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.

Multiresidue Gas Chromatographic Method for Determining Organochlorine Pesticides in Poultry Fat: Collaborative Study

1984 ◽  
Vol 67 (2) ◽  
pp. 284-289 ◽  
Author(s):  
James A Ault ◽  
Tim E Spurgeon ◽  
◽  
M M Anderson ◽  
R Bowers ◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Gel Permeation Chromatography ◽  
Accuracy And Precision ◽  
Coefficients Of Variation ◽  
Poultry Fat ◽  
Gel Permeation ◽  
Detector Method ◽  
Gas Chromatographic Method

Abstract A gas chromatographic electron capture detector method is described for the quantitative determination of organochlorine pesticide residues in poultry fat. The samples are rendered and cleaned up using automated gel permeation chromatography. The collaborative samples consisted of 10 fortified samples and one incurred residue sample, all in duplicate. Fortification levels ranged from 0.15 to 1.0 ppm for a-BHC, lindane, cis- and frans-chlordane, octachlor epoxide, o,p' and p,p'-DDT, p,p'-DDE, p,p'-TDE, hexachlorobenzene, heptachlor epoxide, dieldrin, endrin, methoxychlor, mirex, and toxaphene. The average recovery was 91.9% with a range of 81-102%. The ranges of coefficients of variation were: CVo = 3.39-14.79%; CVL = 0-16.6%; and CVx = 5.82-19.0%. The results indicate accuracy and precision comparable to other official methodology. The method has been adopted official first action.

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 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 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 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.

Determination of Menthol in Cigarette Tobacco Filler

1967 ◽  
Vol 50 (4) ◽  
pp. 770-773
Author(s):  
Charles L Tucker ◽  
C L Ogg
Keyword(s):  
Chromatographic Method ◽  
Colorimetric Method ◽  
Cigarette Tobacco ◽  
Mean Values ◽  
Accuracy And Precision ◽  
Standard Deviations ◽  
Gas Chromatographic Method

Abstract A gas chromatographic and a colorimetric method for determining menthol in cigarette tobacco filler were studied collaboratively by 15 laboratories. No statistically significant differences were found in the precisions within or between laboratories. There were no significant differences between mean values for the two methods for any of the samples. Trends toward higher mean values for the colorimetric method and lower within-laboratory standard deviations for the gas chromatographic method were noted. Remarks by collaborators suggest that the accuracy and precision of the colorimetric method may be improved, and further studies are recommended.

Comparison of Emmerie-Engel Method and Gas Chromatographic Method for Determination of Supplemental α-Tocopheryl Acetate in Feed Concentrates

1987 ◽  
Vol 70 (3) ◽  
pp. 417-419
Author(s):  
Michael P Labadie ◽  
Charles E Boufford
Keyword(s):  
Gas Chromatography ◽  
Vitamin E ◽  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Tocopheryl Acetate ◽  
High Potency ◽  
Gc Analysis ◽  
Gas Chromatographic Method ◽  
Official Procedure

Abstract The determination of supplemental a-tocopheryl acetate in high potency vitamin E powders and oils was compared using the Emmerie- Engel method and gas chromatography (GC). The Emmerie-Engel reaction requires saponification, extraction of the saponiflable fracaon, and quantitation by colorimetry. GC analysis requires only an extraction and/or dilution before quantitation. These are represented essentially by AOAC methods 43.147-43.151 (colorimetry) and 43.152-43.159 (GC) for high potency vitamin E concentrates. Each method was statistically evaluated for precision and sample-to-sample reproducibility. Each Emmerie-Engel value was divided by the GC value obtained for the same sample; an average of 1.049 with a coefficient of variation of 2.89% was obtained. It was concluded that (he GC procedure was superior to the Emmerie-Engel method, and ahould be the official procedure for determination of supplemental a-tocopheryl acetate in feed concentrates.

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