Determination of 109 pesticide residues in potato using QuEChERS clean-up and gas chromatography-mass spectrometry

Objective A modified QuEChERS method for simultaneous determination of 109 pesticide residues in potato using gas chromatography coupled with mass spectrometry was established and validated. Methods The pesticide residues were extracted from the potato samples with acetonitrile,and purified by dispersion solid phase extraction( d-SPE) using N-propyl ethlene diamine( PSA) as the adsorbent. The GC-MS analysis was carried out under selected ion monitoring mode and the quantification was performed using the external standard calibration. Results The limits of quantification( LOQ) for 109 pesticide were in the range of 0. 001-0. 010 mg / kg. The recoveries were between 72. 7% and 118. 7% with the RSD of 1. 1%-17. 3%. When using electron impact( EI) mode,most pesticides exhibited matrix enhancement effects in potato matrix. To ensure an accurate determination,the matrix-matched calibration was used for quantitation. The established method was successfully applied to the potato samples provided by European proficiency test in fruits and vegetables organized by European Union Reference Laboratory for Residues of Pesticides in Fruits and Vegetables,and 13 pesticides were detected with the concentration in the range of 0. 002-1. 669 mg / kg with the Z-scores in the range of- 1. 00 to 1. 00. Conclusion The method was simple,sensitive,accurate and suitable for the fast screening test for multi-residue pesticides in potato.