Optimization of Solid Phase Microextraction Procedure Followed by Gas Chromatography with Electron Capture Detector for Pesticides

In this study, headspace solid phase microextraction (HS-SPME) followed by gas chromatography using electron capture detection system (GC-ECD) were developed for the determination of chlo-raacetanilide (butachlor) and chlorpyrifos presented in biological samples. Different parameters affecting the extraction procedure were optimized including extraction time (30 minutes), extrac-tion temperature (80˚C), sample volume (3 mL), sample pH (2), added NaCl (0.3 gram) and sample stirring rate (400 rpm). Different concentrations of 1- 100 ng/ml were applied for butachlor and a linear calibration curve was obtained. Furthermore, a similar linearity was obtained for chlorpy-rifos, using a concentration range of 1- 250 ng/ml. The limit of detection (LOD) obtained for bu-tachlor and chlorpyrifos were 0.088 and 0.53 ng/ml respectively. The optimized methods for bot