Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Organophosphorous Pesticides Part 5, Assay and Identification of Standard-Grade Reference Materials: Specifications and Tests eISBN: 9780841230460 Tom Tyner Chair, ACS Committee on Analytical Reagents James Francis Secretary, ACS Committee on Analytical Reagents
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ABSTRACT This ACS Reagent Chemicals Standard-Grade Reference Materials monograph for Organophosphorous Pesticides, in addition to common physical constants, details the following specifications and corresponding tests for verifying that a substance meets ACS Standard-Grade specifications including: Identity by Gas Chromatography−Mass Spectrometry, Identity by Infrared Spectroscopy, Assay by Gas Chromatography, and Assay by Thin-Layer Chromatography.
SPECIFICATIONS Identity by Gas chromatography−mass spectrometry. . . . . Passes test Infrared spectroscopy. . . . . . . . . . . . . . . . . Passes test
Assay by Gas chromatography . . . . . . . . . . . . . . . . . ≥98.0% Thin-layer chromatography . . . . . . . . . . . . . Passes test
TESTS Identity by Gas Chromatography−Mass Spectrometry Analyze the sample by gas chromatography–mass spectrometry using method GCMS–OP1 described below. Method GCMS−OP1 Ionization Mode . . . . . . . . . . . . . . . . . . . . Electron ionization/70 eV Column . . . . . . . . . . . . . . . . . . . . . . . . . . 5% Diphenyl–95% dimethylpolysiloxane, 30 m × 0.25 mm i.d., 0.25 µm film thickness Temperature Program. . . . . . . . . . . . . . . . . 50 °C, hold 1 min, then 10 °C/min to 300 °C Carrier Gas . . . . . . . . . . . . . . . . . . . . . . . Helium at 1 mL/min Injector . . . . . . . . . . . . . . . . . . . . . . . . . Split/splitless (20:1 split) Injector Temperature . . . . . . . . . . . . . . . . . 250 °C
© 2017 American Chemical Society
A
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.5008 ACS Reagent Chemicals, Part 5
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
Scan Range . . . . . . . . . . . . . . . . . . . . . . . 45–500 amu Sample Size . . . . . . . . . . . . . . . . . . . . . . . 1 µL of a 5000 µg/mL solution The identifying ions for the compounds listed in Table 5-7 must be present. The spectrum is compared to the NIST standardized library of compounds, if available. Ions in the test spectrum must match those found in the NIST spectrum.
Downloaded by NEW YORK UNIV on May 18, 2017 | http://pubs.acs.org Publication Date (Web): February 28, 2017 | doi: 10.1021/acsreagents.5008
Table 5-7. Organophosphorous Pesticides Compound Data
Name
CAS No.
Chemical Formula
Formula Weight
MS (m/ MS (m/ MS (m/ IR (cm−1) IR (cm−1) IR (cm−1) z) z) z) IR-1 IR-2 IR-3 MS-1 MS-2 MS-3
Acephate
30560-19-1
C4H10NO3PS
183.16
136
94
95
1221
999
951
Chlorpyrifos
2921-88-2
C9H11Cl3NO3PS
350.57
197
199
314
829
965
1016
Diazinon
333-41-5
C12H21N2O3PS
304.34
137
179
304
1017
815
977
Dichlorvos
62-73-7
C4H7Cl2O4P
220.97
109
79
185
1033
847
975
Dimethoate
60-51-5
C5H12NO3PS2
229.25
87
93
125
638
1001
825
Fenthion
55-38-9
C10H15O3PS2
278.32
278
125
109
818
1027
960
Malathion
121-75-5
C10H19O6PS2
330.35
125
127
173
652
1007
1732
Methamidophos
10265-92-6
C2H8NO2PS
141.12
94
95
141
773
1038
1211
Paraoxon
311-45-5
C10H14NO6P
275.20
109
81
149
1022
922
1346
Parathion-ethyl
56-38-2
C10H14NO5PS
291.26
97
109
291
913
1015
1345
Parathion-methyl
298-00-0
C8H10NO5PS
263.20
263
125
109
1025
765
831
Phenthoate
2597-03-7
C12H17O4PS2
320.36
274
125
121
651
1007
819
Phorate
298-02-2
C7H17O2PS3
260.36
75
97
260
650
1008
954
Pirimiphos-methyl
29232-93-7
C11H20N3O3PS
305.33
290
276
305
816
1014
1033
Terbufos
13071-79-9
C9H21O2PS3
288.42
231
57
97
1009
652
954
Identity by Infrared Spectroscopy Analyze the sample using the general procedure cited in [Part 2: Infared Spectroscopy]. The spectrum must be consistent with either (1) the characteristic absorbances at the wavenumbers (cm–1) listed in Table 5-7 or (2) the spectrum listed for the compound in the NIST standardized library of compounds. However, absorbance frequency and intensity may be different due to different analysis techniques. The spectrum may also be compared to other published libraries of infrared spectra, if available.
Assay by Gas Chromatography Analyze the sample by gas chromatography using method GC–OP1 described below. Method GC–OP1 Column . . . . . . . . . . . . . . . . . . . . . . . . . . 5% Diphenyl–95% dimethylpolysiloxane, 30 m × 0.53 mm i.d., 1.5 µm film thickness Detector . . . . . . . . . . . . . . . . . . . . . . . . . Flame ionization Detector Temperature . . . . . . . . . . . . . . . . 300 °C Injector . . . . . . . . . . . . . . . . . . . . . . . . . Split/splitless (10:1 split) Injector Temperature . . . . . . . . . . . . . . . . . 250 °C Sample Size . . . . . . . . . . . . . . . . . . . . . . . 1 µL of a 5000 µg/mL solution Carrier Gas . . . . . . . . . . . . . . . . . . . . . . . Helium at 3.5 mL/min Temperature Program. . . . . . . . . . . . . . . . . 50 °C, hold 1 min, then 10 °C/min to 300 °C, hold 5 min
© 2017 American Chemical Society
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ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.5008 ACS Reagent Chemicals, Part 5
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
Measure the area under all peaks (excluding the solvent peak), and calculate the analyte content in area percent.
Assay by Thin-Layer Chromatography Analyze the sample by thin-layer chromatography using the general procedure described in [Part 2: Chromatography; Recommended Procedures; Thin-Layer Chromatography]. The following specific conditions are also required. Stationary Phase . . . . . . . . . . . . . . . . . . . . Silica Mobile Phase . . . . . . . . . . . . . . . . . . . . . . Ethyl acetate:hexane 1:6 (ratio of ethyl acetate may be varied to achieve desired Rf as needed for specific compounds). Detection Method . . . . . . . . . . . . . . . . . . . UV at 254 nm and iodine
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Compound must exhibit a single spot.
© 2017 American Chemical Society
C
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.5008 ACS Reagent Chemicals, Part 5
