Collaborative Study of Gas Chromatographic Method for Determining Captan in Formulations

1971 ◽  
Vol 54 (3) ◽  
pp. 688-696
Author(s):  
A A Carlstrom
Keyword(s):  
Systematic Error ◽  
Sample Size ◽  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Size Variation ◽  
Measuring Technique ◽  
Performance Requirements ◽  
Glass Column ◽  
Gas Chromatographic Method

Abstract Captan is extracted from inert substances with a solution containing dieldrin in dioxane. The GLC procedure is stated in performance requirements except to specify XE-60 packing in a glass column. The ratio of captan to HEOD peak heights is measured for the sample and compared to the same ratio calculated for standard captan. Effects of extraction, peak measuring technique, sample size variation, and captan degradation on column and in solution were investigated. Twenty chemists from 18 laboratories quantitatively measured captan content of 6 samples. The coefficient of variation for the 2 technicals was 3.67%, for the two 50% wettable powders, 2.07%, and for the 10% dusts, 5.78%. A significant amount of systematic error was detected. Submitted chromatograms of a standard injection revealed that if captan degraded, as detected by formation of tetrahydrophthalimide, answers were often outliers rejected by the Dixon test. The method has been adopted as official first action and it is recommended that the problem of captan degradation be studied further.

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 Methods for the Analysis and Control of AG-Chlordane and Its Formulations

1973 ◽  
Vol 56 (3) ◽  
pp. 591-595
Author(s):  
Marshall A Malina
Keyword(s):  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Assay Method ◽  
Good Precision ◽  
Accuracy And Precision ◽  
Infrared Method ◽  
Gas Chromatographic Method ◽  
And Control ◽  
Excellent Accuracy

Abstract Four methods for the analysis of AG-chlordane and its formulations were submitted to a collaborative study. Fifteen laboratories, including 5 CIPAC laboratories, participated in this study. The infrared method for the analysis of the content of the 2 chlordane isomers was precise, with a coefficient of variation of 0.015. The gas chromatographic method for the analysis of the heptachlor content also yielded good precision with a standard deviation of 0.16. The infrared assay method for granular formulations exhibited excellent accuracy and precision, with a coefficient of variation of 0.067 and an error of only +0.25% relative. The gas chromatographic assay method for emulsifiable concentrates exhibited poor accuracy and precision and was found unacceptable. The first 3 methods have been adopted as official first action.

Gas Chromatographic Method for Determination of Cypermethrin in Pesticide Formulations: Collaborative Study

1987 ◽  
Vol 70 (1) ◽  
pp. 51-53
Author(s):  
J F C Tyler
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Coefficients Of Variation ◽  
Pesticide Formulations ◽  
Glass Column ◽  
Technical Material ◽  
Gas Chromatographic Method ◽  
Ethylhexyl Phthalate

Abstract A gas chromatographic method for determination of total cypermethrin in technical and formulated products has been developed and subjected to a collaborative study involving IS participating laboratories. Each sample was dissolved in methyl isobutyl ketone containing di(2-ethylhexyl) phthalate as internal standard and analyzed by gas chromatography on a glass column with 3% OV-101 on Chromosorb W-HP. Each collaborator was furnished with reference stdard and 4 samples of technical material, 3 emulsifiable concentrates, one wettable powder, and one ultralow volume formulation for analysis. The coefficients of variation of the results obtained ranged from 0.955 to 1.7462%. The method has been adopted as official first action by AOAC.

Gas Chromatographic Method for Determination of Permethrin in Pesticide Formulations: Collaborative Study

1987 ◽  
Vol 70 (1) ◽  
pp. 53-55
Author(s):  
J F C Tyler
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Isobutyl Ketone ◽  
Coefficients Of Variation ◽  
Pesticide Formulations ◽  
Glass Column ◽  
Technical Material ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method for determination of permethrin in technical and formulated products has been developed and subjected to a collaborative study involving 19 participating laboratories. Each sample was dissolved in methyl isobutyl ketone containing n-octacosane as internal standard and analyzed by gas chromatography on a glass column with 3% OV-210 on Chromosorb W-HP. Each collaborator was furnished with reference standard and 5 samples of technical material (90-95%), 8 emulsifiable concentrates (10-50%), 2 wettable powders (20-30%), one dustable powder (1-2%), and one mter-dispersible granules (1-2%) for analysis. The coefficients of variation of the results obtained ranged from 0.79 to 4.24%. The method has been adopted as official first action by AOAC.

scholarly journals Gas Chromatographic Determination of Alachlor in Microencapsulated Formulations: Mini-Collaborative Study

1987 ◽  
Vol 70 (6) ◽  
pp. 1056-1058
Author(s):  
David F Tomkins
Keyword(s):  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Chromatographic Column ◽  
Data Points ◽  
Gas Chromatographic Method ◽  
Isothermal Gas

Abstract An isothermal gas chromatographic method for measuring alachlor in Micro-Tech® (microencapsulated) formulations was tested by 5 collaborators. The samples were prepared in acetone, and alachlor was determined using a gas chromatographic column of 10% SP- 2250 on 100-120 mesh Supelcoport. Di-n-pentylphthalate was used as the internal standard. Collaborators made single determinations on 5 samples distributed as blind duplicates. The mini-collaborative study generated 47 data points. The coefficient of variation (CV„- pooled) was 1.35%, and CVx-pooled was 0.73%. The method was simple to use and did not reveal any interferences in samples tested. The method has been adopted official first action as an AOACCIPAC method.

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.

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.

Gas Chromatographic Determination of Pentachlorophenol in Gelatin: Collaborative Study

1985 ◽  
Vol 68 (3) ◽  
pp. 419-421
Author(s):  
George Yip
Keyword(s):  
Gas Chromatography ◽  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
Coefficients Of Variation ◽  
Gas Chromatographic Method ◽  
Hydrolysis Of ◽  
Ppm Level

Abstract Eleven collaborators participated in this study of a gas chromatographic method for the determination of pentachlorophenol (PCP) in gelatin. Following acid hydrolysis of a 2 g sample, PCP is extracted with hexane and partitioned into KOH solution. After reacidification, PCP is again extracted with hexane for determination by electron capture gas chromatography on a 1 % SP-1240DA column. Three duplicate practice samples (0.0, 0.5, and 1.5 ppm) and 5 blind duplicate collaborative samples (0.0, 0.02, 0.1, 0.5, and 2.0 ppm) were analyzed by each collaborator. Mean recoveries of PCP in the collaborative samples ranged from 88% at the 0.02 ppm fortification level to 102% at the 0.1 ppm level; the overall mean recovery was 96%. Interlaboratory coefficients of variation ranged from 16.4% for the 0.1 ppm fortification level to 22.9% for the 0.5 ppm level; the overall interlaboratory coefficient of variation was 19.5%. The method has been adopted official first action.

Collaborative Study of Gas Chromatographic Analysis of Heptachlor Content of Formulations

1968 ◽  
Vol 51 (3) ◽  
pp. 565-568
Author(s):  
Marshall Malina
Keyword(s):  
Correction Factor ◽  
Chromatographic Analysis ◽  
Free Choice ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Gas Chromatographic Analysis ◽  
Glass Column ◽  
Response Correction ◽  
Gas Chromatographic Method

Abstract A collaborative study was conducted on a gas chromatographic method for analysis of heptachlor formulations that employs a glass column filled with a nonreactive packing to minimize losses of the heptachlor during chromatography. An internal standard and a response correction factor are used to convert peak size to formulation assay. An alternative gas chromatographic (GC) method that permitted free choice of GC parameters was also studied collaboratively. Collaborative results indicate that parameters must be controlled. Results by the described method were excellent, and it is recommended for adoption as official, first action.

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