This method based on direct immersion solid-phase microextraction combined with corona discharge ion mobility spectrometry (CD-IMS) for the extraction and determination of diazinon in underground water and grape juice samples. The solid-phase microextraction (SPME) fiber coated with polypyrrole/sol–gel composite was prepared through electrochemical deposition. Effect of different parameters including salt concentration, extraction time, temperature, pH, stirring rate, desorption time and desorption temperature were investigated and optimized. Under the optimized conditions, calibration curves were plotted indicated dynamic range of 3.0-200.0, 0.2-20.0 and 0.2-20.0?g L -1 , for grape juice, underground water and standard water samples respectively. The relative standard deviation for the standard water, underground water and grape juice was less than 10% and the detection limit was obtained 0.08, 0.09 and 1.3 ?g L -1 , for the eaxtraction of diazinon from standard water, spiked underground water and spiked grape juice respectively. The relative recoveries obtained by the polypyrrole/sol-gel coating fiber from grape juice and underground water samples were in the range of 71% to 98%. Diazinon was successfully extracted and determined in grape juice samples and underground water without significant matrix effect.
