Combination of microwave assisted micellar extraction and liquid chromatography for the determination of organophosphorous pesticides in soil samples

A new methodology based on the microwave assisted micellar extraction (MAME) technique has been optimised, using soil samples, to extract and determine a mixture of the eight organophosphorous pesticides mainly used in agriculture. The pesticides under study have been extracted using the non-ionic surfactants polyoxyethylene 10 lauryl ether (POLE) and oligoethylene glycol monoalkyl ether (Genapol X-080). The optimal extraction variables, such as surfactant concentration, pH, radiation time and microwave power were determined for each surfactant. The results show the advantage of using POLE instead of Genapol X-080 for the extraction of the organophosphorus pesticides with recoveries higher than 70% for most of the compounds and relative standard deviations (RSD) below 2.6%. This method was successfully applied to fresh samples as well as to aged samples for the analysis of soils with different characteristics and compared with the traditional Soxhlet technique.