Abstract:

A method was established for determining carbendazim, 2,4-D, enrofloxacin residues in bean sprouts by ultra
performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS). Samples were extracted with acidified
acetonitrile, and cleaned up on a WAX cartridge. The target analytes were separated on a Waters C18 column with gradient
elution using a mobile phase made up of methanol and 0.1% formic acid. Detection was carried out using positive/
negative electrospray ionization and multiple-reaction monitoring (MRM), and the external standard method was used for
quantification. In the linear range of 5–150 μg/L, the correlation coefficients were all larger than 0.999 0 for carbendazim,
2,4-D and enrofloxacin. The limits of detection (LODs) were 0.5 μg/kg and the limits of quantitation (LOQs) were 1.5 μg/kg.
The recovery rates at three spiked levels of 5.0, 10.0 and 25.0 μg/kg were in the range of 80.4%–97.8%. The relative
standard deviation (RSD) of intra-day and inter-day assays was 1.25%–5.47%. The method proved to be simple, sensitive,
rapid and suitable for the determination of carbendazim, 2,4-D and enrofloxacin residues in bean sprouts.

Key words: ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS), carbendazim, 2,4-D, enrofloxacin, residue, bean sprout