Collaborative Study of Gas-Liquid Chromatographic Method for Determining Fluometuron

Abstract

Abstract A gas-liquid chromatographic (GLC) method for determining fluometuron in a wettable powder formulation containing about 80% active ingredient was collaboratively studied using a matched pair scheme. The samples were dissolved in chloroform containing diethyl phthalate as an internal standard, derivatized with trifluoroacetic anhydride, and chromatographed on OV-3, using a flame ionization detector. Analyses of the 2 samples by 14 collaborators, using peak height measurements, showed the following results: 0.99% overall coefficient of variation, 1.08% coefficient of variation for the random error, and no evidence of systematic error. The validity of these results was verified by a concurrent collaborative effort using high pressure liquid chromatography. Analyses of the 2 samples by 8 collaborators, using peak height measurements, showed a 1.17 standard deviation of the total for liquid chromatography vs. 0.76 standard deviation of the total for GLC. The averages for Sample A and Sample B by liquid chromatography showed a relative difference of 0.19 and 0.00%, respectively, when compared with the results by the GLC method. The GLC method has been adopted as official first action.