Multi-residue determination of pesticides in fruit-based soft drinks by fast liquid chromatography time-of-flight mass spectrometry.

This work reports a rapid and reliable method for the determination of 33 multi-class pesticides in fruit-based soft drinks. The proposed method consists of a sample treatment step based on solid-phase extraction using hydrophilic-lipophilic balanced polymer-based reverse-phase SPE cartridges, followed by identification and quantitation of the target pesticides by rapid resolution liquid chromatography using a short C(18) column (4.6mm x 50mm) with 1.8microm particle size and mass spectrometric detection using electrospray time-of-flight mass spectrometry (LC-TOFMS). The identification and confirmation of the compounds were based on retention time matching along with the accurate mass measurements of the protonated molecules (M+H) and their main fragment ions. Fruit-based soft drinks spiked at different fortification levels (10 and 50microgL(-1)) yielded average recoveries in the range 66-124% with RSD (%) below 14% (n=6). The obtained limits of quantitation varied in the range 0.02-2microgL(-1). The proposed method was successfully applied to the analysis of 14 market-purchased fruit-based soft drinks samples collected in some European countries, showing its potential applicability and revealing the presence of some of the target species in the microgL(-1) range.