&EPA
United States
Environmental Protection
Agency
Office of Research and
Development
Washington DC 20460
EPA/540/R-95/518
August 1995
Clor-N-Soil PCB Test Kit,
Dexsil Corp.
Innovative Technology
Evaluation Report
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
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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.
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EPA/540/R-95/518
August 1995
CLOR-N-SOIL PCB TEST KIT, DEXSIL CORP.
INNOVATIVE TECHNOLOGY EVALUATION REPORT
NATIONAL RISK MANAGEMENT RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
NATIONAL EXPOSURE RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
LAS VEGAS, NEVADA 89193
Printed on Recycled Paper
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Notice
The information in this document has been funded wholly or in part by the U.S. Environmental Protection
Agency (EPA) in partial fulfillment of Contract No. 68-CO-0047, Work Assignment No. 0-40, to PRC
Environmental Management, Inc. It has been subject to the Agency's peer and administrative review, and it
has been approved for publication as an EPA document. The opinions, findings, and conclusions expressed
herein are those of the contractor and not necessarily those of the EPA or other cooperating agencies.
Mention of company or product names is not to be construed as an endorsement by the agency.
11
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Foreword
The U.S. Environmental Protection Agency is charged by Congress with protecting the Nation's land,
air, and water resources. Under a mandate of national environmental laws, the Agency strives to formulate and
implement actions leading to a compatible balance between human activities and the ability of natural systems
to support and nurture life. To meet this mandate, EPA's research program is providing data and technical
support for solving environmental problems today and building a science knowledge base necessary to manage
our ecological resources wisely, understand how pollutants affect our health, and prevent or reduce environmental
risks in the future.
The National Risk Management Research Laboratory is the Agency's center for investigation of
technological and management approaches for reducing risks from threats to human health and the environment.
The focus of the Laboratory's research program is on methods for the prevention and control of pollution to air,
land, water and subsurface resources; protection of water quality in public water systems ; remediation of
contaminated sites and ground water; and prevention and control of indoor air pollution. The goal of this research
effort is to catalyze development and implementation of innovative, cost-effective environmental technologies;
develop scientific and engineering information needed by EPA to support regulatory and policy decisions; and
provide technical support and information transfer to ensure effective implementation of environmental
regulations and strategies.
This publication has been produced as part of the Laboratory's strategic long-term research plan. It is
published and made available by EPA's Office of Research and Development to assist the user community and
to link researchers with their clients.
E. Timothy Oppelt, Director
National Risk Management Research Laboratory
m
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Abstract
This innovative technology evaluation report (ITER) presents the evaluation of two field screening technologies for
determining polychlorinated biphenyl (PCB) contamination hi soil. The demonstration was conducted by PRC
Environmental Management, Inc. (PRC), under contract to the Environmental Protection Agency's (EPA)
Environmental Monitoring Systems Laboratory—Las Vegas (EMSL-LV).
The Clor-N-Soil Test Kit and the L2000 PCB/Chloride Analyzer, both developed by the Dexsil Corporation, were
demonstrated hi August 1992 hi Kansas City, Missouri. The Clor-N-Soil Test Kit is designed to provide
semiquantitative results for PCBs hi soil. It provides a greater than or less than 50 milligrams per kilogram (mg/kg)
result. Compounds containing organic chlorine, such as PCBs, are extracted from the soil samples; through a series
of chemical steps, the chloride ions are stripped from the compound, transferred to an aqueous solution, and mixed
with a reagent to induce a color change. Because the test kit reacts to all sources of organic chlorine, the presence of
some compounds other than PCBs will cause it to produce false positive results. The presence of sulfur hi samples
may produce the same result. During this demonstration, the test kit produced 87 correct assays, 58 false positives,
and 1 false negative. Because the test kit reacts with the chlorine hi PCBs, it will produce different responses to
individual Aroclors, each of which contains a different percentage of chlorine. The test kit will produce false negative
results for samples containing Aroclors 1016, 1221, and 1232, which contain lower percentages of chlorine than
Aroclor 1260, the Aroclor the kit is designed to detect.
Like the Clor-N-Soil Test Kit, the L2000 PCB/Chloride Analyzer uses the principle of total organic chlorine detection.
The analyzer, though, uses a chloride-specific electrode to measure the amount of total organic chlorine hi the extract.
The analyzer also is capable of electronically converting the chloride concentration to produce quantitative results for
two different Aroclors. The detection limit of the analyzer is reported to be 5 mg/kg, although a detection limit of
2 mg/kg was used during this demonstration. Because the analyzer reacts with the chlorine hi PCBs, it will produce
various responses to individual Aroclors. The analyzer has a high likelihood of producing false negative results for
samples containing Aroclors 1016, 1221,-and 1232, which contain lower percentages of chlorine than the Aroclors
the analyzer is set to detect. If, however, the Aroclor type is known prior to analysis, the analyzer can be set to "total
chlorine" and the result divided by the appropriate factor (0.21 for Aroclor 1221, 0.32 for Aroclor 1232, and so
forth.) During this demonstration the analyzer's precision was found to be acceptable after reviewing its performance
on duplicate samples. To assess its accuracy, PRC used a linear regression approach to compare the analyzer's data
to corresponding confirmatory laboratory data. This analysis was based on 47 matched pairs of positive sample
results. For this regression analysis, the r2 factor was 0.86, indicating that a relationship existed between the two data
sets. The analysis defined a regression line with a y-intercept of 26.6 mg/kg and a slope of 0.84. These results
indicate that the analyzer is not accurate, but can be corrected mathematically.
This report was submitted hi 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
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Table of Contents
Section
Page
Notice |j
Foreword jjj
Abstract iv
List of Figures vii
List of Tables vii
List of Abbreviations and Acronyms viii
Acknowledgements x
1 Executive Summary 1
Clor-N-Soil Test Kit 1
L2000 PCB/Chloride Analyzer 2
2 Introduction 4
EPA's Site Program and MMTP: An Overview 4
The Role of Monitoring and Measurement Technologies 4
Defining the Process 5
Components of a Demonstration 5
Demonstration Purpose, Goals, and Objectives 5
3 Predemonstration Activities 7
Identification of Developers 7
Site Selection 7
Selection of Confirmatory Laboratory and Methods 8
Operator Training 8
Sampling and Analysis .8
4 Demonstration Design and Description 9
Sample Collection g
Quality Assurance Project Plan 10
Experimental Design 11
Field Analysis Operations 14
5 Confirmatory Analysis Results 15
Confirmatory Laboratory Procedures 15
Soil Sample Holding Times 15
Soil Sample Extraction , 15
Initial and Continuing Calibrations 16
Sample Analysis 16
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Table of Contents (Continued)
Section
Page
Detection Limits 16
Quality Control Procedures 17
Confirmation of Analytical Results 17
Second Column Confirmation 17
Gas Chromatographic Mass Spectrometer Confirmation 17
Data Reporting 17
Aroclors Reported by the Confirmatory Laboratory 18
Data Quality Assessment of Confirmatory Laboratory Data 18
Accuracy 18
Precision 18
Completeness 19
Use of Qualified Data for Statistical Analysis 19
6 Dexsil Corporation: Clor-N-Soil Test Kit ... 20
Theory of Operation and Background Information 20
Operational Characteristics , 21
Performance Factors 22
Detection Limits and Sensitivity 22
Sample Matrix Effects 23
Sample Throughput and Linear Range 24
Specificity 24
Potential Interferences 24
Aroclor Specificity Results 25
Intramethod Assessment 26
Comparison of Results to Confirmatory Results 28
Accuracy 28
Precision 31
7 Dexsil Corporation: L2000 PCB/Chloride Analyzer 32
Theory of Operation and Background Information 32
Operational Characteristics 32
Performance Factors 34
Detection Limits and Sensitivity 34
Sample Matrix Effects 36
Sample Throughput • 36
Linear Range 36
Drift 37
Specificity 37
Intramethod Assessment 39
Comparison of Results to Confirmatory Results 41
Accuracy 41
Precision 45
8 Applications Assessment 46
Clor-N-Soil Test Kit ; 46
L2000 PCB/Chloride Analyzer 46
9 References 48
VI
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List of Figures
Figure
6-1 Semiquantitative Assessment of Data
7-1 Quantitative Regression of Data
28
42
List of Tables
Table
6-1 Aroclor Specificity Test Results: Clor-N-Soil Test Kit
6-2 Matrix Spike and Matrix Spike Duplicate Results
6-3 Laboratory Duplicate Sample Results
6-4 Summary of Clor-N-Soil Test Kit Data
7-1 Aroclor Specificity Test Results: L2000 PCB/Chloride Analyzer
7-2 Reagent Blank Results
7-3 Matrix Spike and Matrix Spike Duplicate Results
7-4 Duplicate Results
7-5 Comparison of L2000 PCB/Chloride Analyzer and Confirmatory Data
Page
26
27
27
29
38
40
41
42
43
VII
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List of Abbreviations and Acronyms
AICO Abandoned Indian Creek Outfall
CCAL continuing calibration
CLP Contract Laboratory Program
CMS corrective measure study
CRQL contract required quantitation limit
DOE Department of Energy
DQO data quality objective
BCD electron capture detector
EMSL-LV Envkonmental 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
LCD liquid crystal display
/tg/kg micrograms per kilogram
meq milliequivalents
mg milligram
mg/kg milligrams per kilogram
mg/L milligrams per liter
mL milliliter
MMTP Monitoring and Measurement Technologies Program
MS mass spectrometer
MSDS material safety data sheet
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
QAPjP 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
VIII
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List of Abbreviations and Acronyms (Continued)
SITE
SOP
SOW
TCL
TPM
uv
Superfund Innovative Technology Evaluation
standard operating procedure
statement of work
target compound list
technical project manager
ultraviolet
ix
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Acknowledgements
This demonstration and the subsequent preparation of this report required the services of numerous personnel from
the Environmental Protection Agency, Environmental Monitoring Systems Laboratory (Las Vegas, Nevada);
Environmental Protection Agency, Region 7 (Kansas City, Kansas); Dexsil Corporation (Hamden, Connecticut); the
U.S. Department of Energy Kansas City Plant (Kansas City, Missouri); Allied-Signal, Inc. (Kansas City, Missouri);
and PRC Environmental Management, Inc. (Kansas City, Kansas; Cincinnati, Ohio; and Chicago, Illinois). The
cooperation and efforts of these organizations and personnel are gratefully acknowledged.
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Section 1
Executive Summary
This innovative technology evaluation report (ITER)
presents information on the demonstration and evaluation
of two field screening technologies for determining
polychlorinated biphenyl (PCB) contamination hi soil.
The demonstration was conducted by PRC Environmen-
tal Management, Inc. (PRC), under contract to the
Environmental Protection Agency's (EPA) Environmen-
tal Monitoring Systems Laboratory—Las Vegas
(EMSL-LV). The demonstration was developed under
the Monitoring and Measurement Technologies Program
(MMTP) of the Superfund Innovative Technology
Evaluation (SITE) Program.
The two technologies selected for this demonstration
and evaluation were the Clor-N-Soil Test Kit and the
L2000 PCB/Chloride Analyzer, both developed by the
Dexsil Corporation. They were demonstrated and
evaluated in August 1992 in Kansas City, Missouri. The
demonstration and evaluation of these two innovative
technologies were conducted hi conjunction with the
demonstration and evaluation of two other field screen-
ing methods, the EnviroGard PCB Test produced by
Millipore, Inc., and the Field Analytical Screening
Program PCB Method developed during the Field
Investigative Team Contract under the EPA Superfund
Program. The demonstration and evaluation of these
two other technologies are discussed in separate ITERs.
The findings of the demonstration of the two tech-
nologies manufactured by Dexsil are summarized below.
Clor-N-Soil Test Kit
The Clor-N-Soil Test Kit is designed to quickly
provide semiquantitative results for PCB concentrations
in soil samples. The test kit used for this demonstration
provides a greater than or less than 50 milligrams per
kilogram (mg/kg) result using the principle of total
organic chlorine detection. Compounds containing
organic chlorine, such as PCBs, are extracted from the
soil sample using an organic solvent. Then, through a
series of chemical steps, the chloride ions are stripped
from the PCB compound and transferred to an aqueous
solution. The extract is then mixed with a reagent to
induce a color change that corresponds to the number of
chloride ions hi the sample. Assuming that all chloride
ions detected in the sample come from PCBs, it is
possible to determine whether PCBs are present at
concentrations above a particular level. Because the test
kit reacts to all sources of organic chlorine, the presence
of chlorine-containing compounds other than PCBs will
cause the kit to produce false positive results. The
presence of sulfur hi samples may produce the same
result.
The Clor-N-Soil Test Kit is portable, easy to
operate, and useful under limited site conditions.
Depending on how the test kit is ordered from the
developer, the cost of this technology ranges from $10
to $14 per analysis. The average tune required to
perform one analysis during the demonstration was
found Ho be 11 minutes.
To ensure that the test kit always produces a positive
result for samples containing at least 50 mg/kg of PCBs,
the kit is designed with a correction factor. This correc-
tion factor accounts for any losses of chloride during its
extraction from the sample. Because of this correction
factor, the test kit is likely to produce a high number of
false positive results when PCBs are present at concen-
tration;; below, but near, the detection level. During this
demonstration, the test kit produced 87 correct assays,
58 false positives, and 1 false negative.
The false negative occurred when the test kit
determined that less than 50 mg/kg of PCBs was present
in the sample, but the confirmatory laboratory indicated
that the sample contained 293 mg/kg. Despite sample
homogenization, though, the confirmatory laboratory
indicated a level of 1.77 mg/kg in a field duplicate of
that sample. This single false negative occurred from
the analysis of a sample that appears as an outlier hi all
other technology data evaluations.
Because the Clor-N-Soil Test Kit reacts with the
chlorine in PCBs, it will produce different responses to
1
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individual Aroclors, each of which contains a different
percentage of chlorine. Because of this, the test kit will
produce false negative results for samples containing
Aroclors 1016, 1221, and 1232, which contain lower
percentages of chlorine than Aroclor 1260, the Aroclor
the kit is designed to detect.
PRC evaluated the test kit's precision by analyzing
duplicate samples. Thirty-two field duplicate samples
were analyzed by the Clor-N-Soil Test Kit during the
demonstration. The results indicated that the test kit was
able to duplicate its results 81 percent of the tune. A
review of the results that did not match showed that the
Clor-N-Soil Test Kit appeared to have more difficulty
duplicating its results when the PCB concentrations were
near 1 mg/kg.
To evaluate the test kit's accuracy, PRC determined
whether each confirmatory laboratory result was above
or below 50 mg/kg. The test kit's results and the
confirmatory laboratory's results were then evaluated
using a 2 by 2 contingency table and the Fisher's Test
statistic. Results from this analysis indicated that there
was no correlation between data from the test kit and
data from the confirmatory laboratory. This suggests
that the Clor-N-Soil Test Kit is not accurate. However,
this absolute assessment of accuracy may not affect the
test kit's usefulness. The test kit's inaccuracies were
primarily the result of false positive results, and this type
of inaccuracy would, at worst, result hi the misidentifi-
cation of clean material as contaminated. To eliminate
the effects of false positive and false negative results, all
critical samples should be confirmed using EPA-
approved methods.
L2000 PCB/Chloride Analyzer
The L2000 PCB/Chloride Analyzer is designed to
quickly provide quantitative results for PCB concentra-
tions in soil samples. Like the Clor-N-Soil Test Kit, the
analyzer uses the principle of total organic chlorine
detection. The principal difference between the Clor-
-N-Soil Test Kit and the L2000 PCB/Chloride Analyzer
is the way total organic chlorine is detected after the
sample is extracted. The analyzer uses a chloride--
specific electrode to measure the amount of total organic
chlorine in the extract and displays the results on a
screen. The analyzer also is capable of electronically
converting the chloride concentration to produce quanti-
tative results for two different Aroclors. Like the
Clor-N-Soil Test Kit, the L2000 PCB/Chloride Analyzer
reacts to all sources of organic chlorine, and the pres-
ence of chlorine-containing compounds other than PCBs
will cause the analyzer to produce false positive results.
The analyzer is very portable, although electricity is
required to operate it. It is easy to operate. During this
demonstration, the analyzer often needed to be re-
calibrated, particularly when analyzing samples with
high PCB concentrations. The analyzer is sold with
enough reagents to perform 200 analyses at a cost of
$3,500. Additional reagents also can be purchased.
Depending on the quantity ordered, the cost of additional
reagents ranges from $8 to $10 per analysis. The
amount of time required to perform one complete sample
analysis during the demonstration averaged nine minutes.
The detection limit of the analyzer is reported by its
developer to be 5 mg/kg, although a detection limit of 2
mg/kg was used during this demonstration.
Because the L2000 PCB/Chloride Analyzer reacts
with the chlorine in PCBs, it will produce various
responses to individual Aroclors. The analyzer has a
high likelihood of producing false negative results for
samples containing Aroclors 1016, 1221, and 1232,
which contain lower percentages of chlorine than the
Aroclors the analyzer is set to detect. If, however, the
Aroclor type is known prior to analysis, the L2000
PCB/Chloride Analyzer can be set to "total chlorine"
and the result divided by the appropriate factor (0.21 for
Aroclor 1221, 0.32 for Aroclor 1232, and so forth.)
To assess the analyzer's precision, PRC evaluated
its performance in analyzing both laboratory and field
duph'cate samples. The L2000 PCB/Chloride Analyzer
had 18 sample pairs in which both the sample and its
duplicate had positive results. PRC used the data from
the duplicate analyses to establish precision control
limits. The determination of precision was based on the
percentage of duplicate sample pairs that had relative
percent differences (RPD) within these control limits.
The precision control limits were set at 0 and 77.4
percent RPD. All but one of the 18 sample pairs' RPDs
fell within the control limits. This one failure caused the
analyzer's overall precision to be 94.5 percent. The goal
for precision for this evaluation was between 95 and 100
percent. While the 94.5 percent is not between 95 and
100 percent, the analyzer could not have come closer to
100 percent without every sample pair falling within the
control limits; therefore, the precision was considered
acceptable.
To evaluate the analyzer's accuracy, PRC used a
linear regression approach to compare the analyzer's
data to the corresponding confirmatory laboratory's data.
This analysis was based on 47 matched pairs of positive
sample results. For this regression analysis, the r2 factor
was 0.86, indicating that a relationship existed between
the two data sets. The analysis defined a regression line
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with a y-intercept of 26.6 mg/kg and a slope of 0.84.
These results indicate that the analyzer is not accurate,
but can be corrected mathematically. In addition to the
regression approach, PRC used a nonparametric test
statistic, the Wilcoxon Signed Ranks Test, to verify the
regression evaluation. It also indicated, at a 95 percent
confidence level, that the analyzer's data was
significantly different from that of the confirmatory
laboratory.
Based on these results, the L2000 PCB/Chloride
Analyzer's results should not be expected to be the same
as those from a confirmatory laboratory. However, if
10 to 20 percent of the samples collected also are sent to
a confirmatory laboratory, then the results from the
other 80 to 90 percent can be corrected. This may result
hi a significant savings in analytical costs.
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Section 2
Introduction
This ITER summarizes the procedures used to
demonstrate the Clor-N-Soil PCB test Kit and L2000
PCB/Chloride Analyzer. It discusses the results of the
demonstration and evaluates the effectiveness and possible
uses of these two innovative technologies at various
hazardous waste sites. The primary goal of the
demonstration was to evaluate these technologies and to
provide Superfund decisionmakers with adequate reliable
information on their 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 SITE
Program, 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 Monitoring and Measurement Technologies
Program (MMTP)
• The Technology Transfer Program
The largest part of the SITE Program is concerned
with treatment technologies and is administered by ORD's
National Risk Management Research Laboratory
(NRMRL) in Cincinnati, Ohio. The MMTP component,
though, 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 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, insure 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.
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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 standards 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 insure 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, are generated during the
demonstration and allow a potential user to make
economic comparisons. Finally, information on practical
matters such as operator training requirements, detection
levels, and ease of operation are reported. Thus, the
demonstration report and other informational materials
produced by 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, MMTP identifies
potential participants and determines whether they are
interested hi 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 insure 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, and probably the most important
component, 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, quality assurance project plan
(QAPjP), 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 the
developer can maximize the field performance of its
innovative technology. Generally, the developers tram
demonstration personnel so that performance is not based
on special expertise. This also insures that 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 insuring 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. Two-page
"Technical Briefs" are prepared to summarize the
demonstration results and to insure rapid and wide
distribution of the information.
Each developer is responsible for providing the
equipment or technology product to be demonstrated, its
own mobilization costs, and the training of EPAdesignated
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 riot cover the costs developers incur to demonstrate
their piroducts.
Demonstration Purpose, Goals,
and Objectives
For this demonstration, the two innovative tech-
nologies produced by the Dexsil Corporation were
evaluated for their accuracy and precision in detecting high
and low levels of PCBs in soil samples, and the ef-fects,
if any, of matrix interferences on the technologies. The
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high and low levels of PCBs in soil samples, and the ef-
fects, if any, of matrix interferences on the technologies.
The accuracy and precision of the technologies were sta-
tistically compared to the accuracy and precision attained
in a conventional, fixed laboratory using standard EPA
analytical methods. The technologies also were qualita-
tively evaluated for the length of time required for
analysis, ease of use, portability, and operating cost.
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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, conduct-
ing operator training, and conducting predemonstration
sampling and analysis. This section summarizes these
activities and presents the findings and results of the pre-
demonstration sampling and analysis.
Identification of Developers
EMSL-LV identified the Clor-N-Soil PCB Test Kit
and L2000 PCB/Chloride Analyzer as showing promise
for use in PCB field screening. After a review of
available data on these technologies, EMSL-LV con-
cluded that they warranted evaluation under the MMTP.
Site Selection
The following criteria were used to select a hazard-
ous waste site suitable for the demonstration:
• The technologies had to be tested at a site with a
wide range of PCB contamination.
• Contaminant concentrations had to be well charac-
terized and documented. Thorough site background
information was needed so mat a demonstration
sampling plan could be designed with a high degree
of confidence that the desired range of PCB concen-
trations 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's
(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 concen-
trations. 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 collecting
samples with a wide range of PCB concentrations
possible.
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 manu-
facture non-nuclear 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 pliant 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 in a former channel of Indian Creek and
is the former location of a storm water outfall (Outfall
002) that 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 contaminant at the
site. Samples from 12 borings were analyzed for
priority pollutants other than PCBs. Only one of these
borings contained non-PCB priority pollutants. This
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boring was found to contain several base neutral or-
ganics, 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 that 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 when
boreholes were drilled during investigation of 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 limestone fragments, wood, asphalt,
and concrete slag up to 4 feet wide are found in the fill
material. Near the surface, up to 20 percent of the fill
is composed of organic matter, such as roots, peat, and
wood (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
low permeability (DOE 1989). The aquifer of concern
beneath the AICO site is the shallow groundwater lying
just above bedrock.
Selection of Confirmatory Laboratory and
Method
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 CLP 1990
Statement of Work (SOW) for analyzing PCBs and
pesticides. The EPA Region 7 Laboratory conducted a
Level II data review of the confirmatory laboratory's
data.
Operator Training
The Clor-N-Soil PCB Test Kit and L2000
PCB/Chloride Analyzer each was demonstrated by a
PRC employee. Prior to the demonstration, the opera-
tors were trained hi the use of the two technologies.
This training included a review of operating procedures
and instructions provided by Dexsil and informal field
training conducted by Dexsil at the start of die demon-
stration. Training was equivalent to that recommended
by Dexsil for actual site characterization projects.
Sampling and Analysis
In May 1992, PRC prepared a predemonstration sam-
pling 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 four replicates. One
replicate of each sample was submitted to Dexsil, the
confirmatory laboratory analyzed one replicate, and the
other two replicates were given to developers of the
other two innovative technologies.
This predemonstration sampling was conducted so
that Dexsil could refine its technologies and revise its
operating instructions, if necessary, before the demon-
stration. This sampling also allowed potential matrix
effects or interferences to be evaluated prior to the
demonstration. The principal finding from pre-
demonstration sampling was that the soil at the AICO
site was more clayey than expected which made homoge-
nizing the samples difficult.
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Section 4
Demonstration Design and Description
This section describes the sample collection proce-
dures and the experimental design used to evaluate the
Clor-N-Soil PCB Test Kit and L2000 PCB/Chloride
Analyzer. These innovative technologies were evaluated
hi conjunction with two other field screening technolo-
gies that also screen for PCBs hi soil. The demonstra-
tion design and description, and the experimental design
described hi this section were common to all four
evaluations. The four evaluations also shared a single
demonstration plan and QAPjP. Key elements of the
QAPjP (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 hi this demonstration. A third
replicate was analyzed in the field using the Clor-N-Soil
Test Kit. A fourth was analyzed hi the field using the
L2000 PCB/Chloride Analyzer. The remaining repli-
cates were analyzed hi the field using the two 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 concentra-
tions. All samples were collected by PRC using the
sample collection and homogenization procedures
specified hi 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 hi the not detected to 100
mg/kg range, for two reasons. First, this range encom-
passes typical regulatory thresholds for PCBs, such as
the 10 mg/kg level for cleanups in unrestricted access
areas and the 50 mg/kg level for cleanups hi industrial
areas, Second, most of the four field screening technol-
ogies demonstrated, including the Clor-N-Soil PCB Test
Kit and L2000 PCB/Chloride Analyzer, were designed
primarily for operation hi this range.
Twenty samples were collected from areas previ-
ously identified as containing PCBs at concentrations
ranging from 100 to 1,000 mg/kg. An additional 20
samples were collected 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 moni-
tor PCBs hi higher concentrations as well as hi the
average range.
After collection, soil samples were placed hi plastic
bags jffld thoroughly homogenized. Samples were then
split and placed hi sample containers. Samples to be
submitted for confirmatory laboratory analysis were
placed hi 8-ounce, wide-mouth glass jars with tef-
lon-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 tef-
lon-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 exam-
hied each sample under an ultraviolet (UV) lamp hi a
portable darkroom. Because fluorescein fluoresces
under UV light, PRC was able to ensure that homogeni-
zation 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, men homog-
-------
enization 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 expected
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 was
possible to determine if the mean of the differences
between the samples and their duplicates was signifi-
cantly 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 their homogenization could have been
better, overall the homogenization technique used was
highly effective.
To apply the matched pair Student's t-test, it was
necessary to have a normally distributed data population.
The differences between confirmatory laboratory sam-
ples and their respective duplicates were statistically
evaluated and found to be normally distributed. Two
data point outliers were noted in the frequency plot.
Samples 91 and 102, respectively, were the low and high
outliers. The Student's paired t-test, however, was
found acceptable even when the outliers were included
in the data set.
The statistical analysis indicates that the homogeni-
zation was acceptable, but even at a 95 percent confi-
dence 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 such as 102 and
102D with high RPDs relative to the population's mean
RPD is masked and does not affect the overall assess-
ment. Therefore, even with a statistical assessment that
indicates overall effective sample homogenization, it is
possible that a limited number of poorly homogenized
samples were included hi the demonstration. The
analysis of such data could produce limited cases of
inaccurate data. For this reason, a large number of
samples were collected and analyzed to prevent any
anomalous samples from affecting the overall results.
Quality Assurance Project Plan
To ensure that all activities associated with this
demonstration met the demonstration objectives, a
QAPjP was prepared (PRC 1992b). The QAPjP, 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 QAPjP, and ulti-
mately, all participants agreed to its content.
The primary purpose of the QAPjP 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 II project. The QAPjP addressed the key
elements required for Category II projects prepared
according to guidelines hi the EPA booklet Preparing
Perfect Project Plans (1989) and the Interim Guidelines
and Specifications for Preparing Quality Assurance
Project Plans (Stanley and Verner 1983).
For sound conclusions to be drawn about 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: representative-
ness, completeness, comparability, accuracy, and
precision. Each of these indicators is discussed hi 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 of the method. It was
critical that the confirmatory laboratory analyses be
sound and within CLP 1990 SOW method specifications
to allow the data it generated to be compared to that
obtained by the technologies. High quality, well docu-
mented 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
10
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sample collection, homogenization, and handling pro-
gram. 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
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 by the Clor-N-Soil Test
Kit, the L2000 PCB/Chloride Analyzer, and the other
technologies with confirmatory laboratory results.
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 die
sample. Bias, a measure of the departure from complete
accuracy, can be caused by variations in instrument
calibration, loss of analyte hi the sample extraction
process, interferences, and systematic contamination or
carryover of analyte from one sample to the next.
One purpose of the demonstration was to assess the
accuracy of the Clor-N-Soil Test Kit and the L2000
PCB/Chloride Analyzer. The accuracy of the
Clor-N-Soil Test Kit and L2000 PCB/Chloride Analyzer
are detailed in Sections 6 and 7. The accuracy DQO for
the confirmatory laboratory was achieved and is dis-
cussed in more detail hi Section 5.
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 then-
duplicates to control limits established through the
statistical methods detailed hi Section 4. Determining
the precision of the Clor-N-Soil PCB Test Kit and L2000
PCB/Chloride Analyzer was one of the objectives of this
demonstration. Data on the precision of the technologies
is detailed hi Sections 6 and 7. The precision DQO for
the confirmatory laboratory was achieved and is dis-
cussed hi Section 5.
Experimental Design
The primary objective of the demonstration was to
evaluate the Clor-N-Soil Test Kit, the L2000
PCB/Chloride Analyzer, and two other field screening
technologies for determining PCB contamination hi soil.
This evaluation included defining the precision, accu-
racy, cost, and range of usefulness for each technology.
This objective also included determining the DQOs that
each technology was capable of achieving. A second
objective was to evaluate the specificity of each technol-
ogy 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 quantitative factor. Costs in-
cluded 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 for each of the field screening technolo-
gies.
Many analytical techniques can have significant
operator effects, hi 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 distinguish-
able from error inherent hi 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 confirma-
tory laboratory. Statistical analysis of these results were
then used to identify the contaminant range hi 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 mix of PCBs.
However, there are other common Aroclors as well. In
11
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the planning stages of this demonstration, interest was
shown hi 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 technolo-
gies 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 of a technology was statistically compared
to the precision of the confirmatory laboratory.
All of the statistical tests used for this demonstration
were stipulated in the demonstration plan, which was
approved in advance of data collection by all demonstra-
tion participants (PRC 1992b). Also stipulated in the
demonstration plan was that all sample pairs that in-
cluded a not detected result would be removed from data
sets. PRC felt that the variance introduced by eliminat-
ing 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 col-
lected, the demonstration plan stated that the results of
the two duplicates would be averaged and that this
average would be used in subsequent statistical analysis.
PRC followed this guideline. In this way, samples were
not unduly weighted in the statistical analyses.
The intramethod comparisons involved a statistical
analysis of RPDs. First, the RPDs of the results for
each sample pair, in which both the sample and its
duplicate were found to contain PCBs, were determined.
The equation used was:
(4-1)
RPD
100
(R, + Rd)l2
where
RPD - relative percent difference.
R, = Initial result.
Rj = duplicate result.
The RPDs were then compared to upper and lower
control limits. Because the technologies being demon-
strated were themselves being assessed, the control
limits used were calculated from data provided during
this investigation. To determine these control limits, the
standard deviation of the RPDs was calculated for each
technology. This standard deviation was then multiplied
by two and added to its respective mean RPDs. This
established the upper control limit for the technology.
Because an RPD of zero would mean that the duplicate
samples matched their respective samples perfectly, zero
was used as the lower control limit. This resulted in a
large range of acceptable values. Because duplicate
analyses seldom match perfectly, even for established
technologies, all samples that fell within the control
limits were considered acceptable. PRC determined that
if at least 95 percent of the duplicate samples fell within
these control limits, the technology had acceptable
precision.
Each field screening technology's data was com-
pared 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 technolo-
gies that were capable of determining quantitative
results. One of those was the L2000 PCB/Chloride
Analyzer. PRC calculated this data by the method of
least squares. Calculating linear regression in this way
makes it possible to determine whether two sets of data
are reasonably related, and if so, how closely. Calculat-
ing linear regression results hi an equation that can be
visually expressed as a line. Three factors are deter-
mined during calculations of linear regression. These
three factors are the y-intercept, the slope of the line,
and the correlation coefficient, also called an r2. All
three of these factors had to have acceptable values
before a technology's accuracy was considered accept-
able.
The r2 expresses the mathematical relationship
between two data sets. If the r2 is one, then the two data
sets are closely related. Lower r2 values indicate less of
a relationship. Because of the nature of environmental
samples, r2 values between 0.80 and 1 were considered
acceptable for this demonstration.
If an r2 below 0.80 was found, the data was re-
viewed to determine whether any particular results were
skewing the r2. This skewing may sometimes occur
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
12
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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 calculat-
ing 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 in an r2 between
0.80 and 1, then the regression line's y-intercept and
slope were examined to determine how closely the two
data sets matched. A slope of one 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 technol-
ogy. Still, a slope or y-intercept can differ slightly from
their expected values without that difference being
statistically significant. To determine whether such
differences were statistically significant, PRC used the
normal deviate test statistic. This test statistic calculates
a value that is compared to a table. The value at the 95
percent confidence level was used for the comparison.
If an r2 between 0.80 and 1 was not found, then the
technology's data was determined to be 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, then
the technology was found to be inaccurate. However, in
this case, results from the technology could be mathe-
matically 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. Still, only in cases where the r2, the y-intercept,
and the slope were all found to be acceptable did PRC
determine that the technology 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 n onp-
arametric 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 mat 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 concen-
trations 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 predeter-
mined 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.
Two of the field screening technologies demon-
strated produce semiquantitative results. One of those
was the Clor-N-Soil Test Kit manufactured by Dexsil.
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 in this demonstra-
tion, is:
(4-2)
= Unobserved value
expected value
expected value) - .5]/
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 was considered accurate.
iFinally, if possible, the precision of each technology
was statistically compared to the precision of the confir-
matory 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 in 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.
13
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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
any difference between the two data sets actually re-
sulted because a technology's data was more precise than
the confirmatory laboratory's.
Field Analysis Operations
The field analysis portion of the demonstration was
performed in a rented, 28-foot trailer. Electricity was
supplied for the equipment, refrigerators, and air
conditioners. Space within the trailer was divided to
provide an area for each technology, 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 demonstra-
tion. All analytical equipment was powered up and
checked to ensure that it was operable. All problems
found were corrected.
14
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Section 5
Confirmatory Analysis Results
All samples collected during this demonstration
"were submitted to the EPA Region 7 Laboratory for
analysis under its CLP. The data supplied by the
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 labora-
tory 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 com-
ments 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 hi this
section, all of the confirmatory laboratory results used to
assess the two innovative technologies produced by
Dexsil are presented in tables in Sections 6 and 7.
Soil Sample Holding Times
The CLP 1990 SOW method requires that all soil sample
extractions be completed within seven 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 proce-
dures outlined in 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 die 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 methy-
lene chloride mixture. The organic solvent is filtered
and combined in 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
15
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extraction column to remove any polar compounds from
the extract. The soil sample extract is diluted to 10 mL
with hexane and is transferred to a test tube to await
sample analysis.
Initial and Continuing Calibrations
The CLP 1990 SOW method for analyzing PCBs
involves an initial calibration (ICAL) for PCBs, which
consists of analyzing one concentration of each of the
seven Aroclors listed hi the Target Compound List
(TCL). The ICAL is used to determine peaks to identify
Aroclors and to determine factors to quantitate PCBs in
samples. The ICAL is performed before sample analysis
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 quantisation.
Continuing calibrations (CCAL) are performed by
analyzing instrument blanks and performance evaluation
(PE) mixture standards. The retention times and calibra-
tion factors determined during the ICAL are monitored
through CCALs. The CCAL standard is typically a
mid-level pesticide standard; however, because PCBs
were the compounds of interest, an Aroclor was used as
the CCAL standard for analyzing these samples.
Retention times were monitored through evaluating
the amount of retention tune shift from the PCB CCAL
standard as compared to the PCB ICAL standard. The
retention tune window was defined as ± 0.07 minutes
for each peak identified hi the ICAL. According to the
CLP 1990 SOW method, any tune a peak of an Aroclor
falls outside of its window, a new ICAL must be con-
ducted. During the analysis of samples for this demon-
stration, the retention tunes of the peaks chosen for
monitoring during the CCAL never exceeded the win-
dows established for them hi the ICAL.
Calibration factors were monitored hi accordance
with the CLP 1990 SOW method and were acceptable as
the CCAL calibration factor never exceeded 25 percent.
Once an ICAL has been performed, sample analysis
begins. Usually, sample analysis begins by analyzing a
method blank to verify that it meets the CLP 1990 SOW
method requirements. After this, sample analysis may
continue for 12 hours. After every 12-hour period, a
CCAL standard must be analyzed. Sample analysis may
continue as long as CCAL standards meet the CLP 1990
SOW method requirements.
Sample Analysis
PCBs are identified in samples by matching peak
patterns found after analyzing the sample with those
found hi 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 hi 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 hi the ICAL standard. The reported results of
this calculation are based on dry weights, as required by
the CLP 1990 SOW method. Because the screening
technologies all reported wet weight results, PRC
converted the results reported by the confirmatory
laboratory from dry to wet weights to account for any
loss of sample weight caused by drying.
Sample extracts frequently exceed the calibration
range determined during the ICAL. When they do so,
they must be diluted to obtain peaks that fall within the
linear range of the instrument. For PCBs, this linear
range is defined as 16 times 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.
Detection Limits
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 concentra-
tion used for Aroclor 1221 was 200 micrograms per
kilogram (/tg/kg); the level used for the other six Aro-
clors was 100 /tg/kg. This corresponds to soil sample
detection limits of 67 /tg/kg for Aroclor 1221 and 33
/tg/kg for the other Aroclors.
Because of 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 hi the
soil sample. However, PRC did not correct the detec-
16
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tion limits to account for the percent moisture present hi
the samples because the CRQLs were listed in pg/kg and
the detection limits of the Dexsil PCB technologies and
the other technologies were listed in rag/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 confir-
matory 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 stan-
dards, 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 recover-
ies.
During the demonstration, 46 samples and then-
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 and 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 spikes and
matrix spike duplicate samples be prepared with six
organochlorine pesticides and analyzed with each batch
of samples. Because the demonstration was only con-
cerned 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 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 the results are
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 required when values obtained from the analysis
of a sample on two columns were different, the reported
value was the lower of the two values. This requirement
was followed for the samples from this demonstration.
Gas Chromatographic Mass
Spectrometer Confirmation
The 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 II
data review. Therefore, these samples were not coded.
Data Reporting
The data report PRC received from the EPA Region
7 Laboratory included a standard EPA Region 7 Analysis
Request Report. PCBs were the only compounds
reported. Results were reported on a dry weight basis,
as required hi the CLP 1990 SOW. PRC obtained data
on the percentage of solids in the sample from the
17
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confirmatory laboratory and used this data to convert the
results to wet weight. This conversion was required
because the data was to be compared to data from the
two Dexsil technologies and two other technologies, all
of which reported concentrations based on wet soil
weight. PRC also converted the confirmatory laboratory
results from jig/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 hi the sample. The third code used was
a "J," which indicated the data was estimated, but not
validated by approved QC procedures. Twenty-nine of
the 146 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 labora-
tory found three additional Aroclors hi the samples
collected during the demonstration. Most of the samples
analyzed by the confirmatory laboratory were found to
contain either Aroclor 1242 or Aroclor 1248. Sev-
enty-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 mix-
ture. Four samples were found to contain a mixture of
Aroclor 1242 and Aroclor 1260. Three samples were
found to contain a mixture of Aroclor 1248 and Aroclor
1260. Two samples were found to contain a mixture of
Aroclor 1242 and Aroclor 1254. In all, 122 soil samples
submitted to the confirmatory laboratory for this demon-
stration 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 precision, accuracy, and
completeness of the confirmatory laboratory data.
Accuracy
Accuracy for the confirmatory laboratory was
assessed through the use of PE samples purchased from
Environmental Research Associates (ERA) and contain-
ing 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 concentra-
tions, 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 concen-
trations and acceptance ranges of the samples were not
known to the confirmatory laboratory. The true concen-
tration of sample 047-4024-114 (die 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 die 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.
Oflier types of data typically used to measure precision
were not available. Laboratory duplicate samples were
not required by die 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 die precision of die analytical meuiod.
Precision can be evaluated by determining die 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 tiiis
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 die sample pah: was calculated as 197.6
percent. Also, Sample 97 had a result of 1.23 mg/kg
while its duplicate had a result of 0.285 mg/kg. The
RPD for Sample 97 and 97D was 124.8 percent. The
18
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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 sam-
ples. 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, com-
pleteness for the samples analyzed by the confirmatory
laboratory was 80 percent, which is below the complete-
ness 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
Twenty 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
were outside of the advisory control limits. In all cases,
the second surrogate recovery was within the advisory
control limit. The remaining 17 samples were consid-
ered 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 QAPjP (PRC 1992b), a rejection
of a large percentage of data would increase the apparent
variation between the confirmatory laboratory data and
the data from die 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 Laboratory had deter-
mined the results to be invalid under approved QC
procedures.
19
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Section 6
Dexsil Corporation: Clor-N-Soil Test Kit
This section provides information on the Clor-N-Soil
Test Kit, including background information, operational
characteristics, performance factors, a data quality
assessment, and a comparison of its results with those of
the confirmatory laboratory. Observations about the
technology made during the demonstration by the
operator are also presented throughout this section.
Theory of Operation
and Background Information
According to its developer, the Clor-N-Soil Test Kit
is designed to provide quick, semiquantitative analytical
results of PCB concentrations in soil samples. During
this demonstration, the Clor-N-Soil Test Kit yielded a
greater than or less than 50 mg/kg result for PCB
concentrations in soil samples. The 50 mg/kg level of
contamination is a common EPA cleanup goal for PCBs
in soil.
The Clor-N-Soil Test Kit operates on the principle
of total organic chlorine detection. Sample extraction is
required before total organic chlorine detection is
performed. PCB compounds are extracted from the soil
sample using butyl diglyme. Dexsil uses this solvent to
extract PCBs from soil samples because of its ability to
permeate soil pores more readily than other common
extraction solvents. This results in greater PCB extrac-
tion efficiency. Once the PCBs are extracted, the extract
is free from sources of inorganic chlorine, water, soil
particles, and some potential interferences, namely
compounds containing polar chlorine.
The organic sample extract is treated with metallic
sodium to strip chlorine from the biphenyl compound.
This reaction is performed with the aid of a catalyst
containing a mixture of naphthalene and diglyme.
Chlorine exists in the form of chloride ions as a result of
the stripping process. An acidic buffer solution is added
to the organic sample extract to quench any unreacted
sodium and to transfer the chloride into an aqueous
phase. The aqueous phase extract containing the chlo-
ride is transferred to an indicator tube where total
organic chlorine detection is performed.
The chloride content hi the aqueous phase is mea-
sured with an indicating solution of mercuric nitrate and
diphenyl carbazone, which results in a colorimetric
determination of chloride content. Mercuric nitrate
disassociates in the aqueous phase and binds to any free
chloride. Diphenyl carbazone is then added to the
aqueous phase where it reacts with any unbound mercury
ions. The diphenyl carbazone and mercury complex
results hi a vivid purple color. The development of the
purple color is inversely proportional to the chloride
content of the aqueous phase. The purple color indicates
an absence of chloride, therefore, the absence of PCBs
in the soil sample. A yellow or clear color indicates the
presence of chloride, therefore, the presence of PCBs in
the soil sample. The amount of mercuric nitrate added
to the aqueous phase will determine the concentration at
which a color change will occur.
The amount of mercuric nitrate added to the aqueous
phase extract is determined by calculating the amount of
chlorine found hi a soil sample containing a predeter-
mined amount of Aroclor 1242. The Clor-N-Soil Test
Kit used during this demonstration was designed to
provide results greater than or less than 50 mg/kg. Kits
designed to operate at this level use enough mercuric
nitrate to completely react with the chlorine present hi a
soil sample containing 44 mg/kg of Aroclor 1242. This
accounts for possible operator error and avoids the
reporting of false negative results. Therefore, soil
samples containing 44 mg/kg or more of Aroclor 1242
are identified as containing greater than 50 mg/kg of
PCBs.
Other sources of organic chlorine also will be
detected using this test kit, and may mistakenly be
identified as PCBs. Sources of organic chlorine other
than PCBs that are commonly found hi environmental
samples include chlorinated solvents, organochlorine
pesticides, and chlorinated disinfectants.
20
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Operational Characteristics
The Clor-N-Soil Test Kit is contained hi a portable,
5-ounce cardboard box. This box is used to store all
items needed to perform an analysis, and doubles as a
test tube rack for holding the different test tubes required
for the analysis. The box contains (1) a stainless-steel
scoop, (2) a hand-held scale, (3) a plastic pipet bulb, (4)
an extraction test tube, (5) organic extraction solvent, (6)
a filter-syringe assembly, (7) a reaction test tube contain-
ing two ampules, (8) an indicator test tube containing
two ampules and 7 mL of buffer solution, and (9)
complete step-by-step instructions, which included a
color chart for use in determining the presence or
absence of PCBs.
Logistical requirements for the Clor-N-Soil Test Kit
are minimal because it is primarily self-contained. No
electrical power is needed to analyze samples. The
glassware and reagents needed for the analysis are
included in the test tubes or other containers supplied in
the cardboard box.
Supplies needed, but not included with the test kit,
include (1) a permanent marker for labeling the card-
board box and test tubes, (2) a table or work space area
at least 8 square feet in size, (3) a refrigerator for
storing samples, (4) a logbook or a report form for
recording sample results, and (5) an ink pen. The
refrigerator is an optional piece of equipment if all
samples are analyzed on the same day they are collected.
However, it is recommended for storing samples over-
night or for storage until it is determined which of the
samples will be transported to a formal laboratory for
further analysis. A refrigerator is not required for
storing reagents. Safety equipment, such as gloves, a
laboratory coat, and safety glasses are also recom-
mended.
The Clor-N-Soil Test Kit is easy to operate. Dexsil
claims that the test kit can be used by anyone, including
nontechnical personnel. Based on this demonstration,
PRC concluded that Dexsil's claim is true and that the
test kit can be used by individuals who have little or no
technical expertise. The test kit instructions provide
detailed descriptions and proved to be invaluable to the
operator. The operator did note, however, that a certain
amount of laboratory skill, such as the ability to transfer
and accurately measure liquids, is needed during one
step of the analysis. This step was made easier, how-
ever, by the marked test tubes included with the test kit
indicating the volume of liquid needed.
The Clor-N-Soil Test Kit is designed for use in the
field. The test kit contains no instrumentation or me-
chanical parts. Most components are made of plastic or
steel. Two exceptions are the organic extraction solvent
vial, which is made of glass, and the crushable glass
ampules contained in both the plastic reaction test tube
and the plastic indicator test tube. This equipment must
be stored with some care so that it is not crushed or
broken.
Instrument reliability was evaluated through the
number of test kits that were received in good working
order. The demonstration required the use of 198
Clor-N-Soil Test Kits. Of the 198 kits used, three
contained bent hand-held scales which could not be used,
two contained organic extraction solvent vials without an
aqueous phase component, one contained a reaction tube
that did not contain the crushable ampules, and six
contained reaction or indicator test tubes that leaked due
to cracks or caps which did not screw down properly.
Also, one reaction test tube unexpectedly foamed and
overflowed when the buffer solution was added. Based
on these findings, the reliability of the Clor-N-Soil Test
Kit was determined to be 93 percent. It should be noted
that the six test kits with the reaction and indicator test
tubes that leaked, and the reaction test tube which
overflowed, may have been the result of sample or
operator effects. This would change the instrument
reliability for the Clor-N-Soil Test Kit to 97 percent.
The Clor-N-Soil Test Kit contains seven different
chemicals. The chemicals used include flammable
solvents, such as naphthalene, diglyme, butyl diglyme,
and ethanol. Each Clor-N-Soil Test Kit contains only
small amounts of these chemicals but care should be
taken when using them to prevent personal exposure and
fire.
To free the chloride from the biphenyl group,
metallic sodium is used. Metallic sodium can react
explosively with water. The amount of metallic sodium
in the Clor-N-Soil Test Kit is 50 milligrams (mg).
Dexsil's material safety data sheets (MSDS) for the test
kit explained that the small amount of metallic sodium
included with the test kit was not explosive and that
water was suitable for extinguishing any sodium-induced
fire. This is probably true, unless large numbers of the
test kits are stored together.
The test kit contains a fiorisil cleanup column.
Florisil is a fine dust and can be a skin and eye irritant.
The operator observed frequent leakage from the fiorisil
columns into the packaging material. A small amount of
mercuric nitrate is included in the test kit. Mercury is
used to bind free chloride ions liberated from the biphe-
nyl group. The small amount of mercury contained in
the test kit (less than 0.5 mg) should not be a major
safety factor; however, adequate ventilation in the work
area is recommended.
21
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Finally, the Clor-N-Soil Test Kit requires that
crushable glass ampules be broken within the confines of
a plastic test tube. The operator received a small
puncture wound to the thumb while crushing one of these
ampules. Apparently, a piece of glass went through the
plastic test tube and the operator's gloves. This was
considered an uncommon occurrence. Still, care should
be taken when crushing these ampules.
The operator chosen to analyze samples using the
Clor-N-Soil Test Kit was Mr. Brad Helland, an em-
ployee of PRC. Mr. Helland has a B.S. degree hi
chemistry and some graduate work. He also spent three
years as a research technician and a laboratory techni-
cian.
Mr. Holland's training in the use of the Clor-N-Soil
Test Kit included one hour of hands-on training, which
was conducted by the demonstration's lead chemist.
Additional instruction was provided to Mr. Helland on
the first day of the demonstration by Mr. Stephen Finch
of Dexsil. This training included Mr. Finch overseeing
Mr. Helland performing each step of the Clor-N-Soil
Test Kit. Mr. Finch also provided information on
filtration rates and separation techniques for troublesome
sample extractions. According to Mr. Helland, some of
this information was not included hi the test kit instruc-
tions. After analyzing 10 demonstration samples under
supervision, Mr. Helland noted that he felt confident hi
his ability to properly analyze soil samples using the
Clor-N-Soil Test Kit. Mr. Helland was able to analyze
six samples concurrently using the test kit.
Costs associated with analyzing samples using the
Clor-N-Soil Test Kit include the cost of the kit, the cost
of the operator, and the cost of waste disposal. Dexsil
sells its test kits individually, in packs of 12, or hi cases.
A case contains four packs. The price for one pack is
$168, which is $14 per kit. The price for one case is
$576, which is $144 per pack or $12 per kit. Dexsil also
offers reduced prices when larger quantities are pur-
chased. The shelf life of each test kit is one year.
Operator costs for the use of the Clor-N-Soil Test Kit
will vary depending on the technical level of the opera-
tor. The Clor-N-Soil Test Kit can be used by individuals
with little technical training, thereby decreasing this
cost. The waste generated by using the 198 test kits
used during this demonstration half-filled a 55-gallon
drum. The appropriate way to dispose of diis waste is
through an approved PCB incinerator facility. The cost
of disposing of one drum of this waste is estimated at
$1,000.
Performance Factors
The following sections describe the Clor-N-Soil Test
Kit's performance factors. These factors include
detection limits and sensitivities, sample throughput,
linear range, and drift. Specificity is another important
performance factor. Due to the complexity of specific-
ity, it is discussed separately.
Detection Limits and Sensitivity
The Clor-N-Soil Test Kit reports semiquantitative
results for the presence of PCBs hi soil samples. The
means of determining whether PCBs are present is the
color of the sample following extraction and subsequent
chemical reactions. According to Dexsil, a vivid purple
color indicates that the PCB concentration hi the soil
sample is below 50 mg/kg. A clear or yellow color
indicates that the PCB concentration of the soil sample
is above 50 mg/kg. A color chart is included with each
Clor-N-Soil Test Kit to help the operator determine
whether the soil sample contains PCBs above or below
50 mg/kg.
The operator of the Clor-N-Soil Test Kit indicated
that comparing the final color of die soil sample extract
to the color chart was difficult when the resulting color
fell between the light purple and the yellow colors shown
on the chart. When this occurred during this demonstra-
tion, the operator reported that the sample contained
concentrations of PCBs above 50 mg/kg. This conserva-
tive approach reduced the likelihood of false negative
results and increased the chance of false positive results.
The detection limit of 50 mg/kg is determined by the
amount of mercury provided hi the test kit. The mer-
cury is hi the form of mercuric nitrate. During the
indicating step, the mercuric nitrate is introduced into
the aqueous soil sample extract where it is liberated from
the nitrate group to form a mercury ion (Hg++). The
mercury ions bind to the free chloride ions from the
sample extraction and reaction steps. The colorimetric
step of the test kit involves binding diphenyl carbazone
to any mercury ions not bound to chloride ions. The
diphenyl carbazone-mercury mixture results in a purple
color indicating the absence of chloride ions, thus the
absence of PCBs.
A discussion with Mr. Finch of Dexsil indicated that
1.65 X 10"3 milliequivalents (meq) of the mercury ion
are available for reaction. The predominant form of
mercury chloride formed during this reaction is
22
-------
[HgCl] + because the reaction is performed under acidic
conditions (Snoeyink and Jenkins 1980). One chloride
ion from the PCBs in the soil sample will react with one
mercury ion from the indicating step. Using this stoi-
chiometric relationship, it will take 1.65 x 10'3 meq of
chloride ions to bind with the 1.65 X 10~3 meq of
mercury in the Clor-N-Soil Test Kit. When this amount
of chloride is in a soil sample extract, there will be no
mercury left to bind to the diphenyl carbazone. This
will result in a clear or yellow color in the final sample
extract, indicating the presence of PCBs.
Dexsil determined the 50 mg/kg detection limit
using Aroclor 1242, the predominant Aroclor found at
the AICO site. The detection limit was stoicbiometri-
cally calculated using the following equation:
(6-1)
([(1.69 x 10'3meg/0.8) x 7/5] x 2) x 35.5 mglmeq =
0.21 mg of chloride needed
where
1.68 x 10"3 meg = chloride Ions react with all mercury
ions.
0.8 = 80 percent extraction efficiency correction factor.
7/5 = ratio of buffer solution added versus buffer solution
used.
2 = ratio of organic extraction solvent added versus
extraction solvent used.
35.5 mg/meq = mill/equivalent formula for chloride.
factor is used to account for any losses of chloride
during the extraction steps of the test kit. Dexsil uses a
correction factor of 80 percent. Twenty percent was
experimentally determined to be the largest amount of
chloride that can be lost during the extraction step.
Multiplying the number of expected chloride ions by 80
percent results in 1.69 x 10'3 meq of chloride should the
20 percent be lost. This amount of chloride would react
completely with the 1.65 X 10'3 meq of mercury ion in
the Clor-N-Soil Test Kit resulting in a positive test
result.
PCBs were manufactured as mixtures of chlorinated
biphenyls known as Aroclors. These Aroclors were
given numbers for identification, such as Aroclor 1242
or Aroclor 1260. The last two numbers indicate the
percentage of chloride present in the Aroclor on a
weight-to-weight basis. Aroclor 1016 is the exception.
Its last two identification numbers do not indicate the
percentage of chlorine present in the Aroclor. Aroclor
1016 contains 41 percent chloride by weight. With this
information it is possible to determine the detection
limits of the Clor-N-Soil Test Kit for each of the seven
major Aroclors. This can be accomplished by determin-
ing the mass of chloride needed to react with all of the
mercury provided in the Clor-N-Soil Test Kit. The
following equation is used:
(6-2)
(0.21 ing/percent chloride of Aroclor) x 0.01 kg =
detection limit for each Aroclor
In this case, if a 10-gram soil sample containing 50
mg/kg of Aroclor 1242 is extracted and analyzed using
the Clor-N-Soil Test Kit, a positive result would be
expected. This is because the 10-gram sample would
contain 50 mg/kg of Aroclor 1242 or 0.5 milligrams of
Aroclor 1242. Aroclor 1242 contains 42 percent chlo-
rine by weight or 0.21 milligrams of chloride. The 0.21
mg is equivalent to 5.92 X 10'3 meq chloride. The
10-gram soil sample is extracted with 10 mL of solvent,
but only 5 mL of the solvent is used in the reaction and
indicating steps of the test kit. The amount of chloride
is reduced by half or 2.96 x 10"3 meq. The reaction
step of the Clor-N-Soil Test Kit uses 7 mL of the buffer
solution to transfer the chloride to the aqueous phase.
Of the 7 mL of buffer solution added, only 5 mL are
used in the indicating step. This results in a reduced
number of chloride ions available for reaction with the
mercury ions. This five-sevenths reduction of the
chloride leaves 2.11 x 10"3 meq of chloride.
To ensure that the Clor-N-Soil Test Kit will give a
positive result hi a soil sample containing 50 mg/kg of
Aroclor 1242, Dexsil uses a correction factor. This
Sample Matrix Effects
The matrix of the soil samples analyzed during the
demonstration was less than ideal. Most of the samples
consisted of clay, which caused some problems hi
extracting and analyzing them. The most common
problem was that a colloidal suspension formed for some
of the samples after the initial extraction. The colloidal
suspension prevented the recovery of the 7 mL of
organic extract needed for the florisil column cleanup.
The 7 mL was the amount of organic sample extract
required to recover 5 mL after the florisil column
cleanup. No guidance was given hi the test kit's instruc-
tions on how to handle this problem.
Centrifugation would have been the ideal solution to
this problem; however, a centrifuge was not provided or
recommended with the test kit, and one was not available
at the trailer. To obtain results from samples with
colloidal suspension, another attempt to extract the
sample was made using less of the soil sample. Instead
of using the recommended 10 grams, 5 grams were
used. If 2.5 mL of the sample extract was obtained, this
23
-------
amount was taken through the rest of the sample analysis
procedure. In some cases this did not solve the problem,
so the sample was again extracted using 2.5 grams.
When the amount of sample analyzed was reduced from
10 grams, the detection limit'for that sample was raised
to account for the difference in the sample weight or
volume extracted and analyzed. For these samples, the
result was S-coded to indicate that, due to sample matrix
effects, less than 10 grams of the soil sample was used
for extraction and analysis. Samples that exhibited this
colloidal suspension and their corresponding elevated
detection levels are Sample 019 (200 mg/kg), Sample
093 (200 mg/kg), Sample 109 (200 mg/kg), Sample
109D (400 mg/kg), and Sample 110 (100 mg/kg).
Another sample matrix effect observed during the
demonstration was a difference between some samples
and their respective field duplicates. The operator of the
Clor-N-Soil Test Kit observed physical differences in the
soil matrix between sample 082 and its field duplicate,
082D. This problem also was noted during the pre-
demonstration activities, and steps were taken to correct
it. Among the steps taken were a more thorough
homogenization of the samples, the use of fluorescein to
enable the sampling personnel to visually inspect the
effectiveness of the homogenization technique, and
increasing the number of field duplicate samples.
Although these steps improved the homogeneity of the
samples, it should be noted that some differences
between duplicate sample results must be expected due
to the nonhomogeneity inherent hi soil samples. It was,
however, the purpose of this demonstration to test this
field screening technology under normal field conditions.
Nonhomogeneity and less than ideal matrices are com-
mon problems with field soil samples. The samples
analyzed during this demonstration are believed to be
typical of those found in normal field operations.
Sample Throughput and Linear Range
Sample throughput evaluates the amount of tune
required to extract and analyze one soil sample and the
number of samples analyzed hi one work day. Dexsil
claims that complete analysis time is about 10 minutes
per sample. Using this information, the number of
samples that could be analyzed in one 8-hour day would
be 48 samples. The operator of the Clor-N-Soil Test Kit
determined that the average time needed to perform a
sample analysis was 11 minutes. This did not include
the time required for sample handling, data documenta-
tion, difficult extractions, or the preparation of QC
samples. The additional time needed to perform these
tasks prevented the operator from being able to complete
the analysis of the reported 48 samples per day. The
largest number of samples analyzed hi one day during
the demonstration was 35 samples. The average number
of samples analyzed was 19 samples a day.
The Clor-N-Soil Test Kit does not exhibit a linear
range. The test kit was designed to give a positive or a
negative result as to whether a soil sample contains 50
mg/kg of PCBs. According to Dexsil, the intensity of
purple color in a negative sample may give some indica-
tion of PCB concentration. However, Dexsil does not
recommend using the test kit quantitatively.
Specificity
The discussion of specificity is divided into two
sections. The first section discusses some potential
interference problems that may be encountered when
using this test kit. The second section details the results
of an Aroclor specificity test that was conducted during
the demonstration.
Potential Interferences
The Clor-N-Soil Test Kit operates on the principle
of total organic chlorine detection. It is responsive to
chloride, particularly when it is found hi an organic
form. The test kit is less responsive to inorganic forms
of chloride, such as salt, for two reasons. First, inor-
ganic forms of chloride are not very soluble hi the
organic solvent used for extraction. Second, the use of
the florisil column removes most sources of inorganic
chloride.
Organic sources of chloride hi soil samples will give
false positive results when analyzed with this test kit.
Common sources of organic chloride hi soil samples
include chlorinated solvents and chlorinated pesticides.
Another source of chloride would be trichlorobenzenes
contained hi transformer oils. Transformer oils are a
common soil contaminant at many PCB-contamination
sites.
It seems logical that other halogenated compounds
would react to the Clor-N-Soil Test Kit hi a similar
manner as chloride compounds. Organic compounds
containing bromine, fluorine, and iodine can be extracted
from soil samples with the organic solvent and can pass
through the florisil column. If these halogenated ions
are liberated from the parent compounds through the
sodium reaction, they may bind to the mercury ions hi
the indicating step, which would lead to false positive
results. Common sources of these halogenated com-
pounds include solvents and pesticides.
Another source of interference is sulfur. Sulfur is
commonly found hi soil samples and is a common
interferant during analysis of PCBs by GC using an
24
-------
BCD. Sulfur can be extracted from soil samples with
the organic solvent used with this test kit and can pass
through the florisil column if the sulfur is present in
sufficient concentrations. If sulfur survives the vigorous
sodium reaction, then it may bind to the mercury ions in
the indicating step. Again, this type of interference
would result hi an increase hi false positive results.
Soil samples containing sources of organic mercury
may result in false negative results if PCBs are also
present. Organic sources of mercury include many types
of organomercury pesticides and explosives. This type
of mercury can be extracted from soil samples with the
organic solvent used with this test kit and can pass
through the florisil column. If the mercury is separated
from the parent compound and survives the sodium
reaction, it may bind with any of the diphenyl carbazone
present hi the final indicating step. If PCBs are also
present in the soil sample, the test kit may not be able to
determine PCB concentrations above SO mg/kg if
sufficient mercury is hi the extract and it binds with the
diphenyl carbazone to produce a purple color. The
chance of this occurring is small, but it is possible to
find both PCBs and organic mercury hi the same sample.
Aroclor Specificity Results
The concentration of PCBs needed to result hi a
positive identification using the Clor-N-Soil Test Kit
depends on the Aroclor and its concentration. The
Aroclors and the concentrations of each that calculations
indicate are needed to produce correct results are:
Aroclor 1016 (51.2 mg/kg), Aroclor 1221 (100.0
mg/kg), Aroclor 1232 (65.6 mg/kg), Aroclor 1242 (50.0
mg/kg), Aroclor 1248 (43.8 mg/kg), Aroclor 1254 (38.9
mg/kg), and Aroclor 1260 (35.0 mg/kg).
The specificity of the Clor-N-Soil Test Kit toward
each of these Aroclors was measured during the demon-
stration. Seven soil samples were chosen to be spiked
with known amounts of each Aroclor. Each sample was
spiked with a different Aroclor. First, each sample was
divided into four aliquots. Two aliquots were then
spiked with about 30 mg/kg of the Aroclor, and two
were spiked with concentrations of about 70 mg/kg. The
results of the Aroclor specificity test are tabulated hi
Table 6-1.
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 concentration
of the Aroclor hi the samples. At the tune that the
Aroclor spikes were prepared, the concentrations of the
PCBs in the original samples were not known. Initial
indications from the Dexsil Clor-N-Soil Test Kit were
available, but the results had not been finalized. Two of
the original samples used for the Aroclor specificity test
were later found to contain PCBs at concentrations above
the 50 mg/kg detection limit. This voided the results for
these samples. Positive results would be expected for all
spikes of these samples because the sample already
contained more than 50 mg/kg of PCB. The two
samples affected had been spiked with Aroclors 1242
and 1260. However, the test kit indicated that one of the
aliquols spiked with Aroclor 1260 contained less than 50
mg/kg of PCBs. This sample result was thought to be an
experimental error. All of the other samples spiked with
Aroclors 1242 and 1260 were greater than the 50 mg/kg
level, as expected.
Sample 003 was spiked with Aroclor 1221. All
results for Aroclor 1221 spikes were reported as less
than the 50 mg/kg detection limit. At least two of these
spikes, therefore, resulted in false negative results. The
expected detection limit was 100 mg/kg for Aroclor
1221. Sample 077 was spiked with Aroclor 1016 at the
two concentrations. The results for all Aroclor 1016
spikes also were reported at less than the 50 mg/kg
detection limit. This did not agree with the expected
detection limit for this Aroclor, which was 51.2 mg/kg.
The 70 mg/kg spike samples should have given positive
results.
Sample 058 was spiked with Aroclor 1248. The
results for the Aroclor 1248 spikes were reported as
greater than 50 mg/kg. The expected detection limit was
43.8 mg/kg. The 30 mg/kg spiked samples gave a
positive result using this test kit. The confirmatory
laboratory results indicate that the sample contained less
than 1 mg/kg of PCB before being spiked. Therefore,
these results did not agree with the expected detection
limit of the Clor-N-Soil Test Kit for Aroclor 1248.
Saimple 034 was spiked with Aroclor 1254. The
results of the Aroclor 1254 spikes were reported at
greater than 50 mg/kg. The expected detection limit was
38.9 ing/kg. The 30 mg/kg spiked samples gave a
positive result using the test kit. The confirmatory
laboratory results for sample 034, though, indicate a
PCB level of 34 mg/kg before the sample was spiked.
Because of the presence of PCBs hi the original sample,
even the total PCBs hi the samples spiked with 30 mg/kg
were above both 50 mg/kg and the expected detection
limit of 38.9 mg/kg.
The Aroclor spike results for Aroclor 1232 were
reported as both greater than and less than the 50 mg/kg
detection limit. Sample 021 was spiked with Aroclor
1232. The original sample, 021, was found to contain
less than 50 mg/kg of PCBs. The 30 mg/kg Aroclor
1232 sipikes were reported at less than the 50 mg/kg
detection limit, while the 70 mg/kg Aroclor 1232 spikes
25
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TABLE 6-1. AROCLOR SPECIFICITY TEST RESULTS: Clor-N-Soil Test Kit
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
Soil Sample
Result
(mg/kg)
<50
<50
<50
<50
>50
>50
>50
>50
<50
<50
<50
<50
<50
<50
<50
<50
>50
>50
>50
>50
<50
<50
<50
<50
<50
<50
<50
<50
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
Amount
(mg/kg)
69.7
29.6
69.6
29.8
39.9
59.8
39.9
59.9
29.7
69.0
29.8
69.7
29.6
29.5
69.4
68.8
29.5
69.2
68.8
29.7
30.0
29.9
68.9
69.9
69.0
29.6
29.9
69.7
Spiked Sample Result
(mg/kg)
<50
<50
<50
<50
>50
>50
<50
>50
<50
>50
<50
>50
>50
>50
>50
>50
> 50
>50
>50
>50
>50
>50
>50
>50
<50
<50
<50
<50
were reported as greater than 50 mg/kg. These results
agreed with the expected detection limit of 65.6 mg/kg.
Intramethod Assessment
Specific QC measures were used during the demonstra-
tion for analyzing soil samples using the Clor-N-Soil
Test Kit. Laboratory contamination and the extraction
and analysis efficiency of this technology were evalu-
ated. Other QC measures were used to evaluate the
ability of the test kit to find expected results and to
reproduce the results it found. Although the types of
QA/QC samples analyzed are often used to evaluate
operator effects, all of these samples Were intended to
evaluate the technology. Operator effects were con-
trolled and uncontrollable operator errors were assumed
to be indistinguishable from errors inherent in the
technology. Because the technology was designed for
use by nontechnical personnel in field conditions, but
was operated during this demonstration by a trained
chemist, operator effects in this demonstration were
expected to be minimal. The QA/QC samples analyzed
and the parameters monitored are discussed hi the
following paragraphs.
Reagent blanks were used to evaluate laboratory-
induced contamination. Eight reagent blanks were
26
-------
analyzed during this demonstration. All reagent blank
results were less than 50 mg/kg of PCBs. The reagent
blanks analyzed by the Clor-N-Soil Test Kit during the
demonstration indicated that there was no problem with
laboratory-induced contamination.
For this demonstration, completeness refers to the
proportion of valid, acceptable data generated using the
Clor-N-Soil Test Kit. Completeness for' the samples
analyzed by the Clor-N-Soil Test Kit during this demon-
stration was 100 percent.
Intramethod accuracy was assessed for the Clor-
N-Soil Test Kit by analyzing PE samples and matrix
spike and matrix spike duplicate samples. Accuracy also
was assessed by comparing the results from the test kit
to those from the confirmatory laboratory. Two PE
samples were analyzed by the Clor-N-Soil Test Kit
during the demonstration. One PE sample had a low
concentration of PCBs; the other, high. The operator
knew that the samples were PE samples, but did not
know the true concentration, the acceptance range, nor
which sample had the high or low concentration.
The true concentration for sample 047-4024-113 (the
low-level sample) was 32.7 mg/kg, with an acceptance
range of 12 to 43 mg/kg. The actual reported result for
this sample analyzed by the Clor-N-Soil Test Kit was
greater than 50 mg/kg. This value was determined to be
outside the acceptance range. The test kit was actually
designed to give a positive result for samples containing
Aroclor 1242 above 44 mg/kg, which is close to the
upper limit of the acceptance range for this PE sample.
Still, the true value of the PE sample was more than 11
mg/kg below the cushion that was designed into the
Clor-N-Soil Test Kit. The result, therefore, is still
considered unacceptable. The true concentration for
sample 047-4024-114 (the high-level sample) was 110
mg/kg, with an acceptance range of 41 to 150 mg/kg.
The result for this sample when analyzed with the
Clor-N-Soil Test Kit was greater than 50 mg/kg, which
was acceptable.
Matrix spike samples were used to evaluate the test
kit's extraction and analysis efficiency. Matrix spike
samples were prepared by adding a known quantity of
PCBs to an actual sample. The PCB used was Aroclor
1242 and enough of a concentrated Aroclor 1242 stan-
dard was added to a 10-gram soil sample to produce a
matrix spike concentration of 50 rng/kg. The spiked
sample was duplicated to produce a matrix spike dupli-
cate sample. The recovery results of the matrix spike
and matrix spike duplicate samples are listed in Table
6-2. Six samples were used for the matrix spike sam-
ples. Each was reported to contain less than 50 mg/kg
TABLE 6-2. MATRIX SPIKE
DUPLICATE RESULTS.
AND MATRIX SPIKE
Sample No.
047-4024-013
047-4024-021
047-4024-049
047-4024-070
047-4024-092
047-4024-102
Sample
Result
(mg/kg)
<50
<50
<50
<50
<50
<50
Matrix
Spike
Result
(mg/kg)
>50
>50
>50
<50
>50
>50
Matrix
Spike Du-
plicate
Result
(mg/kg)
>50
>50
>50
>50
>50
>50
TABLE 6-3. LABORATORY DUPLICATE SAMPLE
RESULTS.
Sample No.
047-4024-008
047-4024-012
047-4024-026
047-4024-047
047-4024-074
047-4024-095
Sample Result
(mg/kg)
>50
>50
<50
<50
>50
>50
Duplicate
Result
(mg/kg)
<50
<50
>50
<50
>50
<50
of PCBs for the original sample result.
In all, six matrix spikes and six matrix spike dupli-
cates were analyzed. Eleven of the results were found to
contain greater than 50 mg/kg of PCBs. One matrix
spike result was found to contain less than 50 mg/kg of
PCBs. The extraction and analysis efficiency for the
samples analyzed by the Clor-N-Soil Test Kit during the
demonstration was 92 percent based on the matrix spike
recovery data.
Precision for this technology was assessed by
comparing each of the results obtained from duplicate
samples. The results for the laboratory duplicate
samples for this demonstration are listed in Table 6-3.
Three types of precision data were generated: data from
laboratory duplicate samples, data from matrix spike
duplicate samples, and data from field duplicate samples.
Laboratory duplicate samples are two analyses per-
formed on a single sample brought to the laboratory.
These samples are used to monitor the precision of the
27
-------
procedures and technology used for the analysis. For
this demonstration, laboratory duplicate samples were
analyzed with each set of 20 samples submitted for
analysis. Six laboratory duplicate samples were ana-
lyzed with the Clor-N-Soil Test Kit. The original goal
was to analyze laboratory duplicate samples determined
to contain greater than 50 mg/kg of PCBs. This goal
later was modified. Four of the samples used for
laboratory duplicate samples had original sample results
of greater than 50 mg/kg of PCBs. Two of the samples
used for laboratory duplicate samples had original
sample results of less than 50 mg/kg of PCBs. It should
be noted that the four samples with results of greater
than 50 mg/kg were selected from among those samples
that the operator had difficulty reading.
Of the six laboratory duplicate sample results
obtained, only two agreed with the result obtained from
the original sample. One of these samples had an
original sample result of less than 50 mg/kg of PCBs;
the other had an original sample result of greater than 50
mg/kg of PCBs. The other four laboratory duplicate
samples did not agree with the results from their respec-
tive original samples.
Six matrix spike duplicate samples were prepared
and their results were compared to the results of their
respective matrix spike samples in this precision evalua-
tion. Five of the matrix spike duplicate sample results
matched the matrix spike sample results. One matrix
spike duplicate sample result (047-4024-070MSD) did
not match the matrix spike sample result.
Thirty-two field duplicate samples were analyzed by
the Clor-N-Soil Test Kit during the demonstration. One
pair of samples produced incomparable data. In six out
of the remaining 31 pairs of results, which is 19 percent,
one result was positive and one was negative. Though
the test kit produces only semiquantitative results, it only
was able to duplicate its results 81 percent of the tune.
A review of the results that did not match seem to show
that the Clor-N-Soil Test Kit had more difficulty dupli-
cating its results when the PCB concentrations were near
1 mg/kg. Five out of the six pairs that did not match
had concentrations in this range. The other pair of
samples had confirmatory laboratory results of 17.5
mg/kg and 31.2 mg/kg.
Comparison of Results
to Confirmatory Results
This section compares data generated by the
Clor-N-Soil Test Kit to the data generated by the confir-
matory laboratory. The confirmatory laboratory's data
is considered correct, and its accuracy and precision are
considered within acceptable limits. The results of the
FIGURE 6-1.
too
80
60
£ 40
a
9
z
20
True Nctitlvci
75
Clor-N-Soil Test Kit analyses and the confirmatory
laboratory analyses are summarized hi Table 6-4. The
assessment of the Clor-N-Soil Test Kit analyses are
presented on Figure 6-1.
Accuracy
The Clor-N-Soil Test Kit is designed and promoted as a
semiquantitative test kit for determining whether a soil
sample contains PCBs above 50 mg/kg. Because it does
not produce quantitative results, PRC determined
whether each confirmatory laboratory result was above
or below 50 mg/kg. The test kit's results and the
confirmatory results were then presented on a 2 by 2
contingency table and a Fisher's Test was used to
determined whether a correlation existed between the
two sets of data.
The Fisher's Test was based on 146 pairs of
matched data. The Clor-N-Soil Test Kit and the confir-
matory laboratory gave the same result 87 times and did
not give the same result 59 tunes. The calculated
Fisher's Test value for the comparison of the two sets of
data was 56.21. The Chi-square^, to which it was
compared was 3.84 at a 95 percent confidence level with
1 degree of freedom. These results indicate that there is
no correlation between data from the test kit and the data
from the confirmatory laboratory. This suggests that
the Clor-N-Soil Test Kit is not accurate.
As discussed earlier, the Clor-N-Soil Test Kit is
designed to do conservative PCB field analysis. While
it is marketed to determine whether a sample contains
PCBs above 50 mg/kg, it actually is designed to give
positive results for samples containing 44 mg/kg of
Aroclor 1242, the main Aroclor at the AICO site. Also
as described earlier, the operator of this technology had
difficulty determining the color of some analysis extracts
and hi these cases determined that the sample had a
positive result. These factors, though, apparently did
not contribute greatly to the large number of incorrect
28
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TABLE 6-4. SUMMARY OF CLOR-N-SOIL TEST KIT DATA.
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
033
034
035
Clor-N-Soil
Test Kit
(50 mg/kg)a
<50
<50
<50
>50
<50
<50
<50
>50
<50
<50
<50
>50
<50
<50
>50
>50
>50
>50
>50
>200S
>50
<50
>50
>50
>50
>50
<50
<50
>50
<50
<50
<50
<50
>50
>50
>50
<50
<50
<50
Confirmatory
Laboratory
(0.033
mg/kg)a
0.593
1.50
0.114
6.71J
1.37
0.679
0.552
2.00
1.30J
0.1 72J
1.1 5J
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
6.00J
34.0
ND
Technology
Accuracy
Correct
Correct
Correct
FP
Correct
Correct
Correct
FP
Correct
Correct
Correct
FP
Correct
Correct
FP
FP
Correct
FP
FP
FP
FP
Correct
FP
FP
FP
FP
Correct
Correct
FP
Correct
Correct
Correct
Correct
FP
FP
FP
Correct
Correct
Correct
Sample
No.
035D
036
037
037D
038
039
040
041
042
042D
043
043D
044
045
046
046D
047
047D
048
049
050
050D
051
052
053
054
055
056
057
058
059
060
060D
061
062
063
063D
064
065
Clor-N-Soil
Test Kit
(50 mg/kg)a
<50
>50
>50
<50
>50
<50
>50
<50
<50
<50
<50
<50
<50
<50
<50
<50
<50
>50
<50
<50
>50
<50
<50
>50
>50
>50
<50
<50
>50
<50
>50
>50
>50
>50
>50
>50
<50
>50
<50
Confirmatory
Laboratory
(0.033
mg/kg)a
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
580
2.35
0.092J
0.1 54J
19.0
3.08
Technology
Accuracy
Correct
Correct
FP
Correct
Correct
Correct
FP
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
FP
Correct
Correct
FP
Correct
Correct
FP
FP
FP
Correct
Correct
FP
Correct
FP
FP
FP
Correct
FP
FP
Correct
FP
Correct
29,
-------
TABLE 6-4. (CONTINUED)
Sample
No.
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
085D
086
086D
087
087D
088
088D
089
Clor-N-Soil
Test Kit
(50 mg/kg)a
>50
<50
>50
>50
>50
<50
<50
<50
>50
>50
>50
>50
>50
<50
>50
>50
<50
>50
>50
<50
>50
<50
<50
>50
>50
>50
>50
<50
<50
<50
<50
<50
<50
>50
Confirmatory
Laboratory
(0.033
mg/kg)a
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
465
1.42
1.25
0.076
ND
2.70
1.77
45.0
Technology
Accuracy
FP
Correct
FP
FP
FP
Correct
Correct
Correct
FP
FP
FP
FP
FP
Correct
FP
FP
Correct
FP
FP
Correct
FP
Correct
Correct
FP
FP
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
FP
Sample
No.
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
106
107
108
109
109D
110
111
112
113
114
Clor-N-Soil
Test Kit
(50 mg/kg)a
<50
>50
>50
>50
<50
<50
>200S
>50
>50
<50
<50
<50
<50
<50
<50
<50
>50
>50
>50
<50
<50
>50
<50
<50
<50
>50
>50
>200S
<400
>100S
<50
>50
>50
>50
Confirmatory
Laboratory
(0.033
mg/kg)a
1.01
1.40
1,630
1,704
1.21
ND
0.295
0.362J
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
2.50
14.1J
3.84J
ND
ND
ND
ND
315
14.9
66.3
Technology
Accuracy
Correct
FP
Correct
Correct
Correct
Correct
FP
FP
FP
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
Correct
FP
FN
Correct
FP
Correct
Correct
Correct
FP
FP
FP
Correct
FP
Correct
Correct
FP
Correct
Notes:
• Detection limit.
J Reported amount is below detected limit or not valid by approved QC procedures.
FP False positive.
FN False negative.
ND PCBs not detected above detection limit.
S Sample matrix effects raised detection limits.
30
-------
results. A review of the actual confirmatory laboratory
values for these samples shows that only six of the 59
samples had levels of PCBs within a wide borderline
range of 30 to 80 mg/kg. Any incorrect results due to
the test kit's conservative design or due to the operator's
difficulty in determining the color of some extracts
should have fallen within this range. That 53 of the
inaccurate results are outside this range indicates that the
test kit's accuracy problem is due to other factors.
The Clor-N-Soil Test Kit's semiquantitative results
would be of primary use during a site characterization or
during removal of contaminated soil at a hazardous
waste site where it would be particularly important not
to have false negative results. Of the 59 inaccurate
results produced by the test kit, only one was a false
negative. While the test kit indicated that the sample
contained less than 50 mg/kg of PCB, the actual
confirmatory laboratory value was 293 mg/kg. The
confirmatory laboratory's duplicate of this sample,
though, had a result of only 1.77 mg/kg. The false
negative rate for the test kit was 1 percent, well within
the 95 percent confidence level used to evaluate
significance in this demonstration. At sites similar to
that used for this demonstration, the test kit should not
result in soil contaminated above the EPA action level
being treated as if it were not contaminated at that level.
False positive results also can cause the costly
disposal of material that is not really contaminated above
EPA action levels, which is in opposition to EPA's
policy of waste minimization. Of the 59 results that did
not match their respective confirmatory laboratory
results, 58 were false positives. Overall, this is a 40
percent false positive rate. A review of the actual values
as determined by the confirmatory laboratory shows that
only six. of these samples had PCB levels between 40 and
50 mg/kg. In 44 of these cases, the test kit indicated the
levels of PCBs were above 50 mg/kg when they were
actually below 10 mg/kg. And in 25 of the cases, the
test kit indicated levels above 50 mg/kg when the values
from the confirmatory laboratory indicated they were
below 1 mg/kg.
In a review of this ITER, Dexsil commented that its
directions state that all samples found to have positive
results should be tested by a PCB-specific method;
however, this would add considerable cost and lost time.
Thus, the decision to use this test kit must be made on
the basis of the site-specific potential impact of false
positives.
Precision
The precision of the Clor-N-Soil Test Kit was not
compared to the precision of the confirmatory laboratory
because the test kit produces only semiquantitative
results.
31
-------
Section 7
Dexsil Corporation: L2000 PCB/Chloride Analyzer
This section provides information on the L2000
PCB/Chloride Analyzer, including background
information, operational characteristics, performance
factors, a data quality assessment, and a comparison of
its results with those of the confirmatory laboratory.
Observations about the technology made during the
demonstration by the operator are presented throughout
this section.
Theory of Operation
and Background Information
The L2000 PCB/Chloride Analyzer is designed and
promoted to provide quick, quantitative results for PCB
concentrations in soil samples. The analyzer uses a
method similar to the Clor-N-Soil Test Kit described in
Section 6, which also was developed by Dexsil.
The analyzer operates on the principle of total
organic chlorine detection. Sample extraction is
required before total organic chlorine detection is
performed. PCBs are extracted from soil samples using
butyl diglyme, an organic solvent. Then, the L2000
PCB/Chloride Analyzer uses a chloride-specific
electrode to measure the amount of total organic chlorine
present hi the sample. Before samples are analyzed, the
analyzer is calibrated by analyzing a standard containing
a 50 mg/kg solution of chloride. The analyzer displays
a result for this standard on its display screen. The
readout on the display is then adjusted to read "50.0"
using the calibration knob located on the analyzer.
The L2000 PCB/Chloride Analyzer is able to
electronically convert the amount of chloride detected by
the analyzer into results for various Aroclors. A
"range" knob on the analyzer allows the operator to
select the Aroclor believed to be present in the sample,
and the analyzer will then convert chloride results into
results for that Aroclor. For this demonstration, the soil
sample results were taken from the Aroclor 1242
analysis range because results from previous sampling at
the AICO site show that Aroclor 1242 is the principal
Aroclor at the site.
The L2000 PCB/Chloride Analyzer is specific to
sources of organic chlorine. If sources of organic
chlorine other than PCBs are present in samples
analyzed using this technology, it will indicate higher
PCB concentrations than are actually present or will
produce false positive results. Common non-PCB
sources of organic chlorine hi environmental samples
include chlorinated solvents, organochlorine pesticides,
and chlorinated disinfectants.
Operational Characteristics
The L2000 PCB/Chloride Analyzer is contained hi
a portable carrying case, approximately 18-inches-long
by 18-inches-wide by 10-inches-high. The weight of the
carrying case containing all the instrumentation needed
to analyze samples is 15 pounds. The instrumentation
and equipment stored hi the carrying case includes the
electronic L2000 PCB/Chloride Analyzer, a step-down
transformer, a portable balance, a 5-mL pipettor, a vial
rack, and a tuner.
Necessary reagents and equipment are provided
separately hi a 12-cubic-foot cardboard box. This box
contains enough equipment and reagents to perform 200
soil sample analyses. The equipment and reagents
shipped hi the cardboard box include (1) stainless-steel
spatulas, (2) disposable pipets, (3) 50 mL of electrode
filling solution, (4) 250 mL of rinse solution, (5)
extraction test tubes, (6) 200 vials (10 mL each) of soil
extraction solvent, (7) 10-cubic-centimeter syringes, (8)
disposable filters, (9) reaction test tubes containing two
ampules, (10) 1 liter of extract solution, (11) drying
tubes, 20-mL glass vials, (12) 250 mL of calibration
solution, (13) four boxes of laboratory wipes, (14) a
marking pen, and (15) operating instructions.
The primary logistical requirement for using the
32
-------
L2000 PCB/Chloride Analyzer is electricity. Electricity
to operate the analyzer during this demonstration was
provided through a 110-volt circuit in the trailer. A
second logistical requirement is a battery to operate the
portable balance supplied with the analyzer.
Replacement batteries are needed periodically when the
analyzer is used over an extended period of tune.
Supplies not included with the L2000 PCB/Chloride
Analyzer, but required for the analysis of samples,
include a table or a work space area at least 8-
square-feet, a refrigerator for storing samples, a logbook
or report form for recording sample results, and an ink
pen. The refrigerator is optional if all samples are
analyzed on the same day they are collected. However,
it is recommended for storing samples overnight or for
storing samples until it is determined which samples will
be transported to a formal laboratory for further
analysis. Reagents used with the L2000 PCB/Chloride
Analyzer do not require refrigeration.
The L2000 PCB/Chloride Analyzer is easy to
operate. The analyzer can be used by persons with little
analytical laboratory experience. The operator noted
that the steps for preparing and analyzing the samples
were simple and straightforward.
The L2000 PCB/Chloride Analyzer is designed for
use as a portable field instrument. However, it does
require special care and handling in the field to avoid
damage. A mechanical pipettor and a portable electronic
balance are provided with the analyzer. These items
must be carefully handled to avoid spilling reagents or
water on the analyzer. The analyzer itself must be
handled carefully to avoid damage to the electronics.
The most sensitive part of the analyzer is the chloride
electrode. This electrode is made of epoxy and is
sensitive to shock. The electrode must be well
maintained for the analyzer to provide accurate,
consistent results.
This was monitored by periodically reanalyzing the
Aroclor standard during sample analysis. The analyzer
is equipped with a warning light to inform the operator
when recalibration is needed. This warning light
functioned on a tuned interval, rather than as a function
of the electrode response. Instrument calibration was
monitored periodically throughout sample analysis and
whenever a sample was found to contain more than
100 mg/kg of PCBs.
The operator noted that after analyzing a sample
containing more than 100 mg/kg of PCBs, the instrument
would frequently lose its calibration. Based on this
observation, the reliability of the analyzer's calibration
was found to be low after analyzing samples containing
greater than 100 mg/kg PCBs. Another factor that may
affect the reliability of the L2000 PCB/Chloride
Analyzer is that a number of sample extraction and
reaction test tubes frequently leaked during sample
preparation. It should be noted that this may have been
due to sample or operator effects. One possible
explanation of the sample extraction test tube leaks is
that when samples were weighed, a small amount of the
soil sample may have been inadvertently left on the test
tube threads. If this occurred, it may have prevented a
good seal of the test tube cap and resulted hi leakage.
This would not explain the leakage from the reaction test
tubes, however, because soil particles do not come into
contact with these tubes. The leakage problems noted by
the operator may have a significant impact on the
reliability of the L2000 PCB/Chloride Analyzer.
Chemicals used include flammable solvents, such as
naphthalene, diglyme, and butyl diglyme. These
chemicals must be handled carefully to avoid exposure
and fire.
To free the chloride ions from the biphenyl group,
50 mg of metallic sodium is used. Metallic sodium can
react explosively with water, making this reaction a
dangerous one. Dexsil's MSDS form for the L2000
PCB/Chloride Analyzer explains that if a fire occurs, it
should be treated as a sodium fire and water should not
be used to extinguish the fire. However, because the
amount of metallic sodium included in each reaction test
tube is small, water would be a suitable medium for
extinguishing a fire that involved fewer than five
reaction test tubes. A dry chemical fire extinguisher
would be an appropriate method of extinguishing a fire
involving more than five of the reaction test tubes.
The analyzer contains a florisil cleanup column.
Florisil is a fine dust and can be a skin and eye irritant.
The raise, extract, and Aroclor standards used with the
L2000 PCB/Chloride Analyzer contain sulfuric acid. The
rinse, extract, and Aroclor standards also contain nickel
nitrate which is an oxidizer. Chemical resistant clothing
and safety glasses should be worn when opening the
packaging material, when handling the florisil column,
and when handling solutions.
The L2000 PCB/Chloride Analyzer requires that
crushable glass ampules be broken within the confines of
a plastic test tube. Care should be taken when crushing
these ampules.
The operator of the L2000 PCB/Chloride Analyzer
was Mir. Keith Brown, an employee of PRC who has a
B.G.S. degree in environmental science, 2 years of
experience hi conducting preliminary site assessments
and investigations at hazardous waste sites and who has
33
-------
performed hydrogeologic investigations at similar sites.
Mr. Brown's training in the use of the L2000
PCB/Chloride Analyzer included one hour of hands-on
training. Further training was provided to a PRC chemist
at the start of the demonstration by Mr. Finch of Dexsil.
This chemist was available to assist Mr. Brown as
required. Mr. Finch provided information regarding
filtration rates and separation techniques for troublesome
sample extractions. According to the operator, some of
this information was not included in the analyzer's
instructions. Mr. Brown then analyzed five samples
using the L2000 PCB/Chloride Analyzer under the
supervision of the lead chemist. Mr. Brown noted that
he felt comfortable with his ability to properly analyze
soil samples with the analyzer after analyzing these
samples.
Costs include the costs of the analyzer and reagents,
the operator, and waste disposal. The L2000
PCB/Chloride Analyzer can be purchased from Dexsil
for $3,500. This cost covers all instrumentation
included with the carrying case and enough reagents and
equipment to analyze 100 soil samples. Additional
reagents can be purchased from Dexsil. The cost of
additional reagents depends on the number of individual
tests required. A test is equivalent to one soil sample
analysis. The cost of reagents to perform 40 tests is
$400, which is $10 per test. If more reagents are
needed, Dexsil offers a package containing enough
reagents to perform 200 tests for $1,600, which is $8.00
per test. According to Dexsil, the shelf-life of the
reagents is one year from the date of purchase. The
shelf-life allows users of the analyzer to maintain a stock
of reagents, which can reduce the response time for PCB
analysis of samples. The L2000 PCB/Chloride Analyzer
can also be rented from Dexsil for $500 per month. A
one-time charge of $230 is also applied for use of the
electrode. Operator costs for using the L2000
PCB/Chloride Analyzer will vary depending on the
technical knowledge of the operator. The waste
generated by these analyses filled half a 55-gallon drum.
The appropriate way to dispose of this waste is 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 paragraphs describe the L2000
PCB/Chloride Analyzer's performance factors including
detection limits and sensitivities, sample throughput,
linear range, and drift. Specificity, due to its
complexity, is discussed separately.
Detection Limits and Sensitivity
The detection limit for the L2000 PCB/Chloride
Analyzer is reported by Dexsil to be 5 mg/kg. The
detection limit for the samples analyzed during the
demonstration was 2 mg/kg. The following paragraphs
explain the reason for the different detection limits.
After analyzing the predemonstration samples,
Dexsil reported two results for each of the samples
analyzed. The first result for each sample is the actual
concentration of PCBs detected hi the sample. The
second result was calculated by subtracting the
concentration of PCBs detected in the reagent blank from
the concentration detected in the sample. This second
set of results includes three results that were below the
5 mg/kg detection limit reported by Dexsil. PRC
discussed the discrepancy between the stated detection
limit for the analyzer and the actual results reported by
Dexsil during the predemonstration with Mr. Finch of
Dexsil. In this discussion, Mr. Finch stated that the
detection limit of the L2000 PCB/Chloride Analyzer is
5 mg/kg. However, this detection limit is based on
results that have not been adjusted by subtracting the
reagent blank result from the sample result. Subtracting
the reagent blank result can result in a lower detection
limit. The instructions provided with the analyzer do not
discuss this issue or state that analysis of reagent blanks
is necessary. According to Mr. Finch, most people
using the L2000 PCB/Chloride Analyzer to analyze soil
samples do not use reagent blanks.
PRC did analyze reagent blank samples with the
L2000 PCB/Chloride Analyzer to evaluate the response
of the analyzer to the reagents used. Every reagent
blank analyzed resulted in positive results. The lead
chemist and the operator determined that reagent blank
results should be subtracted from positive sample results
to reduce effects caused by the analyzer responding to
reagents used for analyzing samples. After the
demonstration, Mr. Finch was consulted about the
decision to subtract reagent blank results from sample
results. Mr. Finch commented that this would produce
better results. He also noted that the detection limit for
the L2000 PCB/Chloride Analyzer could be lowered
from 5 mg/kg to 2 mg/kg when using this approach.
Mr. Finch was confident in the ability of the analyzer to
reach this lower detection limit and stated that this limit
could be used for the samples analyzed during the
demonstration. The detection limit was then lowered for
the demonstration from 5 mg/kg to 2 mg/kg, only after
the reagent blank samples were analyzed and these
results were subtracted from sample results.
34
-------
The sensitivity of the L2000 PCB/Chloride
Analyzer, which is established by calibration, is
dependent on the amount of chloride extracted from a
soil sample. Before the analyzer is calibrated, the
chloride-specific electrode must be filled with solution.
The electrode is then checked for proper response by
monitoring the millivolt readout that results from the
electrode being placed in a vial of clean rinse solution.
The electrode must give a readout of above 140
millivolts before analysis continues. After proper
response of the electrode is verified, the analyzer is
calibrated. Calibration is performed by placing the
electrode into a vial of Aroclor standard containing 50
mg/L of chloride solution. The readout of the analyzer
is adjusted to read 50.0 mg/kg with the analysis range
set in the "CAL" mode. After successfully completing
the calibration, sample analysis can begin.
The L2000 PCB/Chloride Analyzer has five
"analytical ranges." These ranges, or readouts, include:
millivolt, chloride, Aroclor 1242, Aroclor 1260, and
Askarel A. The Aroclor 1242 readout was used during
this demonstration because this Aroclor is the primary
contaminant at the AICO site. The Aroclor 1260 range
also was monitored for samples that gave a response of
10.0 mg/kg or greater in the Aroclor 1242 range;
however, this data was not used for reporting purposes.
The L2000 PCB/Chloride Analyzer electronics
automatically convert the readout of the electrode signal
to appropriate amounts of Aroclor 1242. This
conversion is based on the fact that Aroclor 1242
contains 42 percent chlorine by weight. The conversion
used was a simple factor in which the amount of chloride
detected by the electrode is divided by the percentage of
chloride present in the Aroclor 1242, which is 42
percent. This value is then multiplied by two to correct
for the loss of PCBs that occurs during sample
extraction. Loss of PCBs during extraction occurs
because 10 grams of sample are extracted into 10 mL of
organic extraction solvent, but only 5 mL of the
extraction solvent is used for the reaction and analysis
steps. Through these automatic conversions, the liquid
crystal display (LCD) readout of the L2000
PCB/Chloride Analyzer calculates and displays the
concentration of Aroclor 1242 in the sample.
The sensitivity of the L2000 PCB/Chloride Analyzer
to PCBs is dependent on the amount of chloride present
in the biphenyl compound. Standard EPA analytical
methods for analyzing PCBs target the seven most
common Aroclors. These Arpclors differ hi the amount
of chloride present hi the biphenyl group. Because the
amount of chloride present hi each Aroclor is known, it
is possible to evaluate the sensitivity of the analyzer to
each Aroclor. Although PRC used a 2 mg/kg detection
limit to evaluate accuracy and precision, it used Dexsil's
stated 5 mg/kg detection limit to evaluate sensitivity.
The sensitivity of the chloride-specific electrode to
Aroclor 1242 can be determined by measuring the
amount of chloride present in a 10-gram sample
containing 5 mg/kg of Aroclor 1242. A 10-gram sample
containing 5 mg/kg of Aroclor 1242 contains 0.05 mg of
Aroclor 1242. Following the instructions for the
analyzer, the PCBs are extracted into 10 mL of organic
solvent. Five mLs of this extract are then taken through
the remaining steps of the analysis. Because only 5 mLs
of extract is used, the amount of Aroclor 1242 in the
extract would be 0.025 mg. Because Aroclor 1242
contains 42 percent chloride by weight, the amount of
chloride present in the 0.025 mg of Aroclor 1242 can be
calculated by multiplying 0.025 mg of Aroclor 1242 by
0.42. This equals 0.0105 mg of chloride. This is the
minimum amount of chloride that can be detected by the
L2000 PCB/Chloride Analyzer according to the stated
detection limit.
The process also can be expressed through the
following equation:
(7-1)
(O.OS mg I 10/5) x 0.42 = 0.0105 mg Cl~
where
0.05 mg = amount of Aroclor 1242 in a 10-gram sample
containing a 5 mglkg concentration.
10/5 = ratio of solvent used for the extraction divided
by amount used for analysis.
0.42 = percent chlorine present In Aroclor 1242.
0.011)5 mg Cl~ = amount of chloride In a 10-gram
sample containing 5 mglkg of Aroclor 1242.
Just as the sensitivity of the analyzer to Aroclor
1242 can be determined as discussed above, the
sensitivity of the analyzer to the other six Aroclors can
be determined when the analyzer is operated in the
Aroclor 1242 range. These sensitivities can be
determined by performing the calculations described
above in reverse order, or the following equation can be
used:
(7-2)
((0.0105 mg Cr I %CI) x 10/5) / 0.01 kg =
sensitivity of the Aroclor
where
0.0105 C/~ = minimum amount of chloride detected
with the chloride-specific electrode.
35
-------
(7-2 continued) Sample Throughput
%CI = percent chloride present in the Aroclor.
10/5 = ratio of solvent used for the extraction
divided by amount used for analysis.
0.01 = weight of soil sample used for analysis.
Using these calculations, the minimum amount of
each Aroclor that can be detected by the analyzer in the
Aroclor 1242 range was determined. The results for
each Aroclor determined through this calculation are the
following: Aroclor 1016 (5.1 mg/kg), Aroclor 1221
(10.0 mg/kg), Aroclor 1232 (6.6 mg/kg), Aroclor 1242
(5.0 mg/kg), Aroclor 1248 (4.4 mg/kg), Aroclor 1254
(3.9 mg/kg), and Aroclor 1260 (3.5 mg/kg).
Sample Matrix Effects
The matrix of the samples analyzed during the
demonstration was problematical due to clay and lack of
a centrifuge. The most common problem was that a
colloidal suspension formed for nine of the samples after
the initial sample extraction. To obtain results from the
samples with colloidal suspension, another attempt to
extract the sample was made using less of the soil
sample. Instead of using the recommended 10 grams of
soil sample, 5 grams were used. In seven of the samples
this did not solve the problem, so the samples were again
extracted using 2.5 grams. In four of the samples this
still did not solve the problem, so these samples were
again extracted using 1.3 grams. When this occurred,
the detection level for the affected sample was raised to
account for the difference in the sample weight extracted
and analyzed.
Data reported for the rune samples that exhibited
this problem were S-coded to indicate that, due to
sample matrix effects, less than 10 grams of the sample
were used for extraction and analysis. The detection
limits for these samples also were raised. Samples
which exhibited this colloidal suspension and their
corresponding detection limits are: Sample 019 (16
mg/kg), Sample 020 (16 mg/kg), Sample 037 (4 mg/kg)
Sample 037D (4 mg/kg), Sample 093 (8 mg/kg), Sample
096 (16 mg/kg), Sample 109 (8 mg/kg), Sample 109D (8
mg/kg), and Sample 111 (16 mg/kg).
Another sample matrix effect observed was a
physical difference between some samples and their
respective field duplicates. As with the Clor-N-Soil Test
Kit, thorough homogenization of the samples, the use of
fluorescein, and increasing the number of field duplicate
samples was used to limit the effects of this problem.
Sample throughput with the L2000 PCB/Chloride
Analyzer was determined by evaluating the amount of
tune required to extract and analyze one soil sample and
the number of samples analyzed hi one work day.
Dexsil claims that a soil sample can be prepared in 10
minutes and that several samples can be prepared
concurrently. Once the samples have been prepared,
Dexsil claims that the actual analysis time for each
sample is less than one minute. According to Dexsil,
multiple samples can be prepared and then analyzed any
time afterwards. Dexsil claims that one operator can
complete 100 soil tests in an 8-hour day.
The operator of the L2000 PCB/Chloride Analyzer
determined that the amount of tune required to perform
one complete sample analysis was 9 minutes. The
operator reported that the 9-minute sample analysis tune
did not include the tune required for sample handling,
data documentation, difficult extractions, or the
preparation of QC samples. The tune required by the
operator to perform these tasks prevented him from
completing analysis of 100 samples per day. The largest
number of samples analyzed in one 8-hour day during
the demonstration was 50 samples. The average number
of samples analyzed in one day was 35. To achieve this,
the operator extracted a number of samples concurrently,
and then analyzed them at the end of the day. This was
the procedure recommended by Dexsil.
Linear Range
Dexsil states that the linear range of the L2000
PCB/Chloride Analyzer is 5 to 2,000 mg/kg; however,
the lower end was changed to 2 mg/kg and this
concentration was used during the precision and
accuracy evaluation. This linear range is dependent on
a single-point calibration of the analyzer using a 50
mg/kg chloride solution. The analyzer is operated in the
normal range during all sample analyses; however, if the
PCB concentration of a sample is found to be above 200
mg/kg, a "1" is displayed on the analyzer's display
screen. The instructions for the analyzer state that when
this occurs, the operator should switch the analyzer into
high range by pushing the "high range" button. If the
sample contains between 200 and 2,000 mg/kg of PCBs,
the concentration can then be read from the instrument's
display screen. If the sample contains above 2,000
mg/kg of PCBs, a "1" will again appear on the display
screen, indicating that it cannot provide a quantitative
result for the sample. Only one sample analyzed during
the demonstration exceeded the upper limit of the L2000
PCB/Chloride Analyzer's linear range. Sample 036 was
found to contain greater than 2,000 mg/kg of PCBs.
36
-------
Drift
The drift of the L2000 PCB/Chloride Analyzer was
not quantitatively measured during this demonstration,
but it was periodically checked by the operator by
examining the deviation of the calibration from the
chloride standard. Dexsil recommends that the
calibration of the analyzer be checked and, if necessary,
corrected after analyzing every 10 samples. Dexsil also
recommends that the analyzer's electrode be placed hi a
rinse solution between measurements to help maintain
calibration. The operator followed these recommended
practices during the demonstration sample analysis. It
was found that a significant amount of drift occurred
after analyzing samples containing greater than 100
mg/kg of PCBs. Whenever this occurred, the operator
recalibrated the instrument using the 50 mg/kg chloride
standard. The operator also noted that the calibration
warning light on the analyzer would come on at regular
intervals to remind the operator to recalibrate.
However, the warning light runs on a timer and does not
actually indicate when the instrument is out of
calibration. The effect of drift on the quality of data
produced by the L2000 PCB/Chloride Analyzer can be
reduced by frequently checking the calibration of the
analyzer.
Specificity
The L2000 PCB/Chloride Analyzer is responsive to
chloride, especially in an organic form. Inorganic forms
of chloride, such as salts, are not very soluble in the
organic solvent used for extracting chloride when
samples are being prepared. The use of the florisil
column also will remove most sources of inorganic
chloride. If sources of organic chlorine other than PCBs
are present in soil samples at mg/kg concentrations, the
analyzer may give false positive results. Common
sources of organic chloride hi soil samples include
chlorinated solvents, chlorinated pesticides, and tri-
chlorobenzenes contained hi transformer oils.
Transformer oils are commonly found at
PCB-contamination sites. If samples are suspected to
contain sources of organic chloride other than PCBs, the
L2000 PCB/Chloride Analyzer may not provide valid
data.
Other halogenated compounds also may cause false
positives in the L2000 PCB/Chloride Analyzer if they
are present hi significant concentrations. The electrode
will respond to halogenated compounds, as well as the
chloride. The electrode will respond to halogens less
strongly than it responds to chloride, probably by orders
of magnitude. Organic compounds containing bromine,
fluorine, and iodine may be extracted from soil samples
with the organic solvent used by this technology and may
pass through the florisil column. If these halogenated
ions are liberated from their parent compounds through
the sodium reaction and are present hi sufficient
concentrations, they may be detected with the electrode.
Common sources of these halogenated compounds
include solvents and pesticides.
The specificity of the L2000 PCB/Chloride Analyzer
to each of the seven Aroclors was measured during the
demonstration by spiking seven soil samples with the
Aroclors. First, each of the seven samples was divided
into four aliquots. All four aliquots were then spiked
with a particular Aroclor at a concentration of about 10
mg/kg. This level was chosen because it is a common
cleanup goal at PCB-contaminated sites. To ensure the
results of the assessment were unbiased by operator
effects, the operator did not know which Aroclor was
used for spiking nor die concentration of the Aroclor hi
the samples. The results of the Aroclor specificity test
are tabulated hi Table 7-1.
All of the Aroclor spikes were analyzed hi the 1242
range. The readouts of the analyzer were not an
accurate indication of the particular Aroclor present. To
obtain an accurate indication, the readout results must be
converted by multiplying them by a factor determined by
dividing the Aroclor's percent chlorination by the
percent chlorination of Aroclor 1242. The readouts
expected when the analyzer is set on the Aroclor 1242
setting and a soil sample spiked to 10 mg/kg for each of
the seven Aroclors is: Aroclor 1016 (9.8 mg/kg),
Aroclor 1221 (5.0 mg/kg), Aroclor 1232 (7.6 mg/kg),
Aroclor 1242 (10.0 mg/kg), Aroclor 1248 (11.4 mg/kg),
Aroclor 1254 (12.9 mg/kg), and Aroclor 1260 (14.3
mg/kg),.
For this demonstration, PRC did not convert its data
using the factors mentioned above. Such conversions
would not be performed under normal field analysis
conditions. An operator hi the field often would not
know which of the Aroclors were present and, therefore,
would not know which conversion factor to use. This
demonstration was to be performed under normal field
conditions and, for this reason, PRC did not convert its
data. However, comments are made hi the following
paragraphs concerning these conversions, and the
specificity results for. each Aroclor can be compared to
the above list to determine whether the analyzer was able
to accurately analyze each Aroclor.
All Aroclor spike samples were extracted and
analyzed the same way as the other samples collected
during the demonstration. Reagent blank results were
subtracted from the analyzer's readouts for these samples
on a daily basis as they were for the other samples.Three
spiked sample results fell between 1 and 2 mg/kg.
37
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TABLE 7-1. AROCLOR SPECIFICITY TEST RESULTS: L2000 PCB/Chloride Analyzer.
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
Soil Sample
Result
(mg/kg)
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
14.4
14.4
14.4
14.4
5.7
5.7
5.7
5.7
ND
ND
ND
ND
ND
ND
ND
ND
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
Amount
(mg/kg)
9.97
9.83
9.83
9.95
9.99
9.83
10.00
9.91
9.79
9.92
9.96
9.96
9.88
9.93
9.84
9.92
9.91
10.00
9.88
9.90
9.97
9.93
10.00
9.92
9.94
9.86
9.83
9.94
Spiked Sample
Result
(mg/kg)
<1
<1
1.7
<1
11.8
4.0
11.3
11.3
2.9
2.8
1.5
1.5
22.5
49.1
40.2
47.2
8.5
19.8
6.9
10.8
4.2
4.2
3.0
4.7
6.9
3.1
2.6
2.5
Percent Recovery
<10
<10
17
<10
118
41
113
114
30
28
15
15
82
349
262
331
28
141
12
52
42
42
30
47
69
31
26
25
Note:
ND Not detected above the 2 mg/kg detection limit.
These data points were still used in the specificity
evaluation, however, because PRC felt that reducing the
size of the data set by removing these results would
result in a reduction in the quality of the evaluation.
When the Aroclor spikes were prepared, the concen-
trations of the PCBs in the original samples were not
known. Initial indications from the L2000 PCB/Chloride
Analyzer were available, but the results had not been
38
-------
finalized. All but two of the original samples chosen for
the Aroclor specificity test were found to contain less
than 2 mg/kg of PCBs as determined by the analyzer.
Sample 034 was found by the analyzer to contain 14.4
mg/kg of PCBs. The confirmatory laboratory result for
this sample was 34 mg/kg, which is significantly higher.
The results of the Aroclor specificity test for Sample 034
were significantly affected by this discrepancy and do
not provide an accurate assessment of the analyzer's
sensitivity to the Aroclor with which it was spiked,
Aroclor 1254. Of the four spiked samples analyzed,
only one resulted hi an acceptable recovery when
compared to its respective soil sample result. That
spiked sample had a recovery of 82 percent. The other
three spiked samples exhibited extremely high recoveries
349, 262, and 331 percent, respectively, when compared
to the analyzer's soil sample results. These recoveries
are much closer to those expected when compared to the
confirmatory laboratory result. This discrepancy may be
attributed to the nonhomogeneity inherent in the soil
samples.
Sample 040 was found to contain 5.7 mg/kg of
PCBs by the analyzer. For the specificity evaluation,
this sample was spiked with Aroclor 1242. The recover-
ies obtained for the four spiked samples used hi the
specificity evaluation were 12, 28, 52, and 141 percent,
respectively. The L2000 PCB/Chloride Analyzer
reported results for all four aliquots above the 2 mg/kg
detection limit; however, assuming that the amount of
PCB hi the sample was consistent from aliquot to
aliquot, the analyzer underestimated the amount of PCB
in the spiked samples three out of four tunes. . The
confirmatory laboratory result for the sample was 4.2
mg/kg, which was close to the analyzer's result. No
conversion factor was needed for Aroclor 1242 because
the analyzer was set at the Aroclor 1242 setting.
When analyzed with the L2000 PCB/Chloride
Analyzer, three of the four aliquots spiked with Aroclor
1221 had results below 1 mg/kg after the reagent blank
results were subtracted. These three spiked samples
were reported at less than a 10 percent recovery. The
fourth sample result was 1.7 mg/kg, resulting hi a
recovery of 17 percent. All four spiked sample results
were below the 2 mg/kg detection limit. This data
indicates that Aroclor 1221 cannot be accurately quanti-
fied by the analyzer on the 1242 setting at levels of 10
mg/kg in soil samples. This means that Aroclor 1221
could be present hi soil samples at levels of 10 mg/kg
and the analyzer would report it as below its detection
limit of 2 mg/kg. The results for these samples were
significantly below 5 mg/kg, the result expected based
on the conversion list.
When analyzed with the L2000 PCB/Chloride
Analyzer, two of the four aliquots spiked with Aroclor
1232 had results below 2 mg/kg after the reagent blank
results were subtracted. The percent recovery values for
these four spiked samples ranged from 15 to 30 percent.
These results indicate that 50 percent of the tune the
analyzer did not identify that Aroclor 1232 had been
spiked into a sample above its detection limit, even
though that spike was at a concentration of 10 mg/kg.
Also, the results for all Aroclor 1232 spike sample
results were significantly below 7.6 mg/kg, the result
expected for these samples based on the conversion list.
/
All of the samples spiked with Aroclor 1016 resulted
hi readouts above the 2 mg/kg detection limit after the
reagent blank results were subtracted. The percent
recovery values for these samples ranged from 25 to 69
percent. Three of the four sample results were signifi-
cantly below 9.8 mg/kg, the expected result based on the
conversion list. These results indicate that the analyzer
was able to detect Aroclor 1016, but had difficulty
accurately determining the concentration that had been
spiked into the samples.
All of the samples spiked with Aroclor 1248 resulted
hi readouts above the 2 mg/kg detection limit after the
reagent blank results were subtracted. The percent
recovery values for these samples ranged from 30 to 47
percent. The results for these samples were significantly
below 11.4 mg/kg, the expected result for this Aroclor
based on the conversion list shown above. These results
again indicate that the analyzer was able to detect the
Aroclor 1248, but that it underestimated the concentra-
tion that had been spiked into the samples.
All of the samples spiked with Aroclor 1260 resulted
hi readouts above the 2 mg/kg detection limit after the
reagent blank results were subtracted. The percent
recoveries for three of the four samples were 113, 114,
118 percent. The percent recovery for the other sample
was 41 percent. Only one of these sample results
differed significantly from 14.3 mg/kg, the expected
result based on the conversion list shown above. These
results indicate that the analyzer was able to quantify the
expected concentration of Aroclor 1260 fairly accu-
rately.
inframethod Assessment
Reagent blank samples were prepared by taking
reagents through all extraction, cleanup, and reaction
steps of the analysis. Ten reagent blanks were analyzed
during the analysis of samples at the demonstration.
Each time, the analysis of these reagent blanks produced
39
-------
TABLE 7-2. REAGENT BLANK RESULTS.
Reagent Blank Sample
No.
RBLK8/17/1
RBLK8/17/2
RBLK8/18/1
RBLK8/18/2
RBLK8/18/3
RBLK 8/20/1
RBLK 8/21/1
RBLK 8/24/1
RBLK 8/24/2
RBLK 8/26/1
Analytical Result
(mg/kg)
3.7
4.3
4.6
3.9
4.4
3.5
5.3
7.2
4.1
5.0
Note:
Sample number translates to: RBLK = Reagent blank;
8/4/1 - Month/day/number of blank run
positive results with the L2000 PCB/Chloride Analyzer.
These results ranged from 3.5 to 7.2 mg/kg. Overall,
the analysis of reagent blanks suggests that the electrode
used with the analyzer causes it to read between 3.5 and
7.2 mg/kg, even when PCBs are not present. Reagent
blank results are presented in Table 7-2.
Completeness for the samples analyzed by the
L2000 PCB/Chloride Analyzer was 99 percent, well
above the objective of 90 percent.
Intramethod accuracy was assessed for the L2000
PCB/Chloride Analyzer through the use of PE samples
and matrix spike and matrix spike duplicate samples.
Accuracy was also assessed by comparing the results
from the analyzer to those from the confirmatory
laboratory.
Two PE samples were analyzed by the L2000
PCB/Chloride Analyzer during the demonstration. The
operator knew that the samples were PE samples, but did
not know the acceptance ranges or which was the high or
low concentration sample. The true concentration for
sample 047-4024-114 (the high-level sample) was 110
mg/kg, with an acceptance range of 41 to 150 mg/kg.
The actual reported result for this sample after it was
analyzed by the L2000 PCB/Chloride Analyzer was 107
mg/kg. This value was within the acceptance range. Its
percent recovery was 97 percent. The true concentration
for sample 047-4024-113 (the low-level sample) was
32.7 mg/kg, with an acceptance range of 12 to 43
mg/kg. The actual reported result for this sample after
it was analyzed by the L2000 PCB/Chloride Analyzer
was 21.8 mg/kg. This value was within the acceptance
range. The percent recovery for the low-level PE
sample was 67 percent.
Matrix spike samples, prepared by adding a known
quantity of PCB Aroclor 1242 to a sample, were used to
evaluate the extraction and analysis efficiency of the
technology. Enough concentrated Aroclor 1242 standard
was added to a 10-gram soil sample to produce a matrix
spike concentration of 25 mg/kg. The spiked sample
also was duplicated to produce a matrix spike duplicate
sample.
Six soil samples were used for matrix spike sam-
ples. In five of these samples, the L2000 PCB/Chloride
Analyzer detected no PCBs before the sample was
spiked. In the sixth sample, only 2.7 mg/kg of PCBs
was detected before it was spiked. The average recov-
ery of the matrix spike samples and their duplicates was
102 percent or 25.5 mg/kg. This is very close to the 25
mg/kg actually added to the samples. The standard
deviation of the matrix spike samples was 19.5 percent
or 4.9 mg/kg. Control limits are defined as ± 2 stan-
dard deviations from the mean, when following guide-
lines outlined in SW-846 Manual Method 8000. For the
matrix spike samples analyzed during the demonstration,
the calculated control limits ranged from 63 to 141
percent recovery. All matrix spike samples analyzed fell
within these control limits.
Precision for the analyzer was assessed by compar-
ing the results obtained on duplicate samples. Three
types of precision data were generated: data from
laboratory duplicate samples, data from field duplicate
samples, and data from matrix spike duplicate samples.
Results for these types of duplicate samples are provided
in Tables 7-3 and 7-4.
Seven pairs of laboratory duplicate samples and
their respective soil samples were analyzed with the
L2000 PCB/Chloride Analyzer. The original results
obtained for these samples ranged from 25.7 to 778
mg/kg. When the analysis was duplicated, the results
ranged from 11.6 to 624 mg/kg. Field duplicate samples
also were analyzed. PRC collected 32 field duplicate
samples. Each sample and its duplicate were analyzed
using each technology and by the confirmatory labora-
tory.
PRC was tasked with determining the precision of
the technology and attempted to control factors other
than those inherent in the technology that might contrib-
ute to a difference between a sample and its duplicate.
To control the problems usually detected by laboratory
duplicates, PRC used one operator per technology.
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 there was little difference between the contamina-
40
-------
TABLE 7-3. MATRIX SPIKE AND MATRIX SPIKE DUPLICATE RESULTS.
Sample No.
047-4024-011
047-4024-024
047-4024-039
047-4024-065
047-4024-082
047-4024-106
Soil Sample
Result
(mg/kg)
2.7
ND
ND
ND
ND
ND
Spike
Amount
(mg/kg)
25
25
25
25
25
25
Matrix Spike
Recovery
123
72
96
109
110
96
Matrix Spike
Duplicate Recovery
116
68
96
136
119
87
Relative Percent
Difference
6
6
0
22
8
10
ND Not detected above the 2 mg/kg detection limit.
tion in a sample and its duplicate. Confirmatory
laboratory data on the field duplicates and their
respective samples indicate that, overall, this process
worked. PRC then used the laboratory and field
duplicates together to determine each technology's
precision. Even the best technology can not reproduce
its results every tune. PRC established control limits to
determine whether the difference between a result from
a duplicate and the result from its respective sample was
reasonable. To establish the control limits, all sample
pairs that did not produce two positive results were
removed from the data population. Then, the RPD for
each pau: 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 control limit were 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 sample pair
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 of them fell within this range, the
data was reviewed, and if no explanation could be found,
the technology's precision was considered inadequate.
The L2000 PCB/Chloride Analyzer had 18 sample
pairs in which both a sample and its duplicate had
positive results. The data from these 18 pairs had a
mean RPD of 29.6 percent and a standard deviation of
23.9. The control limits were, therefore, set at 0 and
77.4 percent. All but one of the 18 sample pairs' RPDs
fell within the control limits. The sample pair that was
outside the control limits had results of 47.3 and 111
mg/kg, respectively. That sample pair had an RPD of
80 percent. Still, 94.5 percent of the sample pairs had
RPDs within the control limits. While this is not
between 95 and 100 percent, the technology could not
have come closer to 100 percent without every pair
falling within the control limits; therefore, the precision
was considered acceptable.
Matrix spike duplicate samples were used to further
evaluate the precision of this technology. Six matrix
spike duplicate samples were analyzed and their results
were compared to the results of their respective matrix
spike samples.
Precision of the matrix spike duplicate samples was
evaluated through the RPD of the matrix spike result and
the matrix spike duplicate result. RPD values for the six
sets of matrix spike samples ranged from 0 to 22
percent. The mean RPD value from these six samples
was 9 percent, and the sample standard deviation was 7
percent. If an upper control limit of two tunes the
standard deviation is used, the upper control limit for
RPD determined for samples analyzed during the
demonstration was 23 percent. All RPD values for the
matrix spike duplicate samples fell within this range.
Comparison of Results
to Confirmatory Results
The following sections compare the accuracy and
precision of the data from analyses using with the L2000
PCB/Chloride Analyzer to mat of the confirmatory
laboratory. The results from the confirmatory
laboratory are considered accurate and its precision is
considered acceptable. The comparison is summarized
on Table 7-5 and on Figure 7-1.
Accuracy
To measure the accuracy of the L2000
PCB/Chloride Analyzer, PRC compared its data to that
of the confirmatory laboratory using linear regression.
41
-------
TABLE 7-4. DUPLICATE RESULTS.
FIGURE 7-1.
Sample No.
015 FD
016 LD
022 FD
023 LD
024 FD
028 FD
035 FD
037 FD
038 LD
042 FD
043 FD
046 FD
047 FD
050 FD
053 LD
060 FD
062 LD
063 FD
069 FD
071 FD
081 FD
082 FD
083 FD
084 FD
085 FD
085 LD
086 FD
087 FD
088 FD
090 FD
091 FD
092 FD
095 FD
097 FD
098 FD
100 FD
100 LD
102 FD
109FD
Soil Sam-
ple Result
(mg/kg)
9.40
484
ND
48.8
ND
ND
ND
<4.00
778
ND
4.10
ND
ND
ND
25.7
2.30
111
ND
5.80
ND
ND
ND
ND
7.60
593
593
ND
ND
ND
2.00
1651
3.10
20.60
ND
ND
384
384
6.30
<8.00
Duplicate
Sample
Result
(mg/kg)
12.5
347
ND
32.7
ND
ND
ND
<4.00
624
ND
3.60
ND
ND
ND
11.6
4.40
47.3
ND
4.40
ND
ND
ND
ND
10.9
596
420
ND
ND
ND
ND
1608
3.40
20.1
ND
ND
363
264
5.00
10.3
Relative
Percent
Difference
(%)
28
33
NA
40
NA
NA
NA
NA
22
NA
13
NA
NA
NA
76
63
80
NA
27
NA
NA
NA
NA
36
1
34
NA
NA
NA
NA
3
9
2
NA
NA
6
37
23
NA
Notes:
FD Field duplicate.
LD Laboratory duplicate.
ND Not detected above the 2 mg/kg detection limit.
NA Not analyzed.
1MO*
f -
1 ,«
1
i
t
False Positives
*
True Negatives * *
True Positives
. . " * •
** *
>
.** .
<* »
*
»
False Negatives
41 »t 1 1* 1W KM* 1*>
Confirmatory Laboratory Concentration (mg/kg)
M*
Generally, the regression produces a correlation
coefficient, also called an r2, that expresses whether two
sets of data are related. If the two sets are related
perfectly, then the r2 would equal 1.0. For this
demonstration, r2 values between 0.80 and 1.0 were
considered acceptable. The linear regression also results
in an equation that expresses the relationship between
two sets of results. That equation can be expressed as a
line on a graph where the results of one set of data
would be expected if the other set of data were given.
Because, ideally, the results from the analyzer and the
results from the confirmatory laboratory were expected
to match, that line should have a slope of 1 and a
y-intercept of zero. All three of these factors, the slope,
the y-intercept, and the r2, had to be acceptable before a
technology was considered accurate.
PRC used a normal deviate test statistic to determine
whether the slope and y-intercept varied, at a two-tailed
95 percent confidence level, from what was expected.
If the slope or y-intercept of the regression line varied
greatly, then the two sets of data were considered
comparable, yet different. In other words, the
analyzer's data was not accurate, yet there was a
relationship between it and the confirmatory laboratory's
data. This relationship would enable the analyzer's
results to be corrected mathematically if a certain
number of samples were sent to a confirmatory
laboratory.
The linear regression for the L2000 PCB/Chloride
Analyzer was based on results from 51 samples. The
other results indicated that no PCBs were detected above
the detection limit. The r2 value for the regression was
0.522. This indicates that little or no relationship existed
between the L2000 PCB/Chloride Analyzer's results and
those of the confirmatory laboratory. This means that
the analyzer's results were not accurate. Figure 7-1
depicts the occurrence of correct and incorrect
measurements by this technology relative to an action
level of 10 mg/kg.
42
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TABLE 7-5. COMPARISON OF L2000 PCB/CHLORIDE ANALYZER AND CONFIRMATORY DATA.
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
033
034
L2000
PCB/
Chloride
Analyzer
(2.0
mg/kg)a
ND
ND
ND
23.6
ND
ND
ND
3.9
6.9
5.1
2.7
ND
ND
ND
9.4
12.5
484
6.5
382
71.1S
<16S
ND
ND
ND
48.8
ND
ND
3.5
ND
ND
ND
ND
ND
ND
ND
36.0
ND
14.4
Confirmatory
Laboratory
(0.033
mg/kg)a
0.593
1.50
0.114
6.71J
1.37
0.679
0.552
2.00
1.30J
0.1 72J
1.1 5J
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
6.00J
34.0
Difference
NA
NA
NA
16.9
NA
NA
NA
1.9
5.6
4.9
1.6
ND
NA
NA
0.27
2.66
1626
4.0
337
64.4
NA
NA
NA
NA
28.0
NA
NA
8.2
NA
NA
NA
NA
NA
NA
NA
11.6
NA
19.6
RPD
NA
NA
NA
111
NA
NA
NA
64.4
136
187
80.5
NA
NA
NA
2.9
23.8
125
87.3
157
165
NA
NA
NA
NA
80.5
NA
NA
35.0
NA
NA
NA
NA
NA
NA
NA
27.8
NA
81.0
Sample
No.
035
035D
036
037
037D
038
039
040
041
042
042D
043
043D
044
045
046
046D
047
047D
048
049
050
050D
051
052
053
054
055
056
057
058
059
060
060D
061
062
063
063D
L2000 PCB/
Chloride
Analyzer
(2.0
mg/kg)a
ND
ND
>2,000
<4.0S
<4.0S
778
ND
5.7
ND
ND
ND
4.1
3.6
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
9.3
25.7
5.1
4.4
ND
ND
ND
ND
2.3
4.4
549
111
ND
ND
Confirmatory
Laboratory
(0.033
mg/kg)a
ND
ND
816
0.055J
0.040J
1030J
0.676
4.25
ND
0.517
0.462J
1.69J
1.74
0.592J
ND
ND
ND
0.094J
0.098J
ND
ND
3.60
4.41
ND
4.21
0.958
0.51 6J
2.40
0.505
ND
0.681
7.86
0.624J
0.577
580
2.35
0.092J
0.1 54J
Difference
ND
ND
NA
NA
NA
252
NA
1.5
ND
NA
NA
2.4
1.9
NA
ND
ND
ND
NA
NA
ND
ND
NA
NA
ND
5.1
24.7
4.584
2.0
NA
ND
NA
NA
1.7
3.8
31
109
NA
NA
RPD
NA
NA
84.1
NA
NA
27.9
NA
29
NA
NA
NA
83
70
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
75
186
163
59
NA
NA
NA
NA
115
154
5.5
192
NA
NA
43
-------
TABLE 7-5. (CONTINUED)
Sample
No.
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
085D
086
086D
087
087D
088
088D
L2000
PCB/
Chloride
Analyzer
(2.t)
nig/kg)"
172
ND
2.1
7.5
8.0
5.8
4.4
ND
ND
ND
ND
37.0
22.0
61.0
82.0
ND
21.0
148
ND
ND
ND
ND
ND
ND
ND
7.6
10.9
593
596
ND
ND
ND
ND
ND
ND
Confirmatory
Laboratory
(0.033
mg/kg)a
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
465
1.42
1.25
0.076
ND
2.70
1.77
Difference
153
NA
.12
7.4
7.5
NA
NA
ND
NA
ND
NA
21.2
8.7
38.0
35.3
ND
18.7
105
NA
NA
NA
ND
NA
NA
NA
6.4
9.82
165
131
NA
NA
NA
ND
NA
NA
RPD
160
NA
5.9
196
176
NA
NA
NA
NA
NA
NA
80.3
49
90.5
54.9
NA
161
110
NA
NA
NA
NA
NA
NA
NA
147
164
32.3
24.7
NA
NA
NA
NA
NA
NA
Sample
No.
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
106
107
108
109
109D
110
111
112
113
114
L2000 PCB/
Chloride
Analyzer
(2.Q
mg/kg)a
ND
2.0
ND
1,650
1,608
3.14
3.4
<80.S
ND
20.6
20.1
<16.S
ND
ND
ND
ND
ND
384
363
8.3
6.3
5.0
75.2
4.1
ND
ND
161
6.1
<80.S
10.3S
ND
20.0S
240
21.8
107
Confirmatory
Laboratory
(0.033
mg/kg)a
45.0
1.01
1.40
1,630
1,704
1.21
ND
0.295
0.362J
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
2.50
14.1J
3.84J
ND
ND
ND
ND
315
14.9
66.3
Difference
NA
0.99
NA
20
96
1.93
NA
NA
NA
3.1
11.1
NA
NA
NA
NA
NA
ND
207
196
7.1
286.7
3.2
34.9
3.6
NA
NA
146.9
2.3
NA
NA
ND
NA
75
6.9
40.7
RPD
NA
66
NA
1.1
5.8
87.7
NA
NA
NA
16
43.3
NA
NA
NA
NA
NA
NA
73.8
74.0
149
192
95
60.4
61
NA
NA
168
46
NA
NA
NA
NA
27
38
47
Notes:
" Detection limit.
ND Not detected above the detection limit.
NA Either the technology, the confirmatory laboratory, or both analyses produced nondetects.
J Reported amount is below the detection limit or not valid by approved quality control procedures.
S Sample matrix effects raised detection limit.
44
-------
A residual analysis of the data identified that the r2
was greatly influenced by the results of Sample 16,
Sample 18, Sample 36 and Sample 91. PRC removed
these four points as outliers and recalculated the linear
regression. The second analysis was calculated on 47
sample results. This time, the r2 factor was 0.86,
indicating that a relationship existed between the two
data sets. The analysis defined a regression line with a
y-intercept of 26.6 mg/kg and a slope of 0.84. The
standard deviation of the slope was O.OS1, indicating
relatively little variance around the regression line. The
normal deviate test statistic indicated that the slope of
0.84 and the y-intercept of 26.6 mg/kg were significantly
different from their expected values. This means that
the results are not accurate, but can be corrected mathe-
matically. In addition, the Wilcoxon Signed Ranks Test
was used to verify these results and indicated, at a 95
percent confidence level, that the analyzer's data was
significantly different from that of the confirmatory
laboratory. This confirms that the results are not
accurate.
Based on these results, the L2000 PCB/Chloride
Analyzer's results should not be expected to be the same
as those from a confirmatory laboratory. However, if
10 to 20 percent of the samples collected are also sent to
a confirmatory laboratory, then the results from the
other 80 to 90 percent could be corrected. This may
result in a significant savings in analytical costs.
Precision
To compare the precision of the L2000
PCB/Chloride Analyzer's results to the precision of the
confirmatory laboratory's results, a Dunnett's Test was
performed on the RPDs determined from the field
duplicates and their respective samples. Dunnett's Test
determines, in a percentage, the probability that the data
sets on which it is based are the same. If die RPDs from
the confirmatory laboratory and those from the technol-
ogy are the same, then it can be assumed that the
precisions are also similar. For this demonstration,
probabilities above 95 percent indicate that the precision
of the technology and that of the confirmatory laboratory
are the same. Lower probabilities indicate that one
cannot be sure they are the same. This does not mean
that the technology's precision is worse than that of the
confirmatory laboratory, only that there is a greater
probability that the precision of the two are different.
When Dunnett's Test compared the RPDs between
the L2000 PCB/Chloride Analyzer's data and the
confirmatory laboratory's data, a probability of 74
percent resulted. This indicates that the precision may
be different from that of the confirmatory laboratory.
45
-------
Section 8
Applications Assessment
This section summarizes the advantages and limita-
tions of the two field screening technologies discussed in
this ITER. It includes a discussion on how each technol-
ogy's characteristics might affect its use at hazardous
waste sites and an assessment of how each technology
might be used in the field.
Clor-N-Soil Test Kit
The principal advantages of the Clor-N-Soil Test Kit
are that it is inexpensive and simple to operate, even for
nontechnical personnel with little training. It is highly
portable and can easily be used outdoors under limited
site conditions. The test kit has a high sample through-
put and is capable of quickly providing results.
One limitation of the Clor-N-Soil Test Kit is that it
can produce a high number of false positive results for
Aroclor 1242, which it was designed to detect. The test
kit also is susceptible to reporting false positive results
for samples containing interferants such as halogenated
organic compounds. A second limitation is that results
of the Aroclor specificity test performed during this
demonstration indicated that there is a significant possi-
bility that the Clor-N-Soil Test Kit will produce false
negative results at sites where the contaminant is an
Aroclor other than 1242. The test kit has substantially
lower sensitivities to Aroclors 1016, 1221, and 1232, in-
dicating that false negatives are likely at sites where
these Aroclors are present. The test kit also is likely to
produce a higher number of false positive results when
Aroclors 1254 or 1260 are present. False negative
results also are possible at sites where mercury and
PCBs are both present in samples. All critical samples
should be confirmed using EPA-approved methods.
The Clor-N-Soil Test Kit is most suitable for use at
sites where the Aroclor of concern is positively known
and where interferants such as halogenated organics,
which can produce false positives, or mercury, which
can produce false negatives, are known not to be pres-
ent. The test kit also would be useful at sites where a
high number of false positive results would not represent
a significant problem. An ideal use for the Clor-N-Soil
Test Kit would be cleanups of transformer spills for
example. At such a site, the Aroclor of concern could
be identified with a high degree of certainty and the
chance that interferants would be present would be
small. Also, because only a small area would be
affected, the cost of disposing of soil incorrectly identi-
fied as being contaminated would be low enough that the
money saved by using the inexpensive Clor-N-Soil Test
Kit might offset any extra disposal costs.
L2000 PCB/Chloride Analyzer
The L2000 PCB/Chloride Analyzer is inexpensive
and easy to operate, It is portable, although electricity
is required to operate it. It has a high sample throughput
and is capable of quickly providing results. It has the
additional advantage of being capable of providing
quantitative results. During this demonstration, the
quantitative results of the analyzer were not found to be
particularly accurate, but it did produce linear results,
which can easily be corrected by comparing them to
results from a percentage of samples analyzed by a
confirmatory laboratory. The analyzer is susceptible to
reporting false positive results when interferants such as
halogenated organic compounds are present in the
samples. It also does not maintain its calibration well
and must be recalibrated frequently, particularly when
analyzing samples containing PCBs at concentrations
above 100 mg/kg.
The results of the Aroclor specificity test performed
during this demonstration indicated that mere is a
significant possibility that the L2000 PCB/Chloride
Analyzer will produce false negative results at sites
where the contaminant is an Aroclor other than 1242. In
particular, the analyzer has substantially lower sensitivi-
ties to Aroclors 1016, 1221, and 1232, indicating that
false negatives are likely at sites where these Aroclors
are present. A higher number of false positive results
will occur when Aroclor 1254 or 1260 is present.
46
-------
The 12000 PCB/Chloride Analyzer is best suited for
use at sites where the Aroclor of concern is positively
known and where interferants such as halogenated
organics, which can produce false positives, are known
not to be present. If the Aroclor is known and is one of
those detectable by the analyzer, and if no interferants
are suspected to be present, it would be useful at sites
where quantitative results are needed quickly. However,
the quantitative results reported by the analyzer must be
corrected for them to be accurate. The correction factor
must be determined by submitting 10 to 20 percent of the
samples collected to a confirmatory laboratory for
analysis using standard EPA analytical methods. This
will increase the cost and lengthen the time required to
obtain accurate, quantified results.
47
-------
Section 9
References
Draper, N. R., andH. Smith. 1981. Applied Regression Analyses. John Wiley & Sons, Inc. New York. 2nd
ed.
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.
Snoeyink, Vernon Li-and David Jenkins. 1980. Water Chemistry. John Wiley and Sons, Inc., New York.
Stanley, T. W. and S. S. Verner. 1983. "Interim Guidelines and Specifications for Preparing Quality Assurance
Project Plans." U.S. Environmental Protection Agency, Washington D.C. EPA/600/4-83/004.
U.S. Department of Energy. 1989. "RCRA Facility Investigation and Corrective Measures Study for the
Abandoned Indian Creek Outfall." Albuquerque Operations Office, Environment and Health Division,
Environmental Programs Branch, Kansas City Plant.
U.S. Environmental Protection Agency. 1989. "Preparing Perfect Project Plans." Cincinnati, OH.
EPA/600/9-89/087.
48
•ftU.S. GOVERNMENT PRINTING OFFICE: 1995-653-448
------- |