Chloropicrin (PC 081501)

MRIDs 49854401/50167601

Analytical method for chloropicrin in ground, drinking, and surface water

Reports:	ECM: EPA MRID No.: 49854401. Todd, M. 2007. CHLOROPICRIN -

VALIDATION OF METHODOLOGY FOR THE DETERMINATION OF
RESIDUES OF CHLOROPICRIN IN GROUND, DRINKING AND
SURFACE WATER. Study No.: SXC 0007/072387. Report prepared by
Huntingdon Life Sciences Ltd., Cambridgeshire, England, and sponsored
and submitted by European Chloropicrin Group, Washington, D.C.; 45
pages. Final report issued June 27, 2007.

Document No.

Guideline:

Statements:

Classification:

PC Code:

EFED Final
Reviewer:

CDM/CSS-
Dynamac JV
Reviewers:

ILV: EPA MRID No. 50167601. Keenan, D. 2017. Independent Laboratory
Validation of Chloropicrin in Ground, Surface, and Drinking Water. PTRL
Project No.: 2854W. Report prepared by PTRL West (now doing business at
EAG Laboratories), Hercules, California, sponsored and submitted by
Chloropicrin Task Force, Niklor Chemical Co. Inc., Mojave, California; 78
pages. Final report issued January 18, 2017.

MRIDs 49854401 & 50167601
850.6100

ECM: The study was conducted in accordance with OECD, UK and UK
Department of Health Good Laboratory Practice (GLP) standards (p. 3;
Appendix 7, p. 88 of MRID 49854401). Signed and dated No Data
Confidentiality, GLP, and Quality Assurance statements were provided (pp.
2-4). A statement of authenticity was included with the QA statement.
ILV: The study was conducted in accordance with German GLP standards,
which are based on OECD GLP standards, which are accepted by European
communities, the USA (FDA and EPA, FIFRA GLP standards, 40 CFR, Part
160) and Japan (p. 3 of MRID 50167601). Signed and dated No Data
Confidentiality, GLP, Quality Assurance, and Authenticity statements were
provided (pp. 2-5).

This analytical method is classified as supplemental. An updated ECM
should be submitted with the ILV modifications. The specificity of the
method was not well-supported by the ECM representative chromatograms
because of chromatogram readability. Two of the three ECM matrices were
not characterized.

081501

James Lin

Environmental Engineer

LisaMuto, M.S.

Environmental Scientist

Joan Gaidos, Ph.D.,

Environmental Scientist

Signature:

Date:

Signature:

Date:

Signature:

Date:	09/14/2018

12/19/2018
08/15/2018

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Chloropicrin (PC 081501)

MRIDs 49854401/50167601

This Data Evaluation Record may have been altered by the Environmental Fate and Effects
Division subsequent to signing by CDM/CSS-Dynamac JVpersonnel. The CDM/CSS-Dynamac
Joint Venture role does not include establishing Agency policies.

Executive Summary

The analytical method, Huntingdon Life Sciences Ltd. Study No. SXC 0007/072387, is designed
for the quantitative determination of chloropicrin in water at the LOQ of 0.1 |ig/L using
GC/ECD (primary) and GC/MS (confirmatory). The LOQ is less than the lowest toxicological
level of concern in water. The ECM validated the method using characterized surface water and
uncharacterized ground and drinking waters; the ILV validated the method using characterized
surface, ground, and drinking water matrices. The ILV validated the method in the second trial
with two modifications to the sample processing procedure to increase analyte recovery:
shortened extraction time and use of a smaller vessel to reduce headspace. The first trial failed
due to low recoveries; therefore, the ECM should be updated with the ILV modifications. All
ILV and ECM data regarding repeatability, accuracy, precision, and linearity were satisfactory
for chloropicrin, except for the ILV linearity for the GC/MS analysis of chloropicrin in drinking
water. ILV representative chromatograms were satisfactory, but ECM representative
chromatograms were very difficult to interpret. The LODs of the ECM and ILV differed.

Table 1. Analytical Method Summary

Analyte(s) by
Pesticide

MRID

EPA
Review

Matrix

Method Date
(dd/mm/yyyy)

Registrant

Analysis

Limit of
Quantitation
(LOQ)

Environmental
Chemistry
Method

Independent
Laboratory
Validation

Chloropicrin

49854401

50167601



Water1-2

27/06/2007

European
Chloropicrin
Group

Chloropicrin
Task Force
(Niklor
Chemical Co.
Inc.)

GC/ECD &
GC/MS

0.1 ng/L

1	In the ECM, surface (lake) water (pH 7.7; 180 mg equiv. CaCCh/L total hardness and alkalinity; 15.2 mg/L total
organic carbon; 12.7 mg/L dissolved organic carbon) was collected from Diss Mere, Diss, Norfolk, and used in
the study (p. 10 of MRID 49854401). The water sample was characterized in a separate study (not specified). The
drinking water was obtained from a tap in the Residue Analysis Department, and the ground water was obtained
from a source in the Huntingdon area by Anglian Water. The drinking and ground water were not characterized;
the source of the ground water was not further specified.

2	In the ILV, the ground water (PTRL ID 2706W-032; pH 7.3; 627 mg equiv. CaCCh/L hardness; 960 ppm total
dissolved solids) obtained from Northwood, North Dakota, drinking (tap) water (PTRL ID 2706W-072/054; pH
7.5; 30 mg equiv. CaCCh/L hardness; 60 ppm total dissolved solids) obtained from Hercules, California, surface
water (PTRL ID 2706W-069; pH 7.8; 1183 mg equiv. CaCCh/L hardness; total dissolved solids not determined)
obtained from Hercules, California, were used in the study (pp. 15-16 of MRID 50167601). The water samples
were provided by EAG-Hercules and previously characterized by Agvise Laboratories.

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Chloropicrin (PC 081501)

MRIDs 49854401/50167601

I. Principle of the Method

Samples (20 mL) of water in 50-mL polypropylene tubes were fortified, as necessary (p. 11 of
MRID 49854401). An aliquot (2 mL) of hexane was added, and the sample was shaken on a
mechanical shaker for 30 minutes. After centrifugation (3500 rpm for 5 minutes), aliquots of the
upper hexane phase were taken for analysis.

Samples were analyzed using a Hewlett Packard 6890 series gas chromatograph coupled to an
electron capture detector (ECD; p. 12 of MRID 49854401). The GC/ECD conditions consisted of
a Phenomenex Zebron ZB-50 column (0.53 mm x 30 m, l-|-im), injector temperature 200°C,
temperature program [40°C for 2 min. then 10°C/min. to 80°C then 30°C/min. to 200°C], carrier
gas nitrogen, and 1 |aL injection volume. Expected retention time was ca. 4.3 minutes.

For confirmation, samples were analyzed using a Varian 1200 series gas chromatograph coupled
to a mass spectrometer (p. 13 of MRID 49854401). The GC/MS conditions consisted of a RTX-
5ms (0.25 mm x 30 m, 0.25-|am), injector temperature 200°C, temperature program [40°C for 3
min. then 10°C/min. to 60°C then 30°C/min. to 200°C], carrier gas helium, 1 |aL injection
volume, and CI- ionization mode. One ion was monitored: m/z 119. Expected retention time was
ca. 4 minutes.

In the ILV, the ECM was performed as written, except for a shortened extraction time (1 minute
with inversion and vortexing), use of a smaller vessel to reduce headspace, and use of a different
analytical instrumentation (pp. 16-17, 19-21, 25; Figure 1, p. 31 of MRID 50167601). For
GC/ECD analysis, an Agilent 6890 series GC [DB-17 column (0.53 mm x 30 m, l-|-im)] coupled
to an ECD was used. All other GC/ECD parameters were the same as those of the ECM. For
GC/MS analysis, an Agilent 7890A series GC [DB-5ms column (0.25 mm x 30 m, 0.25-|am)]
coupled to a MS was used. All other GC/MS parameters were the same as those of the ECM.
Expected retention times were ca. 4.7 minutes for GC/ECD and ca. 2.6 minutes for GC/MS.

The Limit of Quantification (LOQ) for chloropicrin in water was 0.10 |ig/L in the ECM and ILV
(pp. 8, 12-13 of MRID 49854401; pp. 12, 22 of MRID 50167601). The Limit of Detection
(LOD) was 0.05 |ig/L in the ECM; in ILV, the LOD was 0.004 |ig/L for ground water and 0.01
|ig/L for drinking and surface water.

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Chloropicrin (PC 081501)

MRIDs 49854401/50167601

II. Recovery Findings

ECM (MRID 49854401): Mean recoveries and relative standard deviations (RSDs) were within
guideline requirements (mean 70-120%; RSD <20%) for analysis of chloropicrin in three water
matrices at fortification levels of 0.1 |ig/L (LOQ) and 1.0 |ig/L (lOxLOQ; Tables 3-8, pp. 19-
24). Chloropicrin was identified using GC/ECD and GC/MS for primary and confirmatory
analyses, respectively. For GC/MS, one ion was monitored. Performance data (recovery results)
from primary and confirmatory analyses were fairly comparable, but more varied for drinking
water. The surface (lake) water (pH 7.7; 180 mg equiv. CaCCb/L total hardness and alkalinity;
15.2 mg/L total organic carbon; 12.7 mg/L dissolved organic carbon) was collected from Diss
Mere, Diss, Norfolk, and used in the study (p. 10). The water sample was characterized in a
separate study (not specified). The drinking water was obtained from a tap in the Residue
Analysis Department, and the ground water was obtained from a source in the Huntingdon area
by Anglian Water. The drinking and ground water were not characterized; the source of the
ground water was not further specified.

ILV (MRID 50167601): Mean recoveries and RSDs were within guideline requirements for
analysis of chloropicrin in three water matrices at fortification levels of 0.1 |ig/L (LOQ) and 1.0
|ig/L (lOxLOQ; Table 1, p. 27). Chloropicrin was identified using GC/ECD and GC/MS for
primary and confirmatory analyses, respectively. For GC/MS, one ion was monitored.
Performance data (recovery results) from primary and confirmatory analyses were fairly varied,
but more comparable for surface water. The ground water (PTRL ID 2706W-032; pH 7.3; 627
mg equiv. CaCCb/L hardness; 960 ppm total dissolved solids) obtained from Northwood, North
Dakota, drinking (tap) water (PTRL ID 2706W-072/054; pH 7.5; 30 mg equiv. CaCCb/L
hardness; 60 ppm total dissolved solids) obtained from Hercules, California, surface water
(PTRL ID 2706W-069; pH 7.8; 1183 mg equiv. CaCCb/L hardness; total dissolved solids not
determined) obtained from Hercules, California, were used in the study (pp. 15-16). The water
samples were provided by EAG-Hercules and previously characterized by Agvise Laboratories.
The method was validated in the second trial with two modifications to the sample processing
procedure to increase analyte recovery: shortened extraction time (1 minute with inversion and
vortexing) and use of a smaller vessel to reduce headspace (pp. 11, 16-17, 19-21, 25). The first
trial failed due to low recoveries; therefore, the ECM should be updated with the ILV
modifications.

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Chloropicrin (PC 081501)

MRIDs 49854401/50167601

Table 2. Initial Validation Method Recoveries for Chloropicrin in Water

Analyte

Fortification
Level (jig/L)

Number
of Tests

Recovery
Range (%)

Mean
Recovery (%)

Standard
Deviation (%)4

Relative Standard
Deviation (%)



GC/ECD



Ground Water

Chloropicrin

0.1

5

82-90

86

3.0

3.5

1.0

5

78-84

82

2.4

3.0



Drinking Water

Chloropicrin

0.1

5

80-96

92

7.0

7.6

1.0

5

84-100

94

7.1

7.6



Surface Water

Chloropicrin

0.1

5

78-93

87

6.2

7.1

1.0

5

77-93

85

6.2

7.3



GC/MS (m/z 119)



Ground Water

Chloropicrin

0.1

5

92-95

94

1.1

1.2

1.0

5

81-88

85

2.6

3.1



Drinking Water

Chloropicrin

0.1

5

76-89

80

5.2

6.4

1.0

5

75-83

80

3.4

4.3



Surface Water

Chloropicrin

0.1

5

75-89

83

6.2

7.5

1.0

5

76-87

80

4.3

5.4

Data (uncorrected recovery results; p. 14) were obtained from Tables 3-8, pp. 19-24 of MRID 49854401.

* The surface (lake) water (pH 7.7; 180 mg equiv. CaCCh/L total hardness and alkalinity; 15.2 mg/L total organic
carbon; 12.7 mg/L dissolved organic carbon) was collected from Diss Mere, Diss, Norfolk, and used in the study
(p. 10). The water sample was characterized in a separate study (not specified). The drinking water was obtained
from a tap in the Residue Analysis Department, and the ground water was obtained from a source in the
Huntingdon area by Anglian Water. The drinking and ground water were not characterized; the source of the
ground water was not further specified.

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Chloropicrin (PC 081501)

MRIDs 49854401/50167601

Table 3. Independent Validation Method Recoveries for Chloropicrin in Water

Analyte

Fortification
Level (jig/L)

Number
of Tests

Recovery
Range (%)

Mean
Recovery (%)

Standard
Deviation (%)4

Relative Standard
Deviation (%)



GC/ECD



Ground Water

Chloropicrin

0.1

5

88-91

90

1

1

1.0

5

85-89

88

2

2



Drinking Water

Chloropicrin

0.1

5

88-97

94

4

4

1.0

5

81-85

83

2

2



Surface Water

Chloropicrin

0.1

5

73-77

75

1

2

1.0

5

83-86

85

1

2



GC/MS (m/z 119)



Ground Water

Chloropicrin

0.1

5

71-76

74

2

3

1.0

5

66-82

72

8

11



Drinking Water

Chloropicrin

0.1

5

108-117

110

4

3

1.0

5

61-89

79

11

14



Surface Water

Chloropicrin

0.1

5

70-77

72

3

4

1.0

5

73-84

79

5

6

Data (uncorrected recovery results, pp. 20-21) were obtained from Table 1, p. 27 of MRID 50167601.

* The ground water (PTRL ID 2706W-032; pH 7.3; 627 mg equiv. CaCCh/L hardness; 960 ppm total dissolved
solids) obtained from Northwood, North Dakota, drinking (tap) water (PTRL ID 2706W-072/054; pH 7.5; 30 mg
equiv. CaCCh/L hardness; 60 ppm total dissolved solids) obtained from Hercules, California, surface water (PTRL
ID 2706W-069; pH 7.8; 1183 mg equiv. CaCCh/L hardness; total dissolved solids not determined) obtained from
Hercules, California, were used in the study (pp. 15-16). The water samples were provided by EAG-Hercules and
previously characterized by Agvise Laboratories.

III. Method Characteristics

The LOQ for chloropicrin in water was 0.10 |ig/L in the ECM and ILV (pp. 8, 12-13, 16 of
MRID 49854401; pp. 12, 22; Tables 2-4, pp. 28-30 of MRID 50167601). In the ECM and ILV,
the LOQ was defined as the lowest fortification level where an acceptable mean recovery is
obtained. The LOD was reported as 0.05 |ig/L (equivalent to 0.05 ng/mL) in the ECM; in ILV,
the LOD was 0.004 |ig/L for ground water and 0.01 |ig/L for drinking and surface water. In the
ILV, the LOD was calculated for each matrix using the following equation:

LOD = (to.99 x SD)

Where, to.99 is the one-tailed t statistic for n = 5 (3.747) and SD is the standard deviation of the
analyte recovery measurements at the target LOQ. No calculations or comparisons to
background levels were reported to justify the LOQ for the method in the ECM or ILV; no
calculations or comparisons to background levels were reported to justify the LOD for the
method in the ECM.

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Chloropicrin (PC 081501)

MRIDs 49854401/50167601

Table 4. Method Characteristics

Analyte1

Chloropicrin



GC/ECD (Primary)

GC/MS (Confirmation)

Limit of Quantitation
(LOQ)

ECM

0.10 ng/L

ILV

Limit of Detection
(LOD)

ECM

0.05 ng/L

ILV

0.004 |ig/L (ground)
0.01 |ig/L (drinking and surface)

Linearity (calibration
curve r2 and
concentration range)

ECM

r2 = 0.9990
(0.5-100 ng/mL)

r2 = 0.9990
(0.5-80 ng/mL)

ILV

r2 = 0.9993 (ground, drinking &
surface)

r2 = 0.99503422 (ground)
r2 = 0.99202763 (drinking)
r2 = 0.99689992 (surface)

(0.5-100 ng/mL

Repeatable

ECM1

Yes at LOQ and lOxLOQ
[characterized surface (lake) water matrix and uncharacterized drinking
and ground water matrices]

ILV2-3

Yes at LOQ and lOxLOQ
[characterized surface, drinking (tap), and ground water matrices]

Reproducible

Yes at LOQ and lOxLOQ

Specific

ECM

No matrix interferences were
observed or quantified; however,
chromatograms were very faint.
Some non-interfering matrix
contaminants were observed in the
drinking water.

Matrix interferences appeared to be
<10% of the LOQ peak (based on

peak height); however,
chromatograms were very difficult
to interpret.

ILV

Matrix interferences were ca. 7%
of the LOQ (based on peak area) in
drinking water.

No matrix interferences were
observed or quantified in ground
and surface water.

No matrix interferences were
observed or quantified.

Data were obtained from pp. 8, 12-13, 15-16 (specificity andLOQ/LOD); Tables 1-2, p. 18 (calibration data);

Tables 3-8, pp. 19-24 (recovery data); Figures 3-14, pp. 27-32 (chromatograms) of MRID 49854401; pp. 12, 22;

Tables 2-4, pp. 28-30 (LOQ/LOD); Table 1, p. 27 (recovery data); Figures 15-19, pp. 45-49 and Figure 32-34, pp.

62-64 (calibration data); Figures 2-14, pp. 32-44; Figures 20-31, pp. 50-61 (chromatograms) of MRID 50167601.

1	In the ECM, surface (lake) water (pH 7.7; 180 mg equiv. CaCCh/L total hardness and alkalinity; 15.2 mg/L total
organic carbon; 12.7 mg/L dissolved organic carbon) was collected from Diss Mere, Diss, Norfolk, and used in
the study (p. 10 of MRID 49854401). The water sample was characterized in a separate study (not specified). The
drinking water was obtained from a tap in the Residue Analysis Department, and the ground water was obtained
from a source in the Huntingdon area by Anglian Water. The drinking and ground water were not characterized;
the source of the ground water was not further specified.

2	In the ILV, the ground water (PTRL ID 2706W-032; pH 7.3; 627 mg equiv. CaCCh/L hardness; 960 ppm total
dissolved solids) obtained from Northwood, North Dakota, drinking (tap) water (PTRL ID 2706W-072/054; pH
7.5; 30 mg equiv. CaCCh/L hardness; 60 ppm total dissolved solids) obtained from Hercules, California, surface
water (PTRL ID 2706W-069; pH 7.8; 1183 mg equiv. CaCCh/L hardness; total dissolved solids not determined)
obtained from Hercules, California, were used in the study (pp. 15-16 of MRID 50167601). The water samples
were provided by EAG-Hercules and previously characterized by Agvise Laboratories.

3	The method was validated in the second trial with two modifications to the sample processing procedure to
increase analyte recovery: shortened extraction time (1 minute with inversion and vortexing) and use of a smaller
vessel to reduce headspace (pp. 11, 16-17, 19-21, 25 of MRID 50167601). The first trial failed due to low
recoveries; therefore, the ECM should be updated with the ILV modifications.

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Chloropicrin (PC 081501)

MRIDs 49854401/50167601

Linearity is satisfactory when r2 >0.995.

IV. Method Deficiencies and Reviewer's Comments

1.	An updated ECM should be submitted with the ILV modifications. The ILV validated the
method in the second trial with two modifications to the sample processing procedure to
increase analyte recovery: shortened extraction time (1 minute with inversion and
vortexing) and use of a smaller vessel to reduce headspace (pp. 11, 16-17, 19-21, 25 of
MRID 50167601). The first trial failed due to low recoveries.

2.	In ILV, the linearity was not satisfactory for the GC/MS analysis of chloropicrin in
drinking water (r2 = 0.99202763; Figures 15-19, pp. 45-49 of MRID 50167601).

3.	The specificity of the method was not well-supported by the ECM representative
chromatograms. GC/ECD chromatograms were very faint, and GC/MS chromatograms
were very difficult to interpret due to poor resolution and the over-laying of the peak area
on the analyte peak.

4.	Two of the three ECM water matrices were not characterized: drinking and ground water
matrices (p. 10 of MRID 49854401).

5.	The estimations of LOQ and LOD in ECM and ILV were not based on scientifically
acceptable procedures as defined in 40 CFRPart 136 (pp. 8, 12-13, 16 of MRID
49854401; pp. 12, 22; Tables 2-4, pp. 28-30 of MRID 50167601). In the ECM and ILV,
the LOQ was defined as the lowest fortification level where an acceptable mean recovery
is obtained. The LOD was reported as 0.05 |ig/L (equivalent to 0.05 ng/mL) in the ECM;
in ILV, the LOD was 0.004 |ig/L for ground water and 0.01 |ig/L for drinking and
surface water. In the ILV, the LOD was calculated for each matrix using the following
equation: LOD = (to.99 x SD), where, to.99 is the one-tailed t statistic for n = 5 (3.747) and
SD is the standard deviation of the analyte recovery measurements at the target LOQ. No
calculations or comparisons to background levels were reported to justify the LOQ for
the method in the ECM or ILV; no calculations or comparisons to background levels
were reported to justify the LOD for the method in the ECM. Detection limits should not
be based on arbitrary values.

6.	In the ECM, the storage stability of the final sample extracts of chloropicrin was
determined to be 3 days when stored at -18°C (n = 2; p. 16; Tables 3-8, pp. 19-24 of
MRID 49854401).

7.	The matrix effects were determined to be insignificant in the ECM (p. 16; Tables 3-8, pp.
19-24 of MRID 49854401).

8.	The ILV study author reported that no communications between the ILV and ECM
occurred (p. 25 of MRID 50167601).

9.	It was reported for the ILV that one sample set (10 fortified samples, 2 matrix controls, 1
solvent control, and 1 reagent blank) required ca. 12 hours (p. 22 of MRID 50167601).

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Chloropicrin (PC 081501)

MRIDs 49854401/50167601

Preparation of standard solutions and samples each required ca. 4 hours. GC/ECD
analysis/data processing and GC/MS analysis/data processing each required ca. 2 hours.

V. References

U.S. Environmental Protection Agency. 2012. Ecological Effects Test Guidelines, OCSPP

850.6100, Environmental Chemistry Methods and Associated Independent Laboratory
Validation. Office of Chemical Safety and Pollution Prevention, Washington, DC. EPA
712-C-001.

40 CFR Part 136. Appendix B. Definition and Procedure for the Determination of the Method
Detection Limit-Revision 1.11, pp. 317-319.

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Chloropicrin (PC 081501)

MRIDs 49854401/50167601

Attachment 1: Chemical Names and Structures
Chloropicrin

IUPAC Name:

CAS Name:

CAS Number:

SMILES String:

CI

CI — i —

I

Page 10 of 10

T ri chl oronitrom ethane
Not reported
76-06-2
Not found


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