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.

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 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.

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.

Collaborative Study of Gas-Liquid Chromatographic Method for Determining Fluometuron

1977 ◽  
Vol 60 (3) ◽  
pp. 716-719
Author(s):  
Arthur H Hofberg ◽  
Lee C Heinrichs ◽  
V Michael Barringer ◽  
Maung Tin ◽  
Gene A Gentry
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Internal Standard ◽  
Relative Difference ◽  
Peak Height ◽  
Matched Pair ◽  
Flame Ionization ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic (GLC) method for determining fluometuron in a wettable powder formulation containing about 80% active ingredient was collaboratively studied using a matched pair scheme. The samples were dissolved in chloroform containing diethyl phthalate as an internal standard, derivatized with trifluoroacetic anhydride, and chromatographed on OV-3, using a flame ionization detector. Analyses of the 2 samples by 14 collaborators, using peak height measurements, showed the following results: 0.99% overall coefficient of variation, 1.08% coefficient of variation for the random error, and no evidence of systematic error. The validity of these results was verified by a concurrent collaborative effort using high pressure liquid chromatography. Analyses of the 2 samples by 8 collaborators, using peak height measurements, showed a 1.17 standard deviation of the total for liquid chromatography vs. 0.76 standard deviation of the total for GLC. The averages for Sample A and Sample B by liquid chromatography showed a relative difference of 0.19 and 0.00%, respectively, when compared with the results by the GLC method. The GLC method has been adopted as 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.

Collaborative Study of a Gas-Liquid Chromatographic Method for the Analysis of Ametryne, Prometone, and Terbutryn

1973 ◽  
Vol 56 (3) ◽  
pp. 586-590
Author(s):  
Arthur H Hofberg ◽  
Robert T Murphy
Keyword(s):  
Active Ingredient ◽  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Peak Height ◽  
Matched Pair ◽  
Flame Ionization ◽  
Two Samples ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method for the determination of ametryne and terbutryn in wettable powder formulations containing about 80% active ingredient and prometone in liquid formulations containing about 25% active ingredient was collaboratively studied, using a matched pair scheme. The ametryne was extracted from the powder with chloroform containing dieldrin as an internal standard and chromatographed on Carbowax 20M, using a flame ionization detector; the same method was used for terbutryn. The sample containing prometone was dissolved in chloroform containing dieldrin and chromatographed in the same manner. Two samples of each pesticide were analyzed, using peak height measurements, with the following results: ametryne (14 collaborators)—1.63% overall coefficient of variation, 0.68% coefficient of variation for the random error, and 1.05% systematic error; prometone (15 collaborators)—2.27, 1.47, and 1.21%; and terbutryn (15 collaborators)—0.95, 0.51, and 0.56%, respectively. The method has been adopted as official first action.

Liquid Chromatographic Method for Determination of Anilazine in Formulated Products: Collaborative Study

1988 ◽  
Vol 71 (1) ◽  
pp. 23-26
Author(s):  
Stephen C Slahck ◽  
◽  
J Arruda ◽  
O O Bennett ◽  
H Cheuk ◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Measurement Techniques ◽  
Collaborative Study ◽  
Internal Standard ◽  
Peak Height ◽  
Liquid Chromatographic Method ◽  
Wettable Powder ◽  
Powder Samples ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for the determination of anilazine (DYRENE®) in formulated products has been developed and subjected to a collaborative study involving 15 participating laboratories. Each collaborator was furnished with reference standard, internal standard, and blind duplicate samples of DYRENE 80% concentrate, 75% wettable powder (75 WP), 50 WP, and 4 flowable formulation. Samples are dissolved in acetonitrile and analyzed by reverse phase chromatography using octanophenone as an internal standard. Collaborators were instructed to evaluate the method by either peak area or peak height measurements. Seven laboratories performed the analyses using peak areas; 8 laboratories used peak heights. Peak area measurements for the wettable powder samples resulted in statistically high bias vs peak height measurements. This was apparently due to inconsistent integration parameters among collaborators. Difficulties in establishing the correct integration parameters are illustrated along with t-test values for the 2 measurement techniques. Coefficients of variation of the peak height values obtained on the 80 concentrate, 75 WP, 50 WP, and 4 flowable were 1.68,1.29,1.74, 1.87%, respectively. The method has been adopted official first action.

High Pressure Liquid Chromatographic Determination of Fensulfothion: Collaborative Study

1983 ◽  
Vol 66 (3) ◽  
pp. 801-803
Author(s):  
Margie E Owen ◽  
◽  
O O Bennett ◽  
L T Chenery ◽  
C J Cohen ◽  
...  
Keyword(s):  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Matched Pair ◽  
Standard Material ◽  
Liquid Chromatographic Determination ◽  
The Difference ◽  
Liquid Chromatographic

Abstract A method for analyzing fensulfothion was tested by 10 collaborators. Formulations were dissolved, or extracted from inerts, in methanol. Benzophenone was used as an internal standard. The solution was diromatographed on a Partisil-10 ODS-2, or equivalent, reverse phase column, and detected at 230 nm. A mobile phase of methanol-water-phosphoric acid was used. The ratio of fensulfothion peak height to benzophenone peak height was calculated from the UV response and compared to the standard material for quantitation. A 15% granular formulation was analyzed as a matched pair. The results of one collaborator were outliers by the Dixon test. The coefficient of variation for the granular formulation was 1.6%. A matched pair of 63% spray concentrate samples was analyzed by 10 collaborators. The difference in results was an outlier for one collaborator; the coefficient of variation for the other collaborators was 1.5%. The method has been adopted official first action.

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