGar^l PCB Test and Confirmatory Laboratory
6-5 Quantitative Results for the Aroclor Specificity Test !
6-6 Quantitative Matrix Spike and Matrix Spike Duplicate Results ......
6-7 Quantitative Laboratory and Field Duplicate Sample Results .......
25
27
29
33
36
39
40
List of Exhibits
Exhibit
6-1 Assay Flow Chart,
20
| VII
-------
List of Abbreviations and Acronyms
A1CO Abandoned Indian Creek Outfall
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
EMSL-LV Environmental Monitoring Systems Laboratory-Las Vegas
EPA Environmental Protection Agency
ERA Environmental Research Associates
GC gas chromatograph
ICAL initial calibration
IDW investigation-derived waste
ITER Innovative Technology Evaluation Report
KCP Kansas City Plant
pL microliter
pg/kg micrograms per kilogram
mg/kg milligrams per kilogram
Millipore Millipore, Inc.
mL milliliters
MMTP Monitoring and Measurement Technologies Program
MS mass spectrometer
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 correlation coefficient
RCRA Resource Conservation and Recovery Act
RFI RCRA facility investigation
RPD relative percent difference
SARA Superfund Amendments and Reauthorization Act of 1986
SITE Superfund Innovative Technology Evaluation
SOP standard operating procedures
SOW statement of work
TCL Target Compound List
TPM technical project manager
UV ultraviolet
viii
-------
Acknowledgments
This demonstration and the subsequent preparation of this report required the services of numerous personnel from the
Environmental Protection Agency, Environmental Monitqring Systems Laboratory (Las Vegas, Nevada); Environmental
Protection Agency, Region 7 (Kansas City, Kansas); Mijlipore, Inc. (Bedford, Massachusetts); the U.S. Department of
Energy Kansas City Plant (Kansas City, Missouri); Alliedj-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 Environmental Protection Agency, Environmental Monitoring Systems Laboratory technical project manager, at (702)
798-2373, or Mr. Eric Hess, the PRC Environmental Management, Inc., project manager, at (913) 573-1822.
I
Additional information on the innovative technology described in this report can be obtained by writing the developer,
Millipore, Inc., at Mail Stop E-5A,' 80 Ashby Road, Bedford, Massachusetts 01730, or by telephoning l-800-225-138o!
IX
-------
-------
Section 1
Executive Summary
This innovative technology evaluation report (ITER)
presents information on the demonstration and evaluatiok
of the EnviroGard PCB Test produced by Millipore, Inc.
(Millipore). The EnviroGard PCB Test is designed tj>
detect polychlorinated biphenyl (PCB) contamination in
soil. The demonstration was conducted by PRC
Environmental Management, Inc. (PRC), under contracjt
to the Environmental Protection Agency's (EPAj)
Environmental Monitoring Systems LaboratoryLaS
Vegas (EMSL-LV). The demonstration was developed
under the Monitoring and Measurement Technologies
Program (MMTP) of the Superfund Innovativi
Technology Evaluation (SITE) Program.
The EnviroGard PCB Test was demonstrated
evaluated hi August 1992 at a site hi Kansas City!
Missouri. The demonstration of the test was done in
conjunction with the demonstration of three other
innovative field screening technologies: the Clor-N-Soil
PCB Test Kit and the L2000 PCB/Chloride Analyzer!
both manufactured by the Dexsil Corporation, and the
Field Analytical Screening Program PCB Method
developed under the Field Investigative Team Contracj,
with the EPA Superfund Program. The demonstratioii
results for these other technologies are presented hi
separate ITERs. !
i
The EnviroGard PCB Test is designed to quick!}}
provide semiquantitative results for PCB concentration^
hi soil samples. The technology can be customized td
report specific results over a particular range of
concentrations. As part of the SITE demonstration, the
technology also was evaluated for its ability to produce
quantitative results.
The EnviroGard PCB Test is an immunoassayj
system that uses polyclonal antibodies to produce
compound-specific reactions to PCBs allowing theuj
detection and quantitation. An anti-PCB antibody is
fixed to the inside wall of a test tube to bind PCBi
compounds. An enzyme conjugate containing a PCBi
derivative labeled with horseradish peroxidase is added
to the test tube where it competes with PCBs for!
anti-PCB antibody binding sites. Reagents are then
added to the test tube where they react with the enzyme
conjugate, causing a color change. Results can be
estimated by observing the degree of color change. For
a more precise quantitative measurement of the PCB
concentration in the sample, the color of the solution can
be compared to Aroclor standards using a differential
photometer.
The EnviroGard PCB Test is portable, easy to
operate, and useful under a variety of site conditions.
The differential photometer requires electricity but can
be operated using a rechargeable battery. Reagents must
be kept refrigerated.
Calibrating the technology was initially difficult
because of the small volume of Aroclor standards
required. As the operator gained experience hi using the
EnviroGard PCB Test, the calibrations became easier.
The EnviroGard PCB Test costs $1,495, which
includes the differential photometer and other equipment
needed to run the test. Additional disposable equipment
and reagents needed to perform 12 analyses cost
$253. The differential photometer required to obtain
quantitative results costs $799.
The developer reports that the detection limit is
3.3 milligrams per kilogram (mg/kg) for Aroclor
1248. This was the detection limit used during the
demonstration. The detection limit differs depending on
the Aroclor. The highest number of samples analyzed hi
an 8-hour day was 52; the average number analyzed per
8-hour day was 25.
Results produced with the EnviroGard PCB Test
may be affected by the cross-reactivity of compounds
other than PCBs to the anti-PCB antibody binding sites.
The developer has evaluated a number of compounds to
determine their levels of cross-reactivity, although this
evaluation was not independently assessed during this
demonstration.
-------
PRC evaluated field and laboratory duplicate
samples to determine the technology's precision in the
semiquantitative mode. Thirty-seven duplicate sample
pairs were used in this semiquantitative evaluation. Of
these 37 duplicate sample pairs, the EnviroGard PCB
Test produced the same results 35 times. One laboratory
duplicate and one field duplicate did not agree with their
respective soil sample results. Based on this data, the
precision of the EnviroGard PCB Test was found to be
95 percent. This meets the demonstration's criteria for
acceptable precision.
PRC evaluated the accuracy of the test in its
semiquantitative mode by comparing its data to that of
the confirmatory laboratory. This comparison showed
that 71 percent of the time the technology was correct.
The other 29 percent of the time, the technology gave
false positive results. It never gave a false negative
result. The technology is conservative when used in the
semiquantitative mode. Using an absolute definition of
accuracy, it was accurate only 71 percent of the tune.
The production of false positive results, though, may not
affect its use in environmental assessments. False
positive results will incorrectly label soil as being
contaminated above a test's threshold level. At worst,
this would lead to the overestimation of contaminated
area or volume.
To assess this technology's precision in a
quantitative mode, PRC evaluated the results produced
from the analysis of laboratory and field duplicate
sample pairs. The EnviroGard PCB Test had
27 duplicate sample pairs in which both a sample and its
duplicate had positive results. PRC used the data from
the duplicate sample analyses to establish precision
control limits. The control limits were set at 0 and
91 percent. All but two of the 27 relative percent
differences (RPD) fell within the control limits. This
equates to a precision of 93 percent, which is below the
95 percent precision deemed acceptable for this
demonstration. However, the technology's precision
would have exceeded this threshold if only one more
duplicate sample pair had fallen within the control limits.
When PRC used the Dunnett's Test to compare the
RPDs between the EnviroGard PCB Test's data and the
confirmatory laboratory's data, a probability of
97.5 percent resulted. This indicates that the technology
is as precise as the confirmatory laboratory.
PRC used linear regression analysis to assess the
accuracy of the technology in its quantitative mode when
compared to the confirmatory laboratory's data. The
regression of 83 matched pairs of positive sample results
defined a correlation coefficient (r2) of 0.87, indicating
that a relationship did exist between the two data sets.
The regression line calculated had a y-intercept of
17.8 mg/kg and a slope of 0.76. These results indicate
that the results from this technology are not accurate.
Although the technology was found to be inaccurate hi
its quantitative mode, the results produced by the
technology were linear, indicating that the results
can be corrected mathematically. If 10 to
20 percent of the soil samples are sent to a confirmatory
laboratory, then the results from the other 80 to
90 percent can be corrected. This could result in a
significant savings in analytical costs. The Wilcoxon
Signed Ranks Test was used to verify these results. It
indicated, at a 95 percent confidence level, that the
EnviroGard PCB Test's data was significantly different
from that of the confirmatory laboratory. This
confirmed the linear regression analysis and indicated
that the EnviroGard PCB Test's data was not accurate.
-------
!
Section 2
Introduction
This ITER summarizes the procedures used to|
demonstrate the EnviroGard PCB Test, discusses the)
results of the demonstration, and evaluates the
effectiveness and possible uses of the test at various
hazardous waste sites. The primary goal of the
demonstration was to evaluate the technology and to
provide Superfund decision makers with information on its
performance and cost effectiveness.
EPA's SITE Program and MMTP:
An Overview
At the time of the Superfund Amendments and!
Reauthorization Act of 1986 (SARA), it was well
recognized that the environmental cleanup problem needed
to be attacked with new and better methods. The
Superfund Innovative Technology Evaluation Program
(SITE) , therefore, was created to fulfill a requirement of
SARA that the EPA address the potential of alternative or
innovative technologies. The EPA made this program a
joint effort between the Office of Solid Waste and
Emergency Response (OSWER) and the Office of
Research and Development (ORD). The SITE Program
includes four component programs:
The Demonstration Program (for remediation
technologies)
The Emerging Technology Program
The Measuring and Monitoring Program
(MMTP)
« The Technology Transfer Program
The largest part of the SITE Program, the
Demonstration Program, is concerned with treatment
technologies and is administered by ORD's National Risk
Management Research Laboratory (NRMRL) in
Cincinnati, Ohio. The MMTP is administered by
EMSL-LV. The MMTP is concerned with monitoring and
measurement technologies that identify, quantify, or
monitor changes in contaminants occurring at hazardous
waste sites or that are used to characterize a site.
The 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. The 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. It is generally understood
that the courts recognize data generated with conventional
laboratory methods; still, there is a tremendous need to
generate data more cost effectively. Therefore, the EPA
must identify innovative approaches, and through
verifiable testing of the technologies under the SITE
Program, to ensure that the innovative technologies are
equivalent or better than conventional 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. Thus, the 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, by distributing the results and
recommendations of those evaluations, the market for the
technologies is enhanced.
Defining the Process
The innovative technology demonstration process
begins by canvassing the EPA's 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 single clear need by
EPA's regions and a reasonable number of innovative
technologies that can address that need. The
demonstrations are designed to judge each technology
against existing stand_ards and not one against the other.
The demonstration is designed to provide for detailed
quality assurance and quality control (QA/QC). This is
done to ensure that a potential user can evaluate the
accuracy, precision, representativeness, completeness, and
comparability of data derived from the innovative
technology. In addition, a description of the necessary
steps and activities associated with operating the
innovative technology is prepared. Cost data, critical to
any environmental activity, is generated during the
demonstration and allows a potential user to make
economic comparisons. Finally, information on practical
matters such as operator training requirements, detection
levels, and ease of operation are reported. Thus, the
demonstration report and other informational materials
produced by the MMTP provide a real-world comparison
of that technology to traditional technologies. With cost
and performance data, as well as "how to" information,
users can more comfortably determine whether a new
technology better meets their needs.
Components of a Demonstration
Once a decision has been made to demonstrate
technologies to meet a particular EPA need, the MMTP
performs a number of activities. First, the 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.
Then, after evaluation of the information, all respondents
are told whether they have been accepted into the
demonstration or not. While participants are being
identified, potential sites also are identified, and basic site
information is obtained. These activities complete the
initial component of an MMTP demonstration.
The next component, probably the most important, is
the development of plans that describe how various aspects
of the demonstration will be conducted. A major part of
the EPA's responsibility is the development of a
demonstration plan, a quality assurance project plan
(QAPP), and a health and safety plan. While the 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 die
developer can maximize the field performance of its
innovative technology. Typically, the developers tram
demonstration personnel to ensure each operator is trained
appropriately. This also ensures mat potential users have
valid information on training requirements and the types of
operators who typically use a technology successfully.
The field demonstration itself is the shortest part of
the process. During the field demonstration, data is
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. The 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 primary product of the
demonstration is an ITER, like this one, which is
peer-reviewed and distributed as part of the technology
transfer responsibility of the MMTP. The ITER fully
documents the procedures used during the field
demonstration, QA/QC results, the field demonstration's
results, and its conclusions. A separate QA/QC data
package also is made available for those interested in
evaluating the demonstration in greater depth. Also, short
technical summaries 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,
funding its own mobilization, and training EPA-designated
operators. The 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 developers incur to demonstrate
their technologies.
-------
Demonstration Purpose, Goals,
and Objectives
During this demonstration, the EnviroGard PCB Test
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 test. The
accuracy and precision of the test was.
statistically compared to the accuracy and precision
attained in a conventional, fixed laboratory using standard
EPA analytical methods. The EnviroGard PCB Test also
was qualitatively evaluated for the length of time required
for analysis, ease of use, portability, and operating cost.
-------
Section 3
Predemonstration Activities
Several predemonstration activities were conducted
by EMSL-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 results of
the predemonstration sampling and analysis.
Identification of Developers
EMSL-LV identified the EnviroGard PCB Test as
one of four technologies showing promise for use in
PCB field screening. After a review of available data on
these four technologies, EMSL-LV concluded that they
warranted evaluation under the MMTP.
Site Selection
The following criteria were used to select a
hazardous waste site suitable for the demonstration:
The four technologies had to be tested at a site
with a wide range of PCB contamination.
Contaminant concentrations had to be well
characterized and documented. Thorough site
background information was needed so that a
demonstration sampling plan could be designed
with a high degree of confidence mat the
desired range of PCB concentrations would be
present in samples.
The site had to be accessible so 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 Department of Energy (DOE)
Kansas City Plant (KCP) was selected as the location for
this demonstration. The soil at the AICO site is
contaminated with a wide range of PCB concentrations.
PCB levels range from not detected at a concentration 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 (DOE 1989). PCB concentrations at the AICO
site are well documented, which made possible collecting
samples with 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 government and operated by Allied-Signal, Inc.,
for DOE. The plant has been used since 1949 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 primarily occupied by suburban residential
and commercial developments (DOE 1989).
The AICO site is located immediately south of the
DOE KCP between 95th Street and Bannister Road. The
site is located hi 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 also was 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 (DOE
1989).
PCBs are the only significant contaminants at the
site. During the RFI and CMS, 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. It is
believed that this sample included a piece of asphalt from
the material used to fill the old creek channel and tjiat
the presence of these compounds was not the result! of
DOE KCP discharges through Outfall 002 (DOE .1989).
According to logbooks kept by Allied-Signal, Int.,
when boreholes were drilled during the investigationsjof
the AICO site, the former Indian Creek channel!is
overlain by 7 to 15 feet of fill material composed
primarily of mottled clays. Shale and limestojne
fragments, wood, asphalt, and concrete slag up to 4 feet
wide are found in the fill material. Near the surface, jip
to 20 percent of the fill is composed of organic matter,
such as roots, peat, and wood (DOE 1989). )
Sediments overlying bedrock consist of soft, dark
brown to gray, homogenous, medium to high plasticity,
moist clayey silt with traces of fine sand. This material
varies in depth from 7 to 15 feet and appears to have Idw
permeability (DOE 1989). The aquifer of concern
beneath the AICO site is the shallow groundwater lyipg
just above bedrock. I
Selection of Confirmatory Laboratory and
Method
... . j
EPA Region 7 Laboratory personnel selected one
laboratory participating in the Contract .Laboratory
Program (CLP) to perform .the confirmatory analysis of
samples for this demonstration. All samples were
analyzed using the method described in the CLJP
1990 Statement of Work (SOW) for analyzing PCBs arid
pesticides. The EPA Region 7 Laboratory conducted! a
Level II data review of the confirmatory laboratory's
data.
Operator Training
The EnviroGard PCB Test was demonstrated by
PRC field personnel. Prior to the demonstration, the
PRC operator was trained in the use of the technology.
This training included a review of operating procedures
and instructions provided by Millipore and informal field
training conducted by Millipore at the start of the
demonstration. Training was equivalent to that
recommended by Millipore for actual site
characterization projects.
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 previously identified as containing high,
medium, low, and not detected concentrations of PCBs.
These samples were split into replicates. One replicate
of each sample was submitted to Millipore, and the
confirmatory laboratory analyzed one replicate.
The predemonstration sampling was conducted so
that Millipore could refine its technology and revise its
operating instructions, if necessary, before the
demonstration. The sampling also allowed potential
matrix effects or interferences to be evaluated prior to
the demonstration. The principal finding from the
predemonstration sampling was that the soil at the AICO
site was more clayey than expected. The high clay
content of the soil made homogenizing the samples
difficult (see Section 4).
-------
Section 4
Demonstration Design and Description
This section describes the sample collection
procedures and the experimental design used to evaluate
the EnviroGard PCB Test. This innovative technology
was evaluated in conjunction with three other field
screening technologies that also analyze PCBs in soil.
The demonstration design and description, and the
experimental design described in this section, are
common to all four evaluations. The four evaluations
also shared'a single demonstration plan and QAPP. Key
elements of the QAPP (PRC 1992b), field analysis
operations, and data management activities are
summarized in this section.
Sample Collection
For the demonstration, 112 soil samples and 32 field
duplicate samples were collected 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 using the CLP 1990 SOW method. A second
replicate was submitted to EMSL-LV for separate
analysis at the request of the EPA technical project
manager (TPM), although the data generated by
EMSL-LV was not used in this demonstration. A third
replicate was analyzed in the field using the EnviroGard
PCB Test. The remaining replicates were analyzed hi
the field using the three other technologies described hi
separate ITERs.
Samples were collected 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. All samples were collected by PRC
using the sample collection and homogenization
procedures specified in the sampling plan (PRC 1992b).
All PRC field activities also conformed with
requirements hi the health and safety plan prepared for
this demonstration (PRC 1992b).
Samples were collected from areas known to exhibit
PCB concentrations ranging from not detected (at a
concentration of 0.16 mg/kg) to 9,680 mg/kg. Most of
the samples were collected from areas previously
identified as containing PCBs in the not detected to
100 mg/kg range, for two reasons. First, this range
encompasses typical regulatory thresholds for PCBs,
such as the 10 mg/kg level for cleanups hi unrestricted
access areas and the 50 mg/kg level for cleanups hi
industrial areas. Second, most of the four field
screening technologies demonstrated, including the
EnviroGard PCB Test, were designed primarily for
operation hi this range.
Samples were also collected from areas previously
identified as containing PCBs at concentrations ranging
from 100 to 1,000 mg/kg, and from areas previously
identified as containing PCBs at concentrations between
1,000 and 10,000 mg/kg. These samples were analyzed
to evaluate the abilities of the field screening
technologies to monitor PCBs hi higher concentrations as
well as hi the average range. After collection, soil
samples were placed hi plastic bags and thoroughly
homogenized. Samples were then split and placed hi
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 EMSL-LV and for analysis by the field
screening technologies were placed hi 4-ounce,
wide-mouth glass jars with Teflon-lined lids.
Homogenization of the samples was monitored by
adding a small amount of powdered uranine, 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 under the UV
light, PRC sliced each sample hi a minimum of five
different places and examined each slice for
fluorescence. If any of the slices did not contain signs
of fluorescence, then homogenization of the sample
continued and the examination process was repeated.
-------
The use of small amounts of fluorescein was found not
to interfere with sample analysis for any of the field
screening technologies, nor for the confirmatory
laboratory. >
<- . ' |
After confirmatory laboratory results were received,
PRC 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 expectjed
difference between a sample and its duplicate was zero.
This assumes that there was perfect homogenization and
that there was no difference introduced by analytical
error. Using a matched pair Student's t-test, it w;as
possible to determine if 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 seem to indicate that homogenization
could have been better, overall the homogenization
technique used was highly effective. ]
I
To apply the matched pair Student's t-test, it wjis
necessary to have a normally distributed data population.
The differences between confirmatory laboratory
samples and their respective duplicates were statistically
evaluated and found to be normally distributed. Tw,o
data point outliers were noted in the frequency plot. The
matched pan- Student's t-test, however, was found
acceptable even when the outliers were included hi the
data set. . j
. I
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 the analysis being greatly
affected. For example, a single pair of samples witp
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, ja
limited number of poorly homogenized samples may
have been included hi the demonstration. The analysis
of such data could produce limited cases of inaccuratk
data. For this reason, a large number of samples werp
collected and analyzed to prevent any anomalous sampleSs
from affecting the overall results. j
i
Quality Assurance Project Plan
To ensure that all activities associated with this
demonstration met demonstration objectives, a QAPP
was prepared (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, and
ultimately, all participants agreed to its content.
The primary 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 EMSL-LV SOW, this demonstration is considered a
Category H project. The QAPP addressed the key
elements required for Category II projects prepared
according to guidelines hi "Preparing Perfect Project
Plans" (EPA 1989) and "Interim Guidelines and
Specifications for Preparing Quality Assurance Project
Plans" (Stanley and Verner 1983).
For sound conclusions to be drawn on the four field
screening technologies, the data obtained during the
demonstration had to be of known quality. For all
monitoring and measurement activities conducted for
EPA, the agency requires that DQOs be established
based on how the data will be used. DQOs must include
at least five indicators of data quality:
representativeness, completeness, comparability,
accuracy, and precision. Each of these indicators is
discussed in more detail below. The success of the
demonstration required that DQOs be met by the
confirmatory laboratory. Some DQOs for the
confirmatory laboratory were indicated in the CLP
1990 SOW, and others were derived from data generated
while using the method. It was critical that the
confirmatory laboratory analyses be sound and within
CLP 1990 SOW method specifications so that the data it
generated could be compared to that obtained by the
technologies. High quality, well-documented
confirmatory results were essential for making this
comparison.
Representativeness refers to the degree to which the
data accurately and precisely represents the condition or
characteristic of the parameter represented by the data
(Stanley and Verner 1983). In this demonstration,
representativeness was ensured by executing a consistent
sample collection, homogenization, and handling
program. Representativeness also was ensured by using
each technology at its optimum capability to provide
results that represented the most accurate and precise
measurements it was capable of achieving.
Completeness refers to the amount of data collected
from a measurement process compared to the amount
that was expected to be obtained (Stanley and Verner
1983). For this demonstration, completeness refers to
i 9
-------
the proportion of valid, acceptable data generated using
each of the technologies and the confirmatory laboratory.
The completeness objective for each technology during
this demonstration was 90 percent, which was achieved.
Comparability refers to the confidence with which
one data set can be compared to another (Stanley and
Verner 1983). The main focus of this demonstration
was to compare data generated from the EnviroGard
PCB Test and the other technologies with confirmatory
laboratory results using the experimental design and
statistical methods discussed in Section 4. Additional
QC for comparability was achieved by analyzing QC
samples, blanks, and Aroclor standards, and by adhering
to standard EPA analytical methods and standard
operating procedures (SOP) for preparing samples and
operating instruments.
Accuracy refers to the difference between the
sample 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,
interferences, and systematic contamination or carryover
of analyte from one sample to the next. During this
demonstration, accuracy was measured by making the
statistical comparisons discussed under Experimental
Design in this section.
Precision refers to the degree of mutual agreement
among individual measurements and provides an estimate
of random error. Precision for this demonstration was
measured by comparing the RPDs of samples and their
duplicates to control limits established through the
statistical methods detailed under Experimental Design
in this section.
Experimental Design
The primary objective of the demonstration was to
evaluate the efficiency of the EnviroGard PCB Test and
three other technologies at determining PCB
contamination in soil. This evaluation included defining
the precision, accuracy, cost, and range of usefulness for
each of these technologies. This objective also included
determining the DQOs that each technology was capable
of achieving. An additional objective was to evaluate the
specificity of each 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 each field screening technology
was another important factor. Costs include expendable
supplies, nonexpendable equipment, labor, and
investigation-derived waste (IDW) disposal. 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. Similar-sized sample batches were
analyzed by each of the field screening technologies.
Many analytical techniques can have significant
operator effects in which individual differences hi
technique have a significant effect on the numerical
results. To reduce the potential impact of measurement
variation, PRC used a single operator for each field
screening technology and accepted that the error
introduced by operator effect would not be
distinguishable from error inherent in the various field
screening technologies. 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 each
field screening technology was determined by comparing
results from each technology to those from the
confirmatory laboratory. Statistical analysis of these
results were then used to identify the contaminant range
in which results from each 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 as well. In the
planning stages of this demonstration, interest was shown
in the cross-reactivity between Aroclors for each
technology. To assess this factor, cross-reactivity for
each technology was evaluated through the use of matrix
spikes for each of the seven Aroclors (1016, 1221, 1232,
1242, 1248, 1254, and 1260) typically analyzed using
standard EPA analytical methods. This information was
then used to determine the sensitivities of the
technologies to each Aroclor.
Statistical Analysis of Results
This demonstration required comparisons of various
groups of data. Sample results from each technology
were statistically compared to duplicate sample results
and other QA/QC sample results. These are called
intramethod comparisons. The sample results, also,
were statistically compared to the results from the
confirmatory laboratory, which were considered as
accurate and precise as possible. Finally, in some cases,
the precision obtained by a technology was statistically
10
-------
compared to the precision obtained by the confirmatory
laboratory.
All of the statistical tests used for this demonstration
were stipulated hi the demonstration plan, which vfas
approved hi advance of data collection by [all
demonstration participants (PRC 1992b). Also stipulated
hi the demonstration plan was that all sample pairs that
included a not detected result would be removed from
data sets. PRC felt that the variance introduced (by
eliminating these data pairs would be less than, or no
more than equal to, the variance introduced by giving
not detected results an arbitrary value.
In cases where field duplicate samples were
collected, the demonstration plan stated that the results
of the two duplicates would be averaged and this average
used in subsequent statistical analysis. PRC followed
this guideline, as well. .In this way, samples were not
unduly weighted in the statistical analyses. j
The intramethod comparisons involved a statistical
analysis of RPDs. First, the RPDs of the results for
each sample pair, hi which both the sample and its
duplicate were found to contain PCBs, were determine*!.
The equation below was used to calculate the RPDs:
RPD =
where
(R, + RJ/2
100
RPD = relative percent difference.
R, = initial result.
R, = duplicate result.
' i
Acceptable RPD values for field duplicate data are
difficult to assess. These ranges are rarely published for
organic parameters and are mainly dependent on the
heterogeneity of contaminant distribution, sample
collection activities, and analytical precision. For this
demonstration, acceptable RPD values for field duplicate
data were established by determining an upper control
limit using guidance stated in SW-846 Method 8000.
Because the technologies being demonstrated wei}e
themselves being assessed, the control limits used were
calculated from data provided during this investigation.
To determine the upper control limit, the standard
deviation of the RPDs was calculated for eacji
technology. This standard deviation was then multiplied
by two and added to its respective mean RPDs. This
established the upper control limit for the technology1.
Because an RPD of zero would mean that the duplicate
samples matched their respective samples perfectly, zero
was used as the lower control limit. This resulted hi 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 technology had acceptable
precision.
Each field screening technology's data was
compared to the confirmatory laboratory data to
determine its'accuracy. This comparison involved three
statistical methods: linear regression analysis, the
Wilcoxon Signed Ranks Test, and the Fisher's Test.
Linear regression was calculated for the
technologies that were capable of determining
quantitative results. One of those was the EnviroGard
PCB Test. PRC calculated this data by the method of
least squares. Calculating linear regression hi this way
makes it possible to determine whether two sets of data
are reasonably related, and if so, how closely.
Calculating linear regression results hi an equation that
can be visually expressed as a line. Three factors are
determined during calculations of linear regression.
These three factors are the y-intercept, the slope of the
line, and the coefficient of determination, also called r2.
All three of these factors had to have acceptable values
before a technology's accuracy was considered
acceptable.
The r2 expresses the mathematical relationship
between two data sets. If r2 is 1, then the two data sets
are perfectly correlated. 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 r2 below 0.80 was found, the data was
reviewed to determine whether any particular results
were skewing the r2. This skewing may sometimes
occurs because technologies are often more accurate
when analyzing samples hi one range than when
analyzing samples hi another range. In particular,
samples with either very high or very low levels of
contamination often skew the results. For this
demonstration, the technique used to identify outliers that
might have skewed the results was residual examination
(Draper and Smith 1981). The computer program used
for calculating the linear regression, hi fact, identified
most of the outliers. When outliers were identified, they
were removed and linear regression was calculated
again.
If the corrected data set resulted hi an r2 between
0.80 and 1, then the regression line's y-intercept and
slope were examined to determine how closely the two
! 11
-------
data sets matched. A slope of 1 and a y-intercept of zero
would mean that the results of the technology matched
those of the confirmatory laboratory perfectly.
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 its expected value without that difference
being statistically significant. To determine whether
such differences were statistically significant, PRC used
the nprmal 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, then the
technology's data was considered inaccurate. The
technology's data was also considered inaccurate if an r2
between 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.
However, in this case, the data 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 where the r2, the y-intercept, and the slope were
all found to be acceptable did PRC determine that the
technology's data was accurate.
A second statistical method used to assess the
accuracy of the data from each technology was the
Wilcoxon Signed Ranks Test. This test is a
nonparametric method for 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. In other words,
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.
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 Wilcoxon Signed Ranks Test and the
linear regression analysis perform similar types of
comparisons, the assumptions on which each is based are
different. 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.
The EnviroGard PCB Test produced
semiquantitative results. Linear regression analysis and
the Wilcoxon Signed Ranks Test cannot be used to
compare semiquantitative results. Instead, PRC used a
2 by 2 contingency table and a Fisher's Test. The
Fisher's Test determines whether both data sets are
correlated. When used in a two-tailed manner, as it was
in this case, its formula is usually conservative.
Therefore, use of a modified Chi-square formula is
recommended (Pearson and Hartley 1976). This
formula, as used hi this demonstration, is:
(4-2)
2 _ ^[(observed value - expected value) - .5f
expected value
The Fisher's Test statistics were compared to the
95 percent confidence level obtained from a standard
Chi-square distribution table. This comparison indicated
whether, overall, there was a correlation between the
results of the two methods. If a correlation existed, the
technology's data was considered accurate.
Finally, the precision obtained by each technology
was statistically compared to the precision obtained by
the confirmatory laboratory using Dunnett's Test. This
test was used to assess whether the precision of the
technology and that of the confirmatory laboratory were
statistically equivalent. First, the mean RPD for all
samples and their respective duplicates analyzed by the
confirmatory laboratory was determined. The RPDs of
each duplicate pair analyzed by each of the technologies
was then statistically compared to this mean. The
Dunnett's Test results hi a single statistical value which
indicates the degree of certainty that the precision of the
two methods is the same. In other words, a 90 percent
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.
It should be noted that results below 95 percent do
not mean 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 or not
12
-------
any difference between the two data sets actually
resulted because a technology's data was more precise
than the confirmatory laboratory's. I
i
Field Analysis Operations j
I
The field analysis portion of the demonstration >jras
performed hi 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, sample storage, and
the storage of sample collection equipment. All of the
equipment, 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.
13
-------
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
confirmatory laboratory is discussed in more detail in the
following sections.
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 CLP 1990 SOW method analysis. This
method requires that organochlorine pesticides and PCBs
be analyzed using a gas chromatograph (GC) equipped
with an electron capture detector (ECD).
EPA Region 7 Laboratory personnel conducted a
Level II data review on 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. A
review of the raw data and a check of the calculations
was performed by the confirmatory laboratory before
submitting the data package to EPA. PRC was not able
to review the raw data generated from the analysis of
samples. However, PRC did review the EPA's
comments generated by the Level II data review.
The following sections discuss specific procedures
used to identify and quantitate PCBs using the CLP
1990 SOW method. Most of these procedures involved
requirements that were mandatory to guarantee the
quality of the data generated.
In addition to being generally discussed in this
Section, all of the confirmatory laboratory results used
to assess the Millipore EnviroGard PCB Test are
presented in tables in Section 6.
Soil Sample Holding Times
The CLP 1990 SOW method requires that all soil
sample extractions be completed within 7 days from the
laboratory's validated sample receipt. The analysis of
soil samples must be completed within 40 days of
validated sample receipt. The holding time requirements
for the samples collected during this demonstration were
met.
Soil Sample Extraction
Soil samples were extracted according to the
procedures outlined hi the CLP 1990 SOW method for
organochlorine pesticides and PCBs. This procedure
involves placing 30 grams of soil into a beaker and then
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 then is added to the
beaker containing the soil and sodium sulfate. 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
two more times with 100 mL of the acetone and
methylene chloride mixture. The organic solvent is
filtered and combined hi a vacuum flask.
After filtration, the solvent is transferred to a
Kuderna-Danish apparatus. The Kuderna-Danish
apparatus is placed hi a hot water bath, and the organic
solvent is concentrated. Once 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 using this system. The
soil sample extract is taken through a florisil solid-phase
14
-------
I
extraction column to remove any polar compounds fr6m
the extract. The soil sample extract is diluted to 10 mL
with hexane and is transferred to a test tube to await
sample analysis. I
Initial and Continuing Calibrations I
The CLP 1990 SOW method for analyzing PCJBs
involves an initial calibration (ICAL) for PCBs, which
consists of analyzing one concentration of each of ijie
seven Aroclors listed in the Target Compound List
(TCL). The ICAL is used to determine peaks to identify
Aroclors and to determine factors to quantitate PCBs Jin
samples. The ICAL is performed before sample analyks
begins. PCBs cause multipeak patterns when analyzed
using gas chromatography. For each Aroclor, three to
five peaks are chosen to monitor retention time shift and
to determine factors used for quantitation. i
Continuing calibrations (CCAL) are performed py
analyzing instrument blanks and performance evaluation
(PE) mixture standards. The retention times aiid
calibration factors determined during the ICAL are
monitored through CCALs. The CCAL standard 'is
typically a mid-level pesticide standard; howevqr,
because PCBs were the compounds of interest, an
Aroclor was used as the CCAL standard for analyzing
these samples. J
Retention times were monitored through evaluating
the amount of retention time shift from the PCB CC^L
standard as compared to the PCB ICAL standard. The
retention time window was defined as + 0.07 minute fbr
each peak identified in the ICAL. According to the CLP
1990 SOW method, any time a peak of an Aroclor fajls
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 monitoririg
during the CCAL never exceeded the windows
established for them in the ICAL.
Calibration factors were monitored in accordance
with the CLP 1990 SOW method and were acceptable,
as the CCAL calibration factor never exceeded 25
percent. j
ysis
Sample Analysis
PCBs are identified in samples by matching peak
patterns found after analyzing the sample with those
found in Aroclor standards. Peak patterns may not
match exactly because of the way the PCBs were
manufactured or because of the effects of weathering.
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, peak pattern
identification is highly dependent on the experience and
interpretation of the analyst.
Quantitation of PCBs is performed by measuring the
response of the peaks hi 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 CLP 1990 SOW method. Because the field
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.
The calculation to convert dry weight results to wet
weight results is shown below:
(4-1)
ww = own -MC
where
WW = Wet weight results.
DW = Dry weight results.
MC = Moisture content ratio provided by confirmatory
laboratory.
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 defined as 16 tunes the response of the Aroclor
standards analyzed during the ICAL. Once a sample is
diluted to within the linear range, it is analyzed again.
Dilutions were performed when appropriate on the
samples for this demonstration.
Once an ICAL has been performed, sample analysis Detection Limits
begins. Usually, sample analysis begins by analyzing
method blank to verify that it meets the CLP 1990 SOW
method requirements. After this, sample analysis mdy
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 CLJP
1990 SOW method requirements.
One concentration of each Aroclor was analyzed
during the ICAL. 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 micrograms per kilogram
0*g/kg); the level used for the other six Aroclors was
15
-------
100 pig/kg. This corresponds to soil sample detection
limits of 67 /*g/kg for Aroclor 1221 and 33 jig/kg for the
other Aroclors.
Because of CLP 1990 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 above 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 EnviroGard PCB
Test and the other technologies were listed hi mg/kg.
Even when corrected to account for percent moisture,
the CRQLs would be significantly below the detection
limits for each technology.
Quality Control Procedures
A number of QC measures were used by the
confirmatory laboratory as required in the CLP
1990 SOW method, including analysis of resolution
standard mixes, method blanks, and instrument blanks,
all requirements of which were met for this
demonstration.
Also, surrogate standards were added to all
standards, method blanks, matrix spikes, and soil
samples analyzed using the CLP 1990 SOW method.
The percent recovery of each surrogate was calculated
and compared to the advisory control limits of 60 to
150 percent found in the CLP 1990 SOW. No corrective
action is needed when surrogate recoveries fall outside
of the advisory control limits. The surrogate recoveries,
though, 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 within the linear range required by the
CLP 1990 SOW; however, the dilutions decreased the
amount of the surrogate standards that were injected onto
the GC. The result was that the surrogates were not
detected 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. Comments from the EPA Level II data
review, though, indicated that 88 of the samples and
their respective duplicate samples resulted in acceptable
surrogate recovery data.
The CLP 1990 SOW requires that matrix spike 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 CLP 1990 SOW also requires that all positive
sample results be confirmed. There are two methods of
confirming sample results. The first, required in all
cases, is to analyze the sample again using a second GC
column. If concentrations identified this way are
sufficiently high, the second method, analyzing the
sample again using a GC and mass spectrometer (MS),
must also be used.
Second Column Confirmation
As required, all samples that were found to contain
PCBs during analysis on the first column were analyzed
on the second column. In all cases, the presence of
PCBs were confirmed. There were 122 samples that
required second column confirmations.
The CLP 1990 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 it is estimated.
For the analysis of the samples from this demonstration,
17 sample results were above the 25 percent requirement
of the CLP 1990 SOW. These results were J-coded to
indicate that the results were estimated but were not
validated by approved QC procedures. Finally,
following the CLP 1990 SOW method, the lower of the
two values was reported.
Gas Chromatographic and Mass Spectrometer
Confirmation
The CLP 1990 SOW requires that when pesticides
or PCBs are present in samples at sufficient quantities,
they must 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 were 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 for identifying individual congeners.
Because all 20 samples were confirmed on the second
GC column, the lack of GC and MS confirmation was
determined to be insignificant during the EPA Level
16
-------
II data review. Therefore, these samples were not
coded.
Data Reporting
The data report PRC received from the EPA Region I
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 CLP 1990 SOW. PRC obtained data j
on the percentage of solids hi the sample from the|
confirmatory laboratory and used this data to convert the j
results to wet weight. This conversion was required |
because the data was to be compared to data from the
EnviroGard PCB Test and three other technologies, all
of which reported concentrations based on 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 was coded with a
"K," indicating that the actual PCB concentration hi the
sample was less than the reported value, or that PCBs (
were not found in the sample. The third code used was
"J", 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 RFI and CMS results from April
1989, the only Aroclor believed to be present at the
AICO site was Aroclor 1242. However, the
confirmatory laboratory found three additional Aroclors
in the samples collected during the demonstration. Most
of the samples analyzed by the confirmatory laboratory
were found to contain either Aroclor 1242 or Aroclor
1243. Seventy-three samples were found to contain only
Aroclor 1242, while 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 was 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 j
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 above the CRQLs.
Data Quality Assessment of Confirmatory
Laboratory Data
This section discusses the accuracy, precision and
completeness of the confirmatory laboratory data.
Accuracy
Accuracy for the confirmatory laboratory results
was assessed through the use of PE samples, purchased
from Environmental Research Associates (ERA), that
contained a known quantity of Aroclor 1242. ERA
supplied data sheets for each PE sample, which included
the true concentration and an acceptance range for the
sample. The acceptance range was based on the
95 percent 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 hi exactly the same manner
as the other soil samples. The confirmatory laboratory
knew that the samples were PE samples, but the true
concentrations and acceptance ranges of the samples
were not known to the confirmatory laboratory. 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 percent. 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 CLP 1990 SOW. Two other types
of data commonly used to measure precision, matrix
spike and matrix spike duplicate RPDs, also were not
available because matrix spike compounds required by
the CLP 1990 SOW method are pesticide compounds,
not PCBs,
The evaluation of field duplicate sample results was
used 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 while 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 097 had a result of
1.23 mg/kg while its duplicate had a result of
0.285 mg/kg. The RPD for Sample 097 and 97D was
124.8 percent. The other RPDs, though, had much
lower percentages. Without these two samples, the
mean RPD fell to 20 percent. Overall, this data shows
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 J-code is defined by
EPA Region 7 Laboratory as data estimated but not
validated by approved QC procedures. Based on the
definition of completeness given above, 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, the
J-coded data was determined to be acceptable by PRC
and EMSL-LV. For this reason, the actual completeness
of data used was 100 percent.
Use of Qualified Data for Statistical Analysis
As noted previously, 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 this J-coded data was not valid
because it had failed at least one of the two QA/QC
criteria specified in the CLP 1990 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 when 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 similar magnitude to that introduced by
using the data. For these reasons, PRC, after consulting
with EMSL-LV, elected to use the J-coded data despite
the fact that the EPA Region 7 Laboratoiy had
determined the results to be invalid under approved QC
procedures.
18
-------
I
Section 6
Millipore EnviroGard PCB Test
This section provides information on the EnvkoGard
PCB Test, including background' information,
operational characteristics, performance factors,!
specificity, a data quality assessment, and a comparisonj
of its results with those of the confirmatory laboratory. |
Observations on the technology made by the operator)
during the demonstration are presented throughout this!
section. ;
The EnviroGard PCB Test was designed by
Millipore for use hi a semiquantitative mode. Most of 1
this section discusses the technology as a
semiquantitative analytical method. However, after
consulting with both Millipore and EMSL-LV, PRC also
tested the technology's ability to produce quantitative
results. Details of its quantitative abilities are included j
in this section. I
Theory of Operation and Background
Information
The EnviroGard PCB Test is designed to provide
quick, semiquantitative results for PCB concentrations in
soil samples using an immunoassay approach. The
approach uses polyclonal antibodies to detect and
quantify PCBs in a sample. These results indicate
whether PCB concentrations are above or below a
specific level within a 99 percent confidence level. The j
technology can be customized to report specific results
over a particular range of concentrations.
The EnvkoGard PCB Test is designed to report
levels of PCBs that are above or below three known
concentrations. These known concentrations are defined
by the standards used to calibrate the technology. The
EnvkoGard PCB Test comes with standards of Aroclor
1248 in the following PCB concentrations: 5, 10, and
50 mg/kg.
Before sample analysis can take place, soil samples
must be extracted. Soil samples are extracted using an
organic solvent and steel ball bearings. An aliquot of the
soil sample extract is then diluted and placed in a test
tube coated with the anti-PCB antibodies. This solution
is mixed and allowed to incubate for 5 minutes so that all
of the PCBs in the sample extract can attach to the
anti-PCB antibody binding sites. After the incubation
period, the test tube is emptied and vigorously washed
with four test-tube volumes of tap or distilled water.
Four drops of enzyme conjugate are then added to the
test tube and allowed to incubate for 5 minutes while
periodically mixed. The enzyme conjugates compete
with PCBs for the binding sites of anti-PCB antibodies
on the test tube. After the 5-minute incubation time, the
test tube is agaki emptied and vigorously washed with
four test-tube volumes of tap or distilled water.
Next, color reagents are added to the test tube.
Four drops of substrate are added to the test tube,
followed by four drops of chromogen. This mixture is
swirled in the test tube and allowed to incubate for
5 minutes. After 5 minutes, a stop solution is added to
the test tube to stop color development. Test results are
estimated visually by observing the color development.
A blue color indicates the absence of PCBs, while a
lighter blue or clear color indicates the presence of
PCBs. To obtain semiquantitative results, the color of
the solution is compared to the colors resulting from the
analysis of the Aroclor standards and a negative control
sample. For a more precise measurement of the PCB
concentration, the color of the solution is compared to
the color resulting from the analysis of the Aroclor
standards and a negative control sample using a
differential photometer (see Exhibit 6-1).
Operational Characteristics
Overall, the EnvkoGard PCB Test was found to be
portable. The test is made up of three kits: the
EnvkoGard PCB Field Lab, the EnviroGard Field Soil
Extraction Kit II, and the EnvkoGard PCB Test Kit.
The EnvkoGard PCB Field Lab is a starter kit and
consists of a portable carrying case about 18 inches long,
-------
EXHIBIT 6-1. ASSAY FLOW CHART.
MILLIPORE ENVIROGARD PCB TEST PROCEDURE
STEP "1" _
Wainh«!oil ^ Extract thB ll.uuiimnla
sampla Polychlorinated * Filter the sample
STEP 5: STEP 6: STEP 7:
Add standards ,, Dilute the ...^ Washmrt
controls or samples samples test tubes
STEP 9: STEP 10: STEP 11:
test tubes reagent reagent
STEP 14a:
Samples can be white background I
STEP 4:
STEPS:
^ Add conjugate ^
reagent
STEP 12: STEP 13:
. |nrj ihatn fnr ^ Add Stop ~^-
5 minutes solution
STEP 14b:
se photometer to
obtain the optical
isities for standards
and samples
18 inches wide, and 6 inches high. The carrying case
and all the equipment contained in it weighs nearly
10 pounds. That equipment includes (1) a differential
spectrophotometer equipped with an electrical cord and
rechargeable battery, (2) a positive displacement
precision pipettor for dispensing volumes between 1 and
25 microliter <>L), (3) an Eppendorf Repeater pipettor,
(4) an electronic tuner, (5) a portable balance with a
50-gram calibrator weight, (6) a 500-mL wash bottle,
(7) two six-position test tube racks, (8) a rack of pipette
tips for the positive displacement precision pipettor, and
(9) an instruction card. Several other items needed to
complete this kit were provided by Millipore hi a
cardboard box. These items included (1) one 12- by
75-mm polystyrene test tube used for blanking the
spectrophotometer, (2) eight 5-mL pipette tips for the
Eppendorf Repeater pipettor, for dispensing volumes
between 0.1 and 0.5 mL, (3) four 12.5-mL pipette tips
for the Eppendorf Repeater pipettor for dispensing
volumes between 0.25 and 0.625 mL, and (4) one
50-mL pipette tip for the Eppendorf Repeater pipettor,
for dispensing volumes between 1.0 and 5.0 mL.
The EnviroGard Field Soil Extraction Kit II and its
associated equipment are provided hi a small cardboard
box. The equipment includes (1) 12 polypropylene
extraction bottles with screw caps containing five steel
ball bearings, (2) 12 filter devices consisting of 12 upper
and 12 lower units, (3) 12 polyethylene prefilters,
(4) 15 wooden spatulas, (5) 12 4-mL, screw-top glass
vials, and (6) 15 polyethylene weigh boats.
The EnviroGard PCB Test Kit comes hi a small
cardboard box and includes enough reagents and. other
equipment to analyze 16 samples. Most of its contents
require refrigeration. This kit contains (1)
20 polystyrene tubes coated with anti-PCB antibody,
(2) a 14-mL vial of assay diluent, (3) a 4.8-mL vial of
PCB enzyme conjugate, (4) a 0.5-mL vial of negative
control solution, (5) a 4.8-mL vial of peroxide solution
(substrate), (6) a 4.8-mL vial of chromogen solution,
(7) a 15-mL vial of 1.0-normal sulfuric acid (stop
solution), (8) three 0.5-mL vials of 5, 10, and 50 mg/kg
Aroclor 1248 standards, and (9) a plastic six-position test
tube rack. Aroclor standards can be obtained hi
different concentrations by contacting Millipore.
Electricity is needed for the differential photometer.
Millipore offers a photometer that can be operated using
either a 115-volt or 230-volt electrical supply. The
differential photometer also is equipped with a
rechargeable battery. This battery requires 8 to 2A hours
of charging, and when fully charged can perform up to
500 tests without being recharged. A battery also is
needed to operate the portable balance. A refrigerator
must be available to keep reagents cool to avoid a
decrease hi the activity of the enzyme conjugate. The
recommended storage temperature of the reagents is
20
-------
between 2 and 8 °C. The activity of the enzym6
conjugate can be decreased by freezing the reagents, by
exposing them to temperatures above 37 °C, or bj^
repeated exposure to ambient temperatures. j
. i
!
Miscellaneous provisions needed to analyze sampled
include (1) methanol for sample extraction and dilution!
(2) distilled or tap water for washing the test tubes
coated with anti-PCB antibodies, (3) a table or work
space of at least 8 square feet, (4) a permanent marker
for writing sample numbers on test tubes and sampl^
containers, (5) a logbook or a report form for recording
sample results, and (6) an ink pen.
The EnviroGard PCS Test is designed for use in the
field or laboratory. Some of its, instrumentation an4
equipment require special handling, such as the
differential photometer, portable balance, and two
pipettors. This equipment must be handled carefully to
avoid damage. j
The reliability of the EnviroGard PCB Test was|
evaluated by monitoring instrument calibrations. Thej
ICAL problems experienced by the operator were
attributed to the small volumes used to prepare the
Aroclor standards and to the operator's inexperience in1
using the pipette required to measure these small
volumes. Preparing the Aroclor standards required
measuring 5 /*L each of the three concentrations. Using
such a small volume may produce large errors!
especially if a single drop of Aroclor standard is left
outside the pipette tip or if the pipette tip is not placed
completely into the vial containing the Aroclor standard,!
allowing air into the pipette tip rather than the Aroclor
standard. I
Thirty-one total calibrations were performed during
this demonstration to produce both the semiquantitative
and quantitative data on PCB concentrations in the
samples. Initially, each calibration consisted of two sets
of Aroclor standards, each containing three concentration1
levels: Aroclor 1248 (5, 10, and 50 mg/kg) provided by!
Millipore, and Aroclor 1242 (1, 5, and 25 mg/kg}
prepared by PRC. PRC prepared the Aroclor!
1242 standards and used them to perform the quantitative
evaluation, discussed later in this section. The Aroclor
1248 standards were used for the semiquantitative
evaluation of the technology. Semiquantitative and
quantitative analyses were conducted concurrently, and!
therefore, the semiquantitative and quantitative batch
calibrations were done at the same tune. The following!
paragraphs discuss problems with the semiquantitative'
calibrations; a discussion of problems found during}
calibrations for the quantitative evaluation is found lateij
in this section.
Five calibration failures occurred within the first
16 semiquantitative calibrations. The first calibration
failure was attributed to operator error and errors
attributed to measuring the small volumes associated
with the analysis step. This problem appeared to be
resolved after a reanalysis of these standards and further
training of the operator. Because of the failures, the use
of the three Aroclor 1248 standards was discontinued.
AH subsequent calibrations with the Aroclor
1248 standard involved only the 10 mg/kg concentration.
This concentration was selected as the sole Aroclor
1248 calibration standard because it is a common action
level for PCB cleanups.
Reanalysis of samples associated with the first
16 Aroclor 1248 standards was required for only two of
the unacceptable calibrations. This is because acceptable
Aroclor 1242 calibration was obtained for the other
three, even though the Aroclor 1248 calibrations failed.
It also should be noted that the predominant Aroclor
expected at the site was Aroclor 1242.
The frequent problems with the Aroclor
1248 standards may have occurred because the actual
concentrations of the standards were not the
concentrations shown on the standards' containers. The
actual concentrations were different because Millipore
built a safety margin into the Aroclor standards. The
stated concentrations of the .Aroclor 1248 standards were
5, 10, and 50 mg/kg. The actual concentrations of these
standards were 3, 5, and 22 mg/kg, respectively. Three
of the five Aroclor 1248 calibrations that failed did so
because the response for the 5 mg/kg standard was
greater than the response of the 10 mg/kg standard.
Because the concentrations of these two standards were
actually 3 and 5 mg/kg, the color changes that resulted
when they were analyzed were very similar. The small
differences in the actual concentrations of the standards
magnified the possibility of errors associated with
analysis of the standards.
Between the 17th and 31st calibrations, there were
two failures. These failures were not associated with
either the Aroclor 1242 or 1248 standards. The first
calibration failure was due to a positive response
exhibited by the negative control sample. A negative
control sample was analyzed with each standard and used
as an assay blank. The samples analyzed during this
unacceptable calibration were reanalyzed during another
acceptable calibration. The second calibration failure
was due to a lack of color formation in any of the
samples, Aroclor standards, or negative control samples.
The cause of this failure was unknown.
. The EnviroGard PCB Test requires the use of
chemicals to perform the analysis. The chemicals used
21
-------
include methanol, a flammable solvent that can be
absorbed through the skin, and sulfuric acid, which can
cause chemical burns. Chemical resistant clothing,
gloves, and safety glasses should be worn when using
this solution to protect against injury while using these
chemicals
The operator chosen to use the EnviroGard PCB
Test was Mr. Keith Brown, an employee of PRC. He
earned a B.G.S. degree in Environmental Science from
the University of Kansas hi 1990. While at PRC, Mr.
Brown has conducted preliminary site assessments and
investigations at hazardous waste sites throughout EPA
Regions 5, 7, and 9. He also has performed
hydrogeologic investigations at similar sites. Mr. Brown
has more than 2 years experience performing these
investigations with PRC and a previous employer.
Mr. Brown reviewed'the information provided by
Millipore concerning the analysis of soil samples using
the EnviroGard PCB Test before the start of the
demonstration. This information included a 20-minute
videotape that explained the fundamentals of
immunoassay analysis and introduced the sample
extraction and analysis techniques used. Additional
training was provided by Dr. Alan Weiss of Millipore at
the start of the demonstration. This training included an
in-depth explanation of the sample preparation and
analysis steps. In addition, Mr. Brown analyzed five
predemonstration samples using the technology under the
supervision of Dr. Weiss. Mr. Brown noted that he felt
comfortable using the EnviroGard PCB Test after
analyzing the five predemonstration samples.
Millipore states that this product is intended for use
by individuals with little or no training in PCB testing.
The operator for this technology had no prior PCB
testing experience and noted that the sample preparation
and analysis steps were simple and straightforward. As
described above, the operator did experience some
problems with the technology's ICAL. The first attempt
at calibration resulted in a higher PCB concentration for
the 5 mg/kg Aroclor 1248 standard than for the
10 mg/kg Aroclor 1248 standard. These standards were
reanalyzed, and an acceptable calibration was obtained.
Analysis of samples then proceeded. All samples
analyzed following the unacceptable calibrations were
reanalyzed.
The EnviroGard PCB Field Lab Kit includes most
of the equipment needed to analyze soil samples. The
cost of this kit is $1,495. Most of this equipment can be
reused for a number of projects, although a few of the
items will wear out over time and eventually need to be
replaced. The EnviroGard Field Soil Extraction Kit
II includes the equipment required to extract 12 soil
samples. The cost of this kit is $60. The kit must be
purchased each tune an analysis is conducted because the
equipment is disposable. The EnviroGard PCB Test Kit
includes the reagents needed to perform 16 analyses.
The cost of this kit is $185. According to Millipore,
these reagents have a 6-month shelf life. Reagents
should not be used after the expkation date printed on
the product label. Millipore also sells the methanol used
to extract PCBs from soil. The cost for 100 mL of
methanol is $7.90. Methanol also may also be
purchased from a number of other chemical supply
companies. A differential photometer can be used with
the technology to obtain more accurate results.
Millipore offers a differential photometer that uses either
115- or 230-volt sources of electricity. The cost of this
photometer is $799. The photometer should be a
one-time purchase.
Operator costs using the EnviroGard PCB Test will
vary depending on the technical level of the operator.
During this demonstration, about 200 samples were
analyzed with this technology, including QA/QC
samples. The waste generated from this analysis filled
half a 55-gallon drum. The appropriate way to dispose
of this waste would be through an approved PCB
incinerator facility. The cost for disposal of one drum
of this waste is estimated at $1,000.
Performance Factors
The following sections describe the EnviroGard
PCB Test's performance factors, including detection
limits and sensitivities, sample matrix effects, sample
throughput, and drift. Specificity, due to its complexity,
it is discussed separately in Section 6.
Detection Limits and Sensitivity
Millipore reports that the limit of quantitation for
the EnviroGard PCB Test is 3.3 mg/kg for Aroclor
1248. This is the lowest concentration of Aroclor
1248 that can be accurately identified in a soil sample
99 percent of the tune. The limit of quantitation differs
for each Aroclor.
The limit of quantitation for the EnviroGard PCB
Test depends on a number of factors. These factors
include the number of active sites present on the wall of
the anti-PCB antibody-coated test tube, the amount of
PCBs present in the sample analyzed, the amount of
enzyme conjugate added to the test tube, and the amount
of coloring reagent added to the test tube. Millipore has
designed the test so that the only factor that will change
when analyzing a soil sample is the amount of PCBs
present.
22
-------
The technology is designed so that the number of
active sites in the test tube will always be the same'
within a certain percentage of error. This will bei
especially true when the same test-tube lots are used.j
There may be some variance between different test-tube!
lots, so it is advisable to use the same lot throughout any!
particular project. . I
The kits are also designed so that the amount of!
enzyme conjugate and coloring reagent will be the same!
for each sample analyzed. Measured amounts of the!
enzyme conjugate solution and coloring reagents are
added to each Aroclor standard, negative control sample,
and sample analyzed.
i
Another factor that will affect the limit of)
quantitation is the particular Aroclor in the sample. The)
EnviroGard PCB Test cannot differentiate between!
Aroclors, but it will respond differently to each Aroclor. j
Millipore states that the response of the technology toi
Aroclors 1016, 1242, 1254, and 1260 should be within!
two tunes its response for Aroclor 1248. Aroclor
specificity for this technology is discussed later in this)
section. I
Sample. Matrix Effects
Most of the soil samples collected during this!
demonstration consisted of clay, which caused some)
problems during extraction and analysis. The most
common problem was that a colloidal suspension formed
for some of the samples after the initial sample
extraction. The colloidal suspension either (1) prevented
good recovery of the organic extraction solvent from the
filtering device or (2) clogged the filter, making it
impossible to push the extraction solvent through the
filter. Many of the samples resulted in organic
extraction solvent recoveries of less than 2 mL.
Millipore suggested that PRC extract another sample
when this filter problem occurred. It was recommended
that this extraction be performed using the standard
5 grams of soil sample and doubling the standard volume
of extraction solvent from 5 mL to 10 mL. If this
approach did not solve the problem, less than 5 grams of
the soil sample was used in the extraction step. Nineteen
samples required this approach: 033, 034, 035, 035D,
048, 056, 057, 065, 070, 071, 071D, 072, 077, 080,
083B, 086, 086D, 104, and 106. Results for these
19 samples were S-coded by the operator to indicate that
due to sample matrix effects, the extraction and analysis
process was modified as described above.
This extra dilution required that a correction factor
be used when calculating the results for these samples.
The correction factor caused results and detection limits
to double those normally used. For semiquantitative
results, when the response of the sample was less than
the response of the 10 mg/kg Aroclor 1248 standard, the
reported result of the sample was raised from "less than
10 mg/kg" to "less than 20 mg/kg."
Another sample matrix effect observed was
differences between some samples and their
corresponding field duplicate samples. This problem
was noted during the predemonstration activities, and
steps were taken to improve sample homogenization.
Sample Throughput
Millipore recommends that no more than
20 individual immunoassay analyses be performed at the
same time. Every analysis performed requires that three
concentrations of Aroclor standards and a negative
control sample be prepared. This means a total of
16 actual sample analyses can be performed at a time.
The operator found that a minimum of 30 minutes was
required to extract 16 samples arid that between 30 and
45 minutes were required to analyze the sample extracts.
The operator also noted that the time required for the
extraction and analysis steps did not include the time
required for sample handling, data documentation,
diluting samples when required, difficult extractions,, or
the preparation of QC samples. During this
demonstration, the highest number of samples analyzed
in a single 8-hour day was 52. The average number of
samples analyzed during an 8-hour day was 25. This
information indicates that the EnviroGard PCB Test can
provide rapid analysis of PCBs hi soil samples.
Drift
Drift normally is a measurement of an instrument's
variability in quantitating a known amount of a standard.
The EnviroGard PCB Test eliminates the variability
associated with drift by requiring that a new calibration
be performed with each set of samples analyzed.
During this demonstration, the optical density values
obtained from the Aroclor standards placed into the
differential photometer were evaluated. These values
were found to drift during the 31 calibrations performed.
The optical density values for the Aroclor 1242 standards
decreased over tune. The standards were stored in a
refrigerator when not hi use to reduce evaporation.
However, the decrease may have been caused by the
evaporation of solvent used to dilute the standards.
The optical density values for the Aroclor
1248 standards also decreased over time, although not as
dramatically as values for the Aroclor 1242 standards.
This is also believed to result from evaporation of
solvent. Although Millipore supplied standards with
23
-------
each EnviroGard PCB Test, new standards were not
used for each new calibration. This was because the
volume of standards provided with the technology was
more than enough to perform a single or multiple
calibration. This may have contributed to the decrease
in optical density for the Aroclor 1248 standards.
Specificity
Immunoassay techniques typically use a "lock and
key" type of chemical bonding to trap both the PCB and
enzyme conjugate. This chemical must be specific to
PCBs to prevent a large number of similar chemicals
from binding to the active sites. The affinity of other
compounds to these sites is called cross-reactivity.
Millipore has designed the EnviroGard PCB Test to
produce a specific binding site for PCBs that is not
cross-reactive to most other compounds.
Millipore has performed studies of the
cross-reactivity of other chemicals to the active sites of
the anti-PCB antibody used. The following compounds
were tested by Millipore and found to have a cross-
reactivity of 0.5 percent or less when compared to
Aroclor 1248 on a weight-to-weight basis:
1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichloro-
benzene, 1,2,4-trichloro-benzene, 2,4-dichlorophenol,
2,5-dichlorophenol, 2,4,5-trichlorophenol, 2,4,6-tri-
chlorophenol, biphenyl, and pentachlorophenol. Milli-
pore explains that for compounds with a cross-reactivity
value of 0.5 percent, a concentration of 200 mg/kg
would be required to produce the same response as a
sample containing 1 mg/kg of Aroclor 1248.
Matrix effects also can influence an immunoassay.
Millipore noted that soils containing greater than
5 percent oil may cause false negative results. However,
careful field observations can reduce the impact of this
effect. Soil samples containing greater than 5 percent oil
should be visibly different from soil samples containing
less than 1 percent oil, and the extract from soils
containing 5 percent oil will appear cloudy during the
first incubation step of the immunoassay process.
This technology is designed specifically to react to
the chlorinated biphenyls present hi Aroclor
1248. Many of these chlorinated biphenyls also are
present hi other Aroclors. Therefore, the technology
will produce a positive response to other Aroclors, but
in varying degrees. During tins demonstration, an
Aroclor specificity test was used to evaluate the response
of the technology to each of the seven Aroclors. For
this test, seven soil samples were each divided into four
aliquots. The aliquots were then spiked with different
Aroclors at approximately 10 mg/kg. This concentration
was chosen because it is a common action level at
contaminated sites. While the actual concentration of the
spike was often slightly less than 10 mg/kg, the spike
was always close enough that the technology result
should have indicated a positive response. The results of
the Aroclor specificity test for the technology hi its
semiquantitative mode are tabulated hi Table 6-1.
The Aroclor-spiked samples were identified with
9-character digit, alphanumeric identification codes.
The first three characters of this code referred to the soil
sample number used for spiking. The next four
characters, "ARSP," are an abbreviation of the words
"Aroclor spike." The next character was a letter, A
through G, identifying which Aroclor was used to spike
the sample. The last character was a number, 1 through
4, referring to the aliquot of the sample. To ensure that
results of the assessment were unbiased by operator
effects, the operator did not know which Aroclor was
used for spiking or the Aroclor concentration hi the
samples.
Sample 077 was spiked with approximately
10 mg/kg of Aroclor 1016. The four spiked samples
indicated that the PCB concentrations of the samples
were less than 10 mg/kg when compared to the Aroclor
1248 standard. It appears that the technology is less
responsive to Aroclor 1016 than to Aroclor 1248.
Sample 058 was then spiked witii 10 mg/kg of
Aroclor 1248. Three of the four spiked sample results
indicated PCB concentrations of greater than 10 mg/kg
when compared to the Aroclor 1248 standard. Two of
these aliquots had been spiked with exactly 10 mg/kg of
Aroclor 1248; the third, with 9.90 mg/kg of Aroclor
1248; and the fourth, with 9.73 mg/kg of Aroclor
1248. The response of me technology to the fourth
aliquot containing 9.73 mg/kg of Aroclor 1248 was less
than its response to the 10 mg/kg standard. This
indicates that the detection limit of the technology for
Aroclor 1248 is 10 mg/kg, as expected.
Sample 021 was spiked with about 10 mg/kg of
Aroclor 1232. The four spiked sample results all
indicated that the PCB concentrations of the samples
were less than 10 mg/kg when compared to the Aroclor
1248 standard. This indicates that the technology cannot
identify a soil sample containing 10 mg/kg of Aroclor
1232 using the Aroclor 1248 standard.
Sample 012 was spiked with 10 mg/kg of Aroclor
1260. The four spiked sample results indicated that the
PCB concentrations hi the samples were greater than
10 mg/kg when compared to the Aroclor 1248 standard.
This indicates that a soil sample containing 10 mg/kg of
Aroclor 1260 can be identified using the Aroclor
1248 standards.
24
-------
TABLE 6-1 . SEMIQUANTITATIVE RESULTS F^)R THE AROCLOR SPECIFICITY TEST.
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
077ARSPG2
077ARSPG3
077ARSPG4
Confirmatory
Laboratory
Result
(mq/kq)
0.1
0.1
0.1
0.1
ND
ND
ND
ND
0.06
0.06
0.06
0.06
34.0
34.0
34.0
34.0
4.3
4.3
4.3
4.3
0.7
0.7
0.7
0.7
ND
ND
ND
ND
Soil Sample
Result
(mq/kq)
<10
<10
Spiked Sample
Aroclor Spike Amount Result
Spike (ma/kg) (mq/ka)
AR1221
AR1221
AR1221
< 10 AR1221
<10 JAR1260
<10
<10
<10
<10
<10
<10
<10
AR1260
AR1260
AR1260
AR1232
AR1232
AR1232
AR1232
> 10 IAR1254
>10 AR1254
>10 AR1254
> 10 AR1254
> 10 AR1242
> 10 AR1242
>10 AR1242
> 10 AR1242
^248'
< 10 AR1248
< 10 AR1248
< 10 AR1016
< 10 AR1016
< 10 AR1016
< 10 AR1016
9.94 <10
9.84 < 10
9.92 <10
9.77 < 10
9.78 > 10
9.80 > 10
9.65 > 10
9.86 >10
9.98 < 10
9.84 < 10
9.88 < 10
9.82 < 10
9.86 >10
9.77 > 10
9.77 > 10
9.67 > 10
9.86 > 10
9.69 >10
9.86 > 10
9.75 > 10
9.73 < 10
10.00 > 10
10.00 > 10
9.90 > 10
9.65 <10
9.96 < 10
9.75 < 10
9.90 < 10
Notes:
ND PCBs not detected above the detection limit of 1.0 mg/kg.
mg/kg Milligrams per kilogram.
Sample 003 was spiked with 10 mg/kg of Aroclor
1221. Results for the four spiked samples indicated that
the PCB concentrations hi the samples were less than
10 mg/kg when compared to the Aroclor 1248 standard.
25
This indicates that a soil sample containing 10 mg/kg of
Aroclor 1221 cannot be identified using the Aroclor
1248 standard.
-------
Sample 034 was then spiked with 10 mg/kg'of
Aroclor 1254, but because the confirmatory laboratory
indicated that Sample 034 had greater than 10 mg/kg of
PCBs prior to these samples being spiked, no
conclusions can be drawn.
Sample 040 was spiked with 10 mg/kg of Aroclor
1242. The results from the four spiked samples
indicated that the PCB concentrations of the samples
were greater than 10 mg/kg when compared to the
Aroclor 1248 standard.
Intramethod Assessment
Six reagent blanks were prepared and analyzed to
evaluate laboratory-induced contamination. These
samples were taken through all extraction, filtration, and
immunoassay steps of the analysis. No PCBs were
detected in any of the reagent blanks analyzed.
For this demonstration, completeness refers to the
proportion of valid, acceptable data generated using the
EnviroGard PCB Test. Semiquantitative results were
obtained for all of the samples; therefore, completeness
for the samples analyzed by the EnviroGard PCB Test
during the demonstration was 100 percent.
Intramethod accuracy was assessed for the
EnviroGard PCB Test by using PE samples and matrix
spike and matrix spike duplicate samples. Accuracy also
was determined by comparing the results of the
technology to those of the confirmatory laboratory. A
discussion of this intennethod accuracy is presented later
in Section 6.
Each PE sample had a different concentration of
PCBs: one was low and the other was high. These
samples were extracted and analyzed in exactly the same
manner as all other soil samples. The operator knew
that the samples were PE samples but did not know their
true values, nor then' ranges. The true result for sample
047-4024-114 (the high-level sample) was 110 mg/kg of
Aroclor 1242, with an acceptance range of 41 to
150 mg/kg. The semiquantitative result for this sample
showed that the PCB concentration was greater than the
10 mg/kg Aroclor 1248 standard. The semiquantitative
result, therefore, was acceptable. The true result for
sample 047-4024-113 (the low-level sample) was
32.7 mg/kg of Aroclor 1242. The semiquantitative
result for this sample showed that the PCB concentration
was greater than the 10 mg/kg Aroclor 1248 standard.
The semiquantitative result, therefore, also was
acceptable.
Matrix spike samples, prepared by adding a known
quantity of PCBs to a sample, were used to evaluate the
extraction and analysis efficiency of the technology and
to determine accuracy. Enough Aroclor 1242 was added
to a 5-gram soil sample to produce a matrix spike
concentration of 25 mg/kg. The spiked sample was
duplicated to produce a matrix spike duplicate sample.
Six matrix spike samples and six matrix spike
duplicate samples were extracted and analyzed using the
EnviroGard PCB Test. Semiquantitative results were
compared to the 10 mg/kg Aroclor 1248 standard. The
results of the soil samples before being spiked showed
that all six samples contained less than 10 mg/kg of
PCBs as determined by the Aroclor 1248 standards. Of
the 12 spiked sample results, 11 were found to contain
greater than 10 mg/kg of PCBs as determined by the
Aroclor 1248 standards. The EnviroGard PCB Test was
able to determine that the matrix spike samples contained
more than 10 mg/kg of PCBs, as determined from the
Aroclor 1248 standards, in 92 percent of the samples.
For this demonstration, three types of precision data
were generated: laboratory duplicate samples, field
duplicate samples, and matrix spike duplicate samples.
Semiquantitative results for laboratory and field
duplicate samples are provided in Table 6-2.
Laboratory duplicate samples are single samples on
which two analyses are performed. Laboratory duplicate
samples were analyzed after each set of 20 samples
submitted for analysis. Five pairs of laboratory
duplicate samples and their respective soil samples were
analyzed with the EnviroGard PCB Test. Field duplicate
samples are two samples collected together but delivered
to the laboratory under separate sample numbers. PRC
collected 32 field duplicate samples during this
demonstration. Each sample and its duplicate was
analyzed by the 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 itself. The laboratory
duplicates are compared to a window of acceptable
values and if one fell outside that window, corrective
action is taken by the laboratory. Field duplicates are
used to ensure that contamination of samples does not
occur during sample collection and to set boundaries of
variance due to the lack of homogenization inherent in
soil contamination.
PRC was tasked, though, not with determining the
precision of those collecting the samples or of the
laboratory, but with determining the precision of the
technology itself. 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
26
-------
I
TABLE 6-2. SEMIQUANTITATIVE RESULTS
FIELD DUPLICATE SAMPLES.
FOR
LABORATORY AND
Sample Duplicate
Result Result
Sample No. (mg/kg) (mq/kq)
047-4024-001 LD > 10 < 10
047-4024-01 5FD > 10 > 10
047-4024-022FD <10 < 10
047-4024-024FD < 10 < 10
047-4024-028FD < 10 < 10
047-4024-035FD < 10 < 10
047-4024-037FD < 10 < 10
047-4024-040LD > 10 > 10
047-4024-042FD > 10 > 10
047-4024-043FD > 10 > 10
047-4024-046FD < 10 < 10
047-4024-047FD < 10 < 10
047-4024-050FD > 10 > 10
047-4024-060FD > 10 < 10
047-4024-062LD > 10 > 10
047-4024-063FD < 1 .0 < 10
047-4024-069FD < 10 < 10
047-4024-071 FD < 10 < 10
047-4024-081 FD < 10 < 10
Sample
Result
Sample No. (mq/kq)
047-4024-082FD < 10
Of7-4024-083FD < 10
047-4024-084FD > 10
047-4024-085FD > 10
047-4024-086FD < 10
0'7-4024-087FD < 10
0< 7-4024-088FD > 10
0< 7-4024-090FD < 10
0' 7-4024-091 FD > 10
0/7-4024-092FD < 10
O<7-4024-095FD > 10 -
0'7-4024-097FD < 10
047-4024-098FD > 10
047-4024-098LD < 10
047-4024-1 OOFD > 10
I
047-4024-102FD > 10
04 7-4024-1 02LD > 10
04 7-4024-1 09FD < 10
Duplicate
Result
(mg/kg)
::
>10
<10
>10
>10
<10
>10
::
>10
<10.
Notes:
mg/kg Milligrams per kilogram.
LD Laboratory duplicate.
FD Field duplicate.
and its duplicate. To control the problems usually
detected by laboratory duplicates, PRC used only one
operator for each technology. It was assumed that any
variance in that operator's laboratory techniques would
be the same for each sample, and therefore, statistically
insignificant. For the field duplicates, PRC put each
sample through a homogenization process designed to
ensure that there was little difference between the
contamination hi a sample and its duplicate.
Confirmatory laboratory data on the field duplicates and
their respective samples indicate that, overall, this
technique worked (see Section 4). Only hi a few sam-
ples did the homogenization appear not to have been
complete.
PRC used both the laboratory and field duplicates to
determine the technology's precision. Thirty-seven
duplicate pairs were used in the semiquantitative
evaluation. Of these 37 duplicate pairs, the EnviroGaird
PCS Test produced the same results 35 times. One
laboratory duplicate, Sample 001, and one field
duplicate. Sample 060D, did not agree with their res-
pective corresponding sample results. Based on this
data, the precision of the EnviroGard PCB Test was
-------
found to be 95 percent, which meets the criteria for
precision.
Matrix spike duplicate samples were used to further
evaluate the precision of this technology. The matrix
spike duplicate sample results were compared to the
matrix spike sample results. The semiquantitative results
for the matrix spike samples were compared to the
Aroclor 1248 standards supplied by Millipore. Aroclor
1242 was added to each of the matrix spike samples at a
concentration of 25 mg/kg. Five of the six matrix spike
duplicate sample results matched those of the matrix
spike samples. The matrix spike duplicate result for
Sample 024 did not match the original matrix spike
sample result. From this data, it was determined that the
precision of the semiquantitative data for the EnviroGard
PCB Test was 83 percent.
Comparison of Results to Confirmatory
Laboratory Results
The following sections compare the accuracy and
precision of the semiquantitative data from the
EnviroGard PCB Test to that of the confirmatory
laboratory. The results from the confirmatory
laboratory are considered accurate, and its precision is
considered acceptable. The results are summarized in
Table 6-3 and on Figure 6-1, following the table.
Accuracy
To measure the accuracy of the EnviroGard PCB
Test, PRC compared the data from the technology to the
data from the confirmatory laboratory by using a 2 by
2 contingency table and a Fisher's Test, as approximated
by a corrected Chi-square statistic.
To obtain semiquantitative results with the
technology, its results must be evaluated relative to a set
of points or ranges. PRC evaluated the technology's
semiquantitative accuracy in two ways: using three
concentrations of Aroclor 1242 standards and using one
concentration of Aroclor 1248 standard.
Results were statistically evaluated with two 2 by
2 contingency tables, one for each range, to compare the
number of times the technology's results indicated results
were within each range to the number of tunes the
confirmatory laboratory indicated results were within
that range. A Fisher's Test, at a 95 percent confidence
level, was then used to determine whether a relationship
existed between the two sets of results.
Aroclor 1242 Standards (5,10, and 50 mg/kg)
PRC used three Aroclor 1242 standards to determine
the semiquantitative results of 52 samples. These results
placed the concentration of each sample within one of
four ranges: (1) less than 5 mg/kg; (2) between 5 and
10 mg/kg; (3) between 10 and 50 mg/kg; and (4) greater
than 50 mg/kg. The confirmatory laboratory's results
also were placed within one of these ranges.
For the first range, less than 5 mg/kg, the
technology indicated that 25 sample results were within
the range and 27 results were above this range. The
confirmatory laboratory indicated that 39 were within the
range and 13 were above it. The Fisher's Test showed
that results from the two sets of data were statistically
different. Since the confirmatory laboratory's data is
assumed to be accurate, the lack of correlation indicates
that within the first range the semiquantitative results
were not accurate when these standards were used.
For the second range, between 5 and 10 mg/kg, the
technology had no sample results within the range and
52 outside the range. The confirmatory laboratory had
five sample results within the range and 47 outside the
range. The Fisher's Test indicated that these two sets of
data were statistically different and that within this range
the semiquantitative results were not accurate.
The technology had 10 results within the third
range, which was between 10 and 50 mg/kg, and
42 outside it. The confirmatory laboratory had five
results within the range and 47 outside. The Fisher's
Test indicated that the data was not statistically different.
Therefore, within this range and using these standards,
the semiquantitative results were accurate.
In the final range, greater than 50 mg/kg, the
technology had 17 sample results above that level and
35 below it. The confirmatory laboratory had three
results above that level and 49 below it. The Fisher's
Test indicated that the data was statistically different.
Therefore, within the fourth range, the results from the
technology were not accurate.
>v
A comparison of the technology's sample results to
the confirmatory laboratory's results shows that 28 of
52 times the technology was correct, or 53.9 percent of
the time. The other 24 tunes the technology gave false
positive results. It never gave a false negative result
when the three Aroclor 1242 standards were used.
28
-------
TABLE 6-3. COMPARISON OF SEMIQUANTITAT VE DATA
CONFIRMATORY LABORATORY.
Sample
No.
001
002
003
004
005
006
007
008
009
010
011
012
013
014
015 .
015D
016
017
018
019
020
021
022
022D
023
024
024D
025
026
027
028
028D
EnviroGard Confirmatory
PCB Test Laboratory
(10mg/kga) (0.033 mg/kga)
>10 0.593
>10 1.50
>10 0.114
>10 6.71J
>10 1.37
> 10 0.679
> 10 0.552
> 10 2.00
>10 1.30J
>10 , 0.172J
>10 1.15J
>10 ND
>10 1.13
> 10 0.18
>10 9.13
> 10 9.84
>10 2,110
> 10 2.55
> 10 45.4
> 10 6.70
> 10 0.068 J
> 10 0.063
>10 0.535
> 10 0.718
>10 20.8
> 10 0.055
> 10 0.049
>10 11.7
>10 1.96
> 10 0.057
> 10 0.216
> 10 0.224J
Technology
Accuracy
FP
FP
Correct
FP
FP
FP
FP
FP
FP
FP
FP
Correct
Correct
Correct
FP
FP
Correct
FP
Correct
FP
Correct
Correct
Correct
Correct
Correct
Correct
Correct
FP
Correct
Correct
Correct
Correct
Sample
No.
029
Q30
OJ31
032
qss
034
035
CJ35D
0*36
C37
q37D
C38
C39
C40
C41
C42
C42D
OJ43
044
045
CJ46
CJ46D
I
CJ47
C47D
C48
C49
C50
C50D
CJ51
052
053
FOR ENVIROGARD PCB TEST AND
EnviroGard Confirmatory
PCB Test Laboratory
(10 mg/kga) (0.033 mg/kga)
> 10 0.229J
>10 1.15
> 10 0.263
> 10 47.6
>1+0 6.00J
> 10 34.0
>10 ND
>10 ND
>10 816
> 10 0.055J
> 10 0.040J
>10 1.030J
>10 0.676
> 10 4.25
>10 ND
> 10 0.517
>10 0.462J
>10 1.69J
>10 1.74
> 10 0.592J
>10 ND
> 10 , ND
>10 ND
> 10 0.094J
> 10 0.098J
>10 ND
>10 ND
> 10 3.60
> 10 4.41
>10 ND
>10 4.21
> 10 0.958
Technology
. Accuracy
Correct
Correct
Correct
Correct
FP
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
FP
Correct
FP
FP
FP
FP
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
FP
FP
Correct
FP
Correct
29
-------
TABLE 6-3 (Continued). COMPARISON OF SEMIQUANTITATIVE DATA FOR ENVIROGARD PCB
TEST AND CONFIRMATORY LABORATORY.
Sample
No.
054
055
056
057
058
059
060
060D
061
062
063
063D
064
065
066
067
068
069
069D
070
071
071 D
072
073
074
075
076
077
078
079
080
EnviroGard Confirmatory
PCB Test Laboratory
(10mg/kga) (0.033 mg/kga)
> 10 0.51 6J
> 10 2.40
> 10 0.505
>10 ND
> 10 0.681
> 10 7.86
> 10 0.624 J
> 10 0.577
> 10 580
> 10 2.35
> 10 0.092J
> 10 0.1 54J
> 10 19.0
> 10 3.08
>10 1.98
> 10 0.081
> 10 0.504 J
>10 ND
>10 ND
>10 ND
> 10 0.052J
>10 ND
> 10 0.035J
> 10 15.8
> 10 13.3
> 10 23.0
> 10 46.7
>10 ND
> 10 2.27
> 10 42.8
> 10 3.77
Technology
Accuracy
Correct
Correct
Correct
Correct
Correct
FP
FP
Correct
Correct
FP
Correct
Correct
Correct
FP
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
FP
Correct
Correct
Sample No.
081
081 D
082
082D
083
083D
084
084D
085
085D
086
086D
087
087D
088
088D
089
090
090D
091
091 D
092
092D
093
094
095
095D
096
097
097D
098
EnviroGard Confirmatory
PCB Test Laboratory
(10mg/kga) (0.033 mg/kga)
>10 0.687
> 10 0.450
>10 ND
> 10 0.244
> 10 0.484
> 10 0.413
>10 1.16
>10 1.08
> 10 428
> 10 465
>10 1.42
>10 1.25
> 10 0.076
>10 ND
>10 2.70
>10 1.77
> 10 45.0
>10 1.01
>10 1.40
>10 1,630
>10 1,704
>10 1.21
> 10 ND
> 10 0.295
> 10 0.362J
> 10 17.5
>10 31.2
>10 0.059 J
>10 1.23
> 10 0.285
>10 1.17
Technology
Accuracy
Correct
Correct
Correct
Correct
Correct
Correct
FP
FP
Correct
Correct
Correct
Correct
Correct
Correct
FP
FP
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
FP
30
-------
TABLE 6-3 (Continued). COMPARISON OF SEMIpUANTITATIVE DATA FOR ENVIROGARD PCB
TEST AND CONFIRMATORY LABORATORY. I
Sample
No.
098D
099
100
100D
101
102
102D
103
104
105
Notes:
a
FP
J
ND
NA
EnviroGard Confirmatory
PCB Test Laboratory
(10 mg/kg1) (0.033 mg/kg')
>10 0.825
,>10 ND
>10 177
> 10 167
>10 1.21
>10 293
>10 1.77
> 10 40.3
> 10 7.66
>10 0.210
Technology
Accuracy
FP
Correct
Correct
Correct
FP
Correct
FP
Correct
FP
Correct
'
EnviroGard
Sample PCB Test
No. (10 mg/kg')
106 > 10
107 > 10
108 > 10
1109 >10
109D > 10
Detection limit.
False positive.
Reported amount is below detection limit or not v
PCBs not detected above the detection limit.
The technology, the confirmatory laboratory, or b
110 >10
111 >10
112 >10
113 >10
114 >10
Confirmatory
Laboratory
(0.033 mg/kg')
2.50
14.1J
3.84J
ND
ND
ND
ND
315
14.9
66.3
Technology
Accuracy
Correct
Correct
FP
Correct
Correct
Correct
Correct
Correct
Correct
Correct
alid by approved QC procedures!
3th did not detect PCBs.
FIGURE 6-1. ASSESSMENT OF SEMIQUANTI-
TATIVE ENVIROGARD PCB TEST DATA.
>-
i
|
_ '
X
?
Falsa Positives f * *
* *** * * **
.';%>**'
True Negatives ^
*» *
... ».
»t » True Positives
.
False Negatives
E ««J *l f 1* 1M !** (MM
O
= Confirmatory Laboratory Concentration (mg/kg)
Aroclor 1248 (10 mg/kg standard)
A 10 mg/kg Aroclor 1248 standard was used to
assess the results of 94 samples. Each sample result was
reported as above 10 mg/kg of PCBs or below 10 mg/kg
of PCBs. The confirmatory laboratory results also were
placed in one of these two ranges.
The technology obtained 53 sample results below the
10 mg/kg level and 41 above it. The confirmatory
laboratory obtained 72 results below that level and
22 above it. The results of the analysis indicated that the
two data sets were statistically different. Since the
confirmatory laboratory's data is considered accurate,
the results from the technology, overall, are considered
not accurate when this Aroclor 1248 standard was used,
Of the 94 results, the technology had 75 correct
results and 19 false positive results. Again, no false
negative results were found.
Summary
Overall, the EnviroGard PCB Test is a conservative
kit when used semiquantitatively. It is not accurate
when assessed in this mode, but in all cases where its
results did not match those from the confirmatory
laboratory, it produced false positive results.
False negatives are the principal concern with
semiquantitative technologies. False negative results
could lead to the belief that soil is not contaminated
t
-------
above an action level when in fact it is. For this reason,
the EnviroGard PCB Test is designed to produce
numerous false positive results, but few false negative
results.
It should be noted that depending on the situation,
false positive results also can be of concern because they
indicate soil is more contaminated than it actually is.
This results in more soil being excavated and disposed of
than necessary. This can be costly and does not comply
with the waste minimization policies of many regulatory
agencies.
Precision
When used to produce semiquantitative results, the
precision of the EnviroGard PCB Test cannot be
compared to that of the confirmatory laboratory.
Quantitative Evaluation
After consulting with both Millipore and EMSL-LV,
PRC determined that with a minimal amount of
additional effort the EnviroGard PCB Test's ability to
produce quantitative results could be evaluated. This
evaluation, therefore, was included in the demonstration.
The following sections detail its results. Table 6-4 and
Figure 6-2 summarize the quantitative results.
Theory of Operation and Background
Information
The EnviroGard PCB Test used during the
quantitative analysis was the same as that used during the
semiquantitative analysis with one exception. Instead of
using the three Aroclor 1248 standards supplied by
Millipore to analyze samples, PRC used the Aroclor
1242 standards it had prepared. Originally, the three
concentrations of Aroclor 1242 used were 1, 5, and
25 mg/kg. The 1 mg/kg concentration was used to
define the detection limit of the technology. However,
a large number of soil samples analyzed with these
concentrations required dilution because the response of
the samples was not within the response range of the
standards. To decrease the number of samples requiring
dilution, the three concentrations were changed to
5, 10, and 50 mg/kg.
Samples were prepared for analysis in the same
manner used for the semiquantitative evaluation. The
test tube was then placed into the differential
photometer, and the optical density was recorded.
Quantitative results were obtained for the samples
through the use of standard curves. These curves were
produced for each set of Aroclor standards used. The
curves were manually plotted on graph paper. The
x-axis of the graph represented the PCB concentration in
the sample; the y-axis represented the optical density, or
absorbance, in the sample. The Aroclor standards and
the negative control sample were plotted on the graph.
A curve was generated by connecting these points. The
optical density values obtained for each soil sample were
then traced from the y-axis to the intersection of the
standard curve line, then to the x-axis. The point where
this line intercepted the x-axis indicated the
concentration of PCBs in the sample. Before the results
were reported, calculations were performed as needed to
correct the concentration for any dilutions performed.
The standard curve produced for each concentration
of the Aroclor 1242 standard resulted in a relatively
linear curve. The curve had a negative slope. The
curve resulted in average slope of -0.29. The slope of
the line did vary somewhat from analysis to analysis.
When the lowest standard was 1 mg/kg, the region of the
standard curve connecting the lowest concentration
standard and the negative control sample, which was
always placed at the y-intercept, changed slope
dramatically from sample to sample. When 5 mg/kg
was used as the lowest standard, the slope of the line
from the 5 mg/kg standard to the y-intercept was not as
dramatic. This suggests that a 5 mg/kg detection limit
for Aroclor 1242 may be more reliable than the 1 mg/kg
detection limit used for this demonstration
Operational Characteristics
The portability, logistical requirements, ease of
operation, and health and safety requirements for the
EnviroGard PCB Test operated in the quantitative mode
are the same as those detailed earlier in this section.
The same operator operated the technology in both
modes, and the costs of the analyses were the same. In
addition to the calibration problems detailed earlier, the
first calibration using the Aroclor 1242 standards was
unacceptable. This was attributed to operator error and
the small amount of standard required for analysis. The
problem was corrected, and all other calibrations with
these Aroclor standards were acceptable.
Performance Factors
Quantitative analysis of soil samples during this
demonstration was performed using 1, 5, 25, and
50 mg/kg Aroclor 1242 standards. The 50 mg/kg
Aroclor standard replaced the 25 mg/kg Aroclor
standard to reduce the number of dilutions needed to
obtain quantitative results. Throughout the demon-
stration, the 1 mg/kg Aroclor 1242 standard consistently
caused a greater response than the negative control
sample, which was expected. Not all samples analyzed
32
-------
TABLE 6-4. COMPARISON OF
QUANTITATIVE Di
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
022D
023
024
024D
025
026
027
028
028D
029
030
031
032
EnviroGard
PCB Test
(1.0 trig/kg")
10
22
2.5
61
30
13
19
16
17
40
24
17
12
20
50
50
300
12
370
29
2.5
1
5
4 "
50
ND
ND
50
14
ND
1
ND
ND
6
6
50
Confirmatory
Laboratory
(0.033 mg/kga) Difference
0.593
1.50
0.114
6.71J
1.37
0.679
0.552
2.00
1.30J
0.1 72J
1.15J
ND
1.13
0.18
9.13
9.84
2,110
2.55
45.4
6.70
0.068J
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
9.4
20.5
2.4
54.3
28.6
12.3
18.5
14.0
15.7
39.8
22.9
NA
10.9
19.8
40.9
40.2
-1,810
9.5
324.6
22.3
2.4
0.9
4.5
3.3
29.2
NA
NA
38.3
12.0
NA
0.8
NA
NA
4.9
5.7
2.4
Relative
Percent
Difference
177.7
174.5
182.6
160.4
182.5
180.1
188.7
155.6
171.6
198.3
181.7
NA
165.6
196.4
138.2
134.2
150.2
129.9
156.3
124.9
189.4
176.3
161.3
139.1
82.5
NA
NA
124.1
150.9
NA
128.9
NA
NA
135.7
183.2
4.9
(
t
'
OA FOR ENVIROGARD PCB TEST AND
Sample
Mo.
)33
034
035
035D
036
637
037D
038
39
040
041
042
(J42D
C|43
CJ43D
044
045
046
Q46D
°
47
047D
J
48
049
0
0
0
0
50
50D
51
52
053
054
055
056
0
o
57
58
OJ59
0
0
3c
po
boo
EnviroGard
PCB Test
(1. Drug/kg')
64S
40S
ND.S
ND.S
2,300
3
4
1,000
5
44
ND
25
9
30
20
2
ND
ND
ND
ND
ND
ND.S
ND
20
30
2
25
15
3
15
4S
ND.S
4
18
17
12
Confirmatory
Laboratory
(0.033 mg/kga)
6.00J
34.0
ND
ND
816
0.055J
0.040J
1.030J
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
58
6.0
NA
NA
1,484
2.9
3.9
-30
4.3
39.8
NA
24.5
8.5
28.3
18.3
1.4
NA
NA
NA
NA
NA
NA
NA
16.4
25.6
NA
20.8
14.0
2.5
12.6
3.5
NA
3.3
10.1
16.4
11.4
Relative
Percent
Difference
165.7
16.2
NA
NA
95.3
192.8
196.0
3.0
152.4
164.8
NA
191.9
180.5
178.7
168.0
108.6
NA
NA
NA
NA
NA
NA
NA
139.0
148.7
NA
142.3
176.0
141.3
144.9
155.2
NA
141.8
78.4
185.8
181.6
-------
TABLE 6-4 (Continued). COMPARISON
AND CONFIRMATORY LABORATORY.
OF QUANTITATIVE DATA FOR ENVIROGARD PCB TEST
Sample
No.
061
062
063
063D
064
065
066
067
068
069
069D
070
071
071 D
072
073
074
075
076
077
078
079
080
081
081 D
082
082D
083
083D
084
084D
085
EnviroGard
PCB Test
(Long/kg")
470
25
3
3
60
78S
14
2
4
ND
1
ND.S
ND.S
ND,S
2S
40
41
35
40
ND,S
23
70
19S
4
3
ND
ND
1
5S
50
49
370
Confirmatory
Laboratory
(0.033 rag/kg")
580
2.35
0.092J
0.1 54J
19.0
3.08
1.98
0.081
0.504J
ND
ND
ND
0.052J
ND
0.035J
15.8
13.3
23.0
46.7
ND
2.27
42.8
3.77
0.687
0.450
ND
0.244
0.484
0.413
1.16
1.08
428
Difference
-110
22.6
2.9
2.8
41.0
74.9
12.0
1.9
3.5
NA
NA
NA
NA
NA
1.9
24.2
27.7
12.0
-6.7
NA
20.7
27.2
15.2
3.3
2.5
NA
NA
0.5
4.6
48.8
48.9
-58
Relative
Percent
Difference
21.0
165.7
188.1
180.5
103.8
184.8
150.4
184.4
155.2
NA
NA
NA
NA
NA
193.1
86.7
102.0
41.4
15.5
NA
164.1
48.2
133.8
141.4
147.8
NA
NA
69.5
169.5
190.9
191.4
14.5
Sample
No.
085D
086
086D
087
087D
088
088D
089
090
090D
091
091 D
092
092D
093
094
095
095D
096
097
097D
098
098D
099
100
100D
101
102
102D
103
104
105
EnviroGard
PCB Test
(1.0mg/kga)
400
14S
15S
6
3
20
23
20
10
8
1,300
1,600
2
2
2
2
10
10
ND
ND
3
46
30
3
400
470
-
30
30
190
54S
ND
Confirmatory
Laboratory
(0.033 mg/kg°)
465
1.42
1.25
0.076
ND
2.70
1.77
45.0
1.01
1.40
1,630
1,704
1.21
ND
0.295
0.362N
17.5
31.2
0.059J
1.23
0.285
1.17
0.825
ND
177
167
1.21
293
1.77
40.3
7.66
0.210
Difference
-65
12.6
13.7
5.9
NA
17.3
21.2
-25
9.0
6.6
-330
-104
0.8
NA
1.7
1.6
-7.5
-21.2
NA
NA
2.7
44.8
29.2
NA
233
303
NA
-263
28.2
149.7
56.3
NA
Relative
Percent
Difference
15.0
163.2
169.2
195.0
NA
152.4
171.4
76.9
163.3
140.4
22.7
6.3
49.2
NA
148.6
138.7
54.5
102.9
NA
NA
165.3
190.1
189.3
NA
77.3
95.1
NA
162.8
177.7
130.0
150.3
NA
,34
-------
TABLE 6-4 (Continued). COMPARISON
AND CONFIRMATORY LABORATORY.
Sample
No.
106
107
108
109
109D
EnviroGard
PCB Test
(1.0 mg/kg1)
10S
40
19
2
ND
Confirmatory
Laboratory
(0.033 mg/kg')
2.50
14.1J
3.84J
ND
ND
Difference
7.5
25.9
15.1
NA
NA
OF QUAN
Relative
Percent
Difference
120.0
95.7
132.8
NA
NA
TITATIVE DATA FOR ENVIROGARD PCB
Sample
No.
110
111
112
113
114
EnviroGard
PCB Test
(1 .0 mg/kg")
2
ND
220
28
90
Confirmatory
Laboratory
,(0.033 mg/kg")
ND
ND
315
14.9
66.3
TEST
Relative
Percent
Difference Difference
NA
NA
-95
13.1
23.7
NA
NA
35.5
61.0
30.3
Notes:
J
S
ND
NA
Detection limit.
Reported amount is below detection limit or not va'lid by approved QC procedures.
Sample matrix effects raised detection limits.
PCBs not detected above detection limit.
The technology, the confirmatory laboratory, or bcjth did not detect PCBs.
No sample result obtained. |
FIGURE 6-2. ASSESSMENT OF QUANTITATIVE
ENVIROGARD PCB TEST DATA
^l IOOT
1
roGard Concentr
ti
a
False Positives
-
f <*l>
.y :.*
True Negatives
True Positives
: " ."
v*-;" .
False Negatives
» «i i » IK iw m
Conlirmatory Laboratory Concentration (mg/kg)
M
were calibrated using the 1 mg/kg Aroclor standard.
However, because the 1 mg/kg Aroclor 1242 standard
appeared correct each time it was used, all quantitative
results reported for the EnviroGard PCB Test were
based on a detection limit of 1 mg/kg.
The sample matrix effects noted in the semi-
quantitative evaluation also were noticed during the
quantitative evaluation. High concentrations of PCBs in
many of the soil samples presented an additional sample
matrix problem in the quantitative evaluation. While
these high concentrations had no effect on the
semiquantitative data, the quantitative data was affected.
The samples that exhibited a higher response than the
highest concentration of the Aroclor 1242 standard had
to be diluted to obtain results. The dilution was
performed by serially diluting the sample extract at a
ratio of 1 to 10. If, after the first dilution, the response
still exceeded the response of the highest Aroclor
1242 standard, the sample was diluted again at the same
ratio. This procedure was continued until the response
of the sample fell within the range of the Aroclor
1242 standards. Of the 146 total samples analyzed
during this demonstration, 42 required dilution.
Thirty-seven of these samples fell within the range of the
Aroclor 1242 standards after only one 1 to 10 ratio
dilution. The other five samples required a second 1 to
10 ratio dilution to provide a response within the range
of the Aroclor 1242 standards. When dilutions were
required, the detection limit was raised appropriately.
Specificity
The specificity of the EnviroGard PCB Test in the
quantitative mode was assessed using the approach
discussed earlier in this section. Table 6-5 summarizes
the quantitative results of the Aroclor specificity test.
Sample 077 was spiked with about 10 mg/kg of
Aroclor 1016. Results ranged from 8 to 12 mg/kg. The
average percent recovery of the four spiked samples was
92 . percent; the standard deviation of the percent
recovery was 22 percent. The technology's response to
Aroclor 1016 was close to its response to the Aroclor
1242 standards.
Sample 058 was spiked with 10 mg/kg of Aroclor
1248. Results ranged from 8 to 19 mg/kg. The average
percent recovery of the samples was 118 percent; the
standard deviation of the percent recovery was 48 per-
35
-------
TABLE 6-5. QUANTITATIVE RESULTS FOR THE AROCLOR SPECIFICITY TEST.
Confirmatory
Laboratory Result
Sample No. (mg/kg)
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
077ARSPG2
077ARSPG3
077ARSPG4
0.1
0.1
0.1
0.1
ND
ND
ND
ND
0.06
0.06
0.06
0.06
34.0
34.0
34.0
4.3
4.3
4.3
4.3
4.3
0.7
0.7
0.7
0.7
ND
ND
ND
ND
Soil Sample
Result
(mg/kg)
2.5
2.5
2.5
2.5
17
17
17
17
1
1
1
1
40
40
40
40
44
44
44
44
4
4
4
4
NDJ
NDJ
NDJ
NDJ
Aroclor
Spike
AR1221
AR1221
AR1221
AR1221
AR1260
AR1260
AR1260
AR1260
AR1232
AR1232
AR1232
AR1232
AR1254
AR1254
AR1254
AR1254
AR1242
AR1242
AR1242
AR1242
AR1248
AR1248
AR1248
AR1248
AR1016
AR1016
AR1016
AR1016
Spike Spiked
Amount Sample Result
(mg/kg) (mg/kg)
9.94
9.84
9.92
9.77
9.78
9.80
9.65
9.86
9.98
9.84
9.88
9.82
9.86
9.77
9.77
9.67
9.88
9.69
9.86
9.75
9.73
io.oo
10.00
9.90
9.65
9.96
9.75
9.90
5
3
2
4
45
36
36
34
10
12
6
8
120
120
120
120
44
28
42
33
8
16
19
19
12
8
8
8
Percent
Recovery
25
5
0
15
286
194
197
172
. 98
111
51
71
811
819
819
827
0
0
0
0
50
120
150
152
124
80
82
81
Notes:
mg/kg Milligrams per kilogram.
ND Not detected above the 1 mg/kg detection limit.
J Detection limit raised to 2 mg/kg due to dilution of sample.
36
-------
cent. The response of the technology to the samples
spiked with the Aroclor 1248 standard was greater than
its response to the Aroclor 1242 standards. Three of the
four sample results were higher than that of the
10 mg/kg Aroclor 1242 standard. This suggests that a
10 mg/kg sample containing Aroclor 1248 should
produce a response greater than the technology's
response to a 10 mg/kg Aroclor 1242 standard.
Sample 021 was then spiked with 10 mg/kg of
Aroclor 1232. Results ranged from 6 to 12 mg/kg. The
average percent recovery of the samples was 83 percent;
the standard deviation of the percent recovery was
27 percent. Results indicated that a soil sample
containing 10 mg/kg of Aroclor 1232 should produce a
response within two times the technology's response to
die Aroclor 1242 standard.
Sample 012 was spiked with 10 mg/kg of Aroclor
-.1260. Results ranged from 34 to 45 mg/kg. The
average percent recovery of the samples was 212 per-
cent; the standard deviation of the percent recovery was
50 percent. The response of the technology to samples
containing Aroclor 1260 was two to three times its
response to the Aroclor 1242 standards. A soil sample
containing 10 mg/kg of Aroclor 1260 should produce a
response within two to three tunes its response to a
10 mg/kg Aroclor 1242 standard.
Sample 003 was spiked with 10 mg/kg of Aroclor
1221. Results ranged from 2 to 5 mg/kg. The average
percent recovery of the samples was 11 percent; the
standard deviation of the percent recovery was 11 per-
cent. The response of the technology to samples
containing Aroclor 1221 was one-fourth, or less, than its
response to the Aroclor 1242 standards. A soil sample
containing 10 mg/kg of Aroclor 1221 should produce a
response equal to or less than one-fourth the response of
the technology to a 10 mg/kg Aroclor 1242 standard.
Sample 034 was found to contain 40 mg/kg of PCBs
when compared to die Aroclor 1242 standards. For the
specificity evaluation, this sample was spiked with
10 mg/kg of Aroclor 1254. The result for all four
aliquots was 120 mg/kg. The average percent recovery
of the samples was 819 percent; the standard deviation
of die percent recovery was 1 percent. The
confirmatory laboratory result for Sample 034 was
34 mg/kg. This indicates that the high results obtained
for all four aliquots were caused by the high recoveries
of Aroclor 1254 in diese samples.
The response of the technology to Sample 034 may
have been affected by the high concentrations of PCBs
in the soil samples prior to spiking. Results were nearly
eight tunes higher than expected, which suggests the
technology is much more sensitive to Aroclor 1254 than
I to Aroclor 1242.
Sample 040 was found to contain 44 mg/kg of PCEJs
when compared to the Aroclor 1242 standards. This
sample was spiked with 10 mg/kg of Aroclor 1242. Re-
sults ranged from 28 to 44 mg/kg. The average percent
recovery of the samples was 0 percent; the standard
deviation of the percent recovery was 0 percent. The
confirmatory laboratory result for Sample 040 was
4.2 mg/kg. EnviroGard PCB Test result of 44 mg/kg
does not compare well with die result from the
confirmatory laboratory. It was suspected that the
original EnviroGard PCB Test result for this soil sample
was a false positive result. The results of the Aroclor
specificity test seem to support this suspicion. The
response of the technology was affected by the high
concentration of PCBs hi Sample 040. All four spiked
samples were 0.0 percent, indicating that the 10 mg/kg
spikes were masked by the high concentration of PCBs
already hi the four aliquots. Because the original
EnviroGard PCB Test result for this sample was much
greater than the result from the confirmatory laboratory,
it is not possible to determine wifli certainty die
technology's specificity to Aroclor 1242.
Intramethod Assessment
No PCBs were found hi any of the reagent blanks
analyzed during either evaluation for this technology.
Quantitative results were obtained for all but Sample
101 because the soil sample required dilution. The
dilution of this sample resulted hi a response comparable
to the negative' control sample. This problem was not
recognized until after die demonstration activities were
completed. The measure of completeness, therefore, for
the quantitative analysis was 99 percent.
Intramethod accuracy was assessed using PE
samples and matrix spike and matrix spike duplicate
samples. The true result for PE sample 047-4024-114
(die high-level sample) was 110 mg/kg of Aroclor
1242, with an acceptance range of 41 to 150 mg/kg.
The quantitative result for the PE sample was determined
using the Aroclor 1242 standards prepared by PRC. The
actual reported result for this sample when analyzed by
the EnviroGard PCB Test was 90 mg/kg. This value-
was within the acceptance range. The percent recovery
for die high-level PE sample was 82 percent. The true
result for PE sample 047-4024-113 (the low-level
sample) was 32.7 mg/kg of Aroclor 1242. It had an
acceptance range of 12 to 43 mg/kg. The quantitative
result for the PE sample when analyzed was determined.
with the Aroclor 1242 standards prepared by PRC. The
result for this sample when analyzed with die Enviro-
,37
-------
Card PCB Test was 28 mg/kg. This value was within
the acceptance range. The percent recovery for the
low-level PE sample was 86 percent.
The quantitative recovery results of the matrix spike
and matrix spike duplicate samples are listed in Table
6-6. They were evaluated by comparing them to
Aroclor 1242 standard responses plotted on a standard
curve. The quantitative results of the soil samples,
before they were spiked, showed that four contained less
than 1 mg/kg of PCBs as determined by the Aroclor
1242 standards. One soil sample was found to contain
1 mg/kg of PCBs. Another soil sample was found to
contain 17 mg/kg PCBs. The average recovery of the
matrix spike samples was 114 percent or 28.5 mg/kg.
The standard deviation of the matrix spike samples was
40.1 percent or 10.0 mg/kg. These results are
summarized in Table 6-6. Following guidelines
outlined in EPA SW846 Method 8000, control 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 ranged from 34 to 194 percent recovery.
All matrix spike samples analyzed fell within these
control limits. The quantitative accuracy, as measured
by the matrix spike and matrix spike duplicate samples,
therefore, is acceptable. Based on an evaluation of PE
samples and matrix spike and matrix spike duplicate
samples, the intramethod accuracy of the EnviroGard
PCB Test is acceptable.
As with the semiquantitative evaluation, three types
of precision data were generated for the quantitative
evaluation: laboratory duplicate samples, field duplicate
samples, and matrix spike duplicate samples. Again,
laboratory and field duplicate samples were used
together because the soil samples were homogenized and
only one operator was used.
Quantitatively, the results of the soil samples ranged
from 1 to 1,300 mg/kg. The results of the duplicates for
those samples ranged from 2 to 1,600 mg/kg.
Quantitative matrix spike duplicate sample results are
given hi Table 6-6. Quantitative laboratory and field
duplicate sample results are presented in Table 6-7.
Even the best technology which determines results
quantitatively can not reproduce its results every time.
Therefore, PRC established control limits like those used
to evaluate laboratory duplicates. These control limits
were then used 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, all sample pairs (sample and duplicate)
that did not produce two positive results were removed
from the data population. Then, the RPD for each
sample pair was calculated and the mean RPD and
population standard deviation were determined. The
lower control limit was set at zero because this would
mean that the results from a duplicate and its respective
soil sample matched perfectly. The upper control limit
was set by multiplying the standard deviation by two and
adding it to the mean RPD. The RPD of each sample
pair was then compared to these control limits. Each
RPD was expected to fall within the control limits. If
greater than 95 percent fell within this range, the
technology's precision was considered adequate. If fewer
than 95 percent fell within this range, the data was
reviewed, and if no explanation could be found, the
technology's precision was considered inadequate.
The EnviroGard PCB Test had 27 sample pairs in
which both a sample and its duplicate had positive
results. The data from these sample pairs had a mean
RPD of 29 percent and a standard deviation of 31. The
control limits were, therefore, set at 0 and 92 percent.
All but two of the 27 RPDs fell within the control limits.
The first of these two sample pairs was Sample 042 and
Sample 042D, which had results of 25 and 9 mg/kg,
respectively. This resulted in an RPD of 94 percent,
2 percent above the upper control limit. The second of
the two sample pairs was Sample 083 and 083D, which
had results of 1 and 5 mg/kg, respectively. This resulted
in an RPD of 133 percent, 41 percent above the upper
control limit. Still, 91.5 percent of the sample pairs had
RPDs within the control limits. While 91.5 percent is
not between the demonstration's acceptable range of
95 to 100 percent, the technology only had two sample
pairs not within the control limits. If one more pair had
been accurate, the percentage acceptable would have
been 96.3. Because so few pairs were involved hi the
statistical evaluation, this percentage was deemed
acceptable.
The quantitative results for the matrix spike samples
were compared to the Aroclor 1242 standards prepared
by PRC. 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 is
the difference between these two results divided by the
mean of the two results, expressed as a percentage.
RPD values for the six matrix spike samples ranged
from 0 to 90 percent. The mean RPD value from these
six samples was 29 percent, and the standard deviation
was 34 percent. If an upper control limit of two times
the standard deviation is used, the upper control limit
was 97 percent. All RPD values for the matrix spike
duplicate samples fell within this range (Table
6-6). Therefore, based on the three types of intramethod
precision data generated, the precision of the EnviroGard
PCB Test is acceptable when used quantitatively.
38
-------
TABLE 6-6. QUANTITATIVE MATRIX SPIKE AND MATRIX SPIKE DUPLICATE RESULTS.
Sample No.
047-4024-012
047-4024-024
047-4024-049
047-4024-069D
047-4024-082
047-4024-111
Sojl Sample
Result
(mg/kg)
17
ND
ND ,
1.0
ND
ND
Matrix Spik<
Amount
(mg/kg)
25
25
25
25
25
25
i Matrix Spike
Recovery
112
136
96
84
64
184
Matrix Spike
Duplicate
Recovery
100
76
84
84
168
176
RPD
11
57
13
0
90
4
Notes: !
mg/kg Milligrams per kilogram.
ND Not detected above the detection limit of 1 mg/kg.
Comparison of Results to Confirmatory
Laboratory Results
The quantitative results of the EnviroGard PCB Test
were analyzed by using the linear regression techniques
detailed hi Section 4. The initial linear regression
analysis was based on results from 89 samples. The
other results indicated that no PCBs were detected above
the detection limit 1.0 mg/kg. The r2 for this regression
was 0.45, indicating that little or no relationship exists
between the data sets. Therefore, the technology is not
accurate. A residual analysis of the data, though,
identified that the r2 was greatly influenced by the results
for Samples 16, 18, 38, 91, and 100. All of these
samples show high levels of contamination. PRC
removed these six points as outliers and recalculated the
linear regression.
When the regression was recalculated on the 83 re-
maining sample results, it defined an r2 factor of
0.87, indicating that a relationship did exist between the
two data sets. The regression line that was calculated
had a y-intercept of 17.8 mg/kg and a slope of
0.76. The normal deviate test statistic, though, indicated
that the slope of 0.76 is significantly different from
1, and the y-intercept of 17.8 mg/kg is significantly
different from 0. This means that the results from this
technology are not accurate. However, if 10 to 20 per-
cent of the soil samples were sent to a confirmatory
laboratory, then the results from the other 80 to 90 per-
cent could be corrected. This could result in a
significant savings in analytical costs.
The Wilcoxon Signed Ranks Test was used to verify
these results. It indicated, at a 95 percent confidence
level, that the EnviroGard PCB Test's data was
significantly different from that of the confirmatory
laboratory. This confirmed the linear regression analysis
and indicated that the EnviroGard PCB Test's data was
not accurate.
To compare the precision of the EnviroGard PCB
Test's results to the precision of the confirmatory
laboratory's results, a Dunnett's Test was performed on
the RPDs determined from the field duplicate samples
and their respective 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, then it can be assumed that the precisions
are also similar. 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 are considered the same.
When the Dunnett's Test compared the RPDs between
the EnviroGard PCB Test's data and the confirmatory
laboratory's data, a probability of 97,5 percent resulted.
This indicates that the technology is as precise as the
confirmatory laboratory.
39
-------
TABLE 6-7. QUANTITATIVE LABORATORY AND FIELD DUPLICATE SAMPLE RESULTS.
Soil Duplicate
Sample Sample
Result Result
Sample No. (mg/kg) (mg/kg)
047-4024-001 LD 10
047-4024-01 5FD 50
047-4024-022FD 5
047-4024-024FD ND
047-4024-028FD 1
047-4024-035FD ND. J
047-4024-037FD 3
047-4024-040LD 40
047-4024-042FD 25
047-4024-043FD 30
047-4024-046FD ND
047-4024-047FD ND
047-4024-050FD 20
047-4024-060FD 17
047-4024-062LD 25
047-4024-063FD 3
047-4024-069FD ND
047-4024-071 FD ND, J .
047-4024-081 FD 4
Notes:
5
50
4
ND
ND
ND
4
44
9
20
ND
ND
30
12
21
3
1
ND
3
Relative
Percent
Difference
(%)
67
0
22
NA
NA
NA
29
10
94
40
NA
NA
40
34
17
0
NA
NA
29
Sample No.
047-4024-082FD
047-4024-083FD
047-4024-084FD
047-4024-085FD
047-4024-086FD
047-4024-087FD
047-4024-088FD
047-4024-090FD
047-4024-091 FD
047-4024-092FD
047-4024-095FD
047-4024-097FD
047-4024-098FD
047-4024-098LD
047-4024-1 OOFD
047-4024-1 02FD
047-4024-1 02LD
047-4024-1 09FD
Soil
Sample
Result
(mg/kg)
ND
1
50
370
14
6
20
10
1,300
2
10
ND
46
46
400
30
30
2
\
Duplicate
Sample
Result
(mg/kg)
ND
5
49
400
15
3
23
8
1,600
2 i
10
3
30
31
470
30
41
ND
Relative
Percent
Difference
(%)
NA
133
2
8
7
B7
I 4
21
:>1
0
0
NA
42
39
16
0 ~
31
NA
mg/kg Milligrams per kilogram.
LD Laboratory duplicate.
FD Field duplicate.
ND Not detected above the 1 mg/kg detection limit.
NA Not analyzed; the sample, duplicate, or both did not contain PCBs.
J Detection limit raised to 2 mg/kg due to dilution of sample.
40
-------
Secti on 7
Applications Assessment
The EnviroGard PCB Test can be operated in either
a semiquantitative or quantitative mode. In either mode,
it is relatively inexpensive and easy to operate. The
technology involves a number of different steps, which
increases the chance of operator error. In particular,
errors can occur during measurements because of the
small quantities of Aroclor standards and samples used.
For this reason, operators must be thoroughly trained.
Experience in common laboratory practices is helpful,
although the technology can still be operated by
nontechnical personnel.
The technology is very portable. Electricity is
required to operate it; however, electricity can be
supplied by a rechargeable battery. Reagents used with
the technology must be refrigerated. It has a high
sample throughput and is capable of quickly providing
results, particularly when used in the semiquantitative
mode. The ability of the technology to provide
quantitative results is an additional advantage. When it
is used hi the quantitative mode, however, samples must
frequently be diluted to bring their PCB concentrations
into the linear range of the technology.
The EnviroGard PCB Test has slight reactions to
some contaminants other than PCBs, such as halogenated
41
organic compounds. For this reason, the technology
does not appear to be highly susceptible to false positive
results due to interferants, unless the interferants are
present in very high concentrations (generally above 200
mg/kg depending on the interferant). The technology
also did not appear prone to produce false negative
results.
The results of the Aroclor specificity test indicated
that the EnviroGard PCB Test will react differently to
different Aroclors. However, Millipore can provide
Aroclor-specific standards if the Aroclor of concern is
known. When used with the correct standard, the
technology can provide semiquantitative or quantitative
results for each Aroclor.
The EnviroGard PCB Test can provide
semiquantitative or quantitative results at sites where the
Aroclor of concern is positively known so that the
appropriate Aroclor standard can be used. If the Aroclor
is known and if no interferants are suspected to be
present at high concentrations, this technology would be
useful at sites where results are needed quickly. If
quantitative results are required, the quantitative results
reported by the technology must be corrected if there is
a need for them to be accurate.
-------
Section 8
References
Department of Energy (DOE). 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.
Draper, N. R., and H. Smith. 1981. Applied Regression Analyses. John Wiley & Sons, Inc. New York. 2nded.
Environmental Protection Agency (EPA). 1989. "Preparing Perfect Project Plans." U.S. Environmental Protection
Agency. Cincinnati, OH. EPA/600/9-89/087.
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., Immunosystems, 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.
Stanley, T. W. and S. S. Veraer. 1983. "Interim Guidelines and Specifications for Preparing Quality Assurance
Project Plans." U.S. Environmental Protection Agency, Washington D.C. EPA/600/4-83/004.
42
* U.S. GOVERNMENT PRINTING OFFICE: 1995-653-291
-------
-------
United States
Environmental Protection Agency
National Risk Management
Research Laboratory (G-72)
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
Please make all necessary changes on the below label,
detach or copy, and return to the address in the upper
left-hand comer.
If you do not wish to receive these reports CHECK HERE D;
detach, or copy this cover, and return to the address in the
upper left-hand corner.
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/540/R-95/517
------- |