2018 Volume 24 Issue 1 Pages 97-103
A simple, rapid and efficient method for the determination of picoxystrobin in watermelon ecosystem was established and validated via QuEChERS (quick, easy cheap, effective, rugged and safe) method using rapid resolution liquid chromatography tandem mass spectrometry (RRLC-MS/MS). The average recoveries (n=5) of picoxystrobin in three matrix at three fortification levels ranged from 89.4% to 102.6%. The limits of detection (LODs) were lower than 1.28×10−4 mg L−1. The limits of quantification (LOQs) were 0.001 mg kg−1 for watermelon flesh (whole watermelon) and 0.005 mg kg−1 for soil. The half-life of picoxystrobin of whole watermelon (soil) in Shandong and Anhui were 1.43 (4.18) days and 3.71 (17.32) days, respectively. The picoxystrobin terminal residues in watermelon were lower than 0.001 mg kg−1 under the recommended dosages, which were far below the maximum residue limit (MRL) set by China (0.05 mg kg−1). These obtained data not only provide scientific information about safety estimation of picoxystrobin in watermelon and the kinetics of dissipation, but also facilitate trade exportation of watermelon for China.