Determination of mancozeb residue in fruit by derivatization and a modified QuEChERS method using ultraperformance liquid chromatography-tandem mass spectrometry.

A liquid chromatography-tandem mass spectrometry method with derivatization and a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation was developed for the determination of mancozeb in fruits. The target compound was determined in less than 4.0 min with use of an electrospray ionization source in positive mode. The limits of detection and the limits of quantification ranged from 1.0 to 3.2 μg kg-1 and from 10 to 15 μg kg-1 in fruit respectively. The linearity was excellent for mancozeb (R 2 ≥ 0.9920). Recoveries in five matrices were obtained at three spiking levels (0.02, 0.1, and 1 mg kg-1). For all concentrations, the mean recoveries ranged from 84.0% to 95.9%, with repeatability relative standard deviation (n = 5) of 0.6 - 7.0%. The interday reproducibility relative standard deviation (n = 3) ranged from 1.4% to 5.5%. This method could be used for the routine detection of mancozeb residues in fruit. Graphical abstract The derivation of mancozeb and the detection process of derivative product by UPLC-MS/MS.