Analysis of molluscicide metaldehyde in vegetables by dispersive solid-phase extraction and liquid chromatography-tandem mass spectrometry.

This paper describes the development and validation of a new reverse-phase liquid chromatography-electrospray ionisation tandem mass spectrometric method (RP-HPLC-ESI-MS/MS) for the determination of metaldehyde in different kinds of vegetables. Metaldehyde was extracted with 20 ml acetonitrile from 10 g vegetable and followed by dispersive solid-phase extraction (Bondesil-primary secondary amine, PSA). The identification of metaldehyde was established by chromatographic retention times, analyte-specific fragmentation patterns and relative peak area ratios of two precursor/product ion pairs. The limit of detection of this method was 0.01 mg kg(-1) using an injection volume of 5 µl. The repeatability of this method is excellent and the relative standard deviation (RSD) is less than 4%.