HPLC determination of oxadiazon in commercial pesticide formulations

Abstract

A simple, fast and precise high performance liquid chromatographic (HPLC) procedure has been developed for the determination of oxadiazon in emulsifiable concentrated pesticide formulations. 20 μL of diluted sample in acetonitrile were injected in a Kromasil C18 (250 x 4.6 mm, 5 μm) column, using acetonitrile:water (80:20) as mobile phase at 1 mL min-1 flow rate and oxadiazon determined by absorbance measurement at 292 nm. A theoretical limit of detection of 0.02 μg mL-1, a limit of quantification of 0.047 μg mL-1, corresponding to a 0.02 and 0.07% m/v in the original sample, and a relative standard deviation of 0.08% for three replicate analysis of samples containing 25% m/v. Oxadiazon were achieved using the developed procedure. The accuracy of the whole method was evidenced by recovery percentages from 98% to 99% for samples spiked with 0.015 to 0.085 mg oxadiazon as well as by the good comparability between results found by the recommended procedure and by Fourier Transform Infrared (FTIR) spectrophotometry for actual samples of formulated products. ©2008 Sociedade Brasileira de Química.