Liquid Chromatographic Determination of Methazole in Technical and Formulated Products: Collaborative Study

1992 ◽  
Vol 75 (6) ◽  
pp. 1103-1106
Author(s):  
Benjamin A Belkind
Keyword(s):  
Active Ingredient ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Matched Pair ◽  
Relative Standard ◽  
Peak Areas ◽  
Stainless Steel Column ◽  
Calibration Solution ◽  
Liquid Chromatographic

Abstract An isocratic normal-phase liquid chromatographic (LC) method for measuring methazole in technical and formulated products was collaboratively studied by 12 laboratories. Samples of technical or formulated products are dissolved in 1,4-dioxane-hexane containing 2-chloro-5-nitrobenzophenone as internal standard. Following centrifugation and further dilution, the sample is analyzed by LC on a 25 cm x 4.6 mm stainless steel column packed with 5 μm silica, with ultraviolet detection at 254 nm. Premixed 1% 2-propanol in hexane is used as the mobile phase. Peak areas are obtained at the retention times corresponding to the internal standard and methazole. The quantity of active ingredient is determined by comparing the area ratio of active ingredient to internal standard in the sample with the same ratio in a single calibration solution. Collaborators were provided with 1 Youden matched pair for each of the technical, 75% wettable granular, and 4 lb/gal flowable products studied. The reproducibility relative standard deviations (RSDR) for the product types studied were 1.05% for technical, 1.80% for granular, and 4.76% for flowable. The method has been adopted first action by AOAC International.

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.

Liquid Chromatographic Determination of Diclazuril in Premix and Supplemented Feed: Interlaboratory Study

1994 ◽  
Vol 77 (6) ◽  
pp. 1359-1361 ◽  
Author(s):  
Andre Fontaine ◽  
Karel Haustraete
Keyword(s):  
Solid Phase ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Reversed Phase ◽  
Poultry Feed ◽  
Uv Detector ◽  
Relative Standard ◽  
Liquid Chromatographic

Abstract Diclazuril, Janssen Research Compound R 64433 (Clinacox), is analyzed by liquid chromatography (LC). Compound R 062646, with a structure analogous to that of diclazuril, is used as internal standard. The drug is extracted from feed with acidified methanol. Diclazuril is then isolated by solid-phase extraction (SPE) with a cartridge containing a C18 phase. The eluate is evaporated, and the residue is redissolved in dimethylformamide. An aliquot is injected onto a reversed-phase ODS LC column, and the drug quantitated at 280 nm with a UV detector. Peak areas are obtained at the retention times corresponding to the internal standard and diclazuril. The quantity of active ingredient is determined by comparing the ratio of the peak height of diclazuril to that of internal standard in the sample with the same ratio in a single calibration solution. SPE is not necessary for the analysis of premixes. Eleven laboratories participated in the collaborative study. Laboratories were provided with 2 samples of premixes and 3 samples of feed for poultry. Feed sample K1 was sent to only 6 laboratories. The reproducibility relative standard deviations (RSDRS) were 7.38 and 7.53% for the 2 premixes and 9.67,13.65, and 18.61% for the 3 samples of supplemented feed.

Capillary Gas Chromatographic Determination Of Cypermethrin In Formulations: Collaborative Study

1985 ◽  
Vol 68 (3) ◽  
pp. 592-595
Author(s):  
Peter D Bland
Keyword(s):  
Active Ingredient ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Fused Silica ◽  
Flame Ionization ◽  
Wettable Powder ◽  
Peak Areas ◽  
Liquid Concentrate

Abstract A method is described for the determination of cypermethrin, 3-(2,2- dichloroethenyl)-2,2-dimethyl-cyclopropanecarboxylate cyano-(3- phenoxyphenyl)methyl ester, in technical and formulated material by capillary gas chromatography (CGC). Samples of technical or formulated material are dissolved in CH2Cl2 containing dicyclohexyl phthalate as internal standard. The solution is injected into a gas chromatograph fitted with a flame ionization detector and capillary column of 25 m x 0.32 mm fused silica with a thick film OV-1 phase at 240°C. Injection is made into a heated injection port fitted with an antidiscrimination device in a split mode. Peak areas obtained at retention times of the internal standard and active ingredient are measured with an integrator. The quantity of cypermethrin is determined by comparing the internal standard and active ingredient peak areas with those obtained from a calibration solution containing known amounts of internal standard and pure active ingredient. Five samples were chosen for collaborative study: technical cypermethrin, 70% liquid concentrate, 3 lb/US gal. emulsifiable, 3 ib/US gal. oil concentrate, and 40% wettable powder. Twelve collaborators carried out replicate determinations on each sample on separate days. Coefficients of variation between laboratories (CVX) were 2.13 for the technical, 2.94 for the emulsifiable concentrate, 3.51 for the liquid concentrate, 2.66 for the wettable powder, and 2.29 for the oil concentrate. The method was adopted official first action.

Gas Chromatographic Determination of Metolachlor in Pesticide Formulations: Collaborative Study

1985 ◽  
Vol 68 (3) ◽  
pp. 570-572
Author(s):  
Thomas G Gale ◽  
Arthur H Hofberg
Keyword(s):  
Active Ingredient ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Matched Pair ◽  
Emulsifiable Concentrate ◽  
Flame Ionization ◽  
Pesticide Formulations ◽  
Better Than

Abstract A gas chromatographic (GC) procedure for the determination of metolachlor in emulsifiable concentrate formulations containing about 76% active ingredient was collaboratively studied using the matched pair scheme. Metolachlor was extracted from the formulation with acetone containing dipentyl phthalate as the internal standard, chromatographed on OV-101, and detected by flame ionization. Determinations on the 4 samples by 21 government, university, and industrial collaborators using peak area measurements showed within-laboratory repeatability of better than 0.5%. Reproducibility was better than 1% for the formulation. The method has been adopted official first action.

Quantitation of Cyfluthrin in Liquid and Solid Formulations by Reversed-Phase Liquid Chromatography: Collaborative Study

1995 ◽  
Vol 78 (6) ◽  
pp. 1335-1338 ◽  
Author(s):  
Donald N Harbin
Keyword(s):  
Collaborative Study ◽  
Internal Standard ◽  
Reversed Phase ◽  
Matched Pair ◽  
Reversed Phase Liquid Chromatography ◽  
Pesticide Formulations ◽  
Relative Standard ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method has been developed for quantitation of cyfluthrin (Baythroid®, Tempo®) in liquid and solid formulations. Cyfluthrin is a synthetic pyrethroid insecticide. Samples are dissolved in acetonitrile and analyzed by reversedphase LC with decanophenone as an internal standard. Seventeen laboratories from 7 countries participated in a collaborative study of the method. Each collaborator was provided with reference standard, internal standard, and matched pair samples of Tempo 20 wettable powder, Tempo 2 emulsifiable concentrate, and Tempo 2 flowable liquid formulations. Collaborators were instructed to use peak area measurements for quantitation. Relative standard deviations for reproducibility (RSDR) were 0.78,0.98, and 2.32, respectively. The LC method for determination of cyfluthrin in pesticide formulations has been adopted first action by AOAC INTERNATIONAL.

Gas Chromatographic Determination of Chlordimeform in Pesticide Formulations: Collaborative Study

1985 ◽  
Vol 68 (3) ◽  
pp. 589-592
Author(s):  
Thomas G Gale ◽  
Arthur H Hofberg
Keyword(s):  
Active Ingredient ◽  
Methylene Chloride ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Matched Pair ◽  
Flame Ionization ◽  
Pesticide Formulations ◽  
Better Than

Abstract Agaschromatographic (GC) procedure for the determination of chlordimeform in emulsiflable concentrate formulations containing about 46% active ingredient was collaboratively studied using the matched pair scheme. Chlordimeform was extracted from the formulation with methylene chloride containing diethyl terephthalate as the internal standard, chromatographed on CBWX-20M, and detected by flame ionization. Determinations on the 4 samples by 20 government, university, and industrial collaborators using peak area measurements showed within-laboratory repeatability of better than 1%. Reproducibility was 1.2% for the formulation. The method has been adopted official first action.

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

1981 ◽  
Vol 64 (6) ◽  
pp. 1315-1318
Author(s):  
Peter D Bland ◽  
◽  
J Bagness ◽  
W Black ◽  
L Brown ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Chloroform Solution ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Technical Product ◽  
Flame Ionization ◽  
Peak Areas ◽  
Liquid Chromatographic

Abstract A method is described for the determination of pirimicarb (2-(dimethylamino)-5,6-dimethyl-4-pyrimidinyl dimethylcarbamate) in formulated products by gas-liquid chromatography (GLC). Samples are dissolved in a chloroform solution of an internal standard and injected into a gas chromatograph equipped with a flame ionization detector. Quantitative data are obtained by comparing peak areas of the compound and internal standard with those obtained by injecting a standard solution. Eleven collaborators made replicate determinations on 6 samples including a technical product, a granular product, and 4 powder products. The average coefficient of variation was 1.14% for the technical product, 1.82% for the granular product, and 0.73% for the powder products.

Gas Chromatographic Determination of Fluazifop-butyl in Formulations: Collaborative Study

1984 ◽  
Vol 67 (3) ◽  
pp. 499-502
Author(s):  
Peter D Bland ◽  
◽  
L Chenery ◽  
N Ellis ◽  
L Firestone ◽  
...  
Keyword(s):  
Active Ingredient ◽  
Methylene Chloride ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Emulsifiable Concentrate ◽  
Coefficients Of Variation ◽  
Peak Areas

Abstract A method is described for the determination of butyl 2-(4-(5-trifluoromethyl- 2-pyridinyloxy)phenoxy) propanoate in technical and formulated material by gas chromatography (GC). Samples of technical or formulated material are dissolved in methylene chloride containing dibenzyl succinate as internal standard. The solution is injected into a gas chromatograph fitted with a flame ionization detector and a 6 ft × 2 mm glass column. The column is packed with 3% OV-17 on 100–120 mesh Chromosorb WHP and is maintained at 230°C. Peak areas obtained at the retention times of the internal standard and the active ingredient are measured with an integrator. The quantity of fluazifop-butyl is determined by comparing the internal standard and active ingredient peak areas with the peak areas obtained from a calibration solution containing known amounts of internal standard and pure active ingredient. Four samples were chosen for collaboration: technical fluazifop-butyl, a 4 lb/US gal. emulsifiable concentrate, a 560 g/L oil concentrate, and a 5% granular. Fourteen collaborators carried out replicate determinations on each sample. Coefficients of variation between laboratories were 0.80 for the technical, 0.88 for the emulsifiable concentrate, 1.03 for the oil concentrate, and 2.04 for the granular. Parallel peak height determinations showed substantially higher coefficients of variation for all except the granular sample. The method has been adopted official first action.

Liquid Chromatographic Determination of Glyphosate and Aminomethylphosphonic Acid (AMPA) in Environmental Water: Collaborative Study

1991 ◽  
Vol 74 (2) ◽  
pp. 317-323 ◽  
Author(s):  
Mark E Oppenhuizen ◽  
John E Cowell
Keyword(s):  
Collaborative Study ◽  
Chromatographic Determination ◽  
Environmental Water ◽  
Aminomethylphosphonic Acid ◽  
Relative Standard ◽  
Total Variability ◽  
Liquid Chromatographic Determination ◽  
Predicted Values ◽  
Liquid Chromatographic

Abstract A new method for determination of glyphosate and amlnomethylphosphonlc acid (AMPA) residues In environmental water was collaboratively studied by 6 laboratories. The method Is simpler and shorter than previous methods. A filtered volume of water is evaporated to dryness and the residue Is dissolved In a buffered EDTA solution. Glyphosate and AMPA are determined by liquid chromatography with postcolumn reaction detection. The method was validated over the range 0.50-5000 ppb, although one of the collaborating laboratories could not reliably quantltate below 1.0 ppb. Statistical analysis of the results showed that typical reproducibility relative standard deviations (RSDR) ranged from 11 to 20% for both glyphosate and AMPA, which compares very well with predicted values for this concentration range. Total variability (as measured by sR) Increased with increasing fortification level. The method has been adopted official first action by AOAC.

Liquid Chromatographic Determination of Diazepam in Tablets: Collaborative Study

1985 ◽  
Vol 68 (3) ◽  
pp. 545-546
Author(s):  
Michael Tsougros
Keyword(s):  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Photometric Detection ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
The Mean ◽  
Liquid Chromatographic

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.

Sign in / Sign up

Export Citation Format

Share Document