Metabolite

Maximum Residue Limit

Biology

Pesticide

Chromatography

Quechers

Biochemistry

Fungicide

Tebuconazole

Residue (chemistry)

Agronomy

Pesticide residue

Mass spectrometry

Chemistry

Liquid chromatography–mass spectrometry

Detection limit

Carbendazim

Tandem mass spectrometry

Food Chemistry

An efficient method was developed and validated for simultaneous determination of tebuconazole, thiophanate-methyl and its metabolite carbendazim in grape and soil using QuEChERS procedure and liquid chromatography-tandem mass spectrometry. The average recoveries of the method were 83.2%-105.4%, the limit of detection (LOD) ranged from 2.1 × 10-5 to 8.7 × 10-4 mg L-1, and the limit of quantitation (LOQ) was 0.1 mg kg-1. The field results showed that tebuconazole and thiophanate-methyl in soil and grape were rapidly dissipated with half-lives less than 24.7 days. The terminal residues of all analytes in grape were lower than the maximum residue limit (MRL) set by China (2 mg kg-1 for tebuconazole; 3 mg kg-1 for both thiophanate-methyl and carbendazim). Risk assessment showed that tebuconazole, thiophanate-methyl and its metabolite would be unlikely to cause health problems. However, carbendazim, the higher active metabolites of thiophanate-methyl, should receive more concerns.

Residue dissipation and risk assessment of tebuconazole, thiophanate-methyl and its metabolite in table grape by liquid chromatography-tandem mass spectrometry