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

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.

1996 ◽  
Vol 79 (4) ◽  
pp. 941-948
Author(s):  
James E Conaway ◽  
J B Audino ◽  
E Bane ◽  
S K Carrigan ◽  
R Glinsky ◽  
...  

Abstract A reversed-phase liquid chromatographic (LC) method for methomyl was studied. Twelve collaborators analyzed 3 solid and 4 liquid formulations on both a Zorbax octadecylsilane (ODS) column and a similar column of their choice. Methomyl and the internal standard were separated by using a mobile phase consisting of approximately 8% acetonitrile in water, which was monitored at 254 nm. The coefficient of variation on the Zorbax column ranged from 0.70 to 5.23%, while the range on the collaborators' house columns was 1.08 to 6.01%. Results with the Zorbax ODS column fell within the 5% 2-tail limits, and 10 of 11 collaborators' results fell within these limits on house columns. The LC method for determination of methomyl in insecticidal formulations has been adopted first action by AOAC INTERNATIONAL.


1998 ◽  
Vol 81 (2) ◽  
pp. 344-348 ◽  
Author(s):  
Michelle M Macke ◽  
◽  
Richard Ambrose ◽  
Lajos Benke ◽  
Ralph Denning ◽  
...  

abstract A liquid chromatographic (LC) method was developed for quantitation of the synthetic insecticide imidacloprid in liquid and solid formulations. Samples are dissolved or extracted in solvent and analyzed by reversed-phase LC with propiophenone as internal standard. Fourteen laboratories in 7 countries participated in the collaborative study of the method. Each collaborator was provided with reference standard, internal standard, and matched-pair samples of imidacloprid technical, flowable, wettable powder, fertilizer, and granular formulations. Collaborators were instructed to use peak area measurements for quantitation. The reversed-phase LC method for determination of imidacloprid in liquid and solid formulations has been adopted first action by AOAC INTERNATIONAL.


1992 ◽  
Vol 75 (4) ◽  
pp. 698-700
Author(s):  
Alan R Hanks

Abstract A reversed-phase liquid chromatographic (LC) method for the determination of technical methamidophos and 5 different formulated products was collaboratively studied in 18 laboratories. Samples were dissolved in water, separated by LC, and detected at 210 nm. Quantitation was done by peak area measurements. Relative standard deviations for repeatability and reproducibility ranged from 0.35 to 0.80 and from 1.14 to 1.60, respectively. The method has been approved first action by AOAC International as a CIPAC-AOAC method.


1998 ◽  
Vol 81 (2) ◽  
pp. 341-343
Author(s):  
Alan R Hanks ◽  
◽  
J Abedi ◽  
E De Aguila ◽  
F Bodzian ◽  
...  

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.


1993 ◽  
Vol 76 (2) ◽  
pp. 287-291 ◽  
Author(s):  
Alan L Scher ◽  
Nicholas C Adamo

Abstract A method is described for the determination of the intermediates and a related impurity in D&C Red No. 36 by reversed-phase liquid chromatography. This method may be used to ensure that limits set forth in the Code of Federal Regulations on the amounts of these 3 impurities in the color are not exceeded. The pigment is dissolved in boiling dioxane and then precipitated. The filtrate is chromatographed by isocratic elution, and then the column is washed and reequilibrated. Impurities were identified as 2-chloro-4-nitroaniline (2-CI-4-NA), 2-naphthol, and 2,4-dinitroaniline (2,4-DNA) by comparison of their retention times and spectra with those of standards. Peak area calibrations were linear to at least 0.375% 2-CI-4-NA, 1.25% 2-naphthol, and 0.025% 2,4-DNA, all with zero intercepts. At the specification levels, 99% confidence limits were 0.30 ± 0.006% for 2-CI-4-NA, 1.0 ± 0.03% for 2-naphthol, and 0.020 ± 0.0004% for 2,4-DNA. The limits of determination calculated from calibration data were 0.019% for 2-CI-4-NA, 0.10% for 2-naphthol, and 0.0014% for 2,4-DNA at the 99% confidence level. Recoveries were 100-104% for 2-CI-4-NA added to purified D&C Red No. 36,100% for 2-naphthol, and 100-110% for 2,4-DNA; relative standard deviations were 0.8-3.4%. A survey of certified D&C Red No. 36 samples showed that the batches contained higher levels of intermediates than were determined previously by a cellulose column method in which the pigment was not dissolved.


1994 ◽  
Vol 77 (2) ◽  
pp. 328-330
Author(s):  
Thomas M Schmitt

Abstract An isocratic reversed-phase liquid chromatographic (LC) procedure for measuring bentazon in commercial herbicide products and aqueous formulations was collaboratively studied by 16 laboratories. Samples are dissolved in LC eluent [0.075M sodium acetate–methanol (60 + 40)] and analyzed by LC on a 30 cm × 3.9 mm octadecylsilyl column with detection by UV absorbance at 340 nm. The quantity of active ingredient is determined by comparing the mean response factor (RF) of the sample to the mean RF of standards injected just before and after each pair of sample injections. The average relative standard deviation (RSDR) for 3 formulations studied was 1.54%; the RSDR for a technical sample was 0.77%. The method has been adopted first action by AOAC INTERNATIONAL.


1994 ◽  
Vol 77 (1) ◽  
pp. 8-10
Author(s):  
Alan R Hanks

Abstract Phosphamidon is determined by reversed-phase liquid chromatography on a C18 column with a mobile phase of acetonitrile—methanol buffer solution, detected by a UV absorbance detector set at 218 nm, and quantitated by area measurements using an external standard. The method was adopted first action by AOAC INTERNATIONAL.


2001 ◽  
Vol 84 (3) ◽  
pp. 676-683 ◽  
Author(s):  
Natividad Ramos-Martos ◽  
Francisco Aguirre-Gómez ◽  
Antonio Molina-Díaz ◽  
Luis F Capitán-Vallvey

Abstract This paper describes a rapid reversed-phase liquid chromatographic method, with UV detection, for the simultaneous determination of acetylsalicylic acid, caffeine, codeine, paracetamol, pyridoxine, and thiamine in pharmaceutical preparations. A reversed-phase C18 Nucleosil column is used. The mobile phase consists of 2 successive eluants: water (5 min) and acetonitrile–water (75 + 25, v/v; 9 min), both adjusted to pH 2.1 with phosphoric acid. Before determination acetylsalicylic acid is completely converted to salicylic acid by alkaline hydrolysis. Salicylic acid, caffeine, paracetamol, pyridoxine, and thiamine are all detected at 285 nm, whereas codeine is detected at 240 nm. Calibration curves were linear for salicylic acid, caffeine, paracetamol, and pyridoxine in the range of 50–500 mg/L, and for codeine and thiamine in the range of 50–1000 mg/L. The method was applied to the analysis of 13 fortified commercial pharmaceutical preparations. Recoveries ranged from 92.6 to 105.5%, with relative standard deviations of 1.1–5.8%.


1994 ◽  
Vol 77 (6) ◽  
pp. 1359-1361 ◽  
Author(s):  
Andre Fontaine ◽  
Karel Haustraete

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.


1995 ◽  
Vol 78 (5) ◽  
pp. 1131-1133
Author(s):  
Alan R Hanks

Abstract A liquid chromatographic method for determination of dithianon in technical products and formulations was evaluated by 22 laboratories participating in a collaborative study. Data received from 19 laboratories were used in the statistical analysis. The study included 3 technical grade materials, 1 suspension concentrate, and 1 wettable powder. Dithianon is determined by reversed-phase liquid chromatography on a C18 column with a mobile phase of acetonitrile and water. Detection at 254 nm with peak area measurements is used with an external standard for quantitation of dithianon. The liquid chromatographic method for determination of dithianon in technical products and formulations has been adopted first action by AOAC INTERNATIONAL.


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