Quantification of fosetyl-aluminium/phosphonic acid and other highly polar residues in pomegranates using Quick Polar Pesticides method involving liquid chromatography-tandem mass spectrometry measurement

Abstract

Interest in the quantification of highly polar substances in crops has noticeably increased in the last five years. This study was designed to assess quantification of six polar residues, chlorate, ethephon, fosetly-aluminium (fosetyl-Al), glyphosate, phosphonic acid and perchlorate. A total of 2513 pomegranate samples intended for export from Turkey were analysed using the Quick Polar Pesticides (QuPPe) method. The method was in-house validated with very good performance results. The limits of quantification (LOQs) for residues were much lower than the respective EU Maximum Residue Levels (MRLs). Phosphonic acid was detected in 38.5% of pomegranate samples at quantifiable concentrations, calculated as fosetyl-Al. The concentrations ranged between 0.005 and 12.9 mg kg−1. The 20% of pomegranate samples showed fosetyl-Al levels above the EU MRL of 2 mg kg−1. Other polar residues were not detected in any pomegranate samples. This is the first report about highly polar pesticides in pomegranates cultivated in Turkey.