Solid phase microextraction associated with microwave assisted extraction of organochlorine pesticides in medicinal plants

The solid phase microextraction (SPME) associated with microwave assisted extraction (MAE) for organochlorine pesticides (OCPs) in medicinal plants were studied. The influence of SPME extraction time, desorption time and temperature, and gas chromatography (GC) inlet conditions for the SPME fiber coated with poly(dimethylsiloxane) (PDMS) were investigated. Extraction time of 90min, desorption time of 2min and desorption temperature of 270°C were selected for SPME. Heating time of 10min and heating power of 80% were the optimum conditions for MAE. Three different commonly used medicinal plants were tested including atractylodis rhizoma, glycyrrhizae radix, and poria. The associated SPME and MAE using water as the extracting solvent shows good results for the medicinal plants. The method detection limits were below 0.13ng/g using GC electron capture detection. The reproducibility of the technique was less than 24% R.S.D.