September 2006
Environmental Technology
Verification Report
SEVERN TRENT SERVICES
Eclox™-Pesticide Strips
Prepared by
Battelle
Battelle
I he Business of Innovation
Under a cooperative agreement with
V8* trr\ U.S. Environmental Protection Agency
ET1/ET1/ET1/
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September 2006
Environmental Technology Verification
Report
ETV Advanced Monitoring Systems Center
Severn Trent Services
Eclox™-Pesticide Strips
By
Raj Mangaraj
Stephanie Buehler
Amy Dindal
Zachary Willenberg
Karen Riggs
Battelle
Columbus, Ohio 43201
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Notice
The U.S. Environmental Protection Agency (EPA), through its Office of Research and
Development, has financially supported and collaborated in the extramural program described
here. This document has been peer reviewed by the Agency. Mention of trade names or
commercial products does not constitute endorsement or recommendation by the EPA for use.
11
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Foreword
The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the
nation's air, water, and land resources. Under a mandate of national environmental laws, the
Agency strives to formulate and implement actions leading to a compatible balance between
human activities and the ability of natural systems to support and nurture life. To meet this
mandate, the EPA's Office of Research and Development provides data and science support that
can be used to solve environmental problems and to build the scientific knowledge base needed
to manage our ecological resources wisely, to understand how pollutants affect our health, and to
prevent or reduce environmental risks.
The Environmental Technology Verification (ETV) Program has been established by the EPA to
verify the performance characteristics of innovative environmental technology across all media
and to report this objective information to permitters, buyers, and users of the technology, thus
substantially accelerating the entrance of new environmental technologies into the marketplace.
Verification organizations oversee and report verification activities based on testing and quality
assurance protocols developed with input from major stakeholders and customer groups
associated with the technology area. ETV consists of six environmental technology centers.
Information about each of these centers can be found on the Internet at http://www.epa.gov/etv/.
Effective verifications of monitoring technologies are needed to assess environmental quality
and to supply cost and performance data to select the most appropriate technology for that
assessment. Under a cooperative agreement, Battelle has received EPA funding to plan,
coordinate, and conduct such verification tests for "Advanced Monitoring Systems for Air,
Water, and Soil" and report the results to the community at large. Information concerning this
specific environmental technology area can be found on the Internet at http://www.epa.gov/
etv/centers/centerl .html.
in
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Acknowledgments
The authors wish to acknowledge the support of all those who helped plan and conduct the
verification test, analyze the data, and prepare this report. Many thanks go to Battelle's
Hazardous Materials Research Center for providing the facilities for and personnel capable of
working with chemical warfare agents. We sincerely appreciate the contribution of drinking
water samples from the Metropolitan Water District of Southern California (Paul Rochelle and
Melinda Stalvey), the New York Department of Environmental Protection (Virginia Murray),
and Orange County Utilities, Orlando, Florida (Theresa Slifko and Liza Robles). We would also
like to thank Armah de la Cruz (U.S. EPA, National Exposure Research Laboratory), Ricardo
DeLeon (Metropolitan Water District of Southern California), Yves Mikol (New York City
Department of Environmental Protection), and Helen Schurz Rogers (Centers for Disease
Control and Prevention National Center for Environmental Health) for their careful review of the
test/QA plan and this verification report.
IV
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Contents
Page
Notice ii
Foreword iii
Acknowledgments iv
List of Abbreviations viii
Chapter 1 Background 1
Chapter 2 Technology Description 2
Chapter 3 Test Design 4
3.1 Introduction 4
3.2 Test Samples 4
3.2.1 PT Samples 5
3.2.2 DW Samples 6
3.2.3 QC Samples 7
3.2.4 Operational Factors 7
3.3 Verification Schedule 8
3.4 Test Procedure 8
3.4.1 Test Sample Preparation and Storage 8
3.4.2 Test Sample Analysis Procedure 9
3.4.3 Drinking Water Characterization 9
Chapter 4 Quality Assurance/Quality Control 11
4.1 Sample Chain-of Custody Procedures 11
4.2 QC Samples 11
4.3 Equipment/Calibration 12
4.4 Characterization of Stock Solutions 12
4.5 Audits 14
4.5.1 Performance Evaluation Audit 14
4.5.2 Technical Systems Audit 14
4.5.3 Audit of Data Quality 15
4.6 QA/QC Reporting 15
4.7 Data Review 15
Chapter 5 Statistical Methods and Reported Parameters 17
5.1 Accuracy 17
5.2 False Positive/False Negative Rates 17
5.3 Precision 18
5.4 Potential Matrix and Interferent Effects 18
5.5 Operational Factors 18
Chapter 6 Test Results 19
6.1 Accuracy 19
6.2 False Positive/False Negative Rates 19
6.3 Precision 21
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6.4 Potential Matrix and Interferent Effects 21
6.4.1 Interferent PT Samples 27
6.4.2 DW Samples 27
6.5 Operational Factors 27
6.5.1 Technical Operators 27
6.5.2 Non-Technical Operator 28
Chapter 7 Performance Summary 30
Technical Operators 36
Non-Technical Operators 36
Chapter 8 References 37
Figures
Figure 2-1. The Eclox™-Pesticide Strip 3
Figure 6-1. Side View of PPE Worn by Non-Technical Operator 29
Figure 6-2. Testing of Eclox™-Pesticide Strips with the Non-Technical Operator Wearing PPE
29
Tables
Table 3-1. Lethal Dose of Target Contaminants 6
Table 3-2. Performance Test Samples 6
Table 3-3. Drinking Water Samples 7
Table 3-4. ATEL Water Quality Characterization of Drinking Water Samples 10
Table 4-1. Reference Methods for Target Contaminants and Interferents 13
Table 4-2. Performance Evaluation Samples and Percent Difference 14
Table 4-3. Summary of Data Recording Process 16
Table 6-1. Contaminant-Only PT Sample Results 20
Table 6-2a. VX False Positive/Negative Results 22
Table 6-2b. GB False Positive/Negative Results 23
Table 6-2c. GD False Positive/Negative Results 24
Table 6-2d. Aldicarb False Positive/Negative Results 25
Table 6-2e. Dicrotophos False Positive/Negative Results 26
Table 7-la. VX Summary Table 31
VI
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Table 7-lb. GB Summary Table 32
Table 7-lc. GD Summary Table 33
Table 7-ld. Aldicarb Summary Table 34
Table 7-le. Dicrotophos Summary Table 35
vn
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List of Abbreviations
AMS
ASTM
ATEL
CWA
Ca
DI
DPD
DW
BCD
EPA
ETV
GB
GC
GD
HAZWOPER
HOPE
HMRC
ICP
kg
L
LC
LD50
LOD
LRB
MB
Mg
mg/L
mL
MS
uMHO
NDR
NTU
OP
Advanced Monitoring Systems
American Society for Testing and Materials
Aqua Tech Environmental Laboratories
chemical warfare agent
calcium
deionized
diethyl-p-phenylene diamine
drinking water
electron capture detection
U.S. Environmental Protection Agency
Environmental Technology Verification
sarin
gas chromatography
soman
Hazardous Waste Operations and Emergency Response
high density polyethylene
Hazardous Materials Research Facility
inductively coupled plasma
kilogram
liter
liquid chromatography
lethal dose for half of test subjects
limit of detection
laboratory record book
method blank
magnesium
milligram per liter
milliliter
mass spectrometry
micromho
negative differential resistance
nephelometric turbidity unit
organophosphate
Vlll
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PE performance evaluation
PPE personal protective equipment
PT performance test
QA quality assurance
QC quality control
QMP quality management plan
SCBA self-contained breathing apparatus
SM standard method
SOP standard operating procedure
ISA technical systems audit
IX
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Chapter 1
Background
The U.S. Environmental Protection Agency (EPA) supports the Environmental Technology
Verification (ETV) Program to facilitate the deployment of innovative environmental
technologies through performance verification and dissemination of information. The goal of the
ETV Program is to further environmental protection by accelerating the acceptance and use of
improved and cost-effective technologies. ETV seeks to achieve this goal by providing high-
quality, peer-reviewed data on technology performance to those involved in the design,
distribution, financing, permitting, purchase, and use of environmental technologies.
ETV works in partnership with recognized testing organizations; with stakeholder groups
consisting of buyers, vendor organizations, and permitters; and with the full participation of
individual technology developers. The program evaluates the performance of innovative
technologies by developing test plans that are responsive to the needs of stakeholders,
conducting field or laboratory tests (as appropriate), collecting and analyzing data, and preparing
peer-reviewed reports. All evaluations are conducted in accordance with rigorous quality
assurance (QA) protocols to ensure that data of known and adequate quality are generated and
that the results are defensible.
The EPA's National Exposure Research Laboratory and its verification organization partner,
Battelle, operate the Advanced Monitoring Systems (AMS) Center under ETV. The AMS Center
recently evaluated the performance of the Severn Trent Services Eel ox™-Pesticide Strips in
detecting chemical agents, carbamate pesticides, and organophosphate (OP) pesticides in
drinking water. Enzymatic test kits were identified as a priority technology category for
verification through the AMS Center stakeholder process.
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Chapter 2
Technology Description
The objective of the ETV AMS Center is to verify the performance characteristics of
environmental monitoring technologies for air, water, and soil. This verification report provides
results for testing the Severn Trent Services Eclox™-Pesticide Strips. Following is a description
of the Eclox™-Pesticide Strips based on information provided by the vendor. The information
provided below was not verified in this test.
The Eclox™-Pesticide Strips (Figure 2-1) are designed to give a qualitative (i.e., "yes/no")
indication for the presence of OP, thiophosphate and carbamate pesticides. It is based on the
inhibition of the enzyme acetylcholinesterase. The absence of pesticides turns the strip blue. In
the presence of pesticides, the strip remains white.
Each Eclox™-Pesticide Strip consists of a strip containing two disks, a smaller white disk and a
larger pink disk covered with foil. After removing the strip from the packaging, the operator
exposes the white disk only and dips it into the sample for one minute. In the next step, the
operator removes the strip from the sample and removes the foil cover to expose the pink disk.
The operator then folds the strip at the perforation and presses the disks together. This step, in
which the disks are held together for three minutes, exposes the pink disk to the suspect test
water sample. After the three minute holding time, the operator visually reads the color of the
smaller disk. Two results are possible: a blue color indicates the absence of a pesticide and the
white color indicates the presence of a pesticide.
The Eel ox™-Pesticide Strips are part of the Eclox™ portable field water quality assessment
system, which detects intentional or accidental contamination of water. The Eclox™ system uses
a luminometer to determine water toxicity and can be used to test for various contaminants in
water. A package of 25 Eclox™-Pesticide Strips may be purchased separately (from the Eclox™
system) for $510.00.
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TM
Figure 2-1. The Eclox -Pesticide Strip
An operator introduces the strip into a water sample (top) and views the resulting color change of
the smaller disk (bottom). In this case, the blue color of the smaller disk (shown toward the
bottom of the lower picture) shows a negative response (indicating the absence of a pesticide in
the test water sample).
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Chapter 3
Test Design
3.1 Introduction
Enzymatic test kits, generally designed to be handheld and portable, detect the presence of
chemical agents, carbamate pesticides, and/or OP pesticides by relying on the reaction of the
cholinesterase enzyme. Under normal conditions, the enzyme reacts as expected with other
chemicals present in the test kit. The activity of the enzyme is inhibited, however, by chemical
agents, carbamate pesticides, and OP pesticides. The effects of this inhibition will then generally
lead to a color change, indicating the presence or absence of these compounds.
The objective of this verification test was to evaluate the ability of the Eclox™-Pesticide Strips
to detect chemical agents, carbamate pesticides, and OP pesticides in drinking water. This
verification test assessed the performance of the Eel ox™-Pesticide Strips relative to
• Accuracy
• False positive and negative rates
• Precision
• Potential matrix and interference effects
• Operational factors (operator observations, ease of use, and sample throughput).
3.2 Test Samples
This test evaluated the ability of the Eclox™-Pesticide Strips to detect VX, sarin (GB), soman
(GD) (chemical agents); aldicarb (carbamate pesticide); and dicrotophos (OP pesticide) in
performance test (PT) and drinking water (DW) samples. Quality Control (QC) samples were
also included as part of the test matrix to ensure the integrity of the test. Contaminants were
tested individually, and stock solutions of each contaminant were prepared separately in
American Society for Testing and Materials (ASTM) Type II deionized (DI) water. Samples
were prepared in the appropriate matrix using these stock solutions and analyzed on the same
day. To minimize the loss of analytes to hydrolysis, contaminant stock solutions prepared in DI
water were made on a daily basis. Chemical agent stock solutions were prepared twice daily,
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once in the morning and once in the afternoon. Aliquots of each stock solution were diluted to
the appropriate concentration using volumetric glassware and volumetric or calibrated pipettes.
In some cases, reference solutions were prepared in ASTM Type IIDI water using the stock
solutions used to prepare the test samples. In other cases, the actual stock solutions were
submitted for concentration confirmation by the respective reference analysis (Table 4-1). Aqua
Tech Environmental Laboratories, Inc. (ATEL) of Marion, OH performed the physiochemical
characterization for each type of DW sample along with reference analyses of the interferent
solutions. All other reference analyses were performed at Battelle.
3.2.1 PT Samples
PT samples were prepared separately in ASTM Type II DI water for each contaminant. The first
type of PT samples consisted of ASTM Type II DI water spiked with the contaminant at five
different concentrations: the lethal dose concentration given in Table 3-1 for each contaminant,
along with dilutions at approximately 10, 100, 1,000, and 10,000 times less than the lethal dose.
The contaminants were added individually to each spiked sample. The lethal dose of each
contaminant was determined by calculating the concentration at which 250 milliliters (mL) of
water is likely to cause the death of a 70-kilogram (kg) person based on human oral LD50 (lethal
dose for half of the test subjects) data.(1>2) Human oral LD50 data were not available for aldicarb,
so rat oral LD50 data were used instead.(3) Each concentration level for the PT samples was
analyzed in triplicate by the Eclox™-Pesticide Strips.
In addition to the contaminant-only PT samples described above, a second type of PT sample
was a potential interferent sample. Three replicates of each interferent PT sample were analyzed
by the Eel ox™-Pesticide Strips to determine the susceptibility of the strips to these commonly
found interferents in DW. One interferent PT sample contained calcium (Ca) and magnesium
(Mg) from carbonates spiked into ASTM Type II DI water, and the other contained humic and
fulvic acids isolated from the Elliot River (obtained from the International Humic Substances
Society) spiked into ASTM Type II DI water. Each interferent mixture was prepared at two
concentration levels: near the upper limit of what would be expected in drinking water
(250 mg/L total concentration for Ca and Mg, 5 mg/L total concentration for humic and fulvic
acids) and at a mid-low range of what would be expected (50 mg/L total concentration for Ca
and Mg, 1 mg/L total concentration for humic and fulvic acids). These spiked interferent levels
were confirmed through analysis of aliquots by ATEL. Also, each contaminant was added to
these samples, along with the potential interferent, at a concentration consistent with a lOx
dilution of the lethal dose. The resulting samples were analyzed in triplicate by the Eclox™-
Pesticide Strips. Table 3-2 lists the PT samples analyzed in this verification test for each
contaminant.
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Table 3-1. Lethal Dose of Target Contaminants
Contaminant
(common name)
VX
GB (sarin)
GD (soman)
aldicarb
dicrotophos
Oral Lethal Dose
Concentration
2.1 milligrams/liter (mg/L)
20mg/L
1.4 mg/L
260 mg/L
1400 mg/L
Contaminant Class
Chemical agent
Chemical agent
Chemical agent
Carbamate pesticide
Organophosphate pesticide
Table 3-2. Performance Test Samples
Type of PT
Sample
Sample Characteristics
Concentrations
Contaminant-
only
Contaminants in DI water
VX: 2.1 to 0.00021 mg/L
GB: 20 to 0.002 mg/L
GD: 1.4 to 0.00014 mg/L
aldicarb: 260 to 0.026 mg/L
dicrotophos: 1400 to 0.14 mg/L
Contaminants in 1 mg/L humic
and fulvic acids
Interferent
Contaminants in 5 mg/L humic
and fulvic acids
Contaminants in 50 mg/L Ca
and Mg
Contaminants in 250 mg/L Ca
andMg
VX: 0.21 mg/L
GB: 2.0 mg/L
GD: 0.14 mg/L
aldicarb: 26 mg/L
dicrotophos: 140 mg/L
3.2.2 DWSamples
Table 3-3 lists the DW samples analyzed for each contaminant in this test. DW samples were
collected from four geographically distributed municipal sources (Ohio, New York, California,
and Florida) to evaluate the performance of the Eel ox™-Pesticide Strips with various DW
matrices. These samples varied in their source, treatment, and disinfection process. All samples
had undergone either chlorination or chloramination disinfection prior to receipt. Samples were
collected from water utility systems with the following treatment and source characteristics:
• Chlorinated filtered surface water source
• Chlorinated unfiltered surface water source
• Chlorinated filtered groundwater source
• Chloraminated filtered surface water source
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Approximately 175 liters (L) of each of the DW samples were collected in pre-cleaned,
translucent, low-density polyethylene containers. . After sample collection, an aliquot of each
DW sample was sent to ATEL to determine the following water quality parameters:
concentration of trihalomethanes, haloacetic acids, total organic halides, Ca and Mg, pH,
conductivity, alkalinity, turbidity, organic carbon, and hardness. All DW samples were
dechlorinated prior to their use with sodium thiosulfate pentahydrate to prevent the degradation
of the target contaminants by chlorine. The dechlorination of the DW was qualitatively
confirmed by adding a diethyl-p-phenylene diamine (DPD) tablet to an aliquot of DW. If the
water did not turn pink, the dechlorination process was successful. If the water did turn pink,
additional dechlorinating reagent was added and the dechlorination confirmation procedure
repeated. Each DW sample was analyzed before addition of contaminant, as well as after
fortification with each individual contaminant at a single concentration level (lOx dilution of the
lethal dose). Aliquots of each contaminant stock solution were diluted with DW samples to the
appropriate concentration. Each sample was tested in triplicate.
Table 3-3. Drinking Water Samples
Drinking Water Sample Description
Water
Utility
Columbus, Ohio
(OH DW)
New York City, New
York (NY DW)
Orlando, Florida
(FL DW)
Metropolitan Water
District of Southern
California (CA DW)
Water
Treatment
chlorinated
filtered
chlorinated
unfiltered
chlorinated
filtered
chloraminated
filtered
Source
Type
surface
surface
ground
surface
Contaminant Concentrations
VX: 0.21 mg/L
GB: 2.0 mg/L
GD: 0.14 mg/L
aldicarb: 26 mg/L
dicrotophos: 140 mg/L
3.2.3 QCSamples
QC samples included method blank (MB) samples consisting of ASTM Type IIDI water. All
MB QC samples were exposed to sample preparation and analysis procedures identical to the test
samples. The MB samples were used to ensure that no sources of contamination were introduced
in the sample handling and analysis procedures. At least 10% of the test samples (seven samples
for each contaminant) were MB samples. All of the test samples and MB samples were analyzed
blindly by the operator in that the samples used for analysis were prepared by someone other
than the operator and were marked with non-identifying numbers.
3.2.4 Operational Factors
3.2.4.1 Technical Operator
All of the test samples were analyzed by a technical operator who was trained by other Battelle
staff who had been trained by the vendor. Operational factors such as ease of use and sample
throughput were evaluated based on observations recorded by the technical operator and the
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Verification Test Coordinator. Operational factors were noted during the laboratory portions of
the verification test. These observations were summarized to describe the operational
performance of the Eclox™-Pesticide Strips in this verification.
3.2.4.2 Non-Technical Operator
A subset of the samples was also tested by a non-technical operator using the Eclox™-Pesticide
Strips. The non-technical operator was someone with little to no laboratory experience who
would be representative of a first responder. For this test, the non-technical operator was a State
of Ohio certified firefighter with Hazardous Waste Operations and Emergency Response
(HAZWOPER) training. The non-technical operator was trained in the use of the Eclox™-
Pesticide Strips by another Battelle staff person who was trained by the vendor. Since many of
the contaminants being tested are highly toxic and unsafe to be handled outside of a special
facility, MB samples were analyzed as part of the operational factors assessment. Because no
samples spiked with the contaminants of interest were used, only the operational aspects of the
Eclox™-Pesticide Strips were evaluated with the non-technical operator. As the Eclox™-
Pesticide Strips may be used by first-responders, its performance was evaluated under simulated
first-response conditions by having the operator don a Level B protective suit, neoprene latex
gloves, boots, and a self-contained breathing apparatus (SCBA). The operator had prior
experience working in personal protective equipment (PPE). One set of MB samples was also
tested without the use of PPE. Ease of use from the perspective of the operator was documented
both with and without the PPE.
3.3 Verification Schedule
The verification test of the Eel ox™-Pesticide Strips took place from November 2005 through
February 2006 at Battelle facilities in Columbus and West Jefferson, Ohio.
3.4 Test Procedure
3.4.1 Test Sample Preparation and Storage
All testing for this verification test was conducted within Battelle laboratories. Aldicarb and
dicrotophos samples were tested at Battelle's Columbus laboratories, while VX, GB and GD
samples were tested at Battelle's Hazardous Materials Research Center (HMRC) facility in West
Jefferson, OH. Appropriate safety guidelines associated with each laboratory were followed
throughout the verification test. Samples were prepared fresh each day from stock solutions in DI
water, an interferent matrix, or a DW matrix. Sample solutions were prepared to the specified
concentration based on the concentration of the stock solution, which was confirmed through
reference analysis. Test solutions were prepared in 1 L quantities. Appropriate aliquots of this
sample preparation were used for each test sample. Triplicate samples of 25 mL were taken from
the same sample preparation. Each sample was placed in its own container and labeled only with
a sample identification number that was also recorded in a laboratory record book (LRB) along
with details of the sample preparation.
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3.4.2 Test Sample Analysis Procedure
TM
The Eel ox -Pesticide Strips have no requirements for the level of experience necessary to
operate the kit. For each sample, the operator opened the foil packet to remove the contents,
keeping the strip while disposing of the packaging (foil and wadding). Though the written
instructions direct the operator to keep the foil packet for use later in the test, the vendor
provided training did not make any use of the foil packet.
For each test sample, the operator dispensed approximately 25 mL of the test solution into a
50 mL beaker. This amount provided sufficient volume for the next step in which the operator,
after folding back the foil covering the white disk (but leaving the larger pink disk covered),
completely exposed the white disk (the smaller of the two disks on the Eclox™-Pesticide Strip)
to the test solution. The operator submerged the white disk in the test solution for one minute,
noting time by use of a wristwatch or stopwatch.
After removing the white disk from the test solution, the operator removed the protective foil
cover from the pink disk. Then, the operator folded the strip in half along the perforations and
pressed the white disk against the pink disk. The strip was then inserted into a supplied clip and
held in the operator's hands for three minutes. In the written instructions, the operator is directed
to place the clipped strip into the foil packet for the three minutes, but as noted above this
process was not directed to be followed when the operators were trained by the vendor.
3.4.3 Drinking Water Characterization
An aliquot of each DW sample, collected as described in Section 3.2.2, was sent to ATEL to
determine the following water quality parameters: turbidity; concentration of dissolved and total
organic carbon; conductivity; alkalinity; pH; concentration of Ca and Mg; hardness; and
concentration of total organic halides, trihalomethanes, and haloacetic acids. Table 3-4 lists the
characterization data from the four water sample types used in this verification test. Water
samples were collected and water quality parameters were measured by ATEL in June 2005,
while verification testing was tested with the DW between November 2005 and February 2006.
The time delay between collection and testing was due to the fact that the water samples were
collected for use during a separate ETV test conducted prior to this one. Because of this, an
aliquot of each DW was tested by ATEL again in January 2006 to verify some of the parameters
with the most potential to change over time. Note that dissolved organic carbon was not retested
as this result was verified by the total organic carbon results, additionally the total organic
halides and calcium and magnesium were not verified as there was no reason to expect a change
in these parameters. The concentrations of most water quality parameters were similar; however,
there was a decrease in levels of volatile compounds such as trihalomethanes and haloacetic
acids over this time-period.
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Table 3-4. ATEL Water Quality Characterization of Drinking Water Samples
Parameter
Turbidity
Dissolved
Organic Carbon
Total Organic
Carbon
Specific
Conductivity
Alkalinity
pH
Calcium
Magnesium
Hardness
Total Organic
Halides
Trihalomethanes
Haloacetic Acids
Unit
NTU(a)
mg/L
mg/L
uMHO(c)
mg/L
mg/L
mg/L
mg/L
ug/L
ug/L/
analyte
ug/L/
analyte
Method
EPA180.1(4)
SM5310(5)
SM5310(5)
SM2510(5)
SM 2320(5)
EPA 150.1(6)
EPA200.8(7)
EPA200.8(7)
EPA 130.2(8)
SM 5320(5)
EPA 524.2(9)
EPA 552.2(10)
Columbus,
OH
(OH DW)
2005
0.1
2.1
2.1
572
40
7.6
33
7.7
118
220
74.9
32.8
2006
0.6
NA
2.3
602
44
7.4
NA
NA
107
NA
16.6
<6.0
New York
City, NY
(NY DW)
2005
1.1
1.1
1.6
84
14
6.9
5.6
1.3
20
82
39.0
39.0
2006
1.3
NA
4.1
78
12
6.8
NA
NA
26
NA
23.1
<6.0
Orlando, FL
(FL DW)
2005
0.5
1.6
1.7
322
142
8.5
8.8
43
143
300
56.4
34.6
2006
0.1
NA
2.1
325
125
7.6
NA
NA
130
NA
41.8
<6.0
MWD (b), CA
(CA DW)
2005
0.1
2.9
2.5
807
71
8.0
45
20
192
170
39.2
17.4
2006
0.2
NA
2.7
812
97
7.9
NA
NA
182
NA
24.1
<6.0
= Nephelometric turbidity unit.
(b) MWD = Metropolitan Water District of Southern California
(iMHO = micromho
10
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Chapter 4
Quality Assurance/Quality Control
QA/QC procedures were performed in accordance with the quality management plan (QMP) for
the AMS Center(11) and the test/QA plan(12) for this verification test.
QC procedures as noted in the reference methods or laboratory's operating procedures were
followed in confirming analyses of stock or reference solutions of contaminants and interfering
compounds and in characterizing the DW. The reference methods for this verification test are
listed in Table 4-1. A summary of the QC samples and acceptance criteria associated with each
method is presented in Table 7 in the test/QA plan.(12)
4.1 Sample Chain-of Custody Procedures
Sample custody was documented throughout collection, shipping, and analysis of the samples.
Sample chain-of-custody procedures were in accordance with ASAT. I-009-Draft, Standard
Operating Procedure for Sample Chain-of-Custody. The chain-of-custody forms summarized the
samples collected and analyses requested and were signed by the person relinquishing samples
once that person had verified that the custody forms were accurate. The original sample custody
forms accompanied the samples; the shipper kept a copy. Upon receipt at the sample destination,
sample custody forms were signed by the person receiving the samples once that person had
verified that all samples identified on the custody forms were present in the shipping container.
4.2 QC Samples
The QC measures for the reference methods included the analysis of a MB sample with the
analyses of the reference or stock solution. MB samples were analyzed to ensure that no sources
of contamination were present. If the analysis of an MB sample indicated a concentration above
the minimum detection limit for the confirmatory instrument, contamination was suspected. Any
contamination source(s) were corrected, and proper blank readings were achieved, before
proceeding with the analyses. In general, a matrix spike or laboratory fortified spike sample was
also analyzed. Average acceptable recoveries for these samples were between 70 and 150%.
Samples outside of the acceptable range were generally flagged and rerun once the QC
acceptance criteria had been met. QC samples were run with every batch of 1 to 20 samples.
Specific QC samples and acceptance criteria associated with each method can be found in the
appropriate reference (see Table 4-1). No QC samples were provided with the Eclox™-Pesticide
11
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Strips. MB samples were run as part of the verification test (Section 3.2.3). No contaminants
were detected in any of the 32 method blank samples, which were analyzed in triplicate with the
Eclox™-Pesticide Strips.
4.3 Equipment/Calibration
The instruments used for the reference analyses were calibrated per the standard reference
methods being used to make each measurement or the standard operation procedures (SOPs) of
the analysis laboratory. Instruments used in the reference analyses for this test included gas
chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-
MS), pH electrodes, inductively coupled plasma-mass spectrometry (ICP-MS), and gas
chromatography with electron capture detector (GC-ECD). All calibrations were documented by
Battelle in the project LRB. Calibration of mass spectrometers involved a 4- to 8-point
calibration curve covering the range of concentrations of the reference solutions to be analyzed.
Calibration of each reference instrument was performed as frequently as required by the
reference method guidelines.
Pipettes used during solution preparation were maintained and calibrated as required by Battelle
SOPs (i.e., minimum of every 6 months). Pipettes were checked and either recalibrated or
replaced if they were found out of calibration over the course of testing.
4.4 Characterization of Stock Solutions
During testing, aliquots of the stock solutions used for sample preparation were submitted for
concentration confirmation via the respective methods. The measured concentration and the
reference method used are listed in Table 4-1 for each contaminant and interferent. Average
measured recovery and standard deviation are given in cases where more than two samples were
tested. Recovery (%R) is calculated by the following equation:
%R = — xlOO W
A
where C is the measured concentration (or average measured concentration if more than one
sample was tested) and^4 is the expected concentration of the contaminant or interferent in
solution. For aldicarb and dicrotophos, aliquots at two different concentration levels were
confirmed through reference analysis. The %R, listed in Table 4-1, represents the average of the
%R across both concentration levels for those compounds. Table 4-1 shows that %R values
ranged from 85% to 123% across all analytes and interferents.
Contaminant stock solutions were prepared and tested individually. Interferent stock solutions
contained multiple analytes in the same solution (e.g., calcium and magnesium or humic and
fulvic acids together). Up to four aliquots of each stock solution were analyzed over the course
of the verification test. In the case of VX, extra aliquots were analyzed and all were reported in
12
-------
Table 4-1. Aliquots were preserved or extracted on the day of preparation and stored as
prescribed by the standard method.
Table 4-1. Reference Methods for Target Contaminants and Interferents
Target
Analyte/Interferent
VX
GB (sarin)
GD (soman)
aldicarb
dicrotophos
calcium (Ca)
magnesium (Mg)
Humic and fulvic
acids
Reference Method
(Instrumentation)
Battelle Internally
Developed Method (LC-MS)
HMRC-IV-1 18-05 (13)
(GC-MS)
HMRC-IV-1 18-05 (13)
(GC-MS)
SOP for Analysis of Water
Sample Extracts for Type 1
Analytes by Liquid
Chromatography/Mass
Spectrometry (14) (LC-MS)
SOP for Extracting and
Preparing Water Samples for
Analysis of Dicrotophos,
Mevinphos, and
Dichlorovos (15) (GC-MS)
EPA 200.8 (7)(ICP-MS)
EPA 200.8 (7) (ICP-MS)
Standard Method 53 10 (5)
Combustion Infrared NDR
Number of
Observations
10
4
4
2
2
4
1
1
1
1
Expected
Concentrations
(mg/L)
2.1
20.0
1.4
26.0
260
140
1400
125
125
1.0
Average
Measured
Concentration
(mg/L) ± SD
2.1±0.1
17.0 ±1.4
1.7 ±0.05
34
303
157 ± 24
1326
140
130
0.9
Recovery
(%R) ± SD
101 ±5
85 ±7
121 ±4
123 ±7 (a)
108 ± 17 (a)
112
104
90
Average of two concentration levels
13
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4.5 Audits
4. 5. 1 Performance Evaluation Audit
The concentration of the standards used to prepare the samples fortified with contaminants and
potential interfering compounds was confirmed by analyzing standards prepared in ASTM Type
II DI water from two separate commercial vendors using the reference methods noted in
Table 4-1. The standards from one vendor were used during the verification test, while the
standards from the second vendor were used exclusively to confirm the accuracy of the standards
from the first vendor.
Given the lack of alternate sources for humic and fulvic acids as well as the security
requirements for the chemical agents (VX, GB, and GD) used in this verification test, PE audits
were not performed for these contaminants. PE audits were done for all remaining compounds
when more than one source of the contaminant or potential interfering compounds was available.
PE audits were performed only on compounds used to prepare test samples. Agreement of the
standards within 25% (percent difference) was required for the measurements to be considered
acceptable. The percent difference (%D) between the measured concentration of the PE sample
and the nominal concentration of that sample was calculated using the following equation:
A
where Mis the absolute value of the difference between the measured and the expected
concentration, and^4 is the expected concentration. The results of the PE samples are given in
Table 4-2. All %D values were within the 25% acceptable tolerance.
Table 4-2. Performance Evaluation Samples and Percent Difference
Contaminant
aldicarb
dicrotophos
Ca
Mg
Expected
Concentration
(mg/L)
50
1000
1000
1000
Measured
Concentration
(mg/L)
57
1103
890
990
Percent
Difference
(%)
14
10
11
1
4.5.2 Technical Systems A udit
The Battelle Quality Manager conducted technical systems audits (TSAs) in November 2005
(11/01, 11/11, 11/16, 11/18), December 2005 (12/01, 12/29), and January 2006 (01/30) to ensure
that the verification test was performed in accordance with the AMS Center QMP,(11) the
test/QA plan,(12) published reference methods, and any SOPs used by Battelle. As part of the
audit, the Battelle Quality Manager reviewed the reference methods, compared actual test
procedures to those specified or referenced in the test/QA plan, and reviewed data acquisition
14
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and handling procedures. The Battelle Quality Manager also observed testing in progress and the
reference method sample preparation and analysis, inspected documentation, and reviewed the
LRBs used to record testing results. The Battelle Quality Manager also checked calibration
certifications and conferred with Battelle staff. Observations and findings from this audit were
documented and submitted to the Battelle Verification Test Coordinator for response. No major
findings were reported from the audits. The records concerning the TSA are permanently stored
with the Battelle Quality Manager.
4.5.3 Audit of Data Quality
At least 10% of the data acquired during the verification test was audited. The Battelle Quality
Manager traced the data from initial acquisition, through reduction and statistical comparisons, to
final reporting. All calculations performed on the data undergoing the audit were checked.
4.6 QA/QC Reporting
Each assessment and audit was documented in accordance with Section 3.3.4 of the AMS Center
QMP.(11) Once the assessment report was prepared, the Battelle Verification Test Coordinator
responded to each potential problem and implemented any necessary follow-up corrective action.
The Battelle Quality Manager ensured that follow-up corrective action was taken. The results of
the TSA were sent to the EPA.
4.7 Data Review
Records generated in the verification test were reviewed before they were used to calculate,
evaluate, or report verification results. Table 4-3 summarizes the types of data recorded. The
review was performed by a technical staff member involved in the verification test but not the
staff member who originally generated the record. The person performing the review added
his/her initials and the date to a hard copy of the record being reviewed.
15
-------
Table 4-3. Summary of Data Recording Process
Data to Be Recorded
Dates, times, and
details of test events
Sample preparation
(dates, concentrations,
etc.)
Enzymatic test kit
procedures and sample
results
Reference method
sample preparation
Reference method
procedures,
calibrations, QA, etc.
Reference method
analysis results
Responsible
Party
Battelle
Battelle
Battelle
Battelle
Battelle or
subcontract
laboratory
Battelle or
subcontract
laboratory
Where
Recorded
ETV laboratory
record book or
data recording
forms
ETV laboratory
record books
ETV data sheets
and laboratory
record book
ETV laboratory
record book
Laboratory
record book or
data recording
forms
Electronically
from reference
analytical method
How Often
Recorded
Start/end of test
procedure, and at
each change of a
test parameter
When each
solution was
prepared
Throughout test
duration
Throughout
sample
preparation
Throughout
sampling and
analysis
processes
Every sample
analysis
Disposition
of Data
Used to organize and
check test results and
manually incorporated
into data spreadsheets
as necessary
Used to confirm the
concentration and
integrity of the
samples analyzed
Manually incorporated
into data spreadsheets
for statistical analysis
and comparisons
Used to demonstrate
validity of samples
submitted for
reference
measurements
Retained as
documentation of
reference method
performance
Converted to
spreadsheets for
calculations
16
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Chapter 5
Statistical Methods and Reported Parameters
The Eclox™-Pesticide Strips were evaluated for qualitative results (i.e., positive/negative
responses to samples). All data analyses were based on these qualitative results. QC and MB
samples were not included in any of the analyses.
5.1 Accuracy
Accuracy was assessed by evaluating how often the results of Eclox™-Pesticide Strips were
positive in the presence of a concentration above the limit of detection (LOD). Contaminant-only
PT samples were used for this analysis. An overall percent agreement was determined by
dividing the number of positive responses by the overall number of analyses of contaminant-only
PT samples greater than the Eel ox™-Pesticide Strip's LOD (see Equation 3). If the LOD was not
known or available, then all analyzed contaminant-only PT samples greater than the
concentration level where consistent negative results were obtained were used.
Accuracy (% Agreement) = # of positive contaminant only PT samples x 100 (3)
total # of contaminant only PT samples
5.2 False Positive/False Negative Rates
A false positive response was defined as a response indicating the presence of a contaminant
when the ASTM Type IIDI water (including interferent samples) or DW sample was not spiked
with contaminant.
A false positive rate was reported as the number of false positive results out of the total number
of unspiked samples (Equation 4). A false negative response was defined as a response
indicating the absence of a contaminant when the sample was spiked with a contaminant at a
concentration greater than the LOD for the Eclox™-Pesticide Strips (as defined above). Spiked
PT (contaminant and interferent) samples and spiked DW samples were included in the analysis.
Contaminant-only PT samples above the LOD (or the level at which consistent negative
responses are obtained if the LOD was not known) were included in the analysis. A false
negative rate was evaluated as the number of false negative results out of the total number of
spiked samples for a particular contaminant (Equation 5). Inconclusive results were not
considered positive or negative (so the total number of unspiked or spiked samples was
decreased accordingly).
17
-------
False Positive Rate = # of positive results (4)
total # of unspiked samples
False Negative Rate = # of negative results (5)
total # of spiked samples
5.3 Precision
Precision measures the repeatability and reproducibility of the responses of the Eclox™-
Pesticide Strips. The precision of three replicates of each sample set was assessed. Responses
were considered inconsistent if one or more of the three replicates differed from the response of
the other samples in the replicate set. The precision for the Eclox™-Pesticide Strip was assessed
by calculating the overall number of consistent responses for all the sample sets. The results are
reported as the percentage of consistent responses out of all replicate sets (Equation 6).
Precision (% Consistent results) = # of consistent responses of replicate sets x 100 (6)
total # of replicate sets
5.4 Potential Matrix and Interferent Effects
The potential effect of the DW matrix on the performance of the Eclox™-Pesticide Strips was
evaluated qualitatively by comparing the results for the spiked and unspiked DW samples to
those for the PT samples spiked with the contaminant at 10 times less than the lethal dose.
Similarly, the potential effect of interferent PT samples was also evaluated. The results
indicating the correct or incorrect reporting of the presence of a contaminant were evaluated.
The findings are reported and discussed in Section 6.4.
5.5 Operational Factors
Operational aspects of the performance of the Eel ox™-Pesticide Strips, such as ease of use and
sample throughput, were evaluated through observations made during testing. Also addressed are
the qualitative observations of the verification staff pertaining to the performance of the
Eclox™-Pesticide Strips from both the technical and non-technical operators' perspective.
18
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Chapter 6
Test Results
The results for the Severn Trent Services Eclox™-Pesticide Strips are discussed in the following
sections.
6.1 Accuracy
Accuracy was determined using contaminant-only PT samples with concentrations equal to or
above the vendor-provided LOD. No LODs were provided by the vendor for the target
contaminants with the exception of aldicarb. If no LOD was provided, only concentrations
above which consistent negative results were obtained were used in the calculation. This level
was defined at 0.021 mg/L for VX, 0.0020 mg/L for GB, and 0.0014 mg/L for GD. The
concentrations used for accuracy testing are denoted in Table 6-1.
Inconclusive results, which occurred when the operator could neither discern the color of the
smaller disk as entirely blue (negative for the presence of a contaminant) nor entirely white
(positive for the presence of a contaminant), may indicate that the tested concentrations may be
around the LOD for the particular contaminant tested. Two inconclusive results occurred during
the testing with GD at the concentration of 0.014 mg/L in DI water. In these tests, the operator
observed the smaller disk to be white with blue color around the edges.
A LOD of 0.2 mg/L for aldicarb was provided by the vendor. For this reason, accuracy is
determined using the PT samples at concentrations of 0.26 mg/L aldicarb and above as shown in
Table 6-1.
6.2 False Positive/False Negative Rates
Contaminant-only PT samples, interferent PT samples, and DW samples were evaluated to
determine false positive and false negative results for the Eclox™-Pesticide Strips. A false
positive response was defined as a positive result when the contaminant was not spiked into the
sample. A false negative response was defined as a negative result when the sample was spiked
with a contaminant at a concentration greater than the level where consistent negative responses
were obtained (see Section 6.1). Tables 6-2a through 6-2e present the false positive and false
negative responses for VX, GB, GD, aldicarb, and dicrotophos, respectively. The number of
positive and negatives samples out of the total replicates analyzed is presented in each table.
19
-------
Table 6-1. Contaminant-Only PT Sample Results
Contaminant
Concentration
(mg/L)
Positive Results
Out of
Total Replicates
Accuracy
vx
GB
GD
aldicarb
dicrotophos
2.1 (a)
0.21
0.021 (b)
0.0021 (b)
0.00021 (b)
20(a)
2.0
0.20
0.020
0.0020 (b)
14(a)
0.14
0.014
0.0014 (b)
0.00014 (b)
260 (a)
26
2.6
0.26 (d)
0.026 (e)
1400 (a)
140
14(b)
14(b)
0.014 (b)
3/3
3/3
0/3
0/3
0/3
3/3
3/3
o /o
3/3
3/3
0/3
o /o
3/3
3/3
1/3 (c)
0/3
0/3
3/3
3/3
0/3
0/3
0/3
3/3
3/3
0/3
0/3
0/3
100% (6/6)
100% (12/12)
78% (7/9)
50% (6/12)
100% (6/6)
(a) Lethal dose
^ Not used in accuracy calculations because concentrations in these samples are at or below level of consistent negative response
^ Two inconclusive results were observed
(d) Vendor-provided LOD for aldicarb of 0.2 mg/L
^ Not used in accuracy calculations because concentration is below vendor-provided LOD
20
-------
For VX, GB, and GD, only one set of unspiked DW and PT interferent samples were tested and
used for the three chemical agents. Thus, the results shown for the unspiked DW and potential
interferent samples in Tables 6-2a through 6-2c are the same and from only one set of triplicate
samples. For aldicarb and dicrotophos, sets of unspiked DW and PT interferent samples were
run separately for each pesticide.
As shown in Tables 6-2a and 6-2b, no false positive or false negative results were observed
during testing with VX and GB. For GD (Table 6-2c), neither false positive results nor false
negatives were observed; however, two replicates of the 0.014 mg/L GD gave inconclusive
results out of 33 total replicates. Testing with aldicarb (Table 6-2d) yielded no false positives yet
gave six false negatives out of 36 total replicates. The false negatives were the three replicates
each for the 2.6 and 0.26 mg/L aldicarb PT samples (which were included in the calculation
since the concentrations are above the vendor-provided LOD). Dicrotophos (Table 6-2e) also
yielded no false positives but 20 of 30 samples were false negatives. These samples were the
spiked potential interferent and DW samples except for one 50 mg/L Ca and Mg, three FL DW
samples, three 140 mg/L contaminant-only PT samples, and three 1400 mg/L contaminant-only
PT sample. This may indicate that the Eclox™-Pesticide Strips are prone to matrix effects when
used to detect dicrotophos (in matrices/concentrations similar to those tested in this verification
test).
6.3 Precision
During testing with VX and GB, the Eclox™-Pesticide Strips gave consistent results. That is, all
of the 21 sample sets, each consisting of three replicates, had the same results within each repli-
cate set. For GD, 20 of 21 sample sets yielded consistent results. The testing of the 0.014 mg/L
GD PT sample yielded two inconclusive results (see Table 6-2c).
Note that only one set of unspiked interferent samples were tested for VX, GB, and GD. These
sample sets were shared among the three contaminants. Three of these 8 sample sets had at least
one replicate that differed from the other two replicates.
For aldicarb, all of the 21 sample sets had consistent results. For dicrotophos, one spiked
interferent sample set (140 mg/L dicrotophos in 50 mg/L total Ca and Mg) gave two non-detect
results and one detect result, yielding consistent results among 20 of 21 sample sets.
6.4 Potential Matrix and Interferent Effects
The EcloxTM-Pesticide Strips were able to consistently detect VX, GB, GD, aldicarb, and
dicrotophos at 10 times less than the respective LD50 concentrations in DI water. The ability of
the EcloxTM-Pesticide Strips to detect these contaminants was challenged with potential
interferents and DW matrices.
21
-------
Table 6-2a. VX False
Sample Type
Contaminant-only
PT samples
Interferent PT
samples (b)
DW samples (b)
Positive/Negative Results
A/r , . Concentration
Matrix , /T .
(mg/L)
DI water
DI water
1 mg/L humic and
fulvic acids
1 mg/L humic and
fulvic acids
5 mg/L humic and
fulvic acids
5 mg/L humic and
fulvic acids
50 mg/L Ca and Mg
50 mg/L Ca and Mg
250 mg/L Ca and Mg
250 mg/L Ca and Mg
OHDW
OHDW
CADW
CADW
FLOW
FLOW
NYDW
NYDW
False Positive Rate
False Negative Rate
2.1(a)
0.21
Blank
0.21
Blank
0.21
Blank
0.21
Blank
0.21
Blank
0.21
Blank
0.21
Blank
0.21
Blank
0.21
Positive Results Out of
Total Replicates
3/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/24
0/30
^Lethal dose
(b) Only one set of unspiked DW and PT interferent samples were run for VX, GB, and GD.
22
-------
Table 6-2b. GB False
Sample Type
Contaminant-only
PT samples
Interferent PT
samples (b)
DW samples (b)
Positive/Negative Results
A/r , . Concentration
Matrix , /T .
(mg/L)
DI water
DI water
DI water
DI water
1 mg/L humic and
fulvic acids
1 mg/L humic and
fulvic acids
5 mg/L humic and
fulvic acids
5 mg/L humic and
fulvic acids
50 mg/L Ca and Mg
50 mg/L Ca and Mg
250 mg/L Ca and Mg
250 mg/L Ca and Mg
OHDW
OHDW
CADW
CADW
FLOW
FLOW
NYDW
NYDW
False Positive Rate
False Negative Rate
20(a)
2.0
0.20
0.02
Blank
2.0
Blank
2.0
Blank
2.0
Blank
2.0
Blank
2.0
Blank
2.0
Blank
2.0
Blank
2.0
Positive Results Out of
Total Replicates
3/3
3/3
3/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/24
0/36
^Lethal dose
(b) Only one set of unspiked DW and PT interferent samples were run for VX, GB, and GD.
23
-------
Table 6-2c. GD False Positive/Negative Results
Sample Type Matrix
DI water
Contaminant-only ^T
„„ , DI water
PT samples
DI water
1 mg/L humic and
fulvic acids
1 mg/L humic and
fulvic acids
5 mg/L humic and
fulvic acids
Interferent PT 5 mg/L humic and
samples (c) &lvic acids
50 mg/L Ca and Mg
50 mg/L Ca and Mg
250 mg/L Ca and Mg
250 mg/L Ca and Mg
OHDW
OHDW
CADW
CADW
DW samples (c)
FLOW
FLOW
NYDW
NYDW
False Positive Rate
False Negative Rate
Concentration
(mg/L)
1.4(a)
0.14
0.014
Blank
0.14
Blank
0.14
Blank
0.14
Blank
0.14
Blank
0.14
Blank
0.14
Blank
0.14
Blank
0.14
Positive Results Out of
Total Replicates
3/3
3/3
1/3 (b)
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/24
0/33
(a) Lethal dose
^ ' Twr> rpsiilts wprp nr>t nnsitivp r>r nptrativp hiit inrnnrliisivp as intprnrptpH hv thp nnpratnr thpsp rpsiilts anp
excluded from the false negative calculations
(c) Only one set of unspiked DW and PT interferent samples were run for VX, GB, and GD.
24
-------
Table 6-2d. Aldicarb
Sample Type
Contaminant-only
PT samples
Interferent PT
samples
DW samples
False Positive/Negative
Matrix
DI water
DI water
DI water
DI water
1 mg/L humic and
fulvic acids
1 mg/L humic and
fulvic acids
5 mg/L humic and
fulvic acids
5 mg/L humic and
fulvic acids
50 mg/L Ca and Mg
50 mg/L Ca and Mg
250 mg/L Ca and Mg
250 mg/L Ca and Mg
OHDW
OHDW
CADW
CADW
FLOW
FLOW
NYDW
NYDW
False Positive Rate
False Negative Rate
Results
Concentration
(mg/L)
260 ^
26
2.6
0.26
Blank
26
Blank
26
Blank
26
Blank
26
Blank
26
Blank
26
Blank
26
Blank
26
Positive Results Out of
Total Replicates (a)
3/3
3/3
0/3 (c)
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/3
3/3
0/24
6/36
(a) Shaded results indicate false negative observations
(b) Lethal dose
(c) These test samples produced non-detects above the vendor-provided LOD.
25
-------
Table 6-2e. Dicrotophos False Positive/Negative Results
Sample Type
Matrix
Concentration
(mg/L)
Positive Results Out of
Total Replicates (a)
Contaminant-only
PT samples
DI water
DI water
1400
140
(b)
3/3
3/3
Interferent PT
samples
1 mg/L humic and
fulvic acids
1 mg/L humic and
fulvic acids
5 mg/L humic and
fulvic acids
5 mg/L humic and
fulvic acids
50 mg/L Ca and Mg
50 mg/L Ca and Mg
250 mg/L Ca and Mg
250 mg/L Ca and Mg
Blank
140
Blank
140
Blank
140
Blank
140
0/3
0/3
DW samples
OHDW
OHDW
CADW
CADW
FLOW
FLOW
NYDW
NYDW
Blank
140
Blank
140
Blank
140
Blank
140
0/3
0/3
0/3
0/3
0/3
3/3
0/3
0/3
False Positive Rate
False Negative Rate
0/24
(a) Shaded results indicate false negative observations
(b) Lethal dose
26
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6.4.1 Interferent PT Samples
As shown in Tables 6-2a through 6-2d, VX, GB, GD, and aldicarb yielded negative results for all
unspiked interferent samples and positive results for all spiked interferent samples for all
replicates. This indicates, that for these target analytes, the Eclox™-Pesticide Strips were not
affected by any matrix effects from these potential interferent solutions. For dicrotophos
(Table 6-2e), however, only one replicate of the 140 mg/L dicrotophos in 50 mg/L Ca and Mg
solution gave a positive result (while the other two replicates gave negative results). The other
eleven spiked samples for dicrotophos gave negative results, indicating that the ability of the
EcloxTM-Pesticide Strips to detect dicrotophos was affected by the interferent matrices.
6.4.2 DWSamples
As shown in Tables 6-2a through 6-2d, VX, GB, GD, and aldicarb yielded negative results for all
unspiked DW samples and positive results for all spiked DW samples for all replicates. This
indicates that the Eclox™-Pesticide Strips were not affected by any matrix effects from these
potential interferent solutions. For dicrotophos (Table 6-2e), however, only the spiked FL DW
gave positive results. All of the other spiked DW samples yielded negative results (as did the
unspiked DW samples) indicating that the ability of the Eclox™-Pesticide Strips to detect
dicrotophos was affected by the OH DW, NY DW, and CA DW matrices.
6.5 Operational Factors
6.5.1 Technical Operators
The Eclox™-Pesticide Strips were used by one Battelle technical operator throughout testing
with the pesticides, and by a different Battelle technical operator throughout testing with CWA.
The technical operators were trained by a Battelle technician, who had received training from the
vendor by phone for one-half hour in the use of the kit. Both technical operators had extensive
laboratory experience. The written instructions, which are provided on a small piece of paper
packaged with the strips, consist of eight steps prior to reading the results of the test. In addition
to the straight-forward text, the instructions also provide a small picture of the Eclox™-Pesticide
Strip in use as well as a sample figure showing the two outcomes ("no pesticide" and
"pesticide"). During testing, the technical operators were able to perform a test, which included
all steps from opening the foil packet to reading the results, in an average of 5 minutes using the
Eclox™-Pesticide Strips. The operators performing one test at a time averaged 11 tests per hour.
Tests can also be conducted in parallel using separate strips for multiple water samples, which
may increase sample throughput. The Eclox™-Pesticide Strips do not require any special
storage considerations other than storage at room temperature. During the verification test, the
strips were kept in a sealed plastic bag that was kept in the laboratory. The Eclox™-Pesticide
Strips are reported by the vendor to have a two-year shelf life. Each foil packet is 8.2 cm by
5.1 cm, with notched edges to aid opening.
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6.5.2 Non-Technical Operator
TM
Unspiked MB samples were tested by a non-technical operator, using the Eclox -Pesticide
Strips, both with and without PPE (see Section 3.2.4). During testing with the PPE on, the
samples were analyzed while the operator wore full PPE, consisting of a Level B suit, neoprene
latex gloves, boots and SCBA, as shown in Figures 6-1 and 6-2. The SCBA was worn
throughout the entire testing procedure by the non-technical operator (only during the tests in
which PPE was to be donned) to represent the physical burden borne by a similarly outfitted first
responder. However, the operator ran the air from the SCBA only part of the time during testing
to conserve the tank. The non-technical operator, in or out of PPE, was able to use the Eclox™-
Pesticide Strips without any difficulty. There were no issues with the duration of the test or
impact of wearing gloves during operation. All MB samples yielded negative (i.e., no target
contaminants detected) results.
The Severn Trent Services Eclox™-Pesticide Strips are highly portable since the test coupons
are small, lightweight, securely packed in foil, and do not require additional reagents or
extensive manipulation of test apparatus beyond a wristwatch or stopwatch to note time. Results
are generally obtained within five minutes. These qualities make it suitable for use in a field or
non-laboratory setting.
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Figure 6-1. Side View of PPE Worn by Non-
Technical Operator
TM
Figure 6-2. Testing of Eclox -Pesticide Strips
with the Non-Technical Operator Wearing PPE
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Chapter 7
Performance Summary
The results of the Severn Trent Services Eel ox™-Pesticide Strip from this verification test for
samples containing VX, GB, GD, aldicarb, and dicrotophos are presented in Tables 7-la-e,
respectively. Qualitative responses for each set of sample replicates as well as accuracy, false
negative and positive rates, and precision are presented in each table. A summary of the other
performance factors associated with the Eclox™-Pesticide Strips is presented at the end of this
chapter. These performance factors apply across all contaminants.
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Table 7-la. VX Summary Table
Parameter
Qualitative
Results
Contaminant-
Only PT
Samples
Interferent PT
Samples
DW Samples
Accuracy
False Positive Rate
False Negative Rate
Matrix
DI Water
Humic and Fulvic
Acids
Ca and Mg
DW
VX
Concentration
2.1mg/L(a)
0.21 mg/L
0.021mg/L(b)
0.0021 mg/L
0.00021 mg/L
0.21 mg/L
0.21 mg/L
0.21 mg/L
Number
Detected/Number
of Samples
3/3
3/3
0/3
0/3
0/3
6/6
6/6
12/12
100% (6 out of 6) of the contaminant-only PT samples gave
positive results during testing with VX.
No false positive results (0 out of 24) were observed during
testing with VX.
No false negative results (0 out of 30) were observed during
testing with VX.
Precision
100% (21 out of 21) of the sample sets showed consistent
results among the individual replicates within each set during
testing with VX.
(a) Lethal dose
(b) Consistently negative results observed at and below this concentration
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Table 7-lb. GB Summary Table
Parameter
Qualitative
Results
Contaminant-
Only PT
Samples
Interferent PT
Samples
DW Samples
Accuracy
False Positive Rate
False Negative Rate
Precision
Matrix
DI Water
Humic and Fulvic
Acids
Ca and Mg
DW
GB
Concentration
20 mg/L (a)
2.0 mg/L
0.2 mg/L
0.02 mg/L
0.002 mg/L (b)
2.0 mg/L
2.0 mg/L
2.0 mg/L
Number
Detected/Number
of Samples
3/3
3/3
3/3
3/3
0/3
6/6
6/6
12/12
100% (12 out of 12) of the contaminant-only PT samples gave
positive results during testing with GB.
No false positive results (0 out of 24) were observed during
testing with GB.
No false negative results (0 out of 36) were observed during
testing with GB.
100% (21 out of 21) of the sample sets showed consistent
results among the individual replicates within each set during
testing with GB.
(a) Lethal dose
(b) Consistently negative results observed at this concentration
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Table 7-lc. GD Summary Table
Parameter
Qualitative
Results
Contaminant-
Only PT
Samples
Interferent PT
Samples
DW Samples
Accuracy
False Positive Rate
False Negative Rate
Precision
Matrix
DI Water
Humic and Fulvic
Acids
Ca and Mg
DW
GD
Concentration
1.4 mg/L (a)
0.14 mg/L
0.0 14 mg/L
0.00 14 mg/L (b)
0.000 14 mg/L
0.14 mg/L
0.14 mg/L
0.14 mg/L
Number
Detected/Number
of Samples
3/3
3/3
1/3 (c)
0/3
0/3
6/6
6/6
12/12
78% (7 out of 9) of the contaminant-only PT samples gave
positive results during testing with GD.
No false positive results (0 out of 24) were observed during
testing with GD.
No false negative results (0 out of 33) were observed during
testing with GD; though two inconclusive results were
observed for the 0.014 mg/L contaminant-only PT sample.
95% (20 out of 21) of the sample sets showed consistent
results among the individual replicates within each set during
testing with GD.
^Lethal dose
(b) Consistently negative results observed at and below this concentration
(c) Two inconclusive results were observed. Inconclusive results occurred when the operator could neither discern
he color of the smaller disk as blue (negative for the presence of a contaminant) nor white (positive for the
presence of a contaminant).
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Table 7-ld. Aldicarb Summary Table
Parameter
Qualitative
Results
Contaminant-
Only PT
Samples
Interferent PT
Samples
DW Samples
Matrix
DI Water
Humic and Fulvic
Ca and Mg
DW
Aldicarb
Concentration
260 mg/L (a)
26 mg/L
2.6 mg/L
0.26 mg/L (b)
0.026 mg/L
26 mg/L
26 mg/L
26 mg/L
Number
Detected/Number
of Samples
3/3
3/3
0/3
0/3
0/3
6/6
6/6
12/12
Accuracy
50% (6 out of 12) of the contaminant-only PT samples gave
positive results above the vendor-provided limit of detection
for aldicarb (0.2 mg/L).
False Positive Rate
No false positive results (0 out of 24) were observed during
testing with aldicarb.
False Negative Rate
Six out of the 36 samples yielded false negative results during
testing with aldicarb. The 2.6 mg/L and 0.26 mg/L
contaminant-only PT samples showed negative responses.
Precision
100% (21 out of 21) of the sample sets showed consistent
results among the individual replicates within each set during
testing with aldicarb.
(> Lethal dose
(b) Vendor-provided limit of detection (LOD) for aldicarb is 0.2 mg/L.
34
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Table 7-le. Dicrotophos Summary Table
Parameter
Qualitative
Results
Contaminant-
Only PT
Samples
Interferent PT
Samples
DW Samples
Accuracy
False Positive Rate
Matrix
DI Water
Humic and Fulvic
Acids
Ca and Mg
DW
Dicrotophos
Concentration
1400 mg/L (a)
140 mg/L
14 mg/L (b)
1.4 mg/L
0.14 mg/L
140 mg/L
140 mg/L
140 mg/L
Number
Detected/Number
of Samples
3/3
3/3
0/3
0/3
0/3
0/6
1/6
3/12
100% (6 out of 6) of the contaminant-only PT samples gave
positive results during testing with dicrotophos.
No false positive results (0 out of 24) were observed during
testing with dicrotophos.
False Negative Rate
Twenty out of the 30 samples yielded false negative results
during testing with dicrotophos. These samples were the
spiked potential interferent and DW samples except for one
50 mg/L Ca and Mg, three FL DW samples, three 140 mg/L
contaminant-only PT samples, and three 1400 mg/L
contaminant-only PT sample.
Precision
95% (20 out of 21) of the sample sets showed consistent
results among the individual replicates within each set during
testing with dicrotophos.
(a) Lethal dose
(b) Consistently negative results observed and below at this concentration
35
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Operational Factors:
Technical Operators
The Eclox™-Pesticide Strips were used by one Battelle technical operator throughout testing
with the pesticides and a different Battelle technical operator throughout testing with CWA.
These technical operators were trained by a Battelle technician, who had received training from
the vendor by phone for one-half hour in the use of the kit. Both technical operators had
extensive laboratory experience. The written instructions, which are provided on a small piece
of paper with the strips, consist of eight steps prior to reading the results of the test. During
testing, the technical operators were able to perform a test, which included all steps from opening
the foil packet to reading the results, in an average of 5 minutes using the Eclox™-Pesticide
Strips.
Non-Technical Operators
Unspiked MB samples were tested by a non-technical operator, using the Eclox™-Pesticide
Strips, both with and without PPE. The SCB A apparatus, including the mask, was worn
throughout the entire testing procedure when PPE was to be donned to represent the physical
burden borne by a similarly outfitted first responder. However, the operator ran the air from the
SCB A only part of the time during testing to conserve the tank. The non-technical operator, in
or out of PPE, was able to use the Eel ox™-Pesticide Strips without any difficulty. There were
no issues with the duration of the test or impact of wearing gloves during operation.
The Severn Trent Services Eclox™-Pesticide Strips are highly portable since the test coupons
are small, lightweight, securely packed in foil, and do not require additional reagents or
extensive manipulation of test apparatus beyond a wristwatch or stopwatch to note time. Results
are generally obtained within five minutes. These qualities make it suitable for use in a field or
non-laboratory setting.
36
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Chapter 8
References
1. U.S. Army Center for Health Promotion and Preventative Medicine, USACHPPM
Technical Guide 230, Chemical Exposure Guidelines for Deployed Military Personnel,
January 2002.
2. Gosselin et al., Clinical Toxicology of Commercial Products. 5th edition, Baltimore, MD,
1984.
3. World Health Organization, The WHO Recommended Classification of Pesticides by
Hazard and Guidelines to Classification: 2004, 2005.
4. EPA-600-R-93/100. EPA Method 180.1. Turbidity (Nephelometric), Methods for the
Determination of Inorganic Substances in Environmental Samples. 1993.
5. American Public Health Association, et al. Standard Methods for Examination of Water
and Wastewater. 19th Edition. 1997. Washington D.C.
6. EPA 600/4-79/020 Method 150.1. pH, Electrometric Method.. 1982.
7. EPA 600/R-94/111 Method 200.8. Determination of Trace Metals by Inductively Coupled
Plasma - Mass Spectrometry. 1994.
8. EPA 600/4-79/020 Method 130.2. Hardness, Total (mg/L as CaCO3) Titrimetric, EDTA.
1982.
9. EPA 600/R-95/131. EPA Method 524.2. Purgeable Organic Compounds by Capillary
Column GC/Mass Spectrometry. Methods for Determination of Organic Compounds in
Drinking Water, Supplement III. 1995.
10. EPA 600/R-95/131. EPA Method 552.2. Haloacetic Acids andDalapon by Liquid-Liquid
Extraction, Derivatization and GC with Electron Capture Detector. Methods for the
Determination of Organic Compounds in Drinking Water, Supplement III. 1995.
37
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11. Quality Management Plan (QMP) for the ETV Advanced Monitoring Systems Center.,
Version 5.0, U.S. EPA Environmental Technology Verification Program, Battelle,
Columbus, Ohio, March 2004.
12. Test/QA Plan for Verification of Enzymatic Test Kits, Battelle, Columbus, Ohio,
September 2005.
13. Battelle, SOP HMRC-IV-118-05: Standard Operating Procedure for the Determination of
CA in Wastewater.
14. Battelle, Standard Operating Procedure for Analysis of Water Extracts for Type I Analytes
by Liquid Chromatography/Mass Spectrometry, Version 1, January 2004.
15. Battelle, Standard Operating Procedure for Extracting and Preparing Water Samples for
Analysis of Dicrotophos, Mevinphos, andDichlorovos, Version 3, March 2005.
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