Residues determination and dietary risk assessment of dimethomorph and benthiavalicarb-isopropyl in table grape using QuEChERS and liquid chromatography tandem mass spectrometry

ABSTRACTA simple, rapid and selective method based on liquid chromatography tandem mass spectrometry and QuEChERS was established for simultaneous determination of dimethomorph and benthiavalicarb-isopropyl residues in grape. The mean intra-day recoveries of dimethomorph and benthiavalicarb-isopropyl in grape were in the range of 91.5–103.5% at four-spiked levels. The inter-day recoveries of dimethomorph and benthiavalicarb-isopropyl in grape were 98.9% and 98.6% at spiked level of 0.5 mg kg−1, respectively. The relative standard deviation (RSD) was lower than 8.4%, and the limit of quantitation (LOQ) was 0.01 mg kg−1 for both fungicides. The residual behaviour of both fungicides in the grape field at two different locations was investigated using the developed and validated method. The half-lives of dimethomorph in grapes were 5.9 to 8.8 d, and that of benthiavalicarb-isopropyl were 7.9 to 11.6 d. The terminal residues of dimethomorph and benthiavalicarb-isopropyl were lower than 1.3 and 0.79 mg kg−1, re...