Test Material:
EPA PC Code:
OCSPP Guideline:
Ethalfluralin
113101
850.6100
MRU):
48915801
Title:
Validation report for Method GRM 07.07 - determination of residues of
benfluralin, ethalfluralin, and trifluralin in soil by gas chromatography
with electron-impact mass spectrometry detection.
For CDM Smith
Primary Reviewer: Lisa Muto
Secondary Reviewer: Dan Hunt
Signature:
Date: 3/31/14
Signature:
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QC/QA Manager: Joan Gaidos
Date: 3/31/14
Signature:
Date: 3/31/14
Test Material:
MRU):
Title:
For CDM Smith
Ethalfluralin
49385901
Independent Laboratory Validation of an Analytical Method for the
Determination of Ethalfluralin in Soil.
Primary Reviewer: Lisa Muto
Secondary Reviewer: Lynne Binari
QC/QA Manager: Joan Gaidos
Signature:
Date: 1/9/15
Signature:
Date: 1/9/15
Signature:
Date: 1/9/15
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Ethalfluralin (PC 113101)
MRID 49385901 (ILV/ECM)
Analytical method for ethalfluralin in soil
Reports:
Document No.
Guideline:
Statements:
Classification:
PC Code:
Reviewer:
Reviewer:
ECM: EPA MRID No. 48915801. Dial, Jr., G.E. 2007. Validation report for
Method GRM 07.07 - determination of residues of benfluralin, ethalfluralin,
and trifluralin in soil by gas chromatography with electron-impact mass
spectrometry detection. Laboratory Study ID: 071040. Report prepared,
sponsored and submitted by Regulatory Laboratories - Indianapolis Lab,
Dow AgroSciences LLC, Indianapolis, Indiana; 51 pages. Final report issued
May 11, 2007.
ILV: EPA MRID 49385901. Garia-Alix, M. 2012. Independent Laboratory
Validation of an Analytical Method for the Determination of Ethalfluralin in
Soil. Dow AgroSciences Study Reference No.: 120138. CEMAS Study No.:
CEMS-5394. Report prepared by CEM Analytical Services (CEMAS),
Berkshire, United Kingdom, sponsored and submitted by Regulatory
Sciences and Government Affairs- Indianapolis Lab, Dow AgroSciences
LLC, Indianapolis, Indiana; 70 pages. Final report issued December 17,
2012.
MRID 49385901
850.6100
ECM: Previously submitted and reviewed. Data Confidentiality, GLP,
Quality Assurance, and Certification of Authenticity statements were not
included in this submission.
ILV: The study was conducted in accordance with OECD and UK Good
Laboratory Practices (GLP; p. 3; Appendix C, p. 70). Signed and dated No
Data Confidentiality, GLP and Quality Assurance statements were included
(pp. 2-4). A statement of the authenticity of the study report was included as
part of the Quality Assurance Statement (p. 4). A signature page was also
included (p. 5).
This analytical method is classified as Supplemental. The ECM included an
insufficient number of samples spiked at the LOQ, did not determine
performance data at lOx LOQ and the soil matrices were not well
characterized. The LOQ is greater than the current lowest toxicological level
of concern and approximately equal to the toxicological level of concern
associated with the current lowest EC25.
113101
Patricia Engel Signature:
Physical Scientist Date: 10/16/2018
Mohammed Ruhman
Ph.D., Senior Scientist
Signature:18
Date: 10/16/2018
Executive Summary
This analytical method, Method GRM 07.07, is designed for the quantitative determination of
ethalfluralin in soil at the LOQ of 0.010 ng/g using GC/MS. The LOQ is greater than the current
Page 2 of 9
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Ethalfluralin (PC 113101)
MRID 49385901 (ILV/ECM)
lowest toxicological level of concern in soil, but maybe used to measure down to the EC25. The
ILV was successful in the first trial.
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
Ethalfluralin
48915801
49385901
Soil
5/11/2007
Dow
AgroSciences
LLC
GC/MS
0.010 ng/g
I. Principle of the Method
Fortified samples (10.0 ± 0.05 g) were extracted by shaking on a reciprocating shaker for a
minimum of 30 minutes (180 excursions/minute) with 20 mL of acetonitrile:water solution (99:1,
v:v; pp. 10-11; Appendix A, pp. 26-27 of 48915801). After centrifugation (2000 rpm for 5
minutes), an aliquot (5.0 mL) of the extract solution was transferred to a 30-mL vial and diluted
with 10 mL of water. The mixture was purified using a 300-mg multi-mode (CI 8, SAX, SCX)
solid phase extraction (SPE) cartridge. The SPE cartridge was conditioned with methanol and
HPLC water. The extract was applied then the analytes were eluted with hexane (2x2 mL). The
eluate was mixed with 3 mg of peanut oil then diluted to 5 mL with hexane. The samples were
vortexed prior to GC/MS analysis.
Samples were analyzed for ethalfluralin by gas chromatography (Durabond-5, 30 m x 0.25 mm,
0.25-|am column, initial column temperature 100°C) with electron impact tandem mass
spectrometry (splitless mode; carrier gas, helium; Appendix A, Appendix 1, pp. 58-59 of
49385901; pp. 10-11; Appendix A, pp. 24-25, 27-28; Appendix A, Figure 11, p. 50 of
48915801). Injection volume was 5 |iL. Three parent-to-daughter ions were monitored: the
333—>276 was the quantitative transition; the 333—>316 was the confirmatory transition; and the
333—>292 was monitored for additional identification. The relative ratios of the three transitions
were quantified for confirmation of ethalfluralin (Appendix A, Appendix 1, pp. 66-67 of
49385901).
In the ILV, the extraction procedure and GC/MS analysis was performed according to the ECM,
without modification (pp. 14-16). The only noted minor change was the 30-mL vial for a 22-mL
vial.
In the ECM and ILV, the LOQ and LOD were 0.010 ng/g and 0.003 i-ig/g, respectively (p. 13 of
48915801; p. 10; Appendix A, Appendix 1, p. 66 of 49385901).
Page 3 of 9
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Ethalfluralin (PC 113101)
MRID 49385901 (ILV/ECM)
II. Recovery Findings
ECM (MRID 48915801): Mean recoveries and relative standard deviations (RSD) were within
guideline requirements (mean 70-120%; RSD <20%) for analysis of ethalfluralin in silt loam and
clay loam soils; however, fortifications were performed at the LOQ and 200*LOQ (pp. 7, 13;
Appendix A, Table 3, p. 37 of 48915801). Confirmation of the identified peaks was based on the
observation of its three parent-to-daughter ion transitions and the quantification of the relative
ratios of those transitions (provided for the silt loam soil; Appendix A, Figure 11, p. 50 of
48915801).
ILV (MRID 49385901): Mean recoveries and relative standard deviations (RSD) were within
requirements (mean 70-120%; RSD <20%) for analysis of ethalfluralin in silty clay loam and
clay loam soils at the LOQ and lOxLOQ (p. 18; Tables 1-8, pp. 24-30 of 49385901). One sample
per matrix was also dosed at the LOD. Confirmation of the identified peaks was based on the
observation of its three parent-to-daughter ion transitions and the quantification of the relative
ratios of those transitions. The soil matrices were fully characterized at CEMAS (UK textural
classifications; p. 12 of 49385901). The reviewer assumed that the method validation was
successful on the first trial, although the number of trials was not specifically reported (pp. 10,
18, 21 of 49385901).
Table 2. Initial Validation Method Recoveries for Ethalfluralin in Soil
Analyte
Fortification
Number
Recovery
Mean
Standard
Relative Standard
Level (ng/g)
of Tests
Range (%)
Recovery (%)
Deviation (%)
Deviation (%)
Silt loam soil (M641)1
Ethalfluralin
0.010 (LOQ)
4
87-98
94
5
5
2.000
5
82-105
94
10
10
Clay loam soil (M649)1
Ethalfluralin
0.010 (LOQ)
4
79-94
86
7
8
2.000
2
77-83
80
4
5
Both soils2
Ethalfluralin
0.010 (LOQ)
8
79-98
90
7.0
7.8
2.000
7
77-105
90
10.6
11.7
Data were obtained from pp. 7, 13; Appendix A, Table 3, p. 37 of MRID 48915801.
1 Reviewer-calculated using data from Appendix A, Table 3, p. 37 of MRID 48915801 (see DER Attachment 2).
2 Provided by study author.
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Ethalfluralin (PC 113101)
MRID 49385901 (ILV/ECM)
Table 3. Independent Validation Method Recoveries for Ethalf
uralin in Soi
1
Analyte
Fortification
Level
(mg/kg)
Number
of Tests
Recovery
Range (%)
Mean
Recovery (%)
Standard
Deviation (%)
Relative Standard
Deviation (%)
Silty Clay loam
m/z 276 (quantitation ion)
Ethalfluralin
0.003 (LOD)
1
2
--
--
--
0.01 (LOQ)
5
85-98
89
5.4
6.1
0.1
5
92-105
97
5.4
5.6
m/z 316 (confirmation ion 1)
Ethalfluralin
0.003 (LOD)
1
2
--
--
--
0.01 (LOQ)
5
86-95
89
3.6
4.0
0.1
5
91-105
97
5.4
5.6
m/z 292 (confirmation ion 2)
Ethalfluralin
0.003 (LOD)
1
2
--
--
--
0.01 (LOQ)
5
87-98
91
4.4
4.8
0.1
5
88-104
94
6.1
6.5
Clay loam
m/z 276 (quantitation ion)
Ethalfluralin
0.003 (LOD)
1
2
--
--
--
0.01 (LOQ)
5
78-87
81
3.9
4.9
0.1
5
75-88
83
6.0
7.3
m/z 316 (confirmation ion 1)
Ethalfluralin
0.003 (LOD)
1
2
--
--
--
0.01 (LOQ)
5
75-87
80
4.8
6.0
0.1
5
73-87
81
6.5
8.0
m/z 292 (confirmation ion 2)
Ethalfluralin
0.003 (LOD)
1
2
--
--
--
0.01 (LOQ)
5
76-86
81
4.1
5.0
0.1
5
74-87
82
5.9
7.2
Data (uncorrected recoveries) obtained from Tables 7-8, p. 30 of MRID 49385901.
1 Soils were fully characterized (UK textural classifications; p. 12).
2 Ethalfluralin recovered ranged 0.0023-0.0027 mg/kg in the silty clay loam soil and 0.0023-0.0025 mg/kg in the
clay loam soil. The % recovery was reported as below the LOQ in the study report.
III. Method Characteristics
In the ECM and ILV, the LOQ and LOD were reported as 0.010 ng/g and 0.003 ng/g,
respectively (p. 13 of 48915801; p. 10; Appendix A, Appendix 1, pp. 65-66, 68 of 49385901).
The LOQ and LOD were calculated from the standard deviation (s) of the 0.010 ng/g recovery
results of the combined soil data. The LOQ and LOD were calculated as 10.s and 3.v, respectively
(based on the method of Keith, L.H. etal. 1983). The calculated LOQ and LOD values for
ethalfluralin, benfluralin and trifluralin ranged 0.0067 to 0.0082 ng/g and 0.0020 to 0.0025 i-ig/g,
respectively (0.0071 |ag/g and 0.0021 i-ig/g, respectively, for ethalfluralin - from Table 6, p. 39 of
MRID 48915801). These values supported the LOQ and LOD for the method. The LOQ and
Page 5 of 9
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Ethalfluralin (PC 113101)
MRID 49385901 (ILV/ECM)
LOD values of the ILV were based on the ECM; the ILV justified the LOQ with the successful
validation results of the ILV.
Table 4. Method Characteristics
Ethalfluralin
Silty clay soil
Clay loam soil
Limit of Quantitation (LOQ)
0.010 g ng/g
Limit of Detection (LOD)
0.003 ng/g
Linearity
(calibration curve
r2 and
concentration
range)2
ECM
r2 = 0.99701
No data reported1
ILV
r2 = 0.9989 (m/z 276)
r2 = 0.9993 (m/z 316)
r2 = 0.9994 (m/z 292)
Cone, range
(0.001-0.1 Hg/mL)
Repeatable
Yes
Reproducible
Yes
Specific
Yes
Data were obtained from p. 13; Appendix A, Figure 6, p. 45 of 48915801 and p. 18; Tables 1-8, pp. 24-30; Figures
1-3, pp. 33-35; Figure 7, p. 39; Figure 11, p. 43 of MRID 49385901.
1 Only one representative calibration curve was included in the ECM report. The soil was identified as Samples Set
071040 S03, which was indicated as M641, Silt loam soil, in Appendix A, Figure 8, p. 47 of 48915801
2 ILV calibration curves were confirmed by the reviewer (r2 = 0.9988-0.9995) using data obtained from Figures 1-3,
pp. 33-35 of MRID 49385901 (see DER Attachment 2).
IV. Method Deficiencies and Reviewer's Comments
1. In the ECM, an insufficient number of samples were spiked at the LOQ. OCSPP
Guideline 850.6100 requires that a minimum of five spiked replicates are analyzed at
each concentration. At the LOQ, only four replicates were analyzed in each soil.
In the ECM, performance data were not determined at lOxLOQ. Performance data should
be determined at the LOQ and lOxLOQ. In this ECM, performance data were determined
at the LOQ and 200xLOQ.
2. The estimation of the LOQ and LOD in the ECM was based on scientifically acceptable
procedures as defined in 40 CFR Part 136. The LOQ is greater than the current lowest
toxicological level of concern in soil. However, this method may provide some utility
because the LOQ is approximately equal to the toxicological level of concern associated
with the lowest EC25.
3. The soils utilized in the ECM were not fully characterized, with only texture, pH and
percent organic carbon reported (p. 9 of 48915801).
4. In the ECM, Method GRM 07.07 directed the correction of sample recoveries for analyte
concentration in the control samples (Section 10.2; Appendix A, pp. 29-30 of 48915801).
The ECM reportedly followed Section 10.2 of Method GRM 07.07 for the calculation of
ethalfluralin recovery in the samples. The calculations of the ILV reported the correction
for background in the controls (p. 17 of 49385901). Generally, since analyte found in the
Page 6 of 9
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Ethalfluralin (PC 113101)
MRID 49385901 (ILV/ECM)
controls was reported as "ND", the reviewer considered the ethalfluralin samples to be
uncorrected for matrix blanks; however, the reviewer noted that "ND" was defined as
"residue.. .below the 0.003 mg/kg limit of detection", so the control values were not
necessarily valued at 0.000 ng/g (Appendix A, Table 3, p. 37 of 48915801; Tables 1-6,
pp. 24-29 of 49385901). In Section 10.3, Method GRM 07.07 also provided calculations
in order to correct recoveries for method efficiency and to determine the dry weight
concentrations of the analytes; however, this correction was not shown in the procedure
or results of the ECM or the ILV (p. 17; Appendix A, Appendix 1, pp. 64-65 of
49385901).
5. The reviewer calculated the ECM recovery values for the individual soils since the study
author only reported overall recovery values for the combined data of both soils.
6. The acceptable recoveries of benfluralin and trifluralin at 0.010 ng/g and 2.000 ng/g
(LOQ and 200*LOQ) from the silt loam and clay loam soils were also reported using the
Method GRM 07.07 in the ECM study report. The LOQ and LOD for benfluralin and
trifluralin were the same as those for ethalfluralin.
7. The matrix effects were assessed for each matrix by the ILV (p. 19; Table 9, p. 31 of
49385901). No significant suppression or enhancement of the instrument (<10%) was
observed for all ions monitored.
8. The storage stability of the final extracts and standard solutions were assessed in the ILV
(pp. 19-20; Tables 10-12, pp. 31-32 of 49385901). The final extracts were found to be
stable up to 7 days at 2-8°C (all three ions measured). Mean recoveries, s.d. and RSDs
ranged 92%, 5.0-7.7% and 6.3-8.4%), respectively, for the silty clay loam soil and 78-
80%o, 6.1-7.3%) and 7.8-9.2%), respectively, for the clay loam soil. The standard solutions
were found to be stable up to 37 days at 2-8°C (m/z 276 quantitation ion measured).
9. In the ECM, the timeframe required for sample set analysis was reported as ca. 6 hours
(Appendix A, p. 33 of 48915801). It was reported for the ILV that one set of thirteen
samples required ca. eight person hours to complete (p. 20 of 49385901). Subsequent
GC/MS analysis was performed overnight. Evaluation of results required ca. two hours.
The overall time for a sample set was ca. 1.5 calendar days.
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.
EPA MRID No. 48915801. Dial, Jr., G.E. 2007. Determination of Residues of Benfluralin,
Page 7 of 9
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Ethalfluralin (PC 113101)
MRID 49385901 (ILV/ECM)
Ethalfluralin, and Trifluralin in Soil by Gas Chromatography with Electron-Impact Mass
Spectrometry Detection. Method GRM 07.07. Laboratory Study ID: 071040. Report
prepared, sponsored and submitted by Regulatory Laboratories - Indianapolis Lab, Dow
AgroSciences LLC, Indianapolis, Indiana; 51 pages. Final report issued May 11, 2007.
Page 8 of 9
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Ethalfluralin (PC 113101)
MRID 49385901 (ILV/ECM)
Attachment 1: Chemical Names and Structures
Ethalfluralin (pp. 61, 71 of MRID 49385902)
IUPAC Name: N-Ethyl-a, a, a4rifluoro-N-(2-rn ethyl allyl)-2,6-dinitro-/Molui dine
CAS Name: N-Ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4-
(trifluoromethyl)benzamine
CAS Number: 55283-68-6
SMILES String: Not reported
CH,
^Oirc~CM,
NO,
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