Collaborative Study of a Gas-Liquid Chromatographic Method for the Determination of Simazine

1976 ◽  
Vol 59 (4) ◽  
pp. 758-760
Author(s):  
Arthur H Hofberg ◽  
Lee C Heinrichs ◽  
Gene A Gentry
Keyword(s):  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Matched Pair ◽  
Inert Material ◽  
Powder Formulation ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic method for the determination of simazine in a wettable powder formulation containing about 80% active ingredient was collaboratively studied, using a matched pair scheme. The samples were dissolved in dimethylformamide containing dioctyl phthalate as an internal standard, chromatographed on Carbowax 20M, and detected by using a flame ionization detector. Analysis of the 2 samples, based on peak height measurements, showed the following results: 1.5% overall coefficient of variation, 1.03% coefficient of variation for random error, and 0.23% systematic error. Sample A was an 80% powder formulation; Sample B was a 5% dilution of Sample A by the addition of inert material. The coefficients of variation were 1.20% for Sample A and 1.54% for Sample B. The larger variation in Sample B most likely resulted from nonuniform mixing during the dilution of Sample A. Since all collaborators used the same reference standard, the variation found in Sample A is more indicative of the variability of the method. The method has been adopted as official first action.

Collaborative Study of a Gas-Liquid Chromatographic Method for the Analysis of Chlorobenzilate and Chloropropylate

1975 ◽  
Vol 58 (3) ◽  
pp. 516-519
Author(s):  
Arthur H Hofberg ◽  
Lee C Heinrichs ◽  
Gene A Gentry
Keyword(s):  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Peak Height ◽  
Matched Pair ◽  
Flame Ionization ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic method for the determination of chlorobenzilate and chloropropylate in liquid formulations containing about 46 and 26% active ingredient, respectively, was collaboratively studied, using a matched pair scheme. The samples were dissolved in acetone containing dibenzyl succinate as an internal standard and chromatographed on Carbowax 20M, using a flame ionization detector. Analyses of 4 samples by 13 collaborators using peak height measurements showed the following results: chlorobenzilate—2.5% overall coefficient of variation, 1.0% coefficient of variation for the random error; and 0.7% systematic error; chloropropylate—2.0, 1.4, and 0.4%, respectively. The method has been adopted as official first action.

Collaborative Study of a Gas-Liquid Chromatographic Method for the Analysis of Propazine

1975 ◽  
Vol 58 (3) ◽  
pp. 513-515
Author(s):  
Arthur H Hofberg ◽  
Lee C Heinrichs ◽  
Gene A Gentry
Keyword(s):  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Peak Height ◽  
Matched Pair ◽  
Flame Ionization ◽  
Liquid Chromatographic Method ◽  
Two Samples ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic method for the determination of propazine in wettable powder formulations containing about 80% active ingredient was collaboratively studied, using a matched pair scheme. The propazine was extracted from the powder with chloroform, with dieldrin as an internal standard, and chromatographed on Carbowax 20M, using a flame ionization detector. Two samples were analyzed using peak height measurements with the following results (13 collaborators): 1.2% overall coefficient of variation and 1.2% coefficient of variation for the random error. Statistical evaluation of these factors reveals no evidence of systematic error contribution. The method has been adopted as official first action.

Liquid Chromatographic Determination of Propoxur in Technical and Formulated Products: Collaborative Study

1984 ◽  
Vol 67 (3) ◽  
pp. 497-499
Author(s):  
Stephen C Slahck ◽  
◽  
J B Audino ◽  
O O Bennett ◽  
B D Folsom ◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Liquid Chromatographic Method ◽  
Wettable Powder ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

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.

Liquid Chromatographic Method for Determination of Azinphos-Methyl in Formulated Products: Collaborative Study

1988 ◽  
Vol 71 (5) ◽  
pp. 988-990
Author(s):  
Stephen C Slahck
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Peak Height ◽  
Azinphos Methyl ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Wettable Powder ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for determination of azinphosmethyl (Guthion®) in formulated products has been developed. Samples are dissolved in acetonitrile and analyzed by reverse-phase chromatography using n-butyrophenone as an internal standard. The method was subjected to a collaborative study involving 15 participating laboratories. Each collaborator was furnished with reference standard, internal standard, and blind duplicate samples of Guthion 50% wettable powder (50WP), 3 flowable (3F), and emulsifiable concentrate (2L and 2S) formulations. Collaborators were instructed to evaluate the method by peak height measurements only. Relative standard deviations for reproducibility (RSDR) were 1.11, 6.28, 2.47, and 1.17% for the 50WP, 3F, 2L, and 2S formulations, respectively. The method has been approved interim official first action for determination of azinphos-methyl in the 50WP, 2L, and 2S formulations.

Gas-Liquid Chromatographic Method for the Analysis of Microencapsulated Ethyl Parathion and Methyl Parathion Insecticides: Collaborative Study

1980 ◽  
Vol 63 (5) ◽  
pp. 999-1002 ◽  
Author(s):  
James J Karr ◽  
◽  
H D Antles ◽  
J B Audino ◽  
W R Bontoyan ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Chromatographic Method ◽  
Methyl Parathion ◽  
Collaborative Study ◽  
Internal Standard ◽  
Original Method ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic ◽  
Collaborative Efforts

Abstract The determination of ethyl parathion in Penncap-E insecticide was studied collaboratively by 14 laboratories. The assay of methyl parathion in Penncap-M insecticide was studied by 8 laboratories. The original method which was adopted official first action for methyl parathion specified dimethoate, which is currently classified as a suspected carcinogen, as the internal standard. The current collaborative efforts were conducted as a supplemental study to evaluate the performance of the new internal standard, bis-2-methoxyethyl phthalate, and to test the gas-liquid chromatographic method for microencapsulated ethyl parathion (internal standard, dibutyl phthalate). The method uses essentially the same grinding and extraction with acetonitrile as the original study. At the 20% methyl parathion level, the standard deviation within laboratories was 0.186%, and among laboratories, 0.737%. Two formulations of ethyl parathion at approximately 16 and 24% were analyzed in replicate on 2 days by the same analyst, and provided excellent agreement within laboratories as well as among laboratories. The standard deviation (pooled) within laboratories was 0.284% and among laboratories, 0.518%. The method has been adopted as official first action.

Collaborative Study of a Gas Chromatographic Method for the Analysis of Diazinon

1971 ◽  
Vol 54 (3) ◽  
pp. 700-702
Author(s):  
R T Murphy ◽  
A H Hofberg ◽  
H R Buser
Keyword(s):  
Systematic Error ◽  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Peak Height ◽  
Matched Pair ◽  
Flame Ionization ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method for the determination of Diazinon in liquid formulations containing about 50% active ingredient was collaboratively studied, using a matched pair scheme. The sample was dissolved in acetone containing aldrin as an internal standard and chromatographed on silicone DC-200, using a flame ionization detector. Determinations on the 2 samples by 18 collaborators using peak height measurements show an overall coefficient of variation of 1.0%. The coefficient of variation of random error is 0.8%, and for the systematic error, 0.4%. Application of the F-test proved this systematic error not to be significant. The method has been adopted as official first action.

Liquid Chromatographic Method for Determination of Oxythioquinox in Technical and Formulated Products: Collaborative Study

1986 ◽  
Vol 69 (3) ◽  
pp. 490-492
Author(s):  
Stephen C Slahck ◽  
◽  
L B Aaron ◽  
O O Bennett ◽  
R M Elliott ◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Reverse Phase ◽  
Reverse Phase Chromatography ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for determination of oxythioquinox (Morestan®) in oxythioquinox technical and formulated products has been developed and collaboratively studied in 14 laboratories. Samples are dissolved in chloroform containing n-valerophenone as an internal standard, diluted with acetonitrile, and analyzed by reverse phase chromatography. Collaborators analyzed blind duplicate samples of oxythioquinox technical and 25 WP. Coefficients of variation were 1.06 and 1.72% for the technical and 25 WP samples, respectively. The method has been adopted official first action.

Rapid Gas-Liquid Chromatographic Method for Determination of Sulfamethazine in Swine Feed

1982 ◽  
Vol 65 (5) ◽  
pp. 1048-1053
Author(s):  
Robert K Munns ◽  
Jose E Roybal
Keyword(s):  
Quantitative Determination ◽  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Internal Standard ◽  
Liquid Chromatographic Method ◽  
Average Coefficient ◽  
Swine Feed ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic method is described for the quantitative determination of trace amounts of sulfamethazine in swine feed. Sulfamethazine is extracted in ammoniated acetone and isolated from other extractants on a Sephadex LH-20 column. The eluate is methylated with diazomethane and evaporated to dryness. The residue is dissolved in a solvent containing an internal standard of methyl sulfasymazine before being injected onto an OV-25 GLC column. An estimation of precision was established by assaying 10 sets of swine feed fortified with 0.5, 1,2, and 5 ppm SMZ. Mean recoveries were 96.0,94.3, 93.5, and 94.0%, respectively, with an average coefficient of variation of 3.07%. The critical steps and ruggedness of the method were also determined.

Collaborative Study of a Gas Chromatographic Method for the Analysis of Prometryne

1971 ◽  
Vol 54 (3) ◽  
pp. 703-705
Author(s):  
R T Murphy ◽  
A H Hofberg ◽  
H R Buser
Keyword(s):  
Systematic Error ◽  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Peak Height ◽  
Matched Pair ◽  
Flame Ionization ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method for the determination of prometryne in wettable powder formulations containing about 80% active ingredient was collaboratively studied, using a matched pair scheme. The prometryne was extracted from the powder with chloroform containing dieldrin as an internal standard and chromatographed on Carbowax 20M, using a flame ionization detector. Determinations on the 2 samples by 12 collaborators using peak height measurements show an overall coefficient of variation of 1.4%, coefficient of variation of random error of 1.3%, and for systematic error, 0.4%. Application of the F-test shows the systematic error not to be significant. The method has been adopted as official first action.

Collaborative Study of a Gas Chromatographic Method for the Analysis of Atrazine

1971 ◽  
Vol 54 (3) ◽  
pp. 697-699
Author(s):  
R T Murphy ◽  
A H Hofberg ◽  
H R Buser
Keyword(s):  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Statistical Evaluation ◽  
Collaborative Study ◽  
Internal Standard ◽  
Peak Height ◽  
Matched Pair ◽  
Flame Ionization ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method for the determination of atrazine in wettable powder formulations containing about 80% active ingredient was collaboratively studied, using the matched pair scheme. The atrazine was extracted from the powder with chloroform containing dieldrin as an internal standard and chromatographed on Carbowax 20M, using a flame ionization detector. Determinations on the 2 samples by 13 collaborators using peak height measurements show an overall coefficient of variation of 1.0% and a coefficient of variation of random error of 1.2%. Statistical evaluation of these factors reveals no evidence of systematic error contribution. The method has been adopted as official first action.

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