Gas-Liquid Chromatographic Determination of Disulfoton in Formulations: Collaborative Study

1980 ◽  
Vol 63 (4) ◽  
pp. 869-872
Author(s):  
Thomas L Jensen ◽  
◽  
J B Audino ◽  
R Bishop ◽  
L Chenery ◽  
...  

Abstract A rapid method is described for the determination of disulfoton (0,0-diethyl S-[2-(ethylthio)-ethyl] phosphorodithioate) in formulations by gasliquid chromatography (GLC). Samples are dissolved in acetone, and, after an internal standard is added, the samples are diluted to volume with solvent. They are then injected into a gas chromatograph equipped with a flame ionization detector and quantitated by peak height or area measurements. Fourteen collaborators made duplicate determinations on 4 samples including the technical product, a liquid, and 2 granular formulations. The average coefficient of variation was 0.847% for the liquid samples and 1.90% for the granules. The method has been adopted as official first action.

1981 ◽  
Vol 64 (4) ◽  
pp. 829-832
Author(s):  
Bram Van Rossum ◽  
Albertus Martijn ◽  
James E Launer ◽  
◽  
E C Calamita ◽  
...  

Abstract The gas-liquid chromatographic determination of tetradifon technical and formulations was collaboratively studied in duplicate with 12 laboratories. Six samples were dissolved in dichloroethane with n-hexacosane as the internal standard, chromatographed on a column of 3% SE-52, and detected by flame ionization. The average coefficients of variation were 1.2% for the 2 technical samples, 1.6% for the 2 wettable powders, and 1.5% for the 2 emulsifiable concentrates. The method has been adopted official first action.


1972 ◽  
Vol 55 (1) ◽  
pp. 166-169
Author(s):  
William T Lampkin

Abstract A collaborative study was conducted on a GLC method for determining paraldehyde in pharmaceutical preparations of paraldehyde elixirs. Eleven collaborating laboratories analyzed 2 unknown paraldehyde solutions and a solution of known paraldehyde concentration. Recoveries of 15–25% paraldehyde solutions averaged 98.5% with a coefficient of variation of about 2%. The method consists of diluting a sample aliquot to a definite volume and determining the paraldehyde content by GLC, using a flame ionization detector and a 6’ × 4 mm coiled glass column packed with 80–100 mesh Diatoport S coated with 2% HIEFF-8BP (cyclohexane dimethanol succinate) plus 20% Carbowax 20M. The internal standard technique was used for calculation. It is recommended that the method be adopted as official first action.


1979 ◽  
Vol 62 (2) ◽  
pp. 292-296
Author(s):  
Richard S Wayne

Abstract A gas-liquid chromatographic method was studied collaboratively for determining malathion in wettable powders, an emulsifiable concentrate, a dust, and the technical grade product. Flame ionization detection, m-diphenoxybenzene as the internal standard, and a column containing 5% SP-2401 or OV-210 on 100-120 mesh Gas-Chrom Q or Supelcoport were used for the determination. Agreement between replicates in individual laboratories was excellent. Agreement between laboratories was satisfactory. The method offers improved specificity and ease of operation when compared to the official first action methods. The method has been adopted as official first action.


1975 ◽  
Vol 58 (5) ◽  
pp. 961-964 ◽  
Author(s):  
Alan R Hanks ◽  
Barbara S Engdahl ◽  
Billy M Colvin

Abstract A simple and rapid gas-liquid chromatographic procedure, using a 6’ × ¼“ glass column packed with 5% SE-30 on Chromosorb W (DMCS) and a flame ionization detector, is described. Grain baits containing strychnine alkaloid are ground, mixed, and extracted by shaking with chloroform containing an internal standard, 1,3,5-triphenylbenzene. Without further cleanup, extract nitrates are injected directly into a gas chromatograph. Peak height ratios are used for quantitation of strychnine. The analysis of commercial samples shows that the method compares well with a commonly employed ultraviolet spectrophotometric method; good precision, with recoveries ranging from 89.9 to 91.7%, is obtained in the analysis of prepared samples. The method is sensitive to 2 μg strychnine.


1983 ◽  
Vol 66 (3) ◽  
pp. 801-803
Author(s):  
Margie E Owen ◽  
◽  
O O Bennett ◽  
L T Chenery ◽  
C J Cohen ◽  
...  

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.


1985 ◽  
Vol 68 (3) ◽  
pp. 545-546
Author(s):  
Michael Tsougros

Abstract A stability indicating liquid chromatographic method for the determination of diazepam in tablets was collaboratively studied by 6 laboratories. The method uses a Cig reverse phase column, a methanolwater mobile phase, p-tolualdehyde as the internal standard, and photometric detection at 254 nm. The collaborators were supplied with a synthetic tablet powder and 3 commercial tablet samples. The mean recovery of diazepam from the synthetic tablet powder was 100.2%. For all samples analyzed, the coefficient of variation was < 1.5%. The method has been adopted official first action.


1984 ◽  
Vol 67 (3) ◽  
pp. 492-493
Author(s):  
Stephen C Slahck ◽  
◽  
A A Carlstrom ◽  
L T Chenery ◽  
N D Ellis ◽  
...  

Abstract An LC method for the determination of methiocarb in methiocarb technical and formulated products has been subjected to a collaborative study with 9 participating collaborators. Formulations are extracted with acetonitrile and analyzed by reverse phase chromatography, with acetophenone as an internal standard. Collaborators were furnished samples of technical, 75% wettable powder, 75% seed treater, 75% concentrate, and 50% hopper box treater. Coefficient of variation values obtained on the 5 samples were 0.71, 0.83, 0.62, 1.57, and 0.82%, respectively. The method has been adopted official first action.


1980 ◽  
Vol 63 (1) ◽  
pp. 33-36
Author(s):  
Molly I Keating

Abstract A rapid method for the analysis of dip washes is described which eliminates the usual solvent extraction procedure. The dip wash is initially diluted with acetone and then with petroleum ether. The diluted dip wash is analyzed by gasliquid chromatography, using an alkali ionization detector sensitive to phosphorus compounds. The method was applied to the determination of dioxathion (2,3-ρ-dioxanedithiol S,S-bis(O,O-diethyl phosphorodithioate)), and quintiofos (O-ethyl O-8-quinolyl phenylphosphonothioate) dip washes. Average recoveries from fouled dip washes were 100 and 104%. GLC of these compounds with an internal standard is described, which improves the precision of the method to ±2%.


1986 ◽  
Vol 69 (5) ◽  
pp. 915-918
Author(s):  
Edward J Kikta ◽  
◽  
E Bane ◽  
A Burns ◽  
A Christensen ◽  
...  

Abstract A liquid chromatographic (LC) method for the analysis of technical and formulated carbofuran samples was evaluated in a collaborative study. Carbofuran is determined by reverse phase LC, using a water-methanol mobile phase and acetophenone as internal standard, and detected at 280 nm. Twelve samples, 5 formulations and technical matched pairs, were analyzed by 17 collaborating laboratories. Accuracy and variability of results are typical of large LC data sets. The method has been adopted official first action.


1985 ◽  
Vol 68 (3) ◽  
pp. 586-589
Author(s):  
Stephen C Slahck

Abstract A liquid chromatographic method for the determination of triadimefon (Bayleton™) in triadimefon technical and formulated products has been developed and subjected to a collaborative study with 7 participating collaborators. Formulations were extracted with mobile solvent and analyzed by normal phase chromatography, with 4-chlorophenyl sulfoxide as an internal standard. Collaborators were furnished with standards and samples of technical products, 50% wettable powders, and 25% wettable powders for analysis. Coefficients of variation of the values obtained on these samples were 1.42, 0.82, and 1.05%, respectively. The method has been adopted official first action.


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