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6.3 Precision
The performance of the Neuro-IQ Tox Test Kit™ in measuring VX within sets of three replicate
samples was generally consistent. Only two sets of replicates were inconsistent: unspiked
5 mg/L humic and fulvic acids and spiked 250 mg/L Ca and Mg. One positive and two negative
responses were found for the unspiked humic and fulvic acid replicates while two positive and
one negative responses were found for the Ca and Mg replicates. Thus, two of the 21 sets of
replicates that were analyzed was determined to be inconsistent, indicating that 90% of the
sample sets showed consistent results among the replicates.
The Neuro-IQ Tox Test Kit™ results for GB and GD were also consistent in 19 out of 21 sets of
replicates, indicating that 90% of the sample sets showed consistent results for these two
contaminants. For GB, samples at the lethal dose of the chemical agent as well as samples in
unspiked 5 mg/L humic and fulvic acids were inconsistent. For GD, inconsistencies were found
in PT samples at 10,000x less than the lethal dose (i.e., at 0.00014 mg/L) and in unspiked 5 mg/L
humic and fulvic acid samples.
Results for samples spiked and not spiked with aldicarb were consistent 95% of the time with
results being the same in 20 out of 21 sample sets. Only the PT sample at 10,000x less than the
lethal dose (i.e., at 0.026 mg/L) were inconsistent. Of the 21 sample sets, 19 showed consistent
results for dicrotophos samples, resulting in 90% precision. Replicates at both the 14 mg/L (in
DI water) concentration level and the 1 mg/L humic and fulvic acids spiked with the pesticide
were inconsistent.
6.4 Potential Matrix and Interferent Effects
6.4.1 Interferent PT Samples
The Neuro-IQ Tox Test Kit™ was able to consistently detect VX, GB, and GD at lOx less than
the lethal dose in DI water (see Tables 6-2a - c, respectively). Across all three chemical agents
at lOx less than the lethal dose spiked into interferent PT samples, the Neuro-IQ Tox test
produced positive responses for all sample replicates except in one instance. The one exception
was that for interferent samples spiked with VX in 250 mg/L Ca and Mg, only two out of three
positive responses were achieved. Only one set of unspiked interferent PT samples provided all
negative responses, that for 250 mg/L Ca and Mg. All other unspiked interferent samples had
one or more positive responses. These results seem to indicate that the Neuro-IQ Tox Test Kit™
may have some sensitivity to the interferents used in this test.
For both aldicarb and dicrotophos samples (see Tables 6-2d and e), unspiked 5 mg/L humic and
fulvic acid samples had positive responses for all three replicates, further confirming the
potential sensitivity of the Neuro-IQ Tox Test Kit™ to this interferent. In interferent PT samples
spiked with aldicarb, results were as expected except for 250 mg/L Ca and Mg replicate. For
these spiked samples, no positive responses were found. Aldicarb spiked into DI water at lOx
less than the lethal dose was consistently detected by the Neuro-IQ Tox Test Kit™. Similarly,
for 1 mg/L humic and fulvic acids spiked with dicrotophos, only one positive response was
26
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generated. Dicrotophos spiked at lOx less than the lethal dose in DI water was not detected in
any of the contaminant-only PT sample replicates. Dicrotophos was however detected in the
next lowest contaminant-only PT sample concentration level, and at lOx less than the lethal dose
in all other spiked interferent samples.
6.4.2 DWSamples
OH and FL unspiked DW samples were positive for all three replicates when tested as part of the
chemical agent's sample set. These results indicate that there could be potential confounding
compounds in these DW samples to which the Neuro-IQ Tox Test Kit™ is sensitive. No false
positives or negatives were found for DW samples tested as part of the pesticides' sample set.
6.5 Operational Factors
6.5.1 Technical Operators
The Neuro-IQ Tox Test Kit™ was operated by one Battelle technician throughout testing with
the pesticides and by a different Battelle technician throughout testing with chemical agents.
The technicians were trained by the vendor in the operation of the test kit. Training was
conducted at Battelle for one half day by the vendor. Both technicians had extensive laboratory
experience.
The combination of the stir plate and the pH meter made the Neuro-IQ Tox Test Kit™
cumbersome to use. Multiple problems were encountered with the test kit operation. At one
point, the pH probe supplied with the kit did not work properly, and the vendor had to supply
another probe for testing to continue. After Reagent B was added and three minutes had passed,
the pH was often still fluctuating, making it hard to determine the actual pH at that point in time.
Since the instructions indicate that taking the pH after exactly three minutes is critical, such an
issue was troublesome. Reaching a stable pH of 8.30 after adding NaOH was also generally
difficult. However, per the vendor's direction, the pH did not have to stabilize at that level in
order to move on with the test.
Two reagents were used to test a water sample with the Neuro-IQ Tox Test Kit™. Reagent A is
stored frozen and must come to room temperature before it can be used. Reagent B had to be
reconstituted with DI water before use. Individual vials of each reagent were provided with the
kit to make daily testing easier.
Because of the Neuro-IQ Tox Test Kit™'s design, only one sample could be analyzed at a time.
It took the operators different lengths of time to complete testing for one group of three
replicates. For one operator, it took, on average, 75 minutes (± 17 minutes) to test a set of three
replicate water samples using the Neuro-IQ Tox Test Kit™. It took the other operator 52 ±
7 minutes to test one set of replicates. Overall, it took an average of 64 minutes (±18 minutes)
to complete testing on a set of three samples using the Neuro-IQ Tox Test Kit™. The operators
were able to analyze between three and six sets of samples per day.
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6.5.2 Non-Technical Operator
Unspiked DI water samples were tested on the Neuro-IQ Tox Test Kit™ by a non-technical
operator both in and not in PPE (see Section 3.2.4). The SCBA apparatus, including the mask,
was worn throughout the entire testing procedure when PPE was to be worn. However, the
operator ran the air from the SCBA only part of the time during testing to conserve the tank. The
pH meter was operated using batteries and a portable (battery-operated) magnetic stir plate was
used for this portion of the test. Figure 6-1 shows the full PPE as worn for this verification test.
Figure 6-2 shows the testing of the Neuro-IQ Tox Test Kit™ with the non-technical operator
wearing PPE. With the PPE on, two negative and one positive response were obtained. Without
the PPE, three negative responses were recorded.
During the initial test of the Neuro-IQ Tox Test Kit™ with PPE, the operator exceeded the
intended pH (8.3) when adding NaOH. Adjusting the pH to 8.3 as the kit directions indicate
proved to be slightly difficult and was easy for the operator to overshoot. The test was restarted
so that the proper pH could be obtained. Reagent A was hard to handle with the gloves on, and
the magnetic stir plate was difficult to adjust while in full PPE.
The Neuro-IQ Tox Test Kit™ instructions indicate that it is to be used by a "technician with
basic laboratory skills." Most first responders do not have any laboratory skills. The pipettes
needed for the test were cumbersome, confusing, and difficult to use for a non-technical
operator. The 50-mL beakers used for each sample were small and the level of the liquid in them
was shallow, making it difficult, particularly while in PPE, to place the pH probe and magnetic
stirrer to obtain proper readings. This setup required patience and time from the operator and
could be problematic in the field, especially for a first-responder when time is critical. Testing of
three MB samples while in PPE took 52 minutes, while testing of three MB samples without PPE
took 40 minutes. Consequently, having the PPE on did slow the operator down a bit as it took
12 more minutes to conduct the test with PPE than without. During the portability testing, a
table-top surface was used, making the setup of the Neuro-IQ Tox Test Kit™ a bit easier. If no
such surface were available in the field, the test kit would be very difficult for the operator to set
up and use. As noted earlier in this report, a control water sample is needed for the Neuro-IQ
Tox Test Kit™ protocol. This means that water that is the same matrix as the test sample but not
contaminated would have to be obtained to use this kit. This could be problematic in the field.
Overall, the Neuro-IQ Tox Test Kit™ would be hard for a first-responder with no experience and
no laboratory skills to use if the operator is donned in the level of PPE used in this verification
test.
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Figure 6-1. Side View of PPE Worn by
the Non-Technical Operator
Figure 6-2. Testing of the Neuro-IQ Tox
Test Kit™ with the Non-Technical
Operator Wearing PPE
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Chapter 7
Performance Summary
The Neuro-IQ Tox Test Kit™ results for this verification test for samples containing VX, GB,
GD, aldicarb, and dicrotophos are presented in Tables 7-1 through 7-5. The results for each
contaminant are presented in a separate table. Qualitative responses for each set of sample
replicates as well as accuracy, false negatives and positives, and precision are presented in each
table. A summary of the other performance factors associated with the Neuro-IQ Tox Test Kit™
is presented at the end of this chapter. These performance factors apply across all contaminants.
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Table 7-1. VX Summary Table
Parameter
Matrix
VX
Concentration
Number
Detected/Number
of Samples
Qualitative
Results
Contaminant-
Only PT
Samples
DI Water
2.1 mg/L (a)
0.21 mg/L
0.021 mg/L
0.0021 mg/L
0.00021 mg/L
3/3
3/3
3/3
3/3
3/3
Interferent PT
Samples
Humic and Fulvic
Acids
0.21 mg/L
6/6
Ca and Mg
0.21 mg/L
5/6
DW Samples
DW
0.21 mg/L
12/12
Accuracy
100% (15 out of 15)o
were positive.
'the contaminant-only PT samples
False Positives
Thirteen false positive responses were obtained. Seven
positive responses were found across unspiked 1 mg/L and
5 mg/L humic and fulvic acids as well as unspiked 50 mg/L
Ca and Mg samples. All six replicates for unspiked OH and
FL DW yielded positive results.
False Negatives
One false negative result was obtained for spiked PT and DW
samples. One replicate of the spiked 250 mg/L Ca and Mg
samples returned a negative result.
Precision
90% (20 out of 21) of the sample sets showed consistent
results among the individual replicates within that set.
^ Lethal dose.
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Table 7-2. GB Summary Table
Parameter
Matrix
GB
Concentration
Number
Detected/Number
of Samples
Qualitative
Results
Contaminant-
Only PT
Samples
DI Water
20 mg/L (a)
2.0 mg/L
0.20 mg/L
0.020 mg/L
0.0020 mg/L
2/3
3/3
3/3
3/3
3/3
Interferent PT
Samples
Humic and Fulvic
Acids
2.0 mg/L
6/6
Ca and Mg
2.0 mg/L
6/6
DW Samples
DW
2.0 mg/L
12/12
Accuracy
93% (14 out of 15) of the contaminant-on
positive.
y PT samples were
False Positives
Thirteen false positive responses were obtained. Seven
positive responses were found across unspiked 1 mg/L and
5 mg/L humic and fulvic acids as well as unspiked 50 mg/L
Ca and Mg samples. All six replicates for unspiked OH and
FL DW yielded positive results.
False Negatives
One false negative result was obtained for spiked PT and DW
samples. One replicate of the spiked DI water samples at the
lethal dose returned a negative result.
Precision
90% (19 out of 21) of the sample sets showed consistent
results among the individual replicates within that set.
^ Lethal dose.
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Table 7-3. GD Summary Table
Parameter
Matrix
GD
Concentration
Number
Detected/Number
of Samples
Qualitative
Results
Contaminant-
Only PT
Samples
DI Water
1.4 mg/L (a)
0.14 mg/L
0.014 mg/L
0.0014 mg/L
0.00014 mg/L
3/3
3/3
3/3
3/3
1/3
Interferent PT
Samples
Humic and Fulvic
Acids
0.14 mg/L
6/6
Ca and Mg
0.14 mg/L
6/6
DW Samples
DW
0.14 mg/L
12/12
Accuracy
87% (13 out of 15) of the contaminant-on
positive.
y PT samples were
False Positives
Thirteen false positive responses were obtained. Seven
positive responses were found across unspiked 1 mg/L and
5 mg/L humic and fulvic acids as well as unspiked 50 mg/L
Ca and Mg samples. All six replicates for unspiked OH and
FL DW yielded positive results.
False Negatives
Two false negative results were obtained for spiked PT and
DW samples. Two replicates of the spiked DI water samples
at 10,000x less than the lethal dose (0.00014 mg/L) returned a
negative result.
Precision
90% (19 out of 21) of the sample sets showed consistent
results among the individual replicates within that set.
(a' Lethal dose.
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Table 7-4. Aldicarb Summary Table
Parameter
Matrix
Aldicarb
Concentration
Number
Detected/Number
of Samples
Qualitative
Results
Contaminant-
Only PT
Samples
DI Water
260 mg/L (a)
26 mg/L
2.6 mg/L
0.26 mg/L
0.026 mg/L
3/3
3/3
3/3
0/3
1/3
Interferent PT
Samples
Humic and Fulvic
Acids
26 mg/L
6/6
Ca and Mg
26 mg/L
3/6
DW Samples
DW
26 mg/L
12/12
Accuracy
67% (10 out of 15) of the contaminant-on
positive.
y PT samples were
False Positives
Three false positive responses were obtained. Positive
responses were found for all replicates of the unspiked
5 mg/L humic and fulvic acids samples.
False Negatives
Eight false negative results were obtained for spiked PT and
DW samples. Five samples of the spiked DI water samples
returned a negative result. All three replicates of the spiked
250 mg/L Ca and Mg samples yielded negative results.
Precision
95% (20 out of 21) of the sample sets showed consistent
results among the individual replicates within that set.
^ Lethal dose.
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Table 7-5. Dicrotophos Summary Table
Parameter
Matrix
Dicrotophos
Concentration
Number
Detected/Number
of Samples
1400 mg/L (a)
3/3
Qualitative
Results
Contaminant-
Only PT
Samples
DI Water
140 mg/L
14 mg/L
1.4 mg/L
0.14 mg/L
0/3
1/3
0/3 (b)
0/3 (b)
Interferent PT
Samples
Humic and Fulvic
Acids
140 mg/L
4/6
Ca and Mg
140 mg/L
6/6
DW Samples
DW
140 mg/L
12/12
Accuracy
44% (4 out of 9) of the contaminant-only PT samples above
the level of consistent negative responses were positive.
False Positives
Three false positive responses were obtained. Positive
responses were found for all replicates of the unspiked 5 mg/L
humic and fulvic acids samples.
False Negatives
Seven false negative results were obtained for spiked PT and
DW samples. Five samples of the spiked DI water samples
returned a negative result. Two replicates of the spiked
1 mg/L fulvic and humic acid samples yielded negative results.
Precision
90% (19 out of 21) of the sample sets showed consistent
results among the individual replicates within that set.
^ Lethal dose.
(b) Not used in accuracy calculations because samples are at or below level of consistent negative response.
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Operational Factors:
Technical Operators
The Neuro-IQ Tox Test Kit™ was operated by one Battelle technician throughout testing with
the pesticides and by a different Battelle technician throughout testing with chemical agents.
Both technicians had extensive laboratory experience. Multiple problems were encountered with
the test kit operation, including a faulty pH probe and unstable pH readings after adding Reagent
B and when trying to reach a pH of 8.30. Two reagents are used to test a water sample with the
Neuro-IQ Tox Test Kit™. Reagent A is frozen and must come to room temperature before it can
be used. Reagent B has to be reconstituted with DI water before use. Individual vials of each
reagent were provided with the kit to make daily testing easier. Between the two operators, it
took an average of 64 ± 18 minutes to complete testing on a set of three samples using the
Neuro-IQ Tox Test Kit™. The operators were able to analyze between three and six sets of
samples a day.
Non-Technical Operator
Unspiked DI water samples were tested on the Neuro-IQ Tox Test Kit™ by a non-technical
operator both with and without PPE. Adjusting the pH to 8.30 was not easy for the operator to
accomplish and many times that pH was exceeded. Reagent A was hard to handle with the
gloves on, and the magnetic stir plate was difficult to adjust while in full PPE. The pipettes
needed for the test were cumbersome, confusing, and difficult to use for a non-technical
operator. The 50-mL beakers used for each sample were small, and the level of the liquid in
them was shallow, making it difficult, particularly while in PPE, to correctly place the pH probe
and magnetic stirrer. Testing of three MB samples while in PPE took 52 minutes, while testing
of three MB samples without PPE took 40 minutes. The test kit would be very difficult for the
operator to set up and use if no table-top surface was available in the field. A control water
sample, or a water sample that is the same matrix as the test sample but not contaminated, is
needed for the Neuro-IQ Tox Test Kit™ protocol. Obtaining such a sample could be
problematic in the field. Overall, the Neuro-IQ Tox Test Kit™ would be hard for a first-
responder with no experience with the kit and no laboratory skills to use if the operator is donned
in the level of PPE used in this verification test.
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, ElectrometricMethod.. 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 Ca("O 3) 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.
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.
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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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