Trace analysis of dithiocarbamate fungicide residues on fruits and vegetables by hydrophilic interaction liquid chromatography/tandem mass spectrometry

The simultaneous determination of dithiocarbamate (DTC) fungicide residues on fruits and vegetables was performed by liquid chromatography (LC) on a ZIC‐pHILIC column coupled to tandem mass spectrometry (MS/MS). For each DTC subclass, i.e. dimethyldithiocarbamates (DMDs), ethylenebis(dithiocarbamates) (EBDs), and propylenebis(dithiocarbamates) (PBDs), the limits of detection and quantification were approximately 0.001 and 0.005 mg kg −1 , respectively. Recoveries from tomatoes, spiked in the range of 0.05–1 mg kg −1 , averaged between 97 and 101%. Several fruits and vegetables from a local market and different countries of origin (apples, pears, grapes, cherry tomatoes, cocktail tomatoes, cucumbers, tomatoes, tamarillos, papaya, and broccoli) were analyzed by LC/MS/MS, LC/MS, and by the routine CS 2 method. In general, the results obtained by both LC/MS and LC/MS/MS were in good agreement with those obtained by the CS 2 method except for the false positive CS 2 results for broccoli and papaya. The results demonstrate that both LC/MS and LC/MS/MS can be used for routine analyses of DTC residues, whereat LC/MS/MS is more sensitive and selective than LC/MS. Copyright © 2008 John Wiley & Sons, Ltd.