United States Office of Research and EPA/600/R-98/110
Environmental Protection Development August 1998
Agency Washington, D.C. 20460
4>EPA Environmental Technology
Verification Report
Immunoassay Kit
Hach Company
PCB Immunoassay Kit
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EPA/600/R-98/110
August 1998
Environmental Technology
Verification Report
Immunoassay Kit
Hach Company
PCB Immunoassay Kit
By
Amy B. Dindal
Charles K. Bayne, Ph.D.
Roger A. Jenkins, Ph.D.
Oak Ridge National Laboratory
Oak Ridge Tennessee 37831-6120
Stephen Billets, Ph.D.
Eric N. Koglin
U.S. Environmental Protection Agency
Environmental Sciences Division
National Exposure Research Laboratory
Las Vegas, Nevada 89193-3478
This demonstration was conducted in cooperation with
U.S. Department of Energy
David Bottrell, Project Officer
Cloverleaf Building, 19901 Germantown Road
Germantown, Maryland 20874
Superfund Innovative Technology
Evaluation Program
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Notice
The U.S. Environmental Protection Agency (EPA), through its Office of Research and
Development (ORD), and the U.S. Department of Energy's Environmental Management (EM)
Program, funded and managed, through Interagency Agreement No. DW89937854 with Oak Ridge
National Laboratory, the verification effort described herein. This report has been peer and
administratively reviewed and has been approved for publication as an EPA document. Mention of
trade names or commercial products does not constitute endorsement or recommendation for use of
a specific product.
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
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*- Office of Research and Development
Washington, D.C. 20460
ENVIRONMENTAL TECHNOLOGY VERIFICATION PROGRAM
VERIFICATION STATEMENT
TECHNOLOGY TYPE: POLYCHLORINATED BIPHENYL (PCB) FIELD ANALYTICAL
TECHNIQUES
APPLICATION: MEASUREMENT OF PCBs IN SOILS
TECHNOLOGY NAME: PCB IMMUNOASSAY KIT
COMPANY: HACH COMPANY
ADDRESS: PO BOX 389
LOVELAND, CO 80539
PHONE: 1-800-227-4224
The U.S. Environmental Protection Agency (EPA) has created a program to facilitate the deployment of innovative
technologies through performance verification and information dissemination. The goal of the Environmental Technology
Verification (ETV) Program is to further environmental protection by substantially accelerating the acceptance and use
of improved and more cost effective technologies. The ETV Program is intended to assist and inform those involved in
the design, distribution, permitting, and purchase of environmental technologies. This document summarizes the results
of a demonstration of the Hach Company PCB immunoassay kit.
PROGRAM OPERATION
The EPA, in partnership with recognized testing organizations, objectively and systematically evaluates the performance
of innovative technologies. Together, with the full participation of the technology developer, they develop plans, conduct
tests, collect and analyze data, and report findings. The evaluations are conducted according to a rigorous demonstration
plan and established protocols for quality assurance. EPA's National Exposure Research Laboratory, which conducts
demonstrations of field characterization and monitoring technologies, with the support of the U.S. Department of
Energy's Environmental Management program, selected Oak Ridge National Laboratory (ORNL) as the testing
organization for the performance verification of polychlorinated biphenyl (PCB) field analytical techniques.
DEMONSTRATION DESCRIPTION
In July 1997, the performance of six PCB field analytical techniques was determined under field conditions. Each
technology was independently evaluated by comparing field analysis results to those obtained using approved reference
methods. Performance evaluation (PE) samples were also used to independently assess the accuracy and comparability
of each technology.
The demonstration was designed to detect and measure PCBs in soil. The demonstration was conducted at ORNL in Oak
Ridge, Tennessee, from July 22 through July 29, 1997. The study was conducted under two environmental conditions.
The first site was outdoors with naturally fluctuating temperatures and relative humidity conditions. The second site was
inside a controlled environmental chamber, with generally cooler temperature and lower relative humidities. Multiple soil
types, collected from sites in Ohio, Kentucky, and Tennessee, were analyzed in this study. The results of the soil analyses
conducted under field conditions by the technology were compared with results from analyses of homogeneous replicate
samples conducted by conventional EPA SW-846 methodology in an approved reference laboratory. Details of the
demonstration, including a data summary and discussion of results, may be found in the report entitled Environmental
Technology Verification Report: Immunoassay Kit, Hach Company PCB Immunoassay Kit, EPA/600/R-98/110.
EPA-VS-SCM-13 The accompanying notice is an integral part of this verification statement August 1998
ni
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TECHNOLOGY DESCRIPTION
The PCB immunoassay kit utilizes analyte-specific antibodies attached to the inside of plastic tubes to bind and remove
PCBs selectively from complex sample matrices. The kit is a semi-quantitative screening method that indicates whether
the PCB concentration is above or below the specified threshold values (1 ppm and/or 10 ppm). The kit has most
applicability to establishing cleanup guidelines. To initiate the test, the sample (that may contain PCBs) and a reagent
containing enzyme conjugate are added to the antibody-coated tubes. An enzyme conjugate consists of an enzyme to
which an analyte is attached. Enzyme conjugates and PCBs competitively bind to the antibodies attached to the inside
of the tube. Samples with higher levels of PCBs will have more antibody sites occupied by the analyte and fewer occupied
by the enzyme conjugate molecules. After incubation, the sample and unbound enzyme conjugate are washed from the
tube and color development reagents are added. The concentration of PCBs in a sample is determined by comparing the
developed color intensity to that of a PCB standard. The PCB concentration is inversely proportional to the color
development, where the lighter the color, the higher the sample PCB concentration.
VERIFICATION OF PERFORMANCE
The following performance characteristics of the PCB immunoassay kit were observed:
Throughput: Throughput was 10 to 13 samples/hour under the outdoor conditions, and 7 to 10 samples/hour under the
chamber conditions. These rates included preparation and analysis.
Ease of use: Two operators analyzed samples during the demonstration, but the technology can be run by a single
operator. Minimal training (2 hours) is required to operate the PCB immunoassay kit, provided that the user has a basic
knowledge of chemistry and lab techniques.
Completeness: The PCB immunoassay kit generated results for all 208 PCB samples for a completeness of 100%.
Blank results: PCBs were detected and reported as 1 to 10 ppm in three of the eight blank soil samples analyzed.
Therefore, the percentage of false positive results was 38%. The PCB immunoassay kit reported 2% (4 of 192 samples)
false negative results.
Precision: The overall precision, based on the percentage of combined sample sets where all four replicates were
reported as the same interval, was 100% for the PE soils and 68% for the environmental soils.
Accuracy: Accuracy was assessed using PE soil samples. Accuracy, defined as the percentage of PCB immunoassay
kit results that agreed with the accepted concentrations, was 90%, while the percentage that was biased high or low was
4 and 6%, respectively. All of the biased low results were at concentrations near the 10-ppm threshold value.
Comparability: Comparability, like accuracy, was defined as the percentage of samples that agreed with, was above
(i.e., biased high), or was below (i.e., biased low) the reference laboratory results. The percentage of PE and
environmental soil samples which agreed with the reference laboratory results was 85%, while the percentage that was
biased high or low was 7 and 9%, respectively. In nearly all cases where the test kit result disagreed with the reference
laboratory result, the concentration was near one of the kit's threshold values of 0, 1, or 10 ppm.
Regulatory decision-making: One objective of this demonstration was to assess the technology's ability to perform at
regulatory decision-making levels for PCBs, specifically 50 ppm for soils. For PE and environmental soil samples in the
range of 40 to 60 ppm, 98% of the PCB immunoassay kit results agreed with the reference laboratory in that the test kit
reported PCB concentrations as greater than 10 ppm. In contrast, only 2% were biased low, while none of the samples
were biased high. As tested, the PCB immunoassay kit's interval ranges would have limited application in determining
whether a sample contained > 50 ppm of PCBs, only that the sample contained > 10 ppm of PCBs.
EPA-VS-SCM-13 The accompanying notice is an integral part of this verification statement August 1998
IV
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Data quality levels: The performance of the PCB immunoassay kit was characterized as unbiased and precise. In the
format that was tested, the kit provided limited information. The kit would be more applicable to cleanup applications,
where it could be utilized as a quick test to determine the status of cleanup activities. Hach is working to incorporate
testing at additional threshold values.
The results of the demonstration show that the PCB immunoassay kit can provide useful, cost-effective data for
environmental problem-solving and decision-making. Undoubtedly, it will be employed in a variety of applications,
ranging from serving as a complement to data generated in a fixed analytical laboratory to generating data that will stand
alone in the decision-making process. As with any technology selection, the user must determine if this technology is
appropriate for the application and the project data quality objectives. For more information on this and other verified
technologies, visit the ETV web site at http://www.epa.gov/etv.
Gary J. Foley, Ph.D.
Director
National Exposure Research Laboratory
Office of Research and Development
NOTICE: EPA verifications are based on an evaluation of technology performance under specific, predetermined criteria and the
appropriate quality assurance procedures. EPA makes no expressed or implied warranties as to the performance of the technology and
does not certify that a technology will always, under circumstances other than those tested, operate at the levels verified. The end user
is solely responsible for complying with any and all applicable Federal, State, and Local requirements.
EPA-VS-SCM-13 The accompanying notice is an integral part of this verification statement August 1998
V
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VI
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Foreword
The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the nation's natural
resources. The National Exposure Research Laboratory (NERL) is EPA's center for the investigation of
technical and management approaches for identifying and quantifying risks to human health and the
environment. NERL's research goals are to (1) develop and evaluate technologies for the characterization and
monitoring of air, soil, and water; (2) support regulatory and policy decisions; and (3) provide the science
support needed to ensure effective implementation of environmental regulations and strategies.
EPA created the Environmental Technology Verification (ETV) Program to facilitate the deployment of
innovative technologies through performance verification and information dissemination. The goal of the ETV
Program is to further environmental protection by substantially accelerating the acceptance and use of
improved and cost-effective technologies. The ETV Program is intended to assist and inform those involved
in the design, distribution, permitting, and purchase of environmental technologies. This program is
administered by NERL's Environmental Sciences Division in Las Vegas, Nevada.
The U.S. Department of Energy's (DOE's) Environmental Management (EM) program has entered into active
partnership with EPA, providing cooperative technical management and funding support. DOE EM realizes
that its goals for rapid and cost-effective cleanup hinge on the deployment of innovative environmental
characterization and monitoring technologies. To this end, DOE EM shares the goals and objectives of the
ETV.
Candidate technologies for these programs originate from the private sector and must be commercially ready.
Through the ETV Program, developers are given the opportunity to conduct rigorous demonstrations of their
technologies under realistic field conditions. By completing the evaluation and distributing the results, EPA
establishes a baseline for acceptance and use of these technologies.
Gary J. Foley, Ph.D.
Director
National Exposure Research Laboratory
Office of Research and Development
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Abstract
In July 1997, the U.S. Environmental Protection Agency (EPA) conducted a demonstration of poly chlorinated
biphenyl (PCB) field analytical techniques. The purpose of this demonstration was to evaluate field analytical
technologies capable of detecting and quantifying PCBs in soils and solvent extracts. The fundamental
objectives of this demonstration were (1) to obtain technology performance information using environmental
and quality control samples, (2) to determine how comparable the developer field analytical results were with
conventional reference laboratory results, and (3) to report on the logistical operation of the technology. The
demonstration design was subjected to extensive review and comment by EPA's National Exposure Research
Laboratory (NERL) Environmental Sciences Division in Las Vegas, Nevada; Oak Ridge National Laboratory
(ORNL); EPA Regional Offices; the U.S. Department of Energy (DOE); and the technology developers.
The demonstration study was conducted at ORNL under two sets of environmental conditions. The first site
was outdoors, with naturally variable temperature and relative humidity conditions typical of eastern Tennessee
in the summer. A second site was located inside a controlled environmental chamber having lower, and
relatively stable, temperature and relative humidity conditions. The test samples analyzed during this
demonstration were performance evaluation soil, environmental soil, and extract samples. Actual environmental
soil samples, collected from sites in Ohio, Kentucky, and Tennessee, were analyzed, and ranged in
concentration from 0.1 to 700 parts per million (ppm). The reference laboratory method used to evaluate the
comparability of data was EPA SW-846 Method 8081.
The field analytical technologies tested in this demonstration were the L2000 PCB/Chloride Analyzer (Dexsil
Corporation), the PCB Immunoassay Kit (Hach Company), the 4100 Vapor Detector (Electronic Sensor
Technology), and three immunoassay kits: D TECH, EnviroGard, and RaPID Assay System (Strategic
Diagnostics Inc.). The purpose of an Environmental Technology Verification Report (ETVR) is to document
the demonstration activities, present demonstration data, and verify the performance of the technology. This
ETVR presents information regarding the performance of Hach Company's PCB immunoassay kit. Separate
ETVRs have been published for the other technologies demonstrated.
The PCB immunoassay kit utilizes analyte-specific antibodies attached to the inside of plastic tubes to bind
and remove PCBs selectively from complex sample matrices. The kit is a semi-quantitative screening method
that indicates whether the PCB concentration is above or below the specified threshold values (1 ppm and/or
10 ppm). The kit has most applicability to establishing cleanup guidelines. The concentration of PCBs in a
sample is determined by comparing the developed color intensity to that of a PCB standard. The PCB
concentration is inversely proportional to the color development, where the lighter the color, the higher the
sample PCB concentration. The PCB immunoassay kit provides no information on Aroclor identification.
The PCB immunoassay kit's semi-quantitative results were based on the analysis of a calibration standard at
1 ppm that was analyzed with every four samples. Because the PCB immunoassay kit was an interval
technique, method detection limits are not applicable. Precision, defined as the percentage of the sample sets
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where all four replicates were reported as the same interval range, was 100% for the PE soil samples and 68%
for the environmental soil samples. Accuracy, defined as the percentage of PCB immunoassay kit results that
agreed with the certified PE concentrations, was 90% for all PE soil samples. In general, the percentage of
samples that was biased high (4%) was comparable to the percentage that was biased low (6%). All of the
biased low results were at concentrations near the 10 ppm threshold value. Comparability was defined similarly
to accuracy, but the PCB immunoassay kit results were compared to the reference laboratory results rather than
the accepted concentrations. For all soil samples (PE and environmental), the percentage of PCB immunoassay
kit results that agreed with the reference laboratory results was 85%, while the percentage that was biased high
(7%) was again comparable to the percentage that was biased low (9%). In nearly all cases where the test kit
result disagreed with the reference laboratory result, the concentration was near the one of the kit's threshold
values of 0, 1, or 10 ppm.
The demonstration found that the PCB immunoassay kit was simple to operate in the field, requiring about one
hour for initial setup and preparation for sample analysis. Once operational, the sample throughput of the PCB
immunoassay kit was 7 to 10 samples per hour under chamber conditions and 10 to 13 samples per hour under
outdoor conditions. Two operators analyzed samples during the demonstration, but the technology can be run
by a single operator. Minimal training (2 hours) is required to operate the PCB immunoassay kit, provided the
user has a fundamental understanding of basic chemical and field analytical techniques. The overall
performance of the PCB immunoassay kit was characterized as unbiased and precise. The demonstration
involved PCB concentrations ranging up to 700 ppm, yet the kit's current interval structure is focused on less
than 10 ppm; therefore, in the format that was tested, the kit provided limited information. The kit could be
applicable to cleanup applications, where it could be utilized as a quick test to determine the status of cleanup
activities. Hach is working to expand the number of interval ranges that can be tested.
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Table of Contents
Notice ii
Verification Statement iii
Foreword vii
Abstract ix
List of Figures xv
List of Tables xvii
List of Abbreviations and Acronyms xix
Acknowledgments xxi
Section 1 Introduction 1
Technology Verification Process 2
Needs Identification and Technology Selection 2
Demonstration Planning and Implementation 3
Report Preparation 3
Information Distribution 3
Demonstration Purpose 4
Section 2 Technology Description 5
Objective 5
Principle 5
Test Kit Description 5
Sensitivity, Concentration Range, and Aroclors 6
Procedure 8
Training Requirements 8
Method Overview 8
Method Phase 1 — Soil Extraction 8
Method Phase 2 — Diluting Standards and Samples 9
Method Phase 3 — Immunoassay 9
Method Phase 4 — Color Development 10
Method Phase 5 — Color Measurement 10
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Measuring Hints 11
Environmental Limits 12
Section 3 Site Description and Demonstration Design 13
Objective 13
Demonstration Site Description 13
Site Name and Location 13
Site History 13
Site Characteristics 14
Experimental Design 14
Environmental Conditions during Demonstration 17
Sample Descriptions 17
Performance Evaluation Materials 17
Environmental Soil Samples 18
Extract Samples 18
Sampling Plan 18
Sample Collection 18
Sample Preparation, Labeling, and Distribution 18
Predemonstration Study 20
Predemonstration Sample Preparation 20
Predemonstration Results 21
Deviations from the Demonstration Plan 21
Section 4 Reference Laboratory Analytical Results and Evaluation 23
Objective and Approach 23
Reference Laboratory Selection 23
Reference Laboratory Method 24
Calibration 24
Sample Quantification 24
Sample Receipt, Handling, and Holding Times 25
Quality Control Results 25
Objective 25
Continuing Calibration Verification Standard Results 25
Instrument and Method Blank Results 26
Surrogate Spike Results 26
Laboratory Control Sample Results 26
Matrix Spike Results 27
Conclusions of the Quality Control Results 27
Data Review and Validation 27
Objective 27
Corrected Results 28
Suspect Results 28
Data Assessment 29
Objective 29
xii
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Precision 29
Performance Evaluation Samples 29
Environmental Soil Samples 30
Extract Samples 32
Accuracy 32
Performance Evaluation Soil Samples 33
Extract Samples 34
Representativeness 34
Completeness 34
Comparability 35
Summary of Observations 35
Section 5 Technology Performance and Evaluation 37
Objective and Approach 37
Interval Reporting 37
Data Assessment 37
Objective 37
Precision 38
Performance Evaluation Samples 38
Environmental Soil Samples 38
Precision Summary 41
Accuracy 41
Performance Evaluation Soil Samples 41
False Positive/False Negative results 43
Representativeness 43
Completeness 43
Comparability 43
Summary of PARCC Parameters 44
Regulatory Decision-Making Applicability 45
Additional Performance Factors 46
Sample Throughput 46
Cost Assessment 46
Hach PCB Immunoassay Kit Costs 46
Reference Laboratory Costs 48
Cost Assessment Summary 49
General Observations 49
Performance Summary 50
Section 6 Technology Update and Representative Applications 51
Objective 51
Technology Update 51
Representative Applications 51
Potential Users of the Technology 51
Actual Users of the Technology 51
xiii
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Data Quality Objective Example 52
xiv
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Section 7 References 53
Appendix A Description of Environmental Soil Samples 55
Appendix B Characterization of Environmental Soil Samples 59
Appendix C Temperature and Relative Humidity Conditions 63
Appendix D Technology Demonstration Sample Data 69
Appendix E Data Quality Objective Example 79
Disclaimer 81
Background and Problem Statement 81
DQO Goals 81
Use of Technology Performance Information to Implement the Decision Rule 82
Determining the Number of Samples 82
Alternate FP Parameter 84
xv
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List of Figures
3-1. Schematic map of ORNL, indicating the demonstration area 15
C-l. Summary of temperature conditions for outdoor site 65
C-2. Summary of relative humidity conditions for outdoor site 66
C-3. Summary of temperature conditions for chamber site 66
C-4. Summary of relative humidity conditions for chamber site 67
xvi
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List of Tables
2-1. Sensitivity to Aroclors and other compounds 7
2-2. Determining if samples are above PCB threshold values 11
3-1. Summary of experimental design by sample type 16
3-2. Summary of Hach's PCB Immunoassay kit predemonstration results 21
4-1. Suspect measurements within the reference laboratory data 28
4-2. Precision of the reference laboratory for PE soil samples 30
4-3. Precision of the reference laboratory for environmental soil samples 31
4-4. Precision of the reference laboratory for extract samples 32
4-5. Accuracy of the reference laboratory for PE soil samples 33
4-6. Accuracy of the reference laboratory for extract samples 34
4-7. Summary of the reference laboratory performance 36
5-1. Hach PCB immunoassay kit reporting intervals 37
5-2. Classification of precision results 38
5-3. Precision of Hach's PCB immunoassay kit for PE soil samples 39
5-4. Precision of Hach's PCB immunoassay kit for environmental soil samples 40
5-5. Overall precision of the Hach PCB immunoassay kit for all sample types 41
5-6. Hach's PCB immunoassay kit accuracy for PE soil samples 42
5-7. Evaluation of agreement between Hach's PCB immunoassay kit's PE sample results and the
certified PE values as a measure of accuracy 42
5-8. Evaluation of agreement between Hach's PCB immunoassay kit's soil results and the reference
laboratory's results as a measure of comparability 44
5-9. Comparison of the Hach's PCB immunoassay kit results with the reference laboratory's suspect
measurements 45
5-10. Hach PCB immunoassay kit performance for precision, accuracy, and comparability 45
5-11. Estimated analytical costs for PCB soil samples 47
5-12. Performance summary for the Hach PCB immunoassay kit 50
A-l. Summary of soil sample descriptions 57
B-l. Summary of environmental soil characterization 61
C-l. Average temperature and relative humidity conditions during testing periods 65
D-l. Hach's PCB technology demonstration soil sample data 71
D-2. Corrected reference laboratory data 77
xvm
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List of Abbreviations and Acronyms
ASTM American Society for Testing and Materials
BHC benzenehexachloride
C concentration at which the false positive error rate is specified
CCV continuing calibration verification standard
CSCT Consortium for Site Characterization Technology
DCB decachlorobiphenyl
DOE U.S. Department of Energy
DQO data quality objectives
ELISA enzyme-linked immunosorbent assay
EM Environmental Management (DOE)
EPA U.S. Environmental Protection Agency
ERA Environmental Resource Associates
ETTP East Tennessee Technology Park
ETV Environmental Technology Verification Program
ETVR Environmental Technology Verification Report
EvTEC Environmental Technology Evaluation Center
fn false negative result
FN false negative decision error rate
fp false positive result
FP false positive decision error rate
HEPA high-efficiency particulate air
ID identifier
LCS laboratory control sample
LMER Lockheed Martin Energy Research
LMES Lockheed Martin Energy Systems
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LV Las Vegas
MS matrix spike
MSB matrix spike duplicate
n number of samples
NERL National Exposure Research Laboratory (EPA)
NRC Nuclear Regulatory Commission
ORNL Oak Ridge National Laboratory
ORO Oak Ridge Operations (DOE)
PARCC precision, accuracy, representativeness, completeness, comparability
PCB polychlorinated biphenyl
PE performance evaluation
ppb parts per billion
ppm parts per million; equivalent units: mg/kg for soils and (jg/mL for extracts
Pr probability
QA quality assurance
QC quality control
R2 coefficient of determination
RDL reporting detection limit
RH relative humidity
RFD request for disposal
RPD relative percent difference
RSD relative standard deviation (percent)
SARA Superfund Amendments and Reauthorization Act of 1986
SD standard deviation
SITE Superfund Innovative Technology Evaluation
SMO sample management office
SOP standard operating procedure
SSM synthetic soil matrix
TCMX tetrachloro-m-xylene
xxi
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Acknowledgments
The authors wish to acknowledge the support of all those who helped plan and conduct the demonstration,
analyze the data, and prepare this report. In particular, we recognize the technical expertise of Mitchell
Erickson (Environmental Measurements Laboratory), Viorica Lopez-Avila (Midwest Research Institute), and
Robert F. O'Brien (Pacific Northwest National Laboratory), who were peer reviewers of this report. For
internal peer review, we thank Stacy Barshick (ORNL); for technical support during the demonstration, Todd
Skeen and Ralph Ilgner (ORNL); for site safety and health support, Kim Thomas, Marilyn Hanner, and Fred
Smith (ORNL); for administrative support, Betty Maestas and Linda Plemmons (ORNL); for sample collection
support, Wade Hollinger, Charlotte Schaefer, and Arlin Yeager (LMES), and Mike Rudacille and W. T.
Wright (EET Corporation); for preliminary soil characterization support, Frank Gardner, John Zutman, and
Bob Schlosser (ORNL, Grand Junction, Colo.); for sample management support, Angie McGee, Suzanne
Johnson, and Mary Lane Moore (LMES); for providing performance evaluations samples, Michael Wilson
(EPA's Office of Solid Waste and Emergency Response's Analytical Operations and Data Quality Center);
and for technical guidance and project management of the demonstration, David Garden, Marty Atkins, and
Regina Chung (DOE's Oak Ridge Operations Office), David Bottrell (DOE, Headquarters), Deana Crumbling
(EPA's Technology Innovation Office), and Stephen Billets, Gary Robertson, and Eric Koglin (EPA's National
Exposure Research Laboratory, Las Vegas, Nevada). The authors also acknowledge the participation of Hach
Company, in particular, John Parsons and James Welch, who performed the analyses during the demonstration.
For more information on the PCB Field Analytical Technology Demonstration, contact
Eric N. Koglin
Project Technical Leader
Environmental Protection Agency
Environmental Sciences Division
National Exposure Research Laboratory
P.O. Box 93478
Las Vegas, Nevada 89193-3478
(702) 798-2432
For more information on Hach's PCB immunoassay kit, contact
James Welch
Hach Company
PO Box 389
5600 Lindbergh Drive
Loveland, Colorado 80539-0389
1-800-227-4224
xxii
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Section 1
Introduction
The performance evaluation of innovative and alternative environmental technologies is an integral part of the
U.S. Environmental Protection Agency's (EPA's) mission. Early efforts focused on evaluating technologies
that supported the implementation of the Clean Air and Clean Water Acts. In 1987, the Agency began to
evaluate the cost and performance of remediation and monitoring technologies under the Superfund Innovative
Technology Evaluation (SITE) program. This was in response to the mandate in the Superfund Amendments
and Reauthorization Act (SARA) of 1986. In 1990, the U.S. Technology Policy was announced. This policy
placed a renewed emphasis on "making the best use of technology in achieving the national goals of improved
quality of life for all Americans, continued economic growth, and national security." In the spirit of the
Technology Policy, the Agency began to direct a portion of its resources toward the promotion, recognition,
acceptance, and use of U.S.-developed innovative environmental technologies both domestically and abroad.
The Environmental Technology Verification (ETV) Program was created by the Agency to facilitate the
deployment of innovative technologies through performance verification and information dissemination. The
goal of the ETV Program is to further environmental protection by substantially accelerating the acceptance
and use of improved and cost-effective technologies. The ETV Program is intended to assist and inform those
involved in the design, distribution, permitting, and purchase of environmental technologies. The ETV Program
capitalizes upon and applies the lessons that were learned in the implementation of the SITE Program to the
verification of twelve categories of environmental technology: Drinking Water Systems, Pollution
Prevention/Waste Treatment, Pollution Prevention/ Innovative Coatings and Coatings Equipment, Indoor Air
Products, Air Pollution Control, Advanced Monitoring Systems, EvTEC (an independent, private-sector
approach), Wet Weather Flow Technologies, Pollution Prevention/Metal Finishing, Source Water Protection
Technologies, Site Characterization and Monitoring Technology [also referred to as the Consortium for Site
Characterization Technology (CSCT)], and Climate Change Technologies. The performance verification
contained in this report was based on the data collected during a demonstration of polychlorinated biphenyl
(PCB) field analytical technologies. The demonstration was administered by CSCT.
For each pilot, EPA utilizes the expertise of partner "verification organizations" to design efficient procedures
for conducting performance tests of environmental technologies. To date, EPA has partnered with federal
laboratories and state, university, and private sector entities. Verification organizations oversee and report
verification activities based on testing and quality assurance protocols developed with input from all major
stakeholder/customer groups associated with the technology area.
In July 1997, CSCT, in cooperation with the U.S. Department of Energy's (DOE's) Environmental
Management (EM) Program, conducted a demonstration to verify the performance of six field analytical
technologies for PCBs: the L2000 PCB/Chloride Analyzer (Dexsil Corporation), the PCB Immunoassay Kit
(Hach Company), the 4100 Vapor Detector (Electronic Sensor Technology), and three immunoassay kits from
Strategic Diagnostics Inc.: D TECH, EnviroGard, and RaPID Assay System. This environmental technology
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verification report (ETVR) presents the results of the demonstration study for one PCB field analytical
technology, Hach's PCB immunoassay kit. Separate ETVRs have been published for the other five
technologies.
Technology Verification Process
The technology verification process is intended to serve as a template for conducting technology demonstrations
that will generate high-quality data that EPA can use to verify technology performance. Four key steps are
inherent in the process:
• Needs identification and technology selection
• Demonstration planning and implementation
• Report preparation
• Information distribution
Needs Identification and Technology Selection
The first aspect of the technology verification process is to determine technology needs of EPA and the
regulated community. EPA, DOE, the U.S. Department of Defense, industry, and state agencies are asked to
identify technology needs and interest in a technology. Once a technology need is established, a search is
conducted to identify suitable technologies that will address this need. The technology search and identification
process consists of reviewing responses to Commerce Business Daily announcements, searches of industry and
trade publications, attendance at related conferences, and leads from technology developers. Characterization
and monitoring technologies are evaluated against the following criteria:
• meets user needs;
• may be used in the field or in a mobile laboratory;
• is applicable to a variety of environmentally impacted sites;
• has high potential for resolving problems for which current methods are unsatisfactory;
• is cost competitive with current methods;
• performs better than current methods in areas such as data quality, sample preparation, or analytical
turnaround time;
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• uses techniques that are easier and safer than current methods; and
• is a commercially available, field-ready technology.
Demonstration Planning and Implementation
After a technology has been selected, EPA, the verification organization, and the developer agree to the
responsibilities for conducting the demonstration and evaluating the technology. The following tasks are
undertaken at this time:
• identifying demonstration sites that will provide the appropriate physical or chemical environment,
including contaminated media;
• identifying and defining the roles of demonstration participants, observers, and reviewers;
• determining logistical and support requirements (for example, field equipment, power and water
sources, mobile laboratory, communications network);
• arranging analytical and sampling support; and
• preparing and implementing a demonstration plan that addresses the experimental design, sampling
design, quality assurance/quality control (QA/QC), health and safety considerations, scheduling of
field and laboratory operations, data analysis procedures, and reporting requirements.
Report Preparation
Innovative technologies are evaluated independently and, when possible, against conventional technologies. The
field technologies are operated by the developers in the presence of independent technology observers. The
technology observers are provided by EPA or a third-party group. Demonstration data are used to evaluate the
capabilities, limitations, and field applications of each technology. Following the demonstration, all raw and
reduced data used to evaluate each technology are compiled into a technology evaluation report, which is
mandated by EPA as a record of the demonstration. A data summary and detailed evaluation of each
technology are published in an ETVR.
Information Distribution
The goal of the information distribution strategy is to ensure that ETVRs are readily available to interested
parties through traditional data distribution pathways, such as printed documents. Documents are also available
on the World Wide Web through the ETV Web site (http://www.epa.gov/etv) and through a Web site supported
by the EPA Office of Solid Waste and Emergency Response's Technology Innovation Office (http://CLU-
in.com).
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Demonstration Purpose
The purpose of this demonstration was to obtain performance information for PCB field analytical
technologies, to compare the results with conventional fixed-laboratory results, and to provide supplemental
information (e.g., cost, sample throughput, and training requirements) regarding the operation of the
technology. The demonstration was conducted under two climatic conditions. One set of activities was
conducted outdoors, with naturally fluctuating temperatures and relative humidity conditions. A second set was
conducted in a controlled environmental facility, with lower, relatively stable temperatures and relative
humidities. Multiple soil types, collected from sites in Ohio, Kentucky, and Tennessee, were used in this study.
PCB soil concentrations ranged from approximately 0.1 to 700 parts per million (ppm). Developers also
analyzed 24 solutions of known PCB concentration that were used to simulate extracted wipe samples. The
extract samples ranged in concentration from 0 to 100 (jg/mL.
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Section 2
Technology Description
Objective
The objective of this section is to describe the technology being demonstrated, including the operating principles
underlying the technology and the overall approach to its use. The information provided here is excerpted from
that provided by the developer. Performance characteristics described in this section are specified by the
developer, and may or may not be substantiated by the data presented in Section 5.
Principle
The Hach Immunoassay Test Kit for field PCB analysis applies the principles of enzyme-linked immunosorbent
assay (ELISA) to the determination of PCB concentrations. In such an assay, an enzyme has been chemically
linked to a PCB molecule or PCB analog to create a labeled PCB reagent. The labeled PCB reagent (called a
conjugate) is mixed with an extract of native sample containing the PCB contaminant. A portion of the mixture
is applied to a surface to which an antibody specific for PCB has been affixed. The native PCB and
PCB-enzyme conjugate compete for a limited number of antibody sites. After a period of time, the solution is
washed away, and what remains is either PCB-antibody complexes or enzyme-PCB- antibody complexes
attached to the test surface. The proportion of the two complexes on the test surface is determined by the
amount of native PCB in the original sample. The enzyme present on the test surface is used to catalyze a color
change reaction in a solution added to the test surface. Because the amount of enzyme present is inversely
proportional to the concentration of native PCB contaminant, the amount of color development is inversely
proportional to the concentration of PCB contaminant.
In the case of the Hach Immunoassay Test Kit, the antibodies are fixed to the interior surface of a tube, and
the color change is read with a small colorimeter. This method is a semi-quantitative screening method which
indicates whether the PCB concentration is above or below 1 ppm and/or 10 ppm threshold values. This is
accomplished by dilution of the sample extract. For each sample, two assays are performed. An aliquot of
sample is prepared identically to an aliquot of 1 ppm calibration standard, and therefore represents a 1 ppm
threshold value. An aliquot of the sample prepared for the 1 ppm threshold is diluted by a factor often,
therefore representing a 10 ppm threshold value. The results from both sample assays are compared to the
assay of a 1 ppm calibration standard. The sample is then determined to be above or below the threshold
values of 1 and 10 ppm.
Test Kit Description
The Hach Immunoassay Test Kit for field analysis of PCB is designed for maximum convenience and is
packaged in a durable polypropylene carrying case. Everything needed for the testing is supplied with the kit.
Components are molded from durable plastic and are ideal for in field use where safety is a concern.
The kit includes a Hach Pocket Colorimeter® instrument designed for use with immunoassay-based analysis,
four AAA batteries, reagents for five PCB tests, labware required to run the analysis (including micro pipets,
test tubes, test tube rack, reagent mixing bottles, and portable scale) and instruction manual. The Hach Pocket
5
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Colorimeter supplied with the kit is a low-cost, high-quality filter photometer designed for single-wavelength
colorimetric measurement. The liquid crystal display provides a readout in counts.
Some features of Hach's PCB immunoassay kit are as follows:
• Weight—The shipping weight of the kit is 26.5 Ib.
• Transportability—The carrying case of the Hach Immunoassay Test Kit for field analysis of PCB is
designed to prevent kit components from shifting and breaking during transportation and use. Inserts
prevent messy spills by keeping reagents stored in an upright position.
• Power needed—Power is supplied by four AAA batteries (supplied with the kit). Typically, a set of
batteries provides approximately 750 tests. A battery-saving feature incorporated into the software will
automatically shut off the instrument if no keystrokes are made for 1 min. Power for the portable
balance is supplied by one 9-V battery.
• Sample matrices—The Hach immunoassay PCB field analysis method instructions cover soil only.
Existing reagents can be modified to address surface wipe or water applications. This was not
evaluated in this demonstration study.
• Speed of analysis—The Hach Immunoassay Test Kit for PCB allows on-site detection in less than 30
min.
Sensitivity, Concentration Range, and Aroclors
For concentration sensitivity, the instructions for the Hach immunoassay PCB field analysis method currently
cover making 1 and 10 ppm threshold values. Result interpretation is restricted to noting samples significantly
above, below, or approximately equal to the threshold values. For the measurement of Aroclors and/or specific
PCB compounds, see Table 2-1. The method cannot differentiate various PCBs. Sensitivity to specific
chemicals varies (see Table 2-1), and it is possible to evaluate the kit's usefulness at a selected threshold for
a specific chemical in a specific matrix.
PCBs were sold under the commercial name Aroclor. This method measures all commercial Aroclors and is
sensitive to the most common Aroclors: 1248, 1254, and 1260 (see Table 2-1). Sensitivity to other halogenated
compounds is generally less than 1% of the response to Aroclor 1260, making interference problems
insignificant. Product validation studies performed at Hach indicate that the test correctly identifies over 95%
of samples that are spiked with PCBs at or above the chosen action (threshold) level.
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Table 2-1. Sensitivity to Aroclors and other compounds
Compound
Aroclor 1260
Aroclor 1254
Aroclor 1248
Aroclor 1242
Aroclor 1016
Aroclor 1232
Other Halogenated Compounds
2,4,6-trichloro-/>-terphenyl
HalowaxlOlS
Halowax 1051
o,p -DDT
2,4-D
Silvex
bifenox
tetradifon
Dicofop methyl
dichlorofenthion
trichloroethylene
1 ,2,4-trichlorobenzene
2,4-dichloro- 1 -naphthol
2,4-dichlorophenyl benzene sulfonate
1 -chloronaphthalene
pentachlorobenzene
hexachlorobenzene
2,5-dichloroanaline
Miscellaneous Compounds
Toluene
Naphthalene
DIALA(R) Oil AX
Envirotemp 200 fluid
Diesel Fuel
Gasoline
Concentration necessary to give a positive result at 1 ppm threshold
0.4 ppm
0.4 ppm
1 ppm
2 ppm
4 ppm
4 ppm
>10,000 ppm
10,000 ppm
1,000 ppm
>10,000 ppm
10,000 ppm
1,000 ppm
1,000 ppm
100 ppm
1,000 ppm
10,000 ppm
>10,000
10,000 ppm
50 ppm
1,000 ppm
>10,000 ppm
>10,000 ppm
>10,000 ppm
>10,000 ppm
>10,000 ppm
>10,000 ppm
>10,000 ppm
>10,000 ppm
>10,000 ppm
>10,000 ppm
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Procedure
Training Requirements
The kit is supplied with detailed instructions to guide the user step by step through each procedure and
interpretation of the results. Although immunoassay kit methods are much simpler to use than many other
methods, some skill and training is required to competently perform analyses. However, the user does not have
to be a trained chemist to get professional results with the Hach method.
Method Overview
Hach immunoassay tests use analyte-specific antibodies attached to the inside of plastic tubes to selectively
bind analyte molecules from extract solutions prepared from complex sample matrices. Sample extracts that
contain the target analyte are mixed with a reagent containing enzyme-labeled conjugate, and the mixture is
added to the antibody-coated tubes. The enzyme-labeled conjugate and the PCB from the sample compete to
bind to the antibodies attached to the inside of the tubes. Samples with higher levels of analyte will have more
antibody binding sites occupied by PCBs from the sample and fewer antibody sites occupied by the enzyme
conjugate after room-temperature incubation.
After incubation, the sample and unbound enzyme conjugate are washed from the tube and color development
reagents are added. Color development only occurs in the presence of enzyme conjugate. The more enzyme
conjugate attached to the antibody on the tube, the more intense the resulting color. If more PCB is present in
the sample being tested, more unlabeled PCB will outcompete the enzyme conjugate to bind to the antibody site,
and the resulting color will be less intense. Hach immunoassay methods compare sample results with a standard
to determine whether the analyte concentrations in the sample are greater or less than the threshold levels.
Method Phase 1 —Soil Extraction
1. Fill the extraction vial to the 0.75-oz. line with Soil Extractant Solution. This is equivalent to adding 20
mL of the Soil Extractant. Note: Read Measuring Hints Section before testing.
2. Place a plastic weighing boat on the AccuLab balance. Zero the balance. Note: Refer to the AccuLab
Instructions for balance operation.
3. Weigh out 10 ± 0.1 g of soil in a plastic weighing boat. Carefully pour the soil into the extraction vial.
4. Cap the extraction vial tightly and shake vigorously for 1 min.
5. Allow to settle for 1 min. Gently open the extraction vial.
6. Using the disposable bulb pipet, withdraw 1.0-1.5 mL from the liquid (top) layer in the extraction vial.
Transfer into the filtration barrel (the bottom part of the filtering assembly; the plunger inserts into it).
Note: Do not use more than 1.5 mL. The bulb is marked in 0.25-mL increments.
7. Insert the filtration plunger into the filtration barrel. Press firmly on the plunger until at least 0.5 mL of
filtered sample is collected in the center of the plunger. Note: The liquid is forced up through the filter.
The liquid in the plunger is the sample extract. It may be necessary to place the filtration assembly on
a table and press down on the plunger.
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Method Phase 2 — Diluting Standards and Samples
1. To prepare a sample to be compared to the 1 ppm threshold, snap open a 1 ppm Dilution Ampule. Label
the Dilution Ampule with appropriate sample information.
2. Using the WireTrol pipet, withdraw 100 \\L (0.1 mL) of sample extract from the filtration plunger and
add it to the 1 ppm Dilution Ampule. Swirl to mix. Discard the capillary tube. Note: The lower line on
the capillary tube is 100 \\L.
3. To prepare a sample to be compared to the 10 ppm threshold, snap open a 10 ppm Dilution Ampule.
Label the Dilution Ampule. Using a TenSette Pipet, withdraw 1.0 mL from the 1 ppm Dilution Ampule
(Step 2) and add it to the 10 ppm Dilution Ampule. Swirl to mix.
4. To prepare the calibration standard, snap open a PCB Standard Ampule. Snap open a 1 ppm Dilution
Ampule. Label the Dilution Ampule as "Standard."
5. Using the WireTrol pipet, withdraw 100 yL (0.1 mL) of the standard and add it to the 1 ppm Dilution
Ampule. Swirl to mix. Note: The standard dilution prepared above is used to evaluate samples prepared
at both the 1 ppm and 10 ppm thresholds. Do not further dilute the standard.
Method Phase 3 —Immunoassay
Note: Steps in this phase require exact timing.
1. Label one PCB Antibody Tube and one PCB Enzyme Conjugate Tube for each sample dilution ampule.
Because the standard is to be analyzed in duplicate, label two PCB Antibody Tubes and two PCB
Enzyme Conjugate Tubes as Standard #1 and Standard #2. Note: The PCB Antibody and PCB Enzyme
Conjugate Tubes are matched lots. Mixing with other reagent lots will cause erroneous results. To
confirm the sample results, the samples can also be analyzed in duplicate (see Deviations to
Demonstration Plan in Section 3).
2. Use a TenSette Pipet to add a 1.0-mL aliquot from each dilution ampule prepared (1 ppm or 10 ppm)
to the bottom of each appropriately labeled PCB Antibody Tube. Do this for each sample and standard.
Use a new pipet tip for each solution.
3. Begin a 10-min reaction period.
4. At the end of the 10-min reaction period, decant the solution from the Antibody Tubes into the respective
Enzyme Conjugate Tubes.
5. Invert and place the Antibody Tubes over the Enzyme Conjugate Tubes until they fit tightly onto the
Enzyme Conjugate Tubes.
6. Begin a 5-min reaction period. Note: Immediately proceed with the next step while the timer counts
down.
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7. Immediately invert the solution repeatedly until the Antibody Tube has been rilled four times and the
enzyme conjugate has been dissolved. After the last inversion make sure that all of the solution is in the
Antibody Tube and that it is upright.
8. Place the Antibody Tube in the rack and remove the Enzyme Conjugate Tube from the mouth of the
Antibody Tube. Discard the used Enzyme Conjugate Tube.
9. After the 5-min period, discard the contents of the PCB Antibody Tubes into an appropriate waste
container.
10. Wash each tube forcefully and thoroughly 4 times with Wash Solution. Empty the tubes into an
appropriate waste container. Shake well to ensure most of the Wash Solution drains after each wash.
Note: Wash Solution is a harmless dilute detergent.
11. Continue to the next phase immediately. Note: Ensure most of the Wash Solution is drained from the
tubes by turning the tubes upside down and gently tapping them on a paper towel to drain. Some foam
may be left from the Wash Solution; this will not affect results.
Method Phase 4 — Color Development
Note: Check reagent labels carefully! Reagents must be added in proper order.
1. Add 5 drops of Solution A to each tube. Replace the bottle cap. Note: Hold all reagent bottles vertically
for accurate delivery, or erroneous results may occur.
2. Begin a 2.5-min reaction period and immediately add 5 drops of Solution B to each tube. Swirl to mix.
Replace the bottle cap. Note: Solution will turn blue in some or all of the tubes.
3. After exactly 2.5 min add 5 drops of Stop Solution to each tube. Replace the bottle cap. Note: Blue
solutions will turn yellow when Stop Solution is added.
4. Using the TenSette Pipet and a new tip, add 0.5 mL of deionized water to each tube. Swirl to mix. Note:
PCB concentration is inversely proportional to color development; less color indicates higher PCB levels.
Method Phase 5 — Color Measurement
1. Label and fill the Zeroing Tube with deionized water. Wipe the outside of all the tubes with a tissue to
remove smudges and fingerprints.
2. Insert the Immunoassay Tube Adapter into the cell holder.
3. Insert the Zeroing Tube into the cell holder. Cover the Zeroing Tube with the instrument cap.
4. Press: ZERO. The instrument will turn on and the display will show , followed by 0. Note: Discard
the Zeroing Tube after use.
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5. Insert the Standard #1 tube into the cell holder. Cover the tube with the instrument cap.
6. Press: READ. Record the count value displayed. Hold the adapter in place when removing the tube.
7. Repeat Steps 5 and 6 for the Standard #2 tube. Note: If Standard #1 and #2 are more than 250 counts
apart, repeat the test beginning at Phase 2 Standard Preparation.
8. Insert the Sample #1 tube into the cell holder. Cover the tube with the instrument cap.
9. Press: READ. Record the count value displayed. Hold the adapter in place when removing the tube.
Note: Flashing 0 indicates analyte concentrations much greater than the standard. Flashing 990 indicates
analyte concentration much less than the standard.
10. Repeat Steps 8 and 9 for the Sample #2 tube.
11. See Table 2-2 to interpret results.
Table 2-2. Determining if samples are above PCB threshold values
If sample count is...
. . less than highest standard count
. . greater than highest standard count
Sample Extract Prepared at the
1 ppm Threshold
Sample PCB is greater than 1 ppm
Sample PCB is less than 1 ppm
Sample Extract Prepared at the
10 ppm Threshold
Sample PCB is greater than 10 ppm
Sample PCB is less than 10 ppm
Measuring Hints
• Timing is critical; follow the instructions carefully.
• For best results, run duplicate tubes for each standard and sample.
• Handle the Antibody Tubes carefully. Scratching the inside or outside may cause erroneous results.
Clean the outside of the tubes with a clean absorbent cloth or tissue before placing them into the
instrument. Hold all dropper bottles vertical and direct the drops at the bottom of the tube.
• Antibody Tubes and Enzyme Conjugate are made in matched lots. Do not mix with other reagent lots.
• Paper towels, liquid waste container, and laboratory tissue are required, but are not supplied with the
kit.
• The tests provide semi-quantitative screening. They are designed to indicate whether the sample
concentrations are above or below a specific threshold. The specific threshold is determined by the
concentration of the standard used and dilution of sample extracts.
• The tests require about 30 min for complete analysis of one set of samples.
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• The Soil Extractant contains methyl alcohol, which is poisonous and flammable. Read Material Safety
Data Sheet before using this reagent.
• Read the entire procedure before starting. Locate and identify all reagents, tubes, and apparatus before
analysis.
Environmental Limits
• Store reagents at room temperature and out of direct sunlight (less than 80°F or 27°C).
• Keep aluminized pouch that contains PCB Antibody Tubes sealed when not in use.
• Operational temperature of the reagents is 40 to 90°F (5 to 32°C).
• Power to the Hach Pocket Colorimeter instrument is supplied by four AAA batteries (supplied
with the kit).
• Dilution solution is provided in the kit.
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Section 3
Site Description and Demonstration Design
Objective
This section describes the demonstration site, the experimental design for the verification test, and the sampling
plan (sample types analyzed and the collection and preparation strategies). Included in this section are the
results from the predemonstration study and a description of the deviations made from the original
demonstration design.
Demonstration Site Description
Site Name and Location
The demonstration of PCB field analytical technologies was conducted at Oak Ridge National Laboratory
(ORNL) in Oak Ridge, Tennessee. PCB-contaminated soils from three DOE sites (Oak Ridge; Paducah,
Kentucky; and Piketon, Ohio) were used in this demonstration. The soil samples used in this study were
brought to the demonstration testing location for evaluation of the field analytical technologies.
Site History
Oak Ridge is located in the Tennessee River Valley, 25 miles northwest of Knoxville. Three DOE facilities are
located in Oak Ridge: ORNL, the Oak Ridge Y-12 Plant, and East Tennessee Technology Park (ETTP).
Chemical processing and warhead component production have occurred at the Y-12 Plant, and ETTP is a
former gaseous diffusion uranium enrichment plant. At both facilities, industrial processing associated with
nuclear weapons production has resulted in the production of millions of kilograms of PCB-contaminated soils.
Two other DOE facilities—the Paducah plant in Paducah, Kentucky, and the Portsmouth plant in Piketon,
Ohio—are also gaseous diffusion facilities with a history of PCB contamination. During the remediation of the
PCB-contaminated areas at the three DOE sites, soils were excavated from the ground where the PCB
contamination occurred, packaged in containers ranging in size from 55-gal to 110-gal drums, and stored as
PCB waste. Samples from these repositories—referred to as "Oak Ridge," "Portsmouth," and "Paducah"
samples in this report—were used in this demonstration.
In Oak Ridge, excavation activities occurred between 1991 and 1995. The Oak Ridge samples were comprised
of PCB-contaminated soils from both Y-12 and ETTP. Five different sources of PCB contamination resulted
in soil excavations from various dikes, drainage ditches, and catch basins. Some of the soils are EPA-listed
hazardous waste due to the presence of other contaminants (e.g., diesel fuels).
A population of over 5000 drums containing PCB-contaminated soils was generated from 1986 to 1987 during
the remediation of the East Drainage Ditch at the Portsmouth Gaseous Diffusion Plant. The ditch was reported
to have three primary sources of potential contamination: (1) treated effluent from a radioactive liquid treatment
facility, (2) runoff from a biodegradation plot where waste oil and sludge were disposed of, and (3) storm sewer
discharges. In addition, waste oil was reportedly used for weed control in the ditch. Aside from PCB
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contamination, no other major hazardous contaminants were detected in these soils. Therefore, no EPA
hazardous waste codes are assigned to this waste.
Twenty-nine drums of PCB-contaminated soils from the Paducah plant were generated as part of a spill
cleanup activity at an organic waste storage area (C-746-R). The waste is considered a listed hazardous waste
for spent solvents (EPA hazardous waste code F001) because it is known to contain trichloroethylene. Other
volatile organic compounds, such as xylene, dichlorobenzene, and cresol, were also detected in the preliminary
analyses of some of the Paducah samples.
Site Characteristics
PCB-contaminated environmental soil samples from Oak Ridge, Portsmouth, and Paducah were collected from
waste containers at storage repositories at ETTP and Paducah. Many of the soils contained interfering
compounds such as oils, fuels, and other chlorinated compounds (e.g., trichloroethylene). Specific sample
descriptions of the environmental soils used in this demonstration are given in Appendix A. In addition, each
sample was characterized in terms of its soil composition, pH, and total organic carbon content. Those results
are summarized in Appendix B.
Field demonstration activities occurred at two sites at ORNL: a natural outdoor environment (the outdoor site)
and inside a controlled environmental atmosphere chamber (the chamber site). Figure 3-1 shows a schematic
map of a section of ORNL indicating the demonstration area where the outdoor field activities occurred.
Generally, the average summer temperature in eastern Tennessee is 75.6° F, with July and August temperatures
averaging 79.1 °F and 76.8 °F, respectively. Average temperatures during the testing periods ranged from 79
to 85 °F, as shown in Appendix C. Studies were also conducted inside a controlled environmental atmosphere
chamber, hereafter referred to as the "chamber," located in Building 5507 at ORNL. Demonstration studies
inside the chamber were used to evaluate performance under environmental conditions that were markedly
different from the ambient outdoor conditions at the time of the test. Average temperatures in the chamber
during the testing periods ranged from 55 to 70°F. The controlled experimental atmosphere facility consists
of a room-size walk-in chamber 10 ft wide and 12 ft long with air processing equipment to control temperature
and humidity. The chamber is equipped with an environmental control system, including reverse osmosis water
purification that supplies the chamber humidity control system. High efficiency particulate air (HEPA) and
activated charcoal filters are installed for recirculation and building exhaust filtration.
Experimental Design
The analytical challenge with PCB analysis is to quantify a complex mixture that may or may not resemble the
original commercial product (i.e., Aroclor) due to environmental aging, and to report the result as a single
number [1]. The primary objective of the verification test was to compare the performance of the field
technology to laboratory-based measurements. Often, verification tests involve a direct one-to-one comparison
of results from field-acquired samples. However, because sample heterogeneity can preclude replicate field or
laboratory comparison, accuracy and precision data must often be derived from the analysis of QC and
performance evaluation (PE) samples. In this study, replicates of all three sample types (QC, PE, and
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Building
Figure 3-1. Schematic map of ORNL, indicating the demonstration area.
environmental soil) were analyzed. The ability to use environmental soils in the verification test was made
possible because the samples, collected from drums containing PCB-contaminated soils, could be thoroughly
homogenized and characterized prior to the demonstration. This facet of the design, allowing additional
precision data to be obtained on actual field-acquired samples, provided an added performance factor in the
verification test.
Another objective of this demonstration was to evaluate the field technology's capability to support regulatory
compliance decisions. For field methods to be used in these decisions, the technology must be capable of
informing the user, with known precision and accuracy, that soil concentrations are greater than or less than
50 ppm, and that wipe samples are greater than or less than 100 (jg/100 cm2 [2]. The samples selected for
analysis in the demonstration study were chosen with this objective in mind.
The experimental design is summarized in Table 3-1. This design was approved by all participants prior to the
start of the demonstration study. In total, the developers analyzed 208 soil samples, 104 each at both locations
(outdoors and chamber). The 104 soil samples comprised 68 environmental samples (17 unique environmental
samples prepared in quadruplicate) ranging in PCB concentration from 0.1 to 700 ppm and 36 PE soils (9
unique PE samples in quadruplicate) ranging in PCB concentration from 0 to 50 ppm. To determine the impact
of different environmental conditions on the technology's performance, each batch of 104 samples contained
five sets of quadruplicate soil samples from DOE's Paducah site. These were analyzed under both sets of
environmental conditions (i.e., outdoor and chamber conditions). For the developers participating in the extract
sample portion (i.e., simulated wipe samples) of the demonstration, 12 extracts, ranging in concentration from
0 to 100 (jg/mL, were analyzed in each
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Table 3-1. Summary of experimental design by sample type
Concentration
Range
Sample ID a
Outdoor Site
Chamber Site
Total #
Samples
Analyzed
PE Materials
0
2.0 ppm
2.0 ppm
5.0 ppm
10.9 ppm
20.0 ppm
49.8 ppm
50.0 ppm
50.0 ppm
126
118
124
120
122
119
125
121
123
226
218
224
220
222
219
225
221
223
8
8
8
8
8
8
8
8
8
Environmental Soils
0.1-2.0 ppm
2. 1-20.0 ppm
20. 1-50.0 ppm
50. 1-700.0 ppm
101,107,108,109,113,114
102, 103, 104, 115
111,116
105, 106, 110, 112, 117
201,202,206
203,207,212,213
204,208,209,214,215
205,210,211,216,217
36
32
28
40
Extracts
0
10 ng/mL
100 |ig/mL
Grand Total
129b/132c
127/130
128/131
116
229/232
227/230
228/231
116
8
8
8
232 d
a Each sample ID was analyzed in quadruplicate.
b Extract prepared in iso-octane for Dexsil and the reference laboratory.
c Extract prepared in methanol for Electronic Sensor Technology, Strategic Diagnostics Inc., and the
reference laboratory.
d All samples were analyzed in random order.
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location (chamber and outdoors). All samples were analyzed without prior knowledge of sample type or
concentration and were analyzed in a randomized order that was unique for each developer.
Environmental Conditions during Demonstration
As mentioned above, field activities were conducted both outdoors under natural environmental conditions and
indoors in a controlled environmental atmosphere chamber to evaluate the effect of environmental conditions
on technology performance. The weather outside was relatively uncomfortable during the July demonstration,
with highs approaching 100°F and 90% relative humidity (RH). Daily average temperatures were around 85 °F
with 70% RH. While outside, the developers set up canopies to provide shade and protection from frequent late
afternoon thundershowers.
In the indoor chamber tests, conditions were initially set to 55 °F and 25% RH. An independent check of the
conditions inside the chamber revealed that the temperature was closer to 68 °F with a 38% RH on the first day
of testing. A maintenance crew was called in to address the inconsistencies between the set and actual
conditions. By the middle of the third day of testing, the chamber was operating properly at 55 °F and 50% RH.
Appendix C contains a summary of the environmental conditions (temperature and relative humidity) during
the demonstration. The Hach team worked outdoors July 25 and 28, 1997, and in the chamber on July 22 and
23, 1997.
Sample Descriptions
PCBs (C^HK^QJ are a class of compounds that are chlorine-substituted linked benzene rings. There are 209
possible PCB compounds (also known as congeners). PCBs were commercially produced as complex mixtures
beginning in 1929 for use in transformers, capacitors, paints, pesticides, and inks [1]. Monsanto Corporation
marketed products that were mixtures of 20 to 60 PCB congeners under the trade name Aroclor. Aroclor
mixtures are identified by a number (e.g., Aroclor 1260) that represents the mixture's chlorine composition as
a percentage (e.g., 60%).
Performance Evaluation Materials
Samples of Tennessee reference soil [3] served as the blanks. Preprepared certified PE samples were obtained
from Environmental Resource Associates (ERA) of Arvada, Colorado, and the Analytical Operations and Data
Quality Center of EPA's Office of Solid Waste and Emergency Response. The soils purchased from ERA had
been prepared using ERA's semivolatile blank soil matrix. This matrix was a topsoil that had been dried,
sieved, and homogenized. Particle size was approximately 60 mesh. The soil was approximately 40% clay. The
samples acquired from EPA's Analytical Operations and Data Quality Center had been prepared using
contaminated soils from various sites around the country in the following manner: The original soils had been
homogenized and diluted with a synthetic soil matrix (SSM). The SSM had a known matrix of 6% gravel, 31%
sand, and 43% silt/clay; the remaining 20% was topsoil. The dilution of the original soils was performed by
mixing known amounts of contaminated soil with the SSM in a blender for no less than 12 h. The samples were
also spiked with target pesticides (a, P, A, and 6-BHC, methoxychlor, and endrin ketone) to introduce some
compounds that were likely to be present in an actual environmental soil. The hydrocarbon background from
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the original sample and the spiked pesticides produced a challenging matrix. The PE soils required no additional
preparation by ORNL and were split for the developer and reference laboratory analyses as received.
Environmental Soil Samples
As noted in the site description above, PCB-contaminated environmental soil samples from Oak Ridge,
Portsmouth, and Paducah were used in this demonstration. The soils were contaminated with PCBs as the result
of spills and industrial processing activities at the various DOE facilities. Originally, the contaminated soils
were excavated from dikes, drainage ditches, catch basins, and organic waste storage areas. The excavated soils
were then packaged into waste containers and stored at the repositories in ETTP and Paducah in anticipation
of disposal by incineration. The environmental soil samples used in this study were collected from these waste
containers. Many of the soils contained interfering compounds such as oils, fuels, and other chlorinated
compounds, while some contained multiple Aroclors. For more information on sampling locations and sample
characteristics (soil composition, pH, and total organic carbon content), refer to Appendices A and B,
respectively.
Extract Samples
Traditionally, the amount of PCBs on a contaminated surface is determined by wiping the surface with a cotton
pad saturated with hexane. The pad is then taken to the laboratory, extracted with additional hexane, and
analyzed by gas chromatography. Unlike soil samples, which can be more readily
homogenized and divided, equivalent wipe samples (i.e., contaminated surfaces or post- wipe pads) were not
easily obtainable. Therefore, interference-free solutions of PCBs were analyzed to simulate an extracted surface
wipe pad. Extract sample analyses provided evaluation data that relied primarily on the technology's
performance rather than on elements critical to the entire method (i.e., sample collection and preparation).
Because different developers required the extract samples prepared in different solvents (e.g., methanol and iso-
octane), the reference laboratory analyzed sets of extracts in both solvents. A total of 12 extracts were analyzed
per site; these consisted of four replicates each of a blank and two concentration levels (10 and 100 (jg/mL).
Hach did not participate in the extract portion of the demonstration.
Sampling Plan
Sample Collection
Environmental soil samples were collected from April 17 through May 7, 1997. Portsmouth and Oak Ridge
Reservation soils were collected from either storage boxes or 55-gal drums stored at ETTP. Briefly, the
following procedure was used to collect the soil samples. Approximately 30 Ib of soil were collected from the
top of the drum or B-25 box using a scoop and placed in a plastic bag. The soil was sifted to remove rocks and
other large debris, then poured into a plastic-lined 5-gal container. All samples were subjected to radiological
screening and were determined to be nonradioactive. Similarly, soil samples were collected from 55-gal drums
stored at Paducah and shipped to ORNL in lined 5-gal containers.
Sample Preparation, Labeling, and Distribution
Aliquots of several of the environmental soils were analyzed and determined to be heterogeneous in PCB
concentration. Because this is unsatisfactory for accurately comparing the performance of the field technology
with the laboratory-based method, the environmental soils had to be homogenized prior to sample distribution.
Each Portsmouth and Oak Ridge environmental soil sample was homogenized by first placing approximately
1500 g of soil in a glass Pyrex dish. The dish was then placed in a large oven set at 35 °C, with the exhaust and
18
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blower fans turned on to circulate the air. After drying overnight, the soil was pulverized using a conventional
blender and sieved using a 9-mesh screen (2 mm particle size). Last, the soil was thoroughly mixed using a
spatula. A comparison of dried and undried soils showed that a minimal amount of PCBs (< 20%) was lost due
to sample drying, making this procedure suitable for use in the preparation of the soil samples. The Paducah
samples, because of their sandy characteristics, only required the sieving and mixing preparation steps. Extract
sample preparation involved making solutions of PCBs in methanol and iso-octane at two concentration levels
(10 and 100 pg/mL). Multiple aliquots of each sample were analyzed using the analytical procedure described
below to confirm the homogeneity of the samples with respect to PCB concentration.
To provide the developers with soils contaminated at higher concentrations of PCBs, some of the environmental
soils (those labeled with an "S" in Appendix B) were spiked with additional PCBs. Spiked soils samples were
prepared after the soil was first dried in a 35 °C oven overnight. The dry soil was ground using a conventional
blender and sieved through a 9-mesh screen (2 mm particle size). Approximately 1500 g of the sieved soil were
spiked with a diethyl ether solution of PCBs at the desired concentration. The fortified soil was agitated using
a mechanical shaker and then allowed to air-dry in a laboratory hood overnight. A minimum of four aliquots
were analyzed using the analytical procedure described below to confirm the homogeneity of the soil with
regard to the PCB concentration.
The environmental soils were characterized at ORNL prior to the demonstration study. The procedure used to
confirm the homogeneity of the soil samples entailed the extraction of 3 to 5 g of soil in a mixture of solvents
(1 mL water, 4 mL methanol, and 5 mL hexane). After the soil/solvent mixture was agitated by a mechanical
shaker, the hexane layer was removed and an aliquot was diluted for analysis. The hexane extract was analyzed
on a Hewlett Packard 6890 gas chromatograph equipped with an electron capture detector and autosampler.
The method used was a slightly modified version of EPA's SW-846 dual-column Method 8081 [4].
After analysis confirming homogeneity, the samples were split into jars for distribution. Each 4-oz sample jar
contained approximately 20 g of soil. Four replicate splits of each soil sample were prepared for each
developer. The samples were randomized in two fashions. First, the order in which the filled jars were
distributed was randomized, such that the same developer did not always receive the first jar filled for a given
sample set. Second, the order of analysis was randomized so that each developer analyzed the same set of
samples, but in a different order. The extract samples were split into 10-mL aliquots and placed into 2-oz jars.
The extracts were stored in the refrigerator (at <4°C) until released to the developers. Each sample jar had
three labels: (1) developer order number; (2) sample identifier number; and (3) a PCB warning label. The
developer order number corresponded to the order in which the developer was required to analyze the samples
(e.g., Hach 1001 through Hach 1116). The sample identifier number was in the format of "xxxyzz," where
"xxx" was the three-digit sample ID (e.g., 101) listed in Table 3-1, "y" was the replicate (e.g., 1 to 4), and "zz"
was the aliquot order of each replicate (e.g., 01 to 11). For example, sample identifier 101101 corresponded
to sample ID "101" (an Oak Ridge soil from RFD 40022, drum 02), "1" corresponded to the first replicate
from that sample, and "01" corresponded to the first jar filled in that series.
Once the samples were prepared, they were stored at a central sample distribution center. During the
demonstration study, developers were sent to the distribution center to pick up their samples. Samples were
distributed sequentially in batches of 12 to ensure that samples were analyzed in the order specified.
Completion of chain-of-custody forms and scanning of bar code labels documented sample transfer activities.
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Some of the developers received information regarding the samples prior to analysis. This was provided at the
request of developers to simulate the type of information that would be available during actual field testing.
Hach, however, did not receive any such information pertaining to the samples. The developers returned the
unused portions of the samples with the analytical results to the distribution center when testing was completed.
The sample bar codes were scanned upon return to document sample throughput time.
Three complete sets of extra samples, called archive samples, were available for distribution in case the
integrity of a sample was compromised. Very few (<5) archive samples were utilized over the course of the
demonstration.
Predemonstration Study
Ideally, environmental soil samples are sent to the developers prior to the demonstration study to allow them
the opportunity to analyze representative samples in advance of the verification test. This gives developers the
opportunity to refine and calibrate their technologies and revise their operating procedures on the basis of the
predemonstration study results. The predemonstration study results can also be used as an indication that the
selected technologies are of the appropriate level of maturity to participate in the demonstration study.
According to ORNL regulations, however, one of two conditions must exist in order to ship environmental soils
that were once classified as mixed hazardous waste. First, the recipient—in this case, the developer's
facilities—must have proper Nuclear Regulatory Commission (NRC) licensing to receive and analyze
radiological materials. Second, the soils must be certified as entirely free of radioactivity, beyond the no-rad
certification issued from radiological screening tests based on ORNL standards. Because none of the developers
had proper NRC licensing and proving that the soils were entirely free of radioactivity was prohibitive, spiked
samples of Tennessee reference soil were used for the predemonstration study. The developers had an
opportunity to evaluate the Tennessee reference soils spiked with PCBs at concentrations similar to what would
be used in the demonstration study. The developers also analyzed two performance evaluation samples and one
solvent extract. The reference laboratory analyzed the same set of samples, which included two extracts
samples, prepared in the two solvents (methanol and iso-octane) requested by the developers.
Predemonstration Sample Preparation
Two soil samples were prepared by ORNL using Tennessee reference soil [3]. The soil was a Captina silt loam
from Roane County, Tennessee, that was slightly acidic (pH ~5) and low in organic carbons (-1.5%). The soil
composition was 7.7% sand, 29.8% clay, and 62.5% silt. To prepare a spiked sample, the soil was first ground
either using a mortar and pestle or a conventional blender. The soil was then sieved through a 16-mesh screen
(1 mm particle size). Approximately 500 g of the sieved soil was spiked with a diethyl ether solution of PCBs
at the desired concentration. The soil was agitated using a mechanical shaker, then allowed to air-dry overnight
in a laboratory hood. A minimum of five aliquots were analyzed by gas chromatography using electron capture
detection. The PCB concentration of the spiked samples was determined to be homogeneous. The remaining
two soil samples used in the predemonstration study were performance evaluation materials acquired from ERA
and EPA (see the section "Performance Evaluation Materials" above). In addition, a solvent extract was
prepared by ORNL to simulate an extracted surface wipe sample. The extracts were prepared in two different
solvents (iso-octane and methanol) to accommodate developer requests.
Predemonstration Results
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The predemonstration samples were sent to the developers and the reference laboratory on June 2, 1997.
Predemonstration results were received by June 26, 1997. Table 3-2 summarizes the the test kit's results for
the predemonstration samples. Results indicated that Hach's PCB immunoassay kit was ready for field
evaluation.
Table 3-2. Summary of Hach's PCB immunoassay kit predemonstration results
Sample Description
2 ppm of Aroclor 1260
100ppm(total)of
Aroclors 1254 and 1260
1 1 ppm of Aroclor 1260
50 ppm of Aroclor 1254
5 ppm of Aroclor 1242
Matrix
soil
soil
soil
soil
extract
Source
ORNL
ORNL
EPA
ERA
ORNL
Hach
Result Duplicate result
(ppm) (ppm)
[1, 10] a [1, 10]
(10, oo ) (10, oo)
[1, 10] [1, 10]
(10,00)"
n/a c n/a c
Reference Laboratory
Result Duplicate result
(ppm) (ppm)
2.2 2.3
78.0 89.0
11.0 9.5
37.0"
4.7 4.9
a The notation [1, 10] indicates that the sample concentration was greater than or equal to 1 and less than or equal to 10. See
Sections 2 and 5 for more information on interval reporting.
b Replicate was not analyzed due to lack of adequate sample for second analyses.
c Hach did not participate in the extract sample portion of the demonstration.
Deviations from the Demonstration Plan
A few deviations from the demonstration plan occurred. In Appendix B of the technology demonstration plan
[5], the reference laboratory's procedure states that no more than 10 samples will be analyzed with each
analytical batch (excluding blanks, standards, QC samples, and dilutions). The analytical batch is also stated
as 10 samples in the Quality Assurance Project Plan of the demonstration plan. The reference laboratory
actually analyzed 20 samples per analytical batch. Because a 20-sample batch is recommended in SW-846
Method 8081, this deviation was deemed acceptable.
Table 5 of the demonstration plan [5] delineates the environmental soils according to concentration. The
classification was based on a preliminary analysis of the soils at ORNL. Table 3-1 of this report arranges the
concentrations as characterized by the reference laboratory. The reference laboratory determined that five
sample sets (sample IDs 102, 105, 110, 111, and 210) were in the next highest concentration range, differing
from what was originally outlined in the demonstration plan. Also, the highest concentration determined by the
reference laboratory was 700 ppm, while the preliminary analysis at ORNL found the highest concentration
to be 500 ppm.
During the demonstration study, the Hach team made one modification to the procedure described in the
technology demonstration plan [5]. This involved the number of antibody tubes used for the analysis of each
sample at the 1 and 10 ppm threshold levels. The written procedure describes four tubes used for each
sample—two replicates at the 1 and 10 ppm thresholds. If either of the two replicates tests positive, the
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concentration is considered to be above that particular threshold value. During the demonstration, only one tube
was analyzed at each threshold level, for a total of two antibody tubes per sample. While this change halved
the number of tubes consumed, it removed the duplicate analysis on each sample, which provides a greater
degree of caution.
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Section 4
Reference Laboratory Analytical Results and Evaluation
Objective and Approach
The purpose of this section is to present the evaluation of the PCB data generated by the reference laboratory.
Evaluation of the results from the analysis of PE, environmental soil, and extract samples was based on
precision, accuracy, representativeness, completeness, and comparability (PARCC) parameters [6]. This
section describes how the analytical data generated by the reference laboratory were used to establish a baseline
performance for PCB analysis.
Reference Laboratory Selection
The Oak Ridge Sample Management Office (SMO) has been tasked by DOE Oak Ridge Operations (DOE-
ORO) with maintaining a list of qualified laboratories to provide analytical services. The technology
demonstration plan [5] contains the SMO's standard operating procedures (SOPs) for identifying, qualifying,
and selecting analytical laboratories. Laboratories are qualified as acceptable analytical service providers for
the SMO by meeting specific requirements. These requirements include providing pertinent documentation
(such as QA and chemical hygiene plans), acceptance of the documents by the SMO, and satisfactory
performance on an on-site prequalification audit of laboratory operations. All laboratory qualifications are
approved by a laboratory selection board, composed of the SMO operations manager and appointees from all
prime contractors that conduct business with the SMO.
All of the qualified laboratories were invited to bid on the demonstration study sample analysis. The lowest-cost
bidder was LAS Laboratories, in Las Vegas, Nevada. A readiness review conducted by ORNL and the SMO
confirmed the selection of LAS as the reference laboratory. Acceptance of the reference laboratory was
finalized by satisfactory performance in the predemonstration study (see Table 3-2). The SMO contracted LAS
to provide full data packages for the demonstration study sample analyses within 30 days of sample shipment.
The SMO conducts on-site audits of LAS annually as part of the laboratory qualification program. At the time
of selection, the most recent audit of LAS had occurred in February 1997. Results from this audit indicated
that LAS was proficient in several areas, including program management, quality management, and training
programs. No findings regarding PCB analytical procedure implementation were noted. A second on-site audit
of LAS occurred August 11-12, 1997, during the analysis of the demonstration study samples. This
surveillance focused specifically on the procedures that were currently in use for the analysis of the
demonstration samples. The audit, jointly conducted by the SMO, DOE-ORO, and EPA-Las Vegas (LV),
verified that LAS was procedurally compliant. The audit team noted that LAS had excellent adherence to the
analytical protocols and that the staff were knowledgeable of the requirements of the method. No findings
impacting data quality were noted in the audit report.
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Reference Laboratory Method
The reference laboratory's analytical method, also presented in the technology demonstration plan [5], followed
the guidelines established in EPA SW-846 Method 8081 [4]. According to LAS's SOP, PCBs were extracted
from 30-g samples of soil by sonication in hexane. Each extract was then concentrated to a final volume that
was further subjected to a sulfuric acid cleanup to remove potential interferences. The analytes were identified
and quantified using a gas chromatograph equipped with dual electron-capture detectors. Each extract was
analyzed on two different chromatographic columns with slightly different separation characteristics (primary
column: RTX-1701, 30 m x 0.53 mm ID x 0.5 (jm; confirmatory column: RTX-5, 30 m x 0.53 mm ID x 0.5
(jm). PCBs were identified when peak patterns from a sample extract matched the patterns of standards for
both columns. PCBs were quantified based on the initial calibration of the primary column.
Calibration
Method 8081 states that, because Aroclors 1016 and 1260 include many of the peaks represented in the other
five Aroclor mixtures, it is only necessary to analyze two multilevel standards for these Aroclors to demonstrate
the linearity of the detector response for PCBs. However, per LAS SOPs, five-point (0.1 to 4 ppm) initial
calibration curves were generated for Aroclors 1016, 1248, 1254, and 1260 and the surrogate compounds
[decachlorobiphenyl (DCB) and tetrachloro-m-xylene (TCMX)]. Single mid-level standards were analyzed for
the other Aroclors (1221, 1232, and 1242) to aid in pattern recognition. All of the multi-point calibration data,
fitted to quadratic models, met the QC requirement of having a coefficient of determination (R2) of 0.99 or
better over the calibration range specified. The detection limits for soil samples were 0.033 ppm (ng/g) for all
Aroclors except Aroclor 1221, which was 0.067 ppm. For extract samples, the detection limits were 0.010 ppm
((ig/mL) for all Aroclors except Aroclor 1221, which was 0.020 ppm. Reporting detection limits were
calculated based on the above detection limits, the actual sample weight, and the dilution factor.
Sample Quantification
For sample quantification, Aroclors were identified by comparing the samples' peak patterns and retention
times with those of the respective standards. Peak height ratios, peak shapes, sample weathering, and general
similarity in detector response were also considered in the identification. Aroclor quantifications were
performed by selecting three to five representative peaks, confirming that the peaks were within the established
retention time windows, integrating the selected peaks, quantifying the peaks based on the calibrations, and
averaging the results to obtain a single concentration value for the multicomponent Aroclor. If mixtures of
Aroclors were suspected to be present, the sample was typically quantified in terms of the most representative
Aroclor pattern. If the identification of multiple Aroclors was definitive, total PCBs in the sample were
calculated by summing the concentrations of both Aroclors. Aroclor concentrations were quantified within the
concentration range of the calibration curve. If PCBs were detected and the concentrations were outside of the
calibration range, the sample was diluted and reanalyzed until the concentration was within the calibration
range. If no PCBs were detected, the result was reported as a non-detect (i.e., "< reporting detection limit").
Sample Receipt, Handling, and Holding Times
The reference laboratory was scheduled to analyze a total of 256 PCB samples (208 soil samples, 24 iso-octane
extract samples, and 24 methanol extract samples). Of these same samples, the developer was scheduled to
analyze a total of 232 PCB samples (208 soil samples and 24 extract samples in solvent of choice). The
samples were shipped to LAS at the start of the technology demonstration activities (July 22). Shipment was
coordinated through the SMO. Completion of chain-of-custody forms documented sample transfer. The
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samples were shipped on ice in coolers to maintain <6°C temperatures during shipment. Samples were shipped
with custody seals to ensure sample integrity and to prevent tampering during transport.
Upon receipt of the samples, the reference laboratory checked the receipt temperature and conditions of the
sample containers, assigned each sample a unique number, and logged each into its laboratory tracking system.
All samples were received at the proper temperature and in good condition. Demonstration samples were
divided into 11 analytical batches (with no more than 20 samples per batch). The samples were analyzed in an
order specified by ORNL to ensure that the analysis of sample types was randomized. Analyses of QC samples,
supplied by the reference laboratory to indicate method performance, were performed with each analytical
batch of soils.
Prior to analysis, samples were stored in refrigerators kept at 4 to 6 ° C to maintain analyte integrity. The
reference laboratory was required to analyze the extract samples and to extract the soil samples within 14 days
of shipment from ORNL. Once the soils were extracted, the reference laboratory had an additional 40 days to
analyze the soil extracts. Maximum holding times were not exceeded for any of the demonstration samples. The
final reference laboratory data package for all samples was received at ORNL in 72 days, on October 1, 1997.
The contractual obligation was 30 days.
The remainder of this section is devoted to summarizing the data generated by the reference laboratory and to
assessing the analytical performance.
Quality Control Results
Objective
The purpose of this section is to provide an assessment of the data generated by the reference laboratory's QC
procedures. The QC samples included continuing calibration verification standards (CCVs), instrument blanks,
method blanks, surrogate spikes, laboratory control samples (LCSs), and matrix spike/matrix spike duplicate
(MS/MSD) samples. Each control type is described in more detail in the following text and in the technology
demonstration plan [5]. Because extraction of these liquid samples was not required, calibration check
standards and instrument blanks were the only control samples implemented for the extract samples. The
reference laboratory's implementation of QC procedures was consistent with SW-846 guidance.
Continuing Calibration Verification Standard Results
A CCV is a single calibration standard of known concentration, usually at the midpoint of the calibration range.
This standard is evaluated as an unknown and is quantified against the initial calibration. The calculated
concentration is then compared with the nominal concentration of the standard to determine whether the initial
calibration is still valid. CCVs were analyzed with every 10 samples or at least every 12. The requirement for
acceptance was a percentage difference of less than 15% for the CCV relative to the initial calibration. This
QC requirement was met for all Aroclors and surrogates, except for one standard that had a 16% difference
for DCB. These results indicated that the reference laboratory maintained instrument calibrations during the
course of sample analysis.
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Instrument and Method Blank Results
Instrument blanks (hexane) were analyzed prior to each CCV. The QC requirement was that instrument blanks
must contain less than the reporting detection limit for any analyte. All instrument blanks were acceptable.
A method blank is an analyte-free soil matrix sample that is taken through the extraction process to verify that
there are no laboratory sources of contamination. One method blank was analyzed for each analytical batch.
The QC requirement was that method blanks must contain less than the reporting detection limit for any
Aroclor. No PCBs were detected in any of the eleven method blanks that were analyzed. These results
demonstrated that the reference laboratory was capable of maintaining sample integrity, and that it did not
introduce PCB contamination into the samples during preparation.
Surrogate Spike Results
A surrogate is a compound that is chemically similar to the analyte group but is not expected to be present in
the environmental sample. A surrogate is added to test the extraction and analysis methods to verify the ability
to isolate, identify, and quantify a compound similar to the analyte(s) of interest without interfering with the
determination. Two different surrogate compounds, DCB and TCMX, were used to bracket the retention time
window anticipated in the Aroclor chromatograms. All soil samples, including QC samples, were spiked with
surrogates at 0.030 ppm prior to extraction. Surrogate recoveries were deemed to be within QC requirements
if the measured concentration fell within the QC acceptance limits that were established by past method
performance. (For LAS this was 39 to 117% for DCB, and 66 to 128% for TCMX). The results were
calculated using the following equation:
measured amount ,„„„/
percent recovery = x 100% (4-1)
actual amount
In all undiluted samples, both of the surrogates had percentage recoveries that were inside the acceptance limits.
Surrogate recoveries in diluted samples were uninformative because the spike concentration (0.030 ppm, as
specified by the method) was diluted below the instrument detection limits. The surrogate recovery results for
undiluted samples indicated that there were no unusual matrix interferences or batch-processing errors for these
samples.
Laboratory Control Sample Results
A LCS is an aliquot of a clean soil that is spiked with known quantities of target analytes. The LCS is spiked
with the same analytes and at the same concentrations as the matrix spike (MS). (MSs are described in the next
section.) If the results of the MS analyses are questionable (i.e., indicating a potential matrix effect), the LCS
results are used to verify that the laboratory can perform the analysis in a clean, representative matrix.
Aroclors 1016 and 1260 were spiked into the clean soil matrix at approximately 0.300 ppm, according to the
reference laboratory's SOP. The QC requirements (defined as percent recovery) for the LCS analyses were
performance-based acceptance limits that ranged from 50 to 158%. In all but one of the eleven LCSs analyzed,
both Aroclor percent recoveries fell within the acceptance limits. Satisfactory recoveries for LCS verified that
the reference laboratory performed the analyses properly in a clean matrix.
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Matrix Spike Results
In contrast to a laboratory control sample (LCS), an MS sample is an actual environmental soil sample into
which target analytes are spiked at known concentrations. MS samples are used to assess the efficiency of the
extraction and analytical methods for real samples. This is accomplished by determining the amount of spiked
analyte that is quantitatively recovered from the environmental soil. An MSB sample is spiked and analyzed
to provide a measure of method precision. Ideally, to evaluate the MS/MSD results, the environmental soil is
analyzed unspiked so that the background concentrations of the analyte in the sample are considered in the
recovery calculation.
For the demonstration study samples, one MS and MSB pair was analyzed with each analytical batch. The MS
samples were spiked under the same conditions and QC requirements as the LCS (50 to 158% acceptance
limits), so that MS/MSD and LCS results could be readily compared. The QC requirement for MS and MSB
samples was a relative percent difference (RPD) of less than 30% between the MS/MSD pair. RPD is defined
as:
r,r.r^ I MS recovery - MSD recovery ,nf\n/
RPD = -! £ t-— x 100% (4_2)
average recovery
A total of eleven MS/MSD pairs were analyzed. Because the MS/MSD spiking technique was not always
properly applied (e.g., a sample which contained 100 ppm of Aroclor 1254 was spiked ineffectively with 0.300
ppm of Aroclor 1260), many of the MS/MSD results were uninformative. For the samples that were spiked
appropriately, all MS/MSD QC criteria were met.
Conclusions of the Quality Control Results
The reference laboratory results met performance acceptance requirements for all of the samples where proper
QC procedures were implemented. Acceptable performance on QC samples indicated that the reference
laboratory was capable of performing analyses properly.
Data Review and Validation
Objective
The purpose of validating the reference laboratory data was to ensure usability for the purposes of comparison
with the demonstration technologies. The data generated by the reference laboratory were used as a baseline
to assess the performance of the technologies for PCB analysis. The reference laboratory data were
independently validated by ORNL and SMO personnel, who conducted a thorough quality check and reviewed
all sample data for technical completeness and correctness.
Corrected Results
Approximately 8% of the results provided by the reference laboratory (20 of 256) were found to have
correctable errors. So as not to bias the assessment of the technology's performance, errors in the reference
laboratory data were corrected. These changes were made conservatively, based on the guidelines provided in
the SW-846 Method 8081 for interpreting and calculating Aroclor results. The errors (see Appendix D, Table
D-3) were categorized as transcription errors, calculation errors, and interpretation errors. The corrections
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listed in Table D-3 were made in the final data set that was used for comparison with the demonstration
technologies.
Suspect Results
Normally, one would not know if a single sample result was "suspect" unless (1) the sample was a performance
evaluation sample, where the concentration is known or (2) a result was reported and flagged as suspect for
some obvious reason (e.g., no quantitative result was determined). The experimental design implemented in this
demonstration study provided an additional indication of the abnormality of data through the inspection of the
replicate results from a homogenous soil sample set (i.e., four replicates were analyzed for each sample ID).
Data sets were considered suspect if the standard deviation (SD) of the four replicates was greater than 30 ppm
and the percent relative standard deviation (RSD) was greater than 50%. Five data sets (sample IDs 106, 205,
216,217, 225) contained measurements that were considered suspect using this criteria, and the suspect data
are summarized in Table 4-1. A number of procedural errors may have caused the suspect measurements (e.g.,
spiking heterogeneity, extraction efficiencies, dilution, etc.). In the following subsections for precision and
accuracy, the data were evaluated with and without these suspect values to represent the best and worst case
scenarios.
Table 4-1. Suspect measurements within the reference laboratory data
Criteria
SD > 30 ppm
and
RSD > 50%
Qualitative Result
Sample ID
106
205
216
217
225
110
112
PCB Concentration (ppm)
Replicate Results
(ppm)
255.9,269.9,317.6
457.0,483.3,538.7
47.0, 54.3, 64.0
542.8, 549.8, 886.7
32.1,36.5,56.4
< reporting detection
limits
Suspect Result(s)
(ppm)
649.6
3,305.0
151.6
1,913.3
146.0
< 66, < 98, < 99, < 490
< 66, < 130, < 200,< 200
Data Usability
Performed data analysis with
and without this value
Used as special case for
comparison with developer
results
Samples that did not fall into the above criteria, but were also considered suspect, were non-blank samples that
could not be quantified and were reported as "< the reporting detection limit." This was the case for
environmental soil sample IDs 110 and 112. It is believed that the reference laboratory had trouble quantifying
these soil samples because of the abundance of chemical interferences. These samples were diluted by orders
of magnitude to reduce interferences, thereby diluting the PCB concentrations to levels that were lower than
the instrument detection limits. With each dilution, the reporting detection limits values were adjusted for
sample weight and dilution, which accounts for the higher reporting detection limits (up to 490 ppm). It is
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believed that these samples should have been subjected to additional pre-analytical cleanup to remove these
interferences before quantification was attempted. Sample IDs 110 and 112 were collected from the same
cleanup site (see Appendix B), so it is not surprising that similar difficulties were encountered with both sample
sets. Because the results for sample IDs 110 and 112 were not quantitative, these data were compared with the
technology data only on a special case basis.
Data Assessment
Objective
The purpose of this section is to provide an evaluation of the performance of the reference laboratory results
through statistical analysis of the data. The reference laboratory analyzed 72 PE, 136 environmental soil, and
48 extract samples. All reference laboratory analyses were performed under the same environmental
conditions. Therefore, site differentiation was not a factor in data assessment for the reference laboratory. For
comparison with the technology data, however, the reference laboratory data are delineated into "outdoor site"
and "chamber site" in the following subsections. For consistency with the technology review, results from both
sites were also combined to determine the reference laboratory's overall performance for precision and
accuracy. This performance assessment was based on the raw data compiled in Appendix D. All statistical tests
were performed at a 5% significance level.
Precision
The term "precision" describes the reproducibility of measurements under a given set of conditions. The SD
of four replicate PCB measurements was used to quantify the precision for each sample ID. SD is an absolute
measurement of precision, regardless of the PCB concentration. To express the reproducibility relative to the
average PCB concentration, RSD is used to quantify precision, according to the following equation:
no^ Standard Deviation inno/
RSD = x 100% (4_3)
Average Concentration
Performance Evaluation Samples
The PE samples were homogenous soils containing certified concentrations of PCBs. Results for these samples
represent the best estimate of precision for soil samples analyzed in the demonstration study. Table 4-2
summarizes the precision of the reference laboratory for the analysis of PE samples. One suspect measurement
(sample ID 225, 146.0 ppm) was reported for the PE soil samples. The RSDs for the combined data ranged
from 9 to 33% when the suspect measurement was excluded, and from 9 to
29
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Table 4-2. Precision of the reference laboratory for PE soil samples
Outdoor Site
Sample
ID
126 a
118
124
120
122
119
125
121
123
Average
Concentration
(ppm)
0
1.6
1.7
5.0
11.1
20.1
37.9
54.6
60.1
SD
(ppm)
n/a
0.6
0.2
1.0
0.9
3.4
6.9
3.4
4.6
RSD
(%)
n/a
39
13
20
8
17
18
6
8
Chamber Site
Sample
ID
226
218
224
220
222
219
225
221
223
Average
Concentration
(ppm)
0
2.6
1.7
5.8
12.8
23.3
41.7"
44.9
55.8
SD
(ppm)
n/a
0.2
0.5
1.8
0.3
6.1
12.9"
11.3
7.7
RSD
(%)
n/a
6
29
31
3
26
31"
25
14
Combined Sites
Average
Concentration
(ppm)
0
2.1
1.7
5.4
11.9
21.7
39.5C
49.8
58.0
SD
(ppm)
n/a
0.7
0.4
1.4
1.1
4.9
9.2 c
9.3
6.3
RSD
(%)
n/a
33
21
26
9
23
23 c
19
11
a All PCB concentrations were reported as non-detects.
b Results excluding the suspect value (results including the suspect value: mean = 67.8 ppm,
c Results excluding the suspect value (results including the suspect value: mean =52.8 ppm,
SD = 53.2 ppm, and RSD =79%).
SD = 38.6 ppm, and RSD = 73%).
79%, including the suspect measurement. The overall precision, determined by the mean RSD for all PE
samples, was 21% for the worst case (including the suspect result) and 18% for the best case (excluding the
suspect result).
Environmental Soil Samples
The precision of the reference laboratory for the analysis of environmental soil samples is reported in Table
4-3. In this table, results including suspect measurements are presented in parentheses. Average concentrations
were reported by the reference laboratory as ranging from 0.5 to 1,196 ppm with RSDs that ranged from 7 to
118% when the suspect results were included. Excluding the suspect results, the highest average concentration
decreased to 660 ppm, and the largest RSD decreased to 71%. Because the majority of the samples fell below
125 ppm, precision was also assessed by partitioning the results into two ranges: low concentrations (< 125
ppm) and high concentrations (> 125 ppm). For the low concentrations, the average RSD was 23% excluding
the suspect value and 26% including the suspect value. These average RSDs were only slightly larger than the
RSDs for the PE soils samples of comparable concentration (18% for best case and 21% for worst case). Five
soil sample sets (sample IDs: 106, 117, 205, 211 and 217) were in the high-concentration category. The
average precision for high concentrations was 56% for the worst case and 19% for the best case. The precision
estimates for the low and high concentration ranges were comparable when the suspect values were excluded.
This indicated that the reference laboratory's precision for the environmental soils was consistent
(approximately 21% RSD), and comparable to the PE soil samples when the suspect values were excluded.
30
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The Paducah soils (indicated as bold sample IDs in Table 4-3) were analyzed by the technologies under both
outdoor and chamber conditions to provide a measure of the effect that two different environmental conditions
had on the technology's performance. Although this was not an issue for the reference laboratory (because all
the samples were analyzed under laboratory conditions), the reference laboratory's results were delineated into
the different site categories for comparison with the technologies. Sample IDs 113 and 201, 114 and 202, 115
and 203, 116 and 204, and 117 and 205 each represent a set of eight replicate samples of the same Paducah
soil. The RSDs for four of the five Paducah pairs (excluding the suspect value for sample ID 205) ranged from
11 to 17%. The result from one pair (sample IDs 113 and 201) had an RSD of 42%, but the reported average
concentration was near the reporting limits.
Table 4-3. Precision of the reference laboratory for environmental soil samples
Outdoor Site
Sample
ID
101
102
103
104
105
106
107
108
109
110
111
112
113 c
114
115
116
117
Average
Concentration
(ppm)
0.5
2.0
2.3
9.4
59.4
281.0 (373.2) a
1.3
1.8
2.0
n/ab
38.7
n/a
1.1
1.3
14.8
41.3
383.9
Standard
Deviation
(ppm)
0.1
0.3
0.6
4.0
16.5
32.4(186.2)
0.3
0.1
0.4
n/a
4.3
n/a
0.6
0.3
1.8
5.9
55.2
RSD
(%)
16
16
27
43
28
12 (50)
20
8
20
n/a
11
n/a
55
20
12
14
14
Chamber Site
Sample
ID
206
207
208
209
210
211
212
213
214
215
216
217
201
202
203
204
205
Average
Concentration
(ppm)
1.9
18.8
30.5
40.2
88.6
404.5
3.2
8.1
25.2
26.7
55.1 (79.2)
659.8(973.2)
0.9
1.4
13.9
44.3
493.0(1196.0)
Standard
Deviation
(ppm)
0.9
3.5
7.9
28.5
25.6
121.8
1.6
1.6
3.7
3.2
8.5 (48.7)
196.6(647.0)
0.2
0.2
1.7
2.9
41.7(1406.4)
RSD
(%)
49
19
26
71
29
30
50
20
15
12
15 (62)
30 (66)
24
12
12
7
8(118)
a Data in parenthesis include suspect values.
bn/a indicates that qualitative results only were reported for this sample.
c Bold sample IDs were matching Paducah sample pairs (i.e., 113/201, 114/202, 115/203, 116/204, 117/205).
31
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Extract Samples
The extract samples, which were used to simulate surface wipe samples, were the simplest of all the
demonstration samples to analyze because they required no extraction and were interference-free. Three types
of extract samples were analyzed: solvent blanks, spikes of Aroclor 1242 at 10 (jg/mL, and spikes of Aroclor
1254 at 100 (jg/mL. Identical extract samples were prepared in two solvents (iso-octane and methanol) to
accommodate the developer's request. The reference laboratory analyzed both solvent sets. A Student's t-test
[7, 8] was used to compare the reference laboratory's average PCB concentrations for the two different solvents
and showed that no significant differences were observed at either concentration. Therefore, the reference
laboratory results for the two extract solvents were combined. Additionally, all blank samples were quantified
as non-detects by the reference laboratory.
Table 4-4 summarizes the reference laboratory results for the extract samples by site. RSDs for the four
replicates for each sample ID ranged from 3 to 24%. For the combined data set (16 replicate measurements),
the average RSD at the lO-pg/mL level was 19%, while the average RSD at the 100-(jg/mL level was 8%. For
the entire extract data set, an estimate of overall precision was 14%. The overall precision for the extract
samples was comparable to the best-case precision for environmental soil samples (21%) and PE soil samples
(18%).
Table 4-4. Precision of the reference laboratory for extract samples
Outdoor Site
Sample
ID
129 a
132 a
127
130
128
131
Average
Cone
(ug/mL)
0
0
10.9
12.1
67.4
63.8
SD
(ug/mL)
n/a
n/a
0.4
2.9
2.3
5.0
RSD
(%)
n/a
n/a
4
24
3
8
Chamber Site
Sample
ID
229
232
227
230
228
231
Average
Cone
(ug/mL)
0
0
9.6
8.9
65.2
57.7
SD
(ug/mL)
n/a
n/a
0.8
1.4
5.1
3.1
RSD
(%)
n/a
n/a
8
16
8
5
Combined Sites
Average
Cone
(ug/mL)
n
i n A
f*~S. S
SD
(ug/mL)
n/a
1.9
5.2
RSD
(%)
n/a
19
8
a All PCB concentrations reported as non-detects by the laboratory.
Accuracy
Accuracy represents the closeness of the reference laboratory's measured PCB concentrations to the accepted
values. Accuracy was examined by comparing the measured PCB concentrations (for PE soil and extract
samples) with the certified PE values and known spiked extract concentrations. Percent recovery was used to
quantify the accuracy of the results. The optimum percent recovery value is 100%. Percent recovery values
greater than 100% indicate results that are biased high, and values less than 100% indicate results that are
biased low.
32
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Performance Evaluation Soil Samples
The reference laboratory's performance for the PE samples is summarized in Table 4-5. Included in this table
are the performance acceptance ranges and the certified PCB concentration values. The acceptance ranges,
based on the analytical verification data, are guidelines established by the provider of the PE materials to gauge
acceptable analytical results. As shown in Table 4-5, all of the average concentrations were within the
acceptance ranges, with the exception of sample ID 218. The average result of sample ID 225 was outside of
the acceptance range only when the suspect result was included. All of the replicate measurements in sample
ID 225 were biased slightly high. Average percent recoveries for the PE samples (excluding suspect values)
ranged from 76 to 130%. Overall accuracy was estimated as the average recovery for all PE samples. The
overall percent recovery was 105% as a worst case when the suspect value was included. Excluding the suspect
value as a best case slightly lowered the overall percent recovery to 101%. A regression analysis [9] indicated
that the reference laboratory's results overall were unbiased estimates of the PE sample concentrations.
Table 4-5. Accuracy of the reference laboratory for PE soil samples
Certified
Concentration
(ppm)
(Acceptance
Range, ppm)
Oa
(n/a)
2.0
(0.7-2.2)
2.0
(0.9-2.5)
5.0
(2.1-6.2)
10.9
(4.0-12.8)
20.0
(11.4-32.4)
49.8
(23.0-60.8)
50.0
(19.7-63.0)
50.0
(11.9-75.9)
Outdoor Site
Sample
ID
126
118
124
120
122
119
125
121
123
Average
Cone
(ppm)
0
1.6
1.7
5.0
11.1
20.1
37.9
54.6
60.1
Recovery
(%)
n/a
79
85
99
102
100
76
109
120
Chamber Site
Sample
ID
226
218
224
220
222
219
225
221
223
Average
Cone
(ppm)
0
2.6
1.7
5.8
12.8
23.3
41.7"
44.9
55.8
Recovery
(%)
n/a
130
85
117
117
116
84"
90
112
Combined Sites
Average
Cone
(ppm)
0
2.1
1.7
5.4
11.9
21.7
39.5 c
49.8
58.0
Recovery
(%)
n/a
105
85
108
109
109
79 c
100
116
a All PCB concentrations reported as non-detects by the laboratory.
b Results excluding the suspect value (results including the suspect value: average = 67.8 ppm and recovery = 136%).
'Results excluding the suspect value (results including the suspect value: average = 52.8 ppm and Recovery = 106%).
33
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Extract Samples
Percent recovery results for extract samples are summarized in Table 4-6 for the reference laboratory. The
average percent recoveries for extract samples ranged from 58 to 121%. In terms of concentration levels, the
average recovery at the lO-pg/mL level (for both solvents) was 104%, compared with 64% at the 100-(jg/mL
level. The reference laboratory classified all 16 samples spiked at 10 (jg/mL as Aroclor 1016; however, these
samples were actually spiked with Aroclor 1242. Despite this misclassification, the results did not appear to
be biased. In contrast, the samples spiked at 100 (ig/mL were correctly classified as Aroclor 1254 but were
all biased low. Although these results suggested that Aroclor classification had little effect on the quantification
of the extract samples, there was an obvious, consistent error introduced into the analysis of the 100-(jg/mL
samples to cause the low bias. For the entire extract data set, the overall percent recovery was 84%.
Table 4-6. Accuracy of the reference laboratory for extract samples
Spike
Concentration
(ug/mL)
Oa
Oa
10
10
100
100
Outdoor Site
Sample
ID
129
132
127
130
128
131
Avg
Cone
(ug/mL)
0
0
10.9
12.1
67.4
63.8
Recovery
(%)
n/a
n/a
109
121
67
64
Chamber Site
Sample
ID
229
232
227
230
228
231
Avg
Cone
(ug/mL)
0
0
9.6
8.9
65.2
57.7
Recovery
(%)
n/a
n/a
96
89
65
58
Combined Sites
Avg
Cone
(ug/mL)
n
in 4
6"? s
Recovery
(%)
n/a
104
64
' All PCB concentrations reported as non-detects by the laboratory.
Representativeness
Representativeness expresses the degree to which sample data accurately and precisely represent the capability
of the method. Representativeness of the method was assessed based on the data generated for clean-QC
samples (i.e., method blanks and laboratory control samples) and PE samples. Based on the data assessment
(discussed in detail in various parts of this section), it was determined that the representativeness of the
reference laboratory data was acceptable. In addition, acceptable performance on laboratory audits
substantiated that the data set was representative of the capabilities of the method. In all cases, the performance
of the reference laboratory met all requirements for both audits and QC analyses.
Completeness
Completeness is defined as the percentage of measurements that are judged to be usable (i.e., the result was
not rejected). Usable results were obtained for 248 of the 256 samples submitted for analysis by the reference
laboratory. Eight results (for sample IDs 110 and 112) were deemed incomplete and therefore not valid because
the measurements were not quantitative. To calculate completeness, the total number of complete results were
divided by the total number of samples submitted for analysis, and then multiplied by 100 to express as a
34
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percentage. The completeness of the reference laboratory was 97%, where a completeness of 95% or better is
typically considered acceptable.
Comparability
Comparability refers to the confidence with which one data set can be compared with another. The
demonstration study was designed to have a one-to-one, sample-by-sample comparison of the PCB results
obtained by the reference laboratory and the PCB results obtained by the technology being evaluated. Based
on thorough examination of the data and acceptable results on the PE samples, it was concluded that the
reference laboratory's SOPs for extraction and analysis, and the data generated using these procedures, were
of acceptable quality for comparison with the field technology results. Additional information on comparability
was available because the experimental design incorporated randomized analysis of blind, replicate samples.
Evaluation of the replicate data implicated some of the individual data points as suspect (see Table D-2). The
reference laboratory's suspect data were compared with the technology data on a special-case basis, and
exceptions were noted.
Summary of Observations
Table 4-7 provides a summary of the performance of the reference laboratory for the analysis of all sample
types used in the technology demonstration study. As shown in Table 4-7, the precision of the PE soils was
comparable to the environmental soils. A weighted average, based on the number of samples, gave a best-case
precision of 21% and a worst-case precision of 28% for all the soil data (PE and environmental). The extract
samples had a smaller overall RSD of 14%. Evaluation of overall accuracy was based on samples with certified
or known spiked concentrations (i.e., PE and extract samples). The overall accuracy, based on percent
recovery, for the PE samples was 105% for the worst case (which included the suspect value) and 101% for
the best case (which excluded the suspect value). These results indicated that the reference laboratory measured
values were unbiased estimates of the certified PE concentrations (for samples that contained <50 ppm of
PCBs). Accuracy for the extract samples at 10 ppm was also unbiased, with an average percent recovery of
104%. However, the accuracy for the extract samples at 100 ppm was biased low, with an average recovery
of 64%. Overall, the average percent recovery for all extract samples was 84%. The reference laboratory
correctly reported all blank samples as non-detects, but had difficulty with two soil sample IDs (110 and 112)
that contained chemical interferences. In general, the reference laboratory's completeness would be reduced,
at the expense of an improvement in precision and accuracy, if the suspect measurements were excluded from
the data analysis. Based on this analysis, it was concluded that the reference laboratory results were acceptable
for comparison with the developer's technology.
35
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Table 4-7. Summary of the reference laboratory performance
Sample Matrix
Blank
Environmental soil with
interferences
Soil
Best Case
(excluding suspect data)
Soil
Worst Case
(including suspect data)
Extract
Sample Type
Soil
Extract
Sample ID 110
Sample ID 112
PE
Environmental
< 125 ppm
> 125 ppm
overall
PE
Environmental
< 125 ppm
> 125 ppm
overall
10 ppm
100 ppm
overall
Number of Samples
8
16
4
4
63
107
17
187
64
108
20
192
16
16
32
Precision
(Average % RSD)
n/aa
n/aa
18
23
19
21
21
26
56
28
19
8
14
Accuracy
(Average % Recovery)
All samples were
reported as non-detects.
All samples were
reported as non-detects.
101
n/ab
n/ab
101
105
n/ab
n/ab
105
104
64
84
a Because the results were reported as non-detects, precision assessment is not applicable.
b Accuracy assessment calculated for samples of known concentration only.
36
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Section 5
Technology Performance and Evaluation
Objective and Approach
The purpose of this section is to present the evaluation of the data generated by the Hach PCB immunoassay
kit. The technology's precision and accuracy performance are presented for the data generated in the
demonstration study. In addition, an evaluation of comparability, through a one-to-one comparison with the
reference laboratory data, is presented. An evaluation of other aspects of the technology (such as cost, sample
throughput, hazardous waste generation, and logistical operation) is also presented in this section.
Interval Reporting
The test kit results were reported as concentration ranges that were designated as intervals incorporating
parentheses/bracket notation. The parentheses indicated that the end-points of the concentration range were
excluded, while brackets indicated that the end-points were included. As shown in Table 5-1, the interval [0,
1) indicates that the PCB concentration range is greater than or equal to 0 and less than 1. All samples are
reported as one of the three intervals listed in Table 5-1, and are not adjusted for Aroclor specificity.
Table 5-1. Hach PCB immunoassay kit reporting intervals
Interval
[0,1)
[1, 10]
(10, oo)
Concentration Range
0< PCBppm< 1
l 10
Data Assessment
Objective
The purpose of the data assessment section is to present the evaluation of the performance of the Hach PCB
immunoassay kit through a statistical analysis of the data. PARCC parameters were used to evaluate the test
kit's ability to measure PCBs in PE, environmental soil, and extract samples. The developer analyzed splits
of replicate samples that were also analyzed by the reference laboratory (72 PE soil samples and 136
environmental soil samples). See Section 4 for a more detailed analysis of the reference laboratory's results.
Replicate samples were analyzed by the developer at two different sites (under outdoor conditions and inside
an environmentally controlled chamber) to evaluate the effect of environmental conditions on the test kit's
performance; see Section 3 for further details on the different sites. Evaluation of the measurements made at
each site indicated that there were no significant difference between the two data sets. Because environmental
conditions did not appear to affect the results significantly, data from both sites were also combined for each
37
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parameter (precision and accuracy) to determine the test kit's overall performance. All statistical tests were
performed at the 5% significance level. Appendix D contains the raw data that were used to assess the
performance of the test kit.
Precision
Precision is the reproducibility of measurements under a given set of conditions. The frequency with which the
same interval was reported within a set of replicates was used to quantify precision. Examples of how the
precision was classified are presented in Table 5-2. Reporting a higher number of replicates in the same interval
for a given replicate set indicates higher precision. In other words, reporting all four replicate results as the
same interval indicates the highest possible precision. Because there were only three possible intervals to be
reported, at least two of the four replicates would be reported as the same interval.
Table 5-2. Classification of precision results
If the replicate results are...
[0, ix [i,io], [i,io], (io,=o)
[0, 1), [1, 10], [1, 10], [1, 10]
[1, 10], [1, 10], [1, 10], [1, 10]
...and the number
reported in identical
intervals are...
2
3
4
..then the precision
classification is...
low
medium
high
Performance Evaluation Samples
Table 5-3 summarizes the precision information for the test kit's analysis of the PE samples. The test kit
reported all four replicates as the same interval (i.e., high precision) for all eight non-blank PE sample sets
under both the outdoor and chamber conditions. The blanks were reported with low and medium precision.
Environmental Soil Samples
Hach's test kit results for the replicate environmental soil sample measurements are presented in Table 5-4.
Under the outdoor conditions, 12 of 17 replicate sets achieved the highest precision classification (i.e., the same
interval was reported for all four replicates). Under the chamber conditions, 11 of 17 sample sets were reported
with high precision. Of the sample sets where precision was classified as medium to low, none differed by more
than one interval range.
38
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Table 5-3. Precision of Hach's PCB immunoassay kit for PE soil samples
Certified
PE
Cone.
(ppm)
0
2.0
2.0
5.0
10.9
20.0
49.8
50.0
50.0
Outdoor site
Sample ID
126 a
118
124
120
122
119
125
121
123
# in each precision
classification
Precision
low high
Number of replicates reported in
identical intervals
2
X
1
3
0
4
X
X
X
X
X
X
X
X
8
Chamber site
Sample ID
226 a
218
224
220
222
219
225
221
223
Precision
low high
Number of replicates reported in
identical intervals
2
0
3
X
1
4
X
X
X
X
X
X
X
X
8
1 Blank data were not included in the determination of the overall precision.
Because the majority of the measurements fell below 125 ppm, precision was also assessed by partitioning the
results into two ranges: low (reference laboratory values < 125 ppm) and high concentrations (reference
laboratory values > 125 ppm). See Section 4 for the delineation of which Sample IDs were in the low and high
categories. For the low concentrations, 66% of the sample sets were reported with all four replicates in the
same interval (i.e., highest possible precision). For the high concentration category, 80% of the sample sets (4
of 5) were reported with the highest possible precision.
The Paducah soils (indicated by bold sample IDs in Table 5-4) were analyzed at both sites to provide an
assessment of the test kit's performance under different environmental conditions. For these samples, the data
generated under both environmental conditions were also combined to provide an overall assessment of
precision. Sample IDs 113 and 201, 114 and 202, 115 and 203, 116 and 204, and 117 and 205 represented
replicate Paducah soil sample sets, where the 100 series were samples analyzed under the outdoor conditions,
and the 200 series were samples analyzed inside the chamber. Additional statistical analysis was used to
compare the effect of the two environmental conditions on the measurements. Results from this analysis showed
that there were no significant differences in the data generated at each
39
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Table 5-4. Precision of Hach's PCB immunoassay kit for environmental soil samples
Outdoor site
Sample
ID
101
102
103
104
105
106
107
108
109
110
111
112
113 a
114
115
116
117
# in each
precision
classification
Precision
low high
Number of replicates reported in
identical intervals
2
X
1
3
X
X
X
X
4
4
X
X
X
X
X
X
X
X
X
X
X
X
12
Chamber site
Sample
ID
206
207
208
209
210
211
212
213
214
215
216
217
201
202
203
204
205
Precision
low high
Number of replicates reported in
identical intervals
2
X
1
3
X
X
X
X
X
5
4
X
X
X
X
X
X
X
X
X
X
X
11
1 Bold sample IDs were matching Paducah sample pairs (i.e., 113/201, 114/202, 115/203, 116/204, 117/205).
site. This indicated that these different environmental conditions did not impact the performance of the test kit.
However, the test kit appeared to have slightly more difficulty with the Paducah samples relative to the other
soil matrices that comprised the environmental soil samples.
40
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Precision Summary
A summary of the test kit's overall precision is presented by sample type (PE and environmental soil) in Table
5-5. For PE and environmental soil samples, 100% and 68% of the samples, respectively, achieved the highest
possible precision (i.e., all four samples replicates were reported as the same interval).
Table 5-5. Overall precision of the Hach PCB immunoassay kit for all sample types
Environmental Site
Outdoor Site
Chamber Site
Combined Sites
Percentage of samples classified in each precision category
PE Samples
low
0
0
0
med high
0 100
0 100
0 100
Environmental Soil Samples
low med high
6 24 71
6 29 65
6 26 68
Accuracy
Accuracy represents the closeness of the test kit's measured PCB concentrations to the certified values.
Because the test kit produced interval results, accuracy was evaluated in terms of the percentage of samples
which agreed with, were above (i.e., biased high), and were below the certified value (i.e., biased low).
Performance Evaluation Soil Samples
Table 5-6 contains a comparison between the test kit's interval result and the corresponding certified PE value.
The interval(s) listed under a particular column indicates how many of the four replicates were reported as that
interval. For example, for sample ID 126, two replicates were reported as [0, 1), and two were reported as [1,
10]. For sample ID 226, three are reported as [0, 1), and one is reported as [1, 10]. Note that performance
acceptance ranges for the PE results, which are the guidelines established by the provider of the PE materials
to gauge acceptable analytical results, are also presented in Table 5-6 for information. These ranges were not
used to evaluate the test kit results because the acceptance ranges overlap several of the test kit's reporting
intervals.
The data in Table 5-6 were used to derive the accuracy results presented in Table 5-7. Accuracy was based
on a comparison of the certified PE value with the interval reported by the test kit. If the interval encompassed
the certified PE value, the test kit result "agreed" with the certified value. If the test kit result was above the
certified value, the result was classified as "biased high." If the test kit result was below the certified value, the
result was classified as "biased low." For example, for sample ID 118, the certified value was 2.0 ppm (for
Aroclor 1248). The comparison would be classified as "agreed" for the test kit's interval result [1, 10], as
"biased high" for the interval result (10, <=°), or as "biased low" for the interval result [0, 1). Separate
comparisons were made for the two environmental conditions to determine if ambient temperature and humidity
had an effect on the technology performance. Statistical analysis showed that there was no significant difference
between the results obtained bv the test kit under the two
41
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Table 5-6. Hach's PCB immunoassay kit accuracy for PE soil samples
Certified
Cone.
(ppm)
(Acceptance
Range, ppm)
0
(n/a)
2.0
(0.7-2.2)
2.0
(0.9-2.5)
5.0
(2.1-6.2)
10.9
(4.0-12.8)
20.0
(11.4-32.4)
49.8
(23.0-60.8)
50.0
(19.7-63.0)
50.0
(11.9-75.9)
Outdoor Site
Sample
ID
126
118
124
120
122
119
125
121
123
# of replicates reported at each interval
1
2
[0,1)
[1, 10]
3
4
[1, 10]
[1, 10]
[1, 10]
(10,°°)
(10, oo)
(10,°°)
(10, oo)
(10, oo)
Chamber Site
Sample
226
218
224
220
222
219
225
221
223
# of replicates reported at each
interval
1
[1, 10]
2
3
[0,1)
4
[1, 10]
[1, 10]
[1, 10]
[1, 10]
(10, oo)
(10, oo)
(10, oo)
(10, oo)
Table 5-7. Evaluation of agreement between Hach's PCB immunoassay kit's PE sample results and the certified PE values
as a measure of accuracy
Environmental
Site
Outdoor Site
Chamber Site
Combined Sites
Relative to Certified Values for Performance Evaluation Samples
Biased . Biased
Low Agree High
0%
11%
6%
94%
86%
90%
6%
3%
4%
Number of Samples
36
36
72
different environmental conditions evaluated in this demonstration. Therefore, all PE sample results were
combined to determine the overall percentage of agreement between test kit results and the certified PE value.
The overall percentage of agreement was 90%. Of the sample results which disagreed, 4% were biased high,
42
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which were three blank results reported as [1, 10]. The remaining 6% of the test kit results were biased low,
which were the four replicates from sample ID 222 that were reported as [1, 10], where the nominal
concentration was 10.9 ppm. Note that for sample ID 122, all four replicates were correctly reported as (10,
False Positive/False Negative results
A false positive (fp) result [10] is one in which the technology detects PCBs in the sample when there actually
are none. A false negative (fh) result [10] is one in which the technology indicates that there are no PCBs
present in the sample, when there actually are. Both fp and fh results are influenced by the method detection
limit of the technology. Of the eight blank soil samples, three were reported as [1, 10], so the fp result was
38%. Of the 192 non-blank soil samples analyzed, the test kit reported four in the lowest reporting interval
(e.g., 0 to 1 ppm), but the corresponding reference laboratory results were greater than 1 ppm. Therefore, the
fn result for the soil samples was 2%.
Representativeness
Representativeness expresses the degree to which the sample data accurately and precisely represent the
capability of the technology. The performance data were accepted as being representative of the technology
because Hach's PCB immunoassay kit was capable of analyzing diverse sample types (PE samples and actual
field environmental samples) under multiple environmental conditions. When using this technology, quality
control samples should be analyzed to assess the performance of the Hach PCB immunoassay kit under the
testing conditions.
Completeness
Completeness is defined as the percentage of measurements that are judged to be useable (i.e., the result was
not rejected). Useable results were obtained by the technology for all 232 samples. Therefore, completeness
was 100%.
Comparability
Comparability refers to the confidence with which one data set can be compared to another. A one-to-one
sample comparison of the test kit results and the reference laboratory results was performed for all soil
samples. Accuracy was evaluated in terms of the percentage of samples which agreed with, were above (i.e.,
biased high), and were below (i.e., biased low) the certified value. For comparability, the kit's results were
compared with the results generated by the reference laboratory, including both environmental soils and PE
samples. Sample IDs 110 and 112 were excluded because the reference laboratory did not generate quantitative
results for these samples. The results are summarized in Table 5-8. The percentage of test kit results that
agreed with the reference laboratory results was 85%. Approximately 7% were biased high, while
approximately 9% were biased low relative to the results reported by the reference laboratory. In nearly all
cases where the test kit result disagreed with the reference laboratory result, the concentration was near one
of the kit's threshold values of 0, 1, or 10 ppm. For example, for sample ID 203, the reference laboratory's
four replicate results were 12.4, 12.8, 14.0, and 16.2 ppm. The test kit reported all four results as [1, 10],
which was classified as biased low. Note that Hach recommends either secondary confirmation or use of the
more conservative interpretation for sample results that are near the threshold values.
43
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Table 5-8. Evaluation of agreement between Hach's PCB immunoassay kit's soil results and the reference laboratory's
results as a measure of comparability
Environmental
Site
Outdoor Site
Chamber Site
Combined Sites
Relative to Reference Laboratory Results for Soil Samples
Biased Agree Biased
Low High
4%
13%
9%
87%
84%
85%
9%
4%
7%
Number of Samples
96
104
200
As discussed in the Precision section, the Paducah samples were analyzed at both environmental sites to
evaluate the effect that environmental conditions had on performance. Results for these samples were more
imprecise than the results for the other matrices (i.e., Oak Ridge and Portsmouth samples). Additional
statistical tests on the Paducah sample results indicated that the test kits results were significantly different
from the reference laboratory results under the chamber conditions. Because the disagreement with the
reference laboratory results was significantly increased for these particular samples, the test kit's difficulty with
the Paducah samples may be related to a matrix effect.
The soil data not included in previous comparability evaluations (because the replicate data for the reference
laboratory were considered suspect) are shown in Table 5-9. Refer to Section 4, in particular Table 4-1, for
more information on the reference laboratory's suspect measurements. The reference laboratory's suspect data
were compared with the test kit's matching results. For sample IDs 110 and 112, the reference laboratory
obtained qualitative results only. The test kit also had some difficulty with sample ID 110, producing results
in two different intervals in contrast to sample ID 112, where all four replicates were reported as the same
interval. For four of the five other suspect values for the reference laboratory data, the test kit generated results
that agreed with the replicate means of the reference laboratory. One of the test kit results ([1, 10]) was biased
low relative to the reference laboratory's replicate mean (493.0 ppm). These comparisons demonstrated that
the test kit did not have difficulty with most of the samples that were troublesome for the reference laboratory.
Summary of PARCC Parameters
Table 5-10 summarizes the test kit's performance for precision, accuracy, and comparability. The percentage
of replicate samples where the highest precision was achieved (i.e., all four replicates were reported as the same
interval) was 100% for the PE samples and 68% for the environmental soil samples. The test kit's agreement
and disagreement with certified values were based on the certified PE values (i.e., accuracy) and the reference
laboratory results (i.e., comparability). Overall, the test kit's performance was similar for all samples, because
the percentages of agreement and disagreement were not significantly different for PE and environmental
samples. The percentage in agreement ranged from 83 to 90%, the percentage biased high was 4 to 7%, and
the percentage biased low was 6 to 10%.
44
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Table 5-9. Comparison of the Hach's PCB immunoassay kit results with the reference laboratory's suspect measurements
Sample ID
110
112
106
205
216
217
225
Reference Laboratory
Suspect Measurement
(ppm)
-------
Additional Performance Factors
Sample Throughput
Sample throughput is representative of the estimated amount of time required to extract the PCBs, to perform
appropriate reactions, and to analyze the sample. Operating under the outdoor conditions, the Hach team's
sample throughput rate ranged from 10 to 13 samples per hour. Working in the chamber, the rate was lower,
around 7 to 10 samples per hour. This increased sample throughput under the outdoor conditions may be
attributed to the analysis order; because Hach analyzed samples under the chamber conditions first, they may
have gained valuable experience that was applied during the analysis of the outdoor samples.
Cost Assessment
The purpose of this economic analysis is to provide an estimation of the range of costs for an analysis of PCB-
contaminated soil samples using the Hach PCB test kit and using a conventional analytical reference laboratory
method. The analysis was based on the results and experience gained from this demonstration, costs provided
by Hach, and representative costs provided by the reference analytical laboratories who offered to analyze these
samples. To account for the variability in cost data and assumptions, the economic analysis was presented as
a list of cost elements and a range of costs for sample analysis by the Hach test kit and by the reference
laboratory.
Several factors affected the cost of analysis. Where possible, these factors were addressed so that decision-
makers can independently complete a site-specific economic analysis to suit their needs. The following
categories are considered in the estimate:
sample shipment costs,
labor costs,
equipment costs,
waste disposal costs.
Each of these cost factors is defined and discussed below and serves as the basis for the estimated cost ranges
presented in Table 5-11. This analysis assumed that the individuals performing the analyses were fully trained
to operate the technology. Hach does not offer a specific training course on the use of the Hach kit, but does
provide free assistance, on an as-needed basis, through its technical service department. Costs for sample
acquisition and pre-analytical sample preparation, which are tasks common
to both methods, were not included here.
Hach PCB Immu noassay Kit Costs
Because the samples were analyzed on-site, no sample shipment charges were associated with the cost of
operating the Hach test kit. Labor costs included mobilization/demobilization, travel, per diem, and on-
46
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Table 5-11. Estimated analytical costs for PCB soil samples
PCB Immunoassay Kit
Hach
Sample throughput rate: 10
(outdoors)
7
Cost Category
Sample Shipment
Labor
Mobilization/demobilization
Travel
Per diem
Rate
Equipment
Mobilization/demobilization
Kit purchase price
Reagents/supplies
Waste Disposal
Company
- 13 samples per hour
- 10 samples per hour (chamber)
Cost (S)
0
250 - 400
15 - 1,000 per analyst
0-150 per day per analyst
30 - 75 per hour per analyst
0-150
955
35 per sample
75 - 1,060
EPA SW-846 Method
8080/8081/8082
Reference Laboratory
Typical turn-around time: 14
Cost Category
Sample Shipment
Labor
Overnight shipping charges
Labor
Mobilization/demobilization
Travel
Per diem
Rate
Equipment
Mobilization/demobilization
Rental/purchase of system
Reagents/supplies
Waste Disposal
- 30 days
Cost (S)
100-200
50-150
included3
included
included
44-239 per sample
included
included
included
included
a "Included" indicates that the cost is included in the labor rate.
site labor.
• Labor mobilization/demobilization: This cost element included the time for one person to
prepare for and travel to each site. The estimate ranged from 5 to 8 hours, at a rate of $50 per
hour.
• Travel: This element was the cost for the analyst(s) to travel to the site. If the analyst is
located near the site, the cost of commuting to the site (estimated to be 50 miles at $0.30 per
mile) would be minimal ($15). The estimated cost of an analyst traveling to the site for this
demonstration ($1,000) included the cost of airline travel and rental car fees.
Per diem: This cost element included food, lodging, and incidental expenses, and was
estimated ranging from $0 (for a local site) to $150 per day per analyst.
• Rate: The cost of the on-site labor was estimated at a rate of $30 to $75 per hour, depending
on the required expertise level of the analyst. This cost element included the labor involved
with the entire analytical process comprising sample preparation, sample management,
analysis, and reporting.
Equipment costs included mobilization/demobilization, rental fees or purchase of equipment, and the reagents
and other consumable supplies necessary to complete the analysis.
47
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Equipment mobilization/demobilization: This included the cost of shipping the equipment to
the test site. If the site is local, the cost would be zero. For this demonstration, the cost of
shipping equipment and supplies was estimated at $150.
Purchase: At the time of the demonstration, the cost of purchasing the Hach test kit was $955.
The kit included: a Hach Pocket Colorimeter instrument designed for use with immunoassay-
based analysis; reagents for five PCB tests; labware required to run the analysis; and
instruction manual. The kit was supplied in a polypropylene carrying case.
• Reagents/Supplies: These items are consumable and are purchased on a per sample basis. At
the time of the demonstration, the cost of the reagents and supplies needed to prepare and
analyze PCB soil samples using the test kit was $35 per sample. This cost included the sample
preparation supplies, assay supplies, and consumable reagents. Standard Ampules were also
available for $19.60 for a package of five.
Waste disposal costs are estimated based on the 1997 regulations for disposal of PCB-contaminated waste.
Using the test kit during the demonstration, Hach generated approximately 20 Ib of vials containing soils and
liquid solvents (classified as incinerable solid PCB waste) and approximately 20 Ib of other solid PCB waste
(i.e., used and unused soil, gloves, paper towels, ampules, etc.). The cost of disposing PCB solid waste by
incineration at a commercial facility was estimated at $1.50 /Ib. The cost for solid PCB waste disposal at
ETTP was estimated at $18/lb. The test kit also generated approximately 19 Ib of liquid waste. The cost for
liquid PCB waste disposal at a commercial facility was estimated at $0.25/lb, while the cost at ETTP was
estimated at $ll/lb.
Reference Laboratory Costs
Sample shipment costs to the reference laboratory included the overnight shipping charges, as well as labor
charges associated with the various organizations involved in the shipping process.
Labor: This cost element included all of the tasks associated with the shipment of the samples
to the reference laboratory. Tasks included packing the shipping coolers, completing the chain-
of-custody documentation, and completing the shipping forms. Because the samples contained
PCBs, the coolers were inspected by qualified personnel to ensure compliance with the U.S.
Department of Transportation's shipping regulations for PCBs. The estimate for completing
this task was 2 to 4 hours at $50 per hour.
• Overnight shipping: The overnight express shipping service cost was estimated to be $50 for
one 50-lb cooler of samples.
The labor bids from commercial analytical reference laboratories who offered to perform the PCB analysis for
this demonstration ranged from $44 per sample to $239 per sample. The bid was dependent on many factors,
including the perceived difficulty of the sample matrix, the current work load of the laboratory, and the
competitiveness of the market. In this case, the wide range of bids may also be related to the cost of PCB waste
disposal in a particular laboratory's state. LAS Laboratories was awarded the contract to complete the analysis
48
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as the lowest qualified bidder ($44 per sample). This rate was a fully loaded analytical cost, including
equipment, labor, waste disposal, and report preparation.
Cost Assessment Summary
An overall cost estimate for Hach's PCB immunoassay kit versus the reference laboratory was not made
because of the extent of variation in the cost factors, as outlined in Table 5-11. The overall costs for the
application of each technology will be based on the number of samples requiring analysis, the sample type, and
the site location and characteristics. Decision-making factors, such as turn-around time for results, must also
be weighed against the cost estimate to determine the value of the field technology versus the reference
laboratory.
General Observations
The following are general observations regarding the field operation and performance of Hach's PCB
immunoassay kit:
• The system was light, easily transportable, and rugged. It took about one hour for the Hach
team to prepare to analyze samples on the first day of testing. While working at the outdoor
site, the Hach team completely disassembled their work station bringing everything inside at
the close of each day. It took the Hach team less than one hour each morning to prepare for
sample analyses.
• Two operators were used for the demonstration because of the number of samples and
working conditions, but the technology can be operated by a single person.
Operators generally require two hours of training and should have a basic knowledge of field
analytical techniques.
• The Hach team calibrated the pocket colorimeter often, analyzing a 1 ppm standard in
duplicate with every batch of four samples. This was done to account for changing
environmental conditions (i.e., temperature and humidity).
• Data processing and interpretation was minimal. The results were reported in terms of
intervals, relative to the calibration standard. No raw data were recorded, other than the
interval result.
• The measurement system (pocket colorimeter) was battery-operated.
• The Hach PCB immunoassay kit generated approximately 20 Ib of vials containing soils and
liquid solvents (classified as incinerable solid PCB waste) and approximately 20 Ib of other
solid PCB waste (i.e., used and unused soil, gloves, paper towels, ampules, etc.). The test kit
also generated approximately 19 Ib of liquid waste (aqueous with trace methanol).
49
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Performance Summary
A summary of the performance characteristics of the Hach PCB immunoassay kit, presented previously in this
chapter, is shown in Table 5-12. The performance of Hach's PCB immunoassay kit was characterized as
unbiased, because nearly all (90%) of the test kit results agreed with the certified PE values, and as precise,
because 100% of the PE replicate results were reported as the same interval. The test kit had three false
positive results (38%) and four false negative results i
Table 5-12. Performance summary for the Hach PCB immunoassay kit
Feature/Parameter
Blank Soil Results
Precision
Accuracy
False Positive Results
False Negative Results
Comparison with Reference Laboratory Results
Regulatory Decision-Making Applicability
Sample Throughput
Power Requirements
Operator Requirements
Cost
Hazardous Waste Generation
Performance Summary
Correctly reported 5 of 8 samples as [0,1) ppm; 3 samples reported as
[1, 10]
Percentage of combined PE sample sets where all four replicates
were reported as the same interval
PE Soils: 100%
Environmental Soils: 68%
PE Soils
agreed = 90%
biased high = 4%
biased low = 6%
Blanks
3 8% (3 of 8 samples)
PE and Environmental Soils
2% (4 of 192 samples)
PE and Environmental Soils
agreed = 85%
biased high = 7%
biased low = 9%
PE and Environmental Soils (40 to 60 ppm)
agreed = 98%
biased low = 2%
7-10 samples/hour (chamber)
10-13 samples/hour (outdoors)
Battery-operated pocket colorimeter (four AAA); provides
approximately 750 tests
Battery-operated portable balance (one 9-V)
Basic knowledge of chemical techniques; 2 hours technology-specific
training
Incremental: $35 per sample
Instrumental: $955 (purchase)
~ 20 Ib of solid/liquid (classified as incinerable solid)
~ 20 Ib of solid (used gloves, pipettes, paper towels, etc.)
~ 1 9 Ib of liquid waste (aqueous with trace methanol)
50
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Section 6
Technology Update and Representative Applications
Objective
In this section, Each describes new technology developments that are planned. The developer has also provided
a list of representative applications where their PCB immunoassay kit has been or is currently being utilized.
The data quality objective example described briefly below (and detailed in Appendix E) was derived by ORNL
from the performance results that are summarized in Section 5.
Technology Update
The addition of a 50 ppm threshold level is anticipated for the near future. This update will simply incorporate
either a different dilution scheme or a different calibrator. This update will provide the ability to test at levels
other than 1 and 10 ppm.
Representative Applications
Potential Users of the Technology
The Hach immunoassay method for field analysis of PCB is suited for environmental professionals, extension
agencies, soil analysts, utilities, and the natural gas pipeline industry. The kit is also ideal for use by analysts
responsible for testing contaminated soils on-site, monitoring remediation sites, and evaluating the progress of
remediation.
Actual Users of the Technology
A query of Hach customers who have purchased the PCB kit over the past year shows that the kit has been
purchased for use in the following industries: refuse systems, utilities, research and development testing,
vocational schools, engineering services, and environmental consulting. The kit is used by customers within
the United States (75%) and overseas (25%). Below are three examples of customers currently using the
product.
HZW Environmental Consultants: HZW is a consulting firm that does phase 1 and phase 2 testing.
Each new job determines the need for testing. All PCB tests are run in the field and all tests are run
per customer demand. HZW personnel have said that the tests were very easy to use and that they were
great for the field. They said that after they ran tests with the Hach kit, they sent selective samples to
a lab for confirmation and got the same results. They feel that Hach's PCB test provides them and their
clients with immediate and accurate results.
51
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Mill Service Inc.: Mill Service Inc. uses the PCB kit to test a waste stream of soil at a treatment
disposal site. It is required to run the tests by the Pennsylvania Department of Environmental
Protection. Personnel run about 5 or 6 samples every other day. They find the tests to be extremely
easy to use and cost effective. They run tests because they need same-day results; if they had to send
them to a lab, it would cost much more and take longer to receive the test results.
Wilson Environmental Labs: This environmental laboratory runs PCB tests at the request of its
customers. It does not run PCB tests on a regular basis; only three jobs have required them in the past
year. Staff do not consider themselves experts at PCB testing, and since they perform the test
infrequently, it is important to them to have a test that is easy to use and accurate. They reported that
they have found the Hach test kit to be cost effective and easy to use.
Data Quality Objective Example
This application of Hach's PCB immunoassay kit is based on data quality objective (DQO) methods for project
planning advocated by ASTM [11, 12] and EPA [13]. The example (given in Appendix E) illustrates the use
of Hach's performance data from the ETV demonstration in the DQO process to select the number of samples
to characterize the decision rule's false positive and false negative error rates.
52
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Section 7
References
[1] Erickson, M. D. Analytical Chemistry ofPCBs, 2nd ed., CRC Press/Lewis Publishers, Boca Raton,
Fla., 1997.
[2] "Polychlorinated Biphenyls (PCBs) Manufacturing, Processing, Distribution in Commerce, and Use
Prohibitions," Code of Federal Regulations, 40 CFR, pt. 761, rev. 7, December 1994.
[3] Maskarinec, M.P., et al. Stability of Volatile Organics in Environmental Soil Samples, ORNL/TM-
12128, Oak Ridge National Laboratory, Oak Ridge, Tenn., November 1992.
[4] U.S. Environmental Protection Agency. "Method 8081: Organochlorine Pesticides and PCBs as
Aroclors by Gas Chromatography: Capillary Column Technique," in Test Methods for Evaluating
Solid Waste: Physical/Chemical Methods (SW-846), 3d ed., Final Update II, Office of Solid Waste
and Emergency Response, Washington, D.C., September 1994.
[5] Oak Ridge National Laboratory. Technology Demonstration Plan: Evaluation of Polychlorinated
Biphenyl (PCB) Field Analytical Techniques, Chemical and Analytical Sciences Division, Oak Ridge
National Laboratory, Oak Ridge, Tenn., July 1997.
[6] U.S. Environmental Protection Agency. Data Quality Objectives for Remedial Response Activities,
EPA 540/G-87/003, EPA, Washington, D.C., March 1987.
[7] Sachs, Lothar. Applied Statistics: A Handbook of Techniques, 2nd ed., Springer-Verlag, New York,
1984.
[8] Snedecor, G. W., and William G. Cochran. Statistical Methods, Iowa State University Press, Ames,
Iowa, 1967.
[9] Draper, N. R., and H. Smith. Applied Regression Analysis, 2nd ed., John Wiley & Sons, New York,
1981.
[10] Berger, Walter, Harry McCarty, and Roy-Keith Smith. Environmental Laboratory Data Evaluation,
Genium Publishing Corp., Schenectady, NY., 1996.
53
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[11] American Society for Testing and Materials (ASTM). Standard Practice for Generation of
Environmental Data Related to Waste Management Activities: Quality Assurance and Quality
Control Planning and Implementation, D5283-92, 1997.
[12] American Society for Testing and Materials (ASTM). Standard Practice for Generation of
Environmental Data Related to Waste Management Activities: Development of Data Quality
Objectives, D5 792-95, 1997.
[13] U.S. Environmental Protection Agency. Guidance for Data Quality Assessment, EPA QA/G-9;
EPA/600/R-96/084, EPA, Washington, D.C., July 1996.
54
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Appendix A
Description of Environmental Soil Samples
55
-------
-------
Table A-l. Summary of soil sample descriptions
Location
Oak Ridge
Oak Ridge
Oak Ridge
Oak Ridge
Oak Ridge
Paducah
Portsmouth
Tennessee
Reference Soil
Request for
Disposal
(RFD)#
40022
40267
24375
43275
134555
97002
7515
n/a
Drum#
02
01
02
03
04
01
02
03
01
02
03
01
02
03
04
858
1069
1096
1898
2143
2528
3281
538
940
4096
n/a
Description
Soil from spill cleanup at the Y-12 Plant in Oak Ridge, Tennessee.
This soil is PCB-contaminated soil excavated in 1992.
Soil from the Elza Gate area, a DOE Formerly Utilized Sites Remedial
Action Program site in Oak Ridge, Tennessee. This soil is PCB-
contaminated soil that was excavated in 1992.
Catch-basin sediment from the K-71 1 area (old Powerhouse Area) at
the DOE East Tennessee Technology Park (formerly known as Oak
Ridge Gaseous Diffusion Plant) in Oak Ridge, Tennessee. This soil is
PCB-contaminated storm drain sediment that was excavated in 1991.
Soil from the K-25 Building area at the DOE East Tennessee
Technology Park (formerly known as Oak Ridge Gaseous Diffusion
Plant) in Oak Ridge, Tennessee. This soil is PCB-contaminated soil
that was excavated in 1993.
Soil from the K-707 area at the DOE East Tennessee Technology Park
(formerly known as Oak Ridge Gaseous Diffusion Plant) in Oak Ridge,
Tennessee. This soil is PCB-contaminated soil from a dike spillage that
was excavated in 1995.
Soil from the DOE Paducah Gaseous Diffusion Plant in Kentucky. This
soil is PCB-contaminated soil from a spill cleanup at the C-746-R
(Organic Waste Storage Area) that was excavated in 1989.
Soil from the DOE Portsmouth Gaseous Diffusion Plant in Ohio. This
soil is PCB-contaminated soil from a probable PCB oil spill into the
East Drainage Ditch that was excavated in 1986.
Captina silt loam from Roane County, Tennessee; used as a blank in
this study (i.e., not contaminated with PCBs)
57
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-------
Appendix B
Characterization of Environmental Soil Samples
59
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-------
Table B-l. Summary of environmental soil characterization
Location
Oak Ridge
Paducah
Portsmouth
Sample
ID
101
102
103
104
105
106
107
108
109
110
111
112
126, 226
113,201
114,202
115,203
116,204
117,205
206
207
208
209
210
216
211
217
212
213
214
215
RFD
Drum # a
40022-02
40267-03
40267-01
40267-04
40267-01 Sb
24375-03
24375-01
40267-02
24375-02
43275-01
134555-03Sb
43275-02
non-PCB soil
97002-04
97002-01
97002-03
97002-02
97002-02S b
7515-4096
7515-1898
7515-1096
7515-2143
7515-0940
7515-0538
7515-0538Sb
7515-0538Sb
7515-2528
7515-3281
7515-0858
7515-1069
Composition
% gravel
0
0.5
0.2
0.6
0.5
0.5
2.5
0.4
0.3
0
0.5
0.1
0
0
0.2
0.1
0.4
0
0.2
0.4
0
0.3
0.5
0.5
0.5
0
1.3
% sand
91.8
99.3
96.7
98.2
94.8
87.8
92.5
94.2
93.1
89.2
88.1
91.4
85.6
92.4
87.6
83.6
93.7
87.1
78.0
74.4
74.3
73.0
73.3
70.4
72.6
65.8
75.0
% silt + clay
8.2
0.2
3.1
1.2
4.7
11.7
5.0
5.4
6.6
10.8
11.4
8.5
14.4
7.6
12.2
16.3
5.8
12.9
21.8
25.2
25.7
26.7
26.3
29.1
26.8
34.2
23.7
Total Organic
Carbon
(mg/kg)
5384
13170
13503
15723
14533
19643
1196
9007
1116
14250
10422
38907
9249
1296
6097
3649
4075
3465
3721
3856
10687
7345
1328
5231
5862
6776
4875
PH
7.12
7.30
7.21
7.07
7.28
7.36
7.26
7.30
7.48
7.57
7.41
7.66
7.33
7.71
7.64
7.59
7.43
7.72
7.66
7.77
7.71
7.78
7.78
7.92
7.67
7.85
7.56
a Request for disposal drum number (see Table A-l).
b "S" indicates that the environmental soil was spiked with additional PCBs.
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Appendix C
Temperature and Relative Humidity Conditions
63
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Table C-l. Average temperature and relative humidity conditions during testing periods
Date
7/22/97
7/23/97
7/24/97
7/25/97
7/26/97
7/27/97
7/28/97
7/29/97
Outdoor Site
Average
Temperature
(°F)
85
85
85
80
85
80
79
b
Average
Relative Humidity
(%)
62
70
67
70
55
75
88
b
Chamber Site
Average
Temperature
(°F)
70 a
60 a
58
56
57
55
57
55
Average
Relative Humidity
(%)
38 a
58 a
66
54
51
49
52
50
a The chamber was not operating properly on this day. See discussion in Section 3.
b No developers were working outdoors on this day.
120
7/22/97 7/23/97 7/24/97 7/25/97 7/26/97
7/27/97
7/28/97
Figure C-l. Summary of temperature conditions for outdoor site.
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120
100 --
I 8°
|5
I 60 +
I 40
20 --
7/22/97 7/23/97 7/24/97 7/25/97 7/26/97 7/27/97 7/28/97
Figure C-2. Summary of relative humidity conditions for the outdoor site.
7/22/97 7/23/97 7/24/97 7/25/97 7/26/97 7/27/97 7/28/97 7/29/97
Figure C-3. Summary of temperature conditions for chamber site.
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90
80
70
T 60
>*
I 50
I
« 4
™
^ 30
20
10
7/22/97 7/23/97 7/24/97 7/25/97 7/26/97 7/27/97 7/28/97
Figure C-4. Summary of relative humidity conditions for chamber site.
7/29/97
67
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68
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Appendix D
Hach's PCB Immunoassay Kit
Technology Demonstration Sample Data
69
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Legend for Appendix D Tables
Table Heading
Obs
Sample ID
Rep
Hach Result
Ref Lab Result
Reference Aroclor
Type
Order
Definition
Observation
Sample identification
101 to 126 = outdoor site soil samples
127 to 130 = outdoor site extract samples
201 to 226 = chamber site soil samples
227 to 230 = chamber site extract samples
Replicate of sample ID (1 through 4)
Hach's measured PCB concentration range (ppm)
LAS reference laboratory measured PCB concentration (ppm)
Values with "<" are samples that the reference
laboratory reported as "< reporting detection limit"
Aroclor(s) identified by the reference laboratory
Sample = environmental soil
1242, 1248, 1254, 1260 = Aroclor in PE samples
Blank = non-PCB-contaminated sample
Order of sample analysis (started with 2001-21 16, then
1001-1116)
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Table D-l. Hach's PCB technology demonstration soil sample data
Obs
Sample
ID
Rep
Hach
Result
(ppm)
Ref Lab
Result
(ppm)
Reference
Aroclor
Type
Order
Non-Detect
Non-Detect
Non-Detect
Non-Detect
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Obs
41
42
43
44
45
46
47
48
Sample
ID
Rep
Hach
Result
(ppm)
Ref Lab
Result
(ppm)
Reference
Aroclor
1254
1254
1254
1254
Non-Detect
Non-Detect
Non-Detect
Non-Detect
Type
Order
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Obs
Sample
ID
Rep
Hach
Result
(ppm)
Ref Lab
Result
(ppm)
Reference
Aroclor
Type
Order
Non-Detect
Non-Detect
Non-Detect
Non-Detect
Blank
Blank
Blank
Blank
202
73
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Obs
Sample
ID
Rep
Hach
Result
(ppm)
Ref Lab
Result
(ppm)
Reference
Aroclor
Type
Order
26.0
74
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Obs
Sample
ID
Rep
Hach
Result
(ppm)
Ref Lab
Result
(ppm)
Reference
Aroclor
Type
Order
75
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Obs
Sample
ID
Rep
Hach
Result
(ppm)
Ref Lab
Result
(ppm)
Reference
Aroclor
Type
Order
Non-Detect
Non-Detect
Non-Detect
Non-Detect
Blank
Blank
Blank
Blank
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Table D-2. Corrected reference laboratory data
Error
Transcription
Calculation
Interpretation
Sample ID
106
130
205
207
210
118
119
209
214
219
101a
101a
107
109
113b
113b
119
127
201
219
Reported Result
(ppm)
<490
5.6
32,000
180
160
3.6
4.3
2.3
43.0
29.0
<0.7
<0.7
<1.3
18.0
<0.9
<1.0
18.0
7.2
< 1.0
21.0
Corrected Result
(ppm)
255.9
10.3
3,305.0
17.8
123.2
2.1
17.4
37.9
26.0
22.4
0.5
0.6
1.2
1.5
0.6
0.7
21.2
10.9
0.6
26.0
a Two of four measurements in Sample ID 101 were corrected.
* Two of four measurements in Sample ID 113 were corrected.
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Appendix E
Data Quality Objective Example
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Disclaimer
The following hypothetical example serves to demonstrate how the information provided in this report may
be used in the data quality objectives (DQO) process. This example serves to illustrate the application of
quantitative DQOs to a decision process, but cannot attempt to provide a thorough education in this topic.
Please refer to other educational or technical resources for further details. In addition, since the focus of
this report is on the analytical technology, this example makes the simplifying assumption that the contents
of these drums will be homogeneous. In the "real world," however, this assumption is seldom valid, and
matrix heterogeneity constitutes a source of considerable uncertainty which must be adequately evaluated if
the overall certainty of a site decision is to be quantified.
Background and Problem Statement
An industrial company discovered a land area contaminated with PCBs from an unknown source. The
contaminated soil was excavated into waste drums. Preliminary evaluation determined that a number of
PCB drums had to be incinerated to reduce or eliminate the PCB contamination. The incinerated soil was
placed in drums for disposal in a landfill. However, a final check of each drum was required to verify for
the regulator that the appropriate level of cleanup had been achieved. The regulator required that no drum
have more than 2 ppm of PCB. The company's DQO team was considering the use of Hach's PCB kit to
measure the PCB concentration in each drum. Soil samples would be randomly selected from each drum
and tested with Hach's PCB kit to determine if the concentration was in one of the three intervals [0,1),
[1,10], or (10,<=°). Recall that this notation describes the concentration ranges 0 ppm < PCB < 1 ppm,
1 ppm < PCB < 10 ppm, and PCB > 10 ppm, as used in Section 5. The DQO team decided that a drum
would be reprocessed by incineration if any of Hach's results indicated a concentration in the intervals
[1,10] or (10,°°). In agreement with regulators, the DQO team determined that a decision rule for disposal
would be based on the number of samples with PCB concentrations in the intervals [1,10], and (10,°°).
General Decision Rule
If all of the PCB sample results show concentrations in [0, 1), then send the soil drum to the landfill.
If any of the PCB sample results are different than [0, 1) then reprocess the soil drum by incineration.
DQO Goals
EPA's Guidance for Data Quality Assessment [13] states in Sect. 1.2: "The true condition that occurs with
the more severe decision error . . . should be defined as the null hypothesis." The DQO team decided that
the more severe decision error would be for a drum to be erroneously sent to a landfill if the drum's PCB
concentration actually exceeded the 2 ppm limit. Therefore, the null hypothesis is constructed to assume
that the a drum's true PCB concentration exceeds the 2 ppm limit; and as a "hot" drum, it should be sent to
the incinerator. Drums would be sent to the landfill only if the null hypothesis is rejected and it is concluded
that the "true" average PCB concentration is less than 2 ppm.
With the null hypothesis defined in this way, a false positive decision is made when it is concluded that a
drum contains less than 2 ppm PCBs (i.e., the null hypothesis is rejected), when actually the drum is "hot"
(i.e., the null hypothesis is true). The team required that the error rate for sending a "hot" drum to the
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landfill (i.e., the false positive error rate for the decision) could not be more than 5%. Therefore, a
sufficient number of samples must be taken from each drum so that the false positive decision error rate
(FP) is 0.05 (or less) if the true drum concentration is 2 ppm. This scenario represents a 5% chance of
sending a drum containing 2 ppm or more of PCBs to the landfill. The Hach interval boundary of 1 ppm
can be used as a conservative estimate of the 2 ppm criterion.
The DQO team did not want to reprocess an excessive number of drums by incineration if the drum PCB
concentration was less than 2 ppm because of the expense. In this situation, a false negative decision is
made when it is concluded that a drum is "hot" (i.e., the null hypothesis is not rejected), when in actuality,
the drum contains soil with less than 2 ppm PCBs (i.e., the null hypothesis is actually false). After
considering the guidelines presented in Section 1.1 of EPA's Guidance for Data Quality Assessment [13],
the DQO team recommended that the false negative decision error rate (FN) for the decision rule be 0.10 if
the true drum concentration was less than 1 ppm. That is, there would be a 10% chance of reprocessing a
drum by incineration if the true PCB concentration for a drum was less than 1 ppm.
Permissible FP and FN Error Rates and Critical Decision Point
FP: Pr[Take Drum to Landfill] < 0.05 when true PCB concentration 1 ppm
FN: Pr[Reprocess Drum in Incinerator] < 0.10 when true PCB concentration < 1 ppm
Use of Technology Performance Information to Implement the Decision Rule
Technology performance information is used to evaluate whether a particular analytical technology can
produce data of sufficient quality to support the site decision. Because the DQO team is considering the use
of Hach's PCB kit, the performance of this technology (as reported in this ETV report) was used to assess
its applicability to this project. The question arises, How many samples are needed from a single drum to
permit a statistically valid decision at the specified certainty? Recall that the simplifying assumption was
made that the PCB distribution throughout the soil within a single drum is homogeneous and thus, matrix
heterogeneity will not contribute to overall variability. The only variability, then, to be considered in this
example is the variability in performance of the Hach kit's analytical method, which is determined by
precision and accuracy studies.
Determining the Number of Samples
The number of samples needed to satisfy the FP and FN requirements depends on the misclassification
error rates of Hach's PCB kit. Two types of misclassifications have to be considered (1) underestimating
the PCB concentration—classifying a sample concentration in [0, 1) when the true PCB concentration is
greater or equal to Ippm, and (2) overestimating the PCB concentration—classifying a sample
concentration in [1, 10] or (10, °°) when the PCB concentration is less than 1 ppm. The ETV demonstration
results on performance evaluation soil samples and on environmental soil samples indicated the error rates
for the two types of misclassifications to be Pv = Pr[ Underestimating the PCB concentration ] = 0.022 and
P0 = Pr[ Overestimating the PCB concentration ] = 0.588.
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The probability distribution of classifying the number of soil samples in different concentration intervals
follows a binomial probability distribution [7, pg. 162-170]. This probability distribution and the
requirements for FP and FN can be used to determine the number of samples to meet the DQO goals. The
FP for the decision rule is related to Pv by
FP = Pr[ All Hack's results < 1 ppm for PCB 1 ppm ] = (Pv)" (E-l)
The FP error rate decreases as the sample size increases. Rearranging to solve for sample size, n, Equation
E-l becomes
Log(FP)
n = — £i - L
Log(Pv)
where
n = number of samples from a drum to be measured,
FP = false positive decision error rate (e.g., FP = 0.05), and
Pv = probability of underestimating the PCB concentration (e.g., Pv = 0.022).
Incorporating the appropriate values for the Hach PCB immunoassay kit into Equation E-2 gives
n-
Zog(0.022) -1.658
The DQO team would have to take one sample to meet the FP requirement. The FN for the decision rule is
related to .Po by
FN = Pr[ Some of Hack's results 1 ppm for PCB < 1 ppm ] = 1 - ( 1 - Po)" (E-3)
The probability of a false negative decision (FN = sending a drum for reprocessing) actually increases with
increasing sample size because the chance of the kit overestimating a result increases with continued
testing. The sample size required to meet the FN requirement is
Log( 1 - FN)
'
83
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where
n = number of samples from a drum to be measured,
FN = false negative decision error rate (e.g., FN = 0.10), and
.PO = probability of overestimating the PCB concentration
„ _ Log(\ - 0.10) _ -0.046 _ Q119 1
Log(l - 0.588) -0.385
The sample size must be rounded up to n = 1. When n=\, and the above equation is solved for FN, it is
found that the DQO team cannot meet their goal of 10% FN, and would have to accept an FN of 59%. This
situation occurs because of the 59% overestimation error rate of the kit. If a decision about a drum is based
on a single sample, and that sample has a 59% chance of being overestimated, there is consequently a 59%
chance that the drum will be unnecessarily sent for reprocessing through the incinerator (which was the
definition of FN). Although this amount of conservatism may be desirable in some situations, in others it
may not be. The only way to reduce the FN in this kind of scenario is to use an analytical technology with a
lower overestimation error rate. The DQO team in our example decided that the sampling procedure would
be to randomly select one soil sample from each drum and test the sample with Hach's PCB kit.
The DQO team would send the drum to the landfill if the result was less than 1 ppm and send the drum to
be reprocessed by incineration if the result was greater than 1 ppm. To meet a 5% FP requirement, the
DQO team would have to accept the FN of 59%.
Decision Rule for 5% FP and 59% FN
If one randomly selected soil sample has a PCB test result reported as the interval [0, 1) then send the
soil drum to the landfill.
If one randomly selected soil sample has a PCB test result different than [0, 1) then reprocess the soil
drum by incineration.
Alternative FP Parameter
The following describes how changing the FP requirement from 5% to 0.1% would affect the decision rule.
Using FP = 0.001, the calculated sample sizes would be n = 1.8 2. For this case, the sample size for FP
would be rounded up to n = 2. The FN would be 83% which is larger than the FN specified by the DQO
team. The higher FN occurs because each of the two samples has a 59% chance of being overestimated,
and therefore there is an 83% chance that one of the two samples from a drum will be overestimated. Even
if only one is overestimated, the drum is sent for reprocessing. The decision rule for the lower FP would be
as shown below.
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Decision Rule for FP = 0.1% and FN = 83%
If two randomly selected soil samples have PCB test results reported as the interval [0, 1) then send the
soil drum to the landfill.
If either of the two randomly selected soil samples have PCB test results different than [0, 1) then
reprocess the soil drum by incineration.
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