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.

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.

Gas-Liquid Chromatographic Method for Analysis of Pentachloronitrobenzene Formulations: Collaborative Study

1982 ◽  
Vol 65 (1) ◽  
pp. 110-114
Author(s):  
Alan R Hanks
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Peak Height ◽  
Matched Pairs ◽  
Commercial Products ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Wettable Powder ◽  
Liquid Chromatographic

Abstract A collaborative study has been conducted on a gasliquid chromatographic (GLC) method for determining pentachloronitrobenzene (PCNB) in formulations. Wettable powder, liquid, and granular matched pairs of commercial products were analyzed by 17 laboratories using peak height measurements and by 12 laboratories using integrator area measurements. Samples were dissolved in chloroform and aliquots were mixed with internal standard before GLC analysis on a 5% SE-30 column. Mean coefficients of variation for the completed study were 1.54% for integrator area measurements and 1.35% for peak height measurements. The method has been adopted 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.

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.

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

1990 ◽  
Vol 73 (3) ◽  
pp. 431-434
Author(s):  
Stephen C Slahck
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Reference Standard ◽  
Reverse Phase ◽  
Methyl Paraben ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method has been developed for the determination of oxydemeton-methyl (Metasystox-RR) In formulated products. Samples are dissolved In acetonltrile and analyzed by reverse-phase chromatography using methyl paraben as an Internal standard. Twelve laboratories participated In a collaborative study of the method. Each collaborator was furnished with reference standard, Internal standard, and blind duplicate samples of Metasystox-R 50% concentrate (MSR 50 Cone), Metasystox-R spray concentrate (MSR SC), and DYLOXR/MSR 1.5-0.5 formulations. Collaborators were instructed to use peak area measurements for quantitation. Relative standard deviations for reproducibility (RSDR) were 1.44, 2.14, and 3.63%, respectively. The method has been approved Interim official first action by AOAC.

Modification of the AOAC Gas-Liquid Chromatographic Method for Indole in Shrimp: Collaborative Study

1982 ◽  
Vol 65 (4) ◽  
pp. 842-845
Author(s):  
Theodore L Chambers ◽  
◽  
E C Netz ◽  
K Ogger
Keyword(s):  
Silica Gel ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Current Method ◽  
Peak Height ◽  
Modified Method ◽  
Liquid Chromatographic Method ◽  
Gas Chromatographic Method ◽  
Liquid Chromatographic

Abstract Several changes were suggested for standardization of the AOAC official final action gas chromatographic method for the determination of indole in shrimp. In a collaborative study, 3 FDA laboratories compared the modified method with the current method. At a 95% confidence level, the same results were obtained for each respective sample by the AOAC or the modified method, which had the following changes. The cleanup column was standardized by drying the silica gel for 2 h at 125°C and equilibrating with 3 g of water/25 g of silica gel. Concentrated ethyl acetate shrimp extracts were treated with anhydrous sodium sulfate before column cleanup and indole was eluted from the column with 15% ethyl ether/hexane. A reduced amount of the internal standard, 2-methylindole, was used to improve peak height measurements at the 25 μg% indole level. The modified method has been adopted official first action to replace method 18.075.

Gas-chromatographic determination of mephenytoin and desmethylmephenytoin, after off-column alkylation.

1979 ◽  
Vol 25 (1) ◽  
pp. 172-175
Author(s):  
V A Raisys ◽  
A M Zebelman ◽  
S F MacMillan
Keyword(s):  
Active Metabolite ◽  
Chromatographic Method ◽  
Seizure Control ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Therapeutic Concentration ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract We describe a gas-liquid chromatographic method for determining mephenytoin and its active metabolite, desmethylmephenytoin, in human serum. 5-Methyl-5-phenylhydantoin is used as the internal standard. The method involves extraction of the drugs by adsorption onto charcoal and off-column derivatization to their pentyl derivatives. Peak height and concentration are linearly related and the day-to-day CV for therapeutic concentration is about 2 to 6%. No interferences by endogenous compounds or drugs commonly used for seizure control have been encountered.

scholarly journals Liquid Chromatographic Method for Determining Thiodicarb in Technical Products and Formulations: CIPAC Collaborative Study

1998 ◽  
Vol 81 (2) ◽  
pp. 341-343
Author(s):  
Alan R Hanks ◽  
◽  
J Abedi ◽  
E De Aguila ◽  
F Bodzian ◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Reversed Phase ◽  
Reversed Phase Liquid Chromatography ◽  
Liquid Chromatographic Method ◽  
Wettable Powder ◽  
Phase Liquid ◽  
Liquid Chromatographic ◽  
Technical Products

abstract A liquid chromatographic method for determining thiodicarb in technical products and formulations was evaluated by 25 participants from 19 laboratories. Data from 19 laboratories were used in statistical analysis to characterize method performance.Two technical materials, a suspension concentrate, a wettable powder, and a water dispersable granule were analyzed. Thiodicarb was determined by reversed-phase liquid chromatography using a mobile phase of methanol and water. Chromatography was performed on a C8 column with detection at 254 nm. Quantitation was achieved by using an internal standard and peak area ratios.

Liquid Chromatographic Method for Determination of Glycerol in Wine and Grape Juice: Collaborative Study

1992 ◽  
Vol 75 (3) ◽  
pp. 379-383 ◽  
Author(s):  
Arthur Caputi ◽  
Eric Christensen ◽  
Nancy Biedenweg ◽  
Susan Miller
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Grape Juice ◽  
External Standard Method ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
External Standard ◽  
Standard Deviations ◽  
Liquid Chromatographic

Abstract An Ion-exchange liquid chromatographic method for the determination of glycerol in wine, white grape juice, and pink grape juice was collaboratively studied by 8 laboratories. Eight wine types and 12 juice samples were provided to each collaborator. Using a strong cation column, blind duplicates and standards were analyzed by an external standard method. Separate statistical evaluations were run on wine, white grape juice, and pink grape juice data. The averages of the relative standard deviations for repeatability, excluding outlying results, were 1.25% for the wine samples, 7.32% for the white grape juice samples, and 8.63% for the pink grape juice samples. The averages of the relative standard deviations for reproducibility, excluding outlying results, were 2.79% for the wine samples, 16.97% for the white grape juice samples, and 19.10% for the pink grape juice samples. The method has been adopted first action by AOAC International.

Liquid Chromatographic Method for Multiresidue Determination of Benzimidazoles in Beef Liver and Muscle: Collaborative Study

1991 ◽  
Vol 74 (3) ◽  
pp. 487-493 ◽  
Author(s):  
Leon W Levan ◽  
Charlie J Barnes
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Study Data ◽  
Beef Liver ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Repeatability And Reproducibility ◽  
Multiresidue Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method for determination of thiabendazole, 5-hydroxythiabendazole, oxfendazole, mebendazole (MBZ), and fenbendazole (FBZ) In cattle liver and muscle was collaboratively studied in 7 laboratories In 1986. For blind fortified samples containing 800 ppb FBZ, average recovery and relative standard deviations for repeatability and reproducibility (RSDr and RSDR) based on results from 6 of the participating laboratories were 83%, 12.7%, and 14.0%, respectively. Recoveries of FBZ from incurred liver samples were more variable. Recoveries of MBZ from livers fortified at the 100 ppb level were encouraging; however, the drug levels were too low in the incurred samples used for MBZ studies. Except for FBZ and MBZ In liver, the study data were not satisfactory. The method has been adopted official first action by AOAC for determination of 800-1600 ppb fenbendazole In liver. The analysis should be repeated using a smaller sample size when Initial analyses show levels greater than 1600 ppb FBZ.

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