Abstract:

Objective: To develop a capillary GC method for the determination of the residues of 24 organochlorines or synthetic pyrethroid and 16 organophosphorus pesticides in shiitake mushroom. Methods: Samples were weighed into Teflon centrifuge tubes and high-speed homogenized with acetonitrile, and the supernatant was then condensed until almost dry and applied to a carbon/NH2 SPE column for cleanup. After recondensation until almost dry, the eluate was rediluted with n-hexane before being injected into the analytical instrument. Electron capture detector was used to detect organochlorines and pyrethroids and flame photometric detector to detect organophosphorus. Using the external standard method, quantitation was carried out. Results: The linear range of the proposed method was between 0.016μg/mL and 0.80 μg/mL, with a correlation coefficient of larger than 0.999, and its recovery, repeatability RSD and detection limit varied from 73.0% to 113%, from 3.2% to 5.9% and from 0.0005 to 0.05 mg/kg. Conclusion: A simple, sensitive and reproducible method applicable to the determination of pesticide multiresidues in shiitake mushroom and other species of mushroom has been developed.

Key words: pesticide residue, shiitake mushroom, edible fungi, capillary GC