Multivariate optimization of a combined static and dynamic supercritical fluid extraction method for trace analysis of pesticides pollutants in organic honey.

Abstract

The intensive application of pesticides to increase crop production has resulted in contamination of the agricultural products. Due to their occurrence at trace levels and the complexity of food samples, analysis of pesticide residues requires selective and efficient sample preparation methods. For this purpose, an extraction method based on supercritical carbon dioxide and acetonitrile as entrainer solvent was developed for trace analysis of atrazine, diazinon, chlorothalonil, and deltamethrin pesticides in honey samples. A Box-Behnken experimental design was applied to optimize extraction variables including static extraction time (5-15min), pressure (200-700bar), and temperature (45-70°C). The optimum extraction conditions were found to be 11.5min static extraction time, 252bar, and 70°C. The proposed analytical method showed a good linearity (≥0.998), low limit of detection (0.005-0.009mg/kg), and good extraction recovery (74-111%). The precision study of the proposed method at two concentration levels of each pesticides, 0.25 and 1.0mg/kg was found to be in the ranges of 2.3-4.21% for intraday (n=3) and 3.93-8.02% for interday precisions (n=3). The developed method is promising for use in trace analysis of pesticides in complex food samples including honey.