Combination of stir bar sorptive extraction–retention time locked gas chromatography–mass spectrometry and automated mass spectral deconvolution for pesticide identification in fruits and vegetables

Fruit and vegetable samples collected at a local market were analyzed using stir bar sorptive extraction (SBSE) followed by thermal desorption, retention time locked (RTL) gas chromatographic separation and full scan mass spectrometric determination. Although the technique is proven to have sufficient extraction efficiency and productivity in pesticide analysis, the full scan chromatograms are loaded with matrix components making qualitative evaluation time consuming and too difficult to be adequate for routine laboratory screening. Identification can be facilitated to a great extent with evaluation methods provided by data evaluation software. Through the comparison of three evaluation methods we found that the mass spectral deconvolution software AMDIS supports most the decision making process, performing best in discovering positive hits and reducing data for supervision, making SBSE suitable for routine applications.