محبوبه شیرانی

In this study solid-phase extraction (SPE) combined with the dispersive liquid–liquid microextraction (DLLME) has been presented for the simultaneous determination of trace amounts of cypermethrin and permethrin in soil and water samples by gas chromatography- mass spectrometry (GC-MS). In this method, soil and water samples were extracted by ultrasound-assisted extraction followed by SPE. Then, the SPE elution solvent was used as a disperser solvent in the next dispersive liquid-liquid microextraction step for the further purification and enrichment of cypermethrin and permethrin. The important parameters influencing SPE- DLLME, such as type and volume of extraction solvent and elution solvent (disperser solvent), and flow rate were investigated through the process. Under the optimum conditions, good linearity in the range of 10-100 µg L-1 with the correlation coefficient (r2)> 0.9996 and 0.9992, low limits of detection (LODs) of 0.08 and 0.06 µg L-1, and relative standard deviations (RSD%, n= 7) of 3.2% and 4.3% were obtained for permethrin and cypermethrin respectively. The proposed procedure showed satisfactory results for simultaneous determination of cypermethrin and permethrin in soil and water samples.