Capillary Gas Chromatographic Determination Of Cypermethrin In Formulations: Collaborative Study

1985 ◽  
Vol 68 (3) ◽  
pp. 592-595
Author(s):  
Peter D Bland

Abstract A method is described for the determination of cypermethrin, 3-(2,2- dichloroethenyl)-2,2-dimethyl-cyclopropanecarboxylate cyano-(3- phenoxyphenyl)methyl ester, in technical and formulated material by capillary gas chromatography (CGC). Samples of technical or formulated material are dissolved in CH2Cl2 containing dicyclohexyl phthalate as internal standard. The solution is injected into a gas chromatograph fitted with a flame ionization detector and capillary column of 25 m x 0.32 mm fused silica with a thick film OV-1 phase at 240°C. Injection is made into a heated injection port fitted with an antidiscrimination device in a split mode. Peak areas obtained at retention times of the internal standard and active ingredient are measured with an integrator. The quantity of cypermethrin is determined by comparing the internal standard and active ingredient peak areas with those obtained from a calibration solution containing known amounts of internal standard and pure active ingredient. Five samples were chosen for collaborative study: technical cypermethrin, 70% liquid concentrate, 3 lb/US gal. emulsifiable, 3 ib/US gal. oil concentrate, and 40% wettable powder. Twelve collaborators carried out replicate determinations on each sample on separate days. Coefficients of variation between laboratories (CVX) were 2.13 for the technical, 2.94 for the emulsifiable concentrate, 3.51 for the liquid concentrate, 2.66 for the wettable powder, and 2.29 for the oil concentrate. The method was adopted official first action.

1985 ◽  
Vol 68 (3) ◽  
pp. 570-572
Author(s):  
Thomas G Gale ◽  
Arthur H Hofberg

Abstract A gas chromatographic (GC) procedure for the determination of metolachlor in emulsifiable concentrate formulations containing about 76% active ingredient was collaboratively studied using the matched pair scheme. Metolachlor was extracted from the formulation with acetone containing dipentyl phthalate as the internal standard, chromatographed on OV-101, and detected by flame ionization. Determinations on the 4 samples by 21 government, university, and industrial collaborators using peak area measurements showed within-laboratory repeatability of better than 0.5%. Reproducibility was better than 1% for the formulation. The method has been adopted official first action.


1985 ◽  
Vol 68 (3) ◽  
pp. 589-592
Author(s):  
Thomas G Gale ◽  
Arthur H Hofberg

Abstract Agaschromatographic (GC) procedure for the determination of chlordimeform in emulsiflable concentrate formulations containing about 46% active ingredient was collaboratively studied using the matched pair scheme. Chlordimeform was extracted from the formulation with methylene chloride containing diethyl terephthalate as the internal standard, chromatographed on CBWX-20M, and detected by flame ionization. Determinations on the 4 samples by 20 government, university, and industrial collaborators using peak area measurements showed within-laboratory repeatability of better than 1%. Reproducibility was 1.2% for the formulation. The method has been adopted official first action.


1981 ◽  
Vol 64 (6) ◽  
pp. 1315-1318
Author(s):  
Peter D Bland ◽  
◽  
J Bagness ◽  
W Black ◽  
L Brown ◽  
...  

Abstract A method is described for the determination of pirimicarb (2-(dimethylamino)-5,6-dimethyl-4-pyrimidinyl dimethylcarbamate) in formulated products by gas-liquid chromatography (GLC). Samples are dissolved in a chloroform solution of an internal standard and injected into a gas chromatograph equipped with a flame ionization detector. Quantitative data are obtained by comparing peak areas of the compound and internal standard with those obtained by injecting a standard solution. Eleven collaborators made replicate determinations on 6 samples including a technical product, a granular product, and 4 powder products. The average coefficient of variation was 1.14% for the technical product, 1.82% for the granular product, and 0.73% for the powder products.


1984 ◽  
Vol 67 (3) ◽  
pp. 499-502
Author(s):  
Peter D Bland ◽  
◽  
L Chenery ◽  
N Ellis ◽  
L Firestone ◽  
...  

Abstract A method is described for the determination of butyl 2-(4-(5-trifluoromethyl- 2-pyridinyloxy)phenoxy) propanoate in technical and formulated material by gas chromatography (GC). Samples of technical or formulated material are dissolved in methylene chloride containing dibenzyl succinate as internal standard. The solution is injected into a gas chromatograph fitted with a flame ionization detector and a 6 ft × 2 mm glass column. The column is packed with 3% OV-17 on 100–120 mesh Chromosorb WHP and is maintained at 230°C. Peak areas obtained at the retention times of the internal standard and the active ingredient are measured with an integrator. The quantity of fluazifop-butyl is determined by comparing the internal standard and active ingredient peak areas with the peak areas obtained from a calibration solution containing known amounts of internal standard and pure active ingredient. Four samples were chosen for collaboration: technical fluazifop-butyl, a 4 lb/US gal. emulsifiable concentrate, a 560 g/L oil concentrate, and a 5% granular. Fourteen collaborators carried out replicate determinations on each sample. Coefficients of variation between laboratories were 0.80 for the technical, 0.88 for the emulsifiable concentrate, 1.03 for the oil concentrate, and 2.04 for the granular. Parallel peak height determinations showed substantially higher coefficients of variation for all except the granular sample. The method has been adopted official first action.


1984 ◽  
Vol 67 (3) ◽  
pp. 492-493
Author(s):  
Stephen C Slahck ◽  
◽  
A A Carlstrom ◽  
L T Chenery ◽  
N D Ellis ◽  
...  

Abstract An LC method for the determination of methiocarb in methiocarb technical and formulated products has been subjected to a collaborative study with 9 participating collaborators. Formulations are extracted with acetonitrile and analyzed by reverse phase chromatography, with acetophenone as an internal standard. Collaborators were furnished samples of technical, 75% wettable powder, 75% seed treater, 75% concentrate, and 50% hopper box treater. Coefficient of variation values obtained on the 5 samples were 0.71, 0.83, 0.62, 1.57, and 0.82%, respectively. The method has been adopted official first action.


1981 ◽  
Vol 64 (4) ◽  
pp. 829-832
Author(s):  
Bram Van Rossum ◽  
Albertus Martijn ◽  
James E Launer ◽  
◽  
E C Calamita ◽  
...  

Abstract The gas-liquid chromatographic determination of tetradifon technical and formulations was collaboratively studied in duplicate with 12 laboratories. Six samples were dissolved in dichloroethane with n-hexacosane as the internal standard, chromatographed on a column of 3% SE-52, and detected by flame ionization. The average coefficients of variation were 1.2% for the 2 technical samples, 1.6% for the 2 wettable powders, and 1.5% for the 2 emulsifiable concentrates. The method has been adopted official first action.


1992 ◽  
Vol 75 (6) ◽  
pp. 1103-1106
Author(s):  
Benjamin A Belkind

Abstract An isocratic normal-phase liquid chromatographic (LC) method for measuring methazole in technical and formulated products was collaboratively studied by 12 laboratories. Samples of technical or formulated products are dissolved in 1,4-dioxane-hexane containing 2-chloro-5-nitrobenzophenone as internal standard. Following centrifugation and further dilution, the sample is analyzed by LC on a 25 cm x 4.6 mm stainless steel column packed with 5 μm silica, with ultraviolet detection at 254 nm. Premixed 1% 2-propanol in hexane is used as the mobile phase. Peak areas are obtained at the retention times corresponding to the internal standard and methazole. The quantity of active ingredient is determined by comparing the area ratio of active ingredient to internal standard in the sample with the same ratio in a single calibration solution. Collaborators were provided with 1 Youden matched pair for each of the technical, 75% wettable granular, and 4 lb/gal flowable products studied. The reproducibility relative standard deviations (RSDR) for the product types studied were 1.05% for technical, 1.80% for granular, and 4.76% for flowable. The method has been adopted first action by AOAC International.


1984 ◽  
Vol 67 (3) ◽  
pp. 497-499
Author(s):  
Stephen C Slahck ◽  
◽  
J B Audino ◽  
O O Bennett ◽  
B D Folsom ◽  
...  

Abstract A liquid chromatographic method for the determination of propoxur in technical and formulated products has been subjected to a collaborative study with 8 participating collaborators. Formulations are extracted with acetonitrile and analyzed by reverse phase chromatography, with n-butyrophenone as an internal standard. Collaborators were furnished with samples of technical, 70% wettable powder, 1.5 emulsifiable, and 2% bait. Coefficient of variation values obtained on the 4 samples were 0.34, 0.68, 3.25, and 5.41%, respectively. The method has been adopted official first action.


1987 ◽  
Vol 70 (1) ◽  
pp. 55-57
Author(s):  
Daniel E Terry

Abstract A gas chromatographic method for the determination of isofenphos (OFTANOL®) in isofenphos technical and liquid formulations has been developed and collaboratively studied by 11 laboratories. Two technical samples and 2 liquid flowable samples were analyzed after shaking/extracting in methanol which contained diisobutyl phthalate as an internal standard. The extracts were analyzed by gas chromatography using an SP-2100 column and either flame ionization or thermal conductivity detection. Coefficients of variation were 0.57 and 1.27% for the technical and formulated products, respectively. The GC method has been adopted official first action as a AOACCTPAC method.


1972 ◽  
Vol 55 (6) ◽  
pp. 1331-1335 ◽  
Author(s):  
A A Carlstrom

Abstract The GLC method described is specific for measuring 4 components of Phosphamidon Insecticide—deschlorophosphamidon, α-phosphamidon, β-phosphamidon, and γ-chlorophosphamidon. The sample is extracted with acetone, an internal standard (dicyclohexyl phthalate) is added, and the solution is diluted to volume and injected into a gas chromatograph equipped with a flame ionization detector. Although the GLC peak areas for phosphamidon are not linear over a wide range of concentration, good results are obtained when sample and standard concentrations are matched to within 10%. A 1.21% coefficient of variation was found for 19 repetitive injections.


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