A systematic approach to optimize solid-phase microextraction.: Determination of pesticides in ethanol water mixtures used as food simulants

The optimization of solid-phase microextraction (SPME) of several organochlorine and organophosphorus pesticides is presented, and the influence of variables is discussed. The optimized method is applied to several selected ethanol/water mixtures used as food simulants, and the influence of the ethanol content on the SPME performance is also discussed. Detection limits ranging from 0.02 to 0.04 ng/g for water simulant and from 38.7 to 205.5 ng/g for 95% ethanol simulant were obtained. The relative standard deviation (% RSD) was <20% in all cases. The optimized method is compared with classical liquid-liquid extraction (LLE).