Gas-Liquid Chromatographic Method for Determining Bolstar Insecticide in Formulations: Collaborative Study

Abstract

A gas-liquid chromatographic (GLC) method for determining Bolstar insecticide in liquid technical material and emulsifiable concentrate formulations was collaboratively studied using Youden’s matched pair scheme. Three matched sample pairs were analyzed by 21 laboratories using integrator area measurements and/or peak height measurements. Samples of a technical material containing about 78% active ingredient, a commercial 6 lb/ gal. emulsifiable concentrate containing about 64% active ingredient, and a synthetic emulsifiable concentrate containing about 64% active ingredient were dissolved in a measured amount of internal standard solution, tetracosane in toluene, and were subjected to gas-liquid chromatography on a column of 1.5% SE-30 + 1.5% OV-210. Bolstar was detected using flame ionization. The mean coefficient of variation by integrator area measurement for the 6 samples was 1.22%, and the mean coefficient of variation by peak height measurement for the 6 samples was 1.65%. The method was adopted as official first action.