A simple solution for boscalid selectivity issue in GC/MS analysis of apples

Gas chromatography coupled with mass spectrometry (GC/MS) is commonly applied in pesticide residue analysis in fruit samples. Sample extracts with a high quantity of co-extractives represent a standing problem in such analysis. Co-extractives mainly affect the GC inlet and the chromatographic column performance. Waxes, identified as the main co-extractives from the apple matrix, represent a significant problem in GC/MS analysis due to low volatility and non-polarity. The purpose of this investigation was to develop and evaluate a simplified method for the analysis of boscalid in apples, with the removal of wax compounds as the main outcome. The waxes herein represented a problem not only for the performance of the instrument but directly for the determination of the boscalid since they co-eluted with the pesticide. The applied method included a combination of solvent exchange and low-temperature precipitation and resulted in complete wax removal.