Patulin in apple and apple juice: Method development, validation by liquid chromatography-tandem mass spectrometry and survey in Brazilian south supermarkets

In this work, a novel single method for patulin determination in apple and apple juice employing liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) is presented. Samples were extracted employing ethyl acetate acidified with acetic acid followed by sodium sulfate addition. The extracts were submitted to dispersive solid phase clean-up employing sodium sulfate and silica gel. The method was validated assessing linearity and linearity range, limits of detection and quantification, matrix effect, precision (RSD%) and accuracy (recovery from samples spiked at 25, 50 and 100 mu g kg(-1)). The method showed to be suitable for patulin determination as the recovery ranged from 76 to 84% for apple and from 102 to 108% for apple juice, in both cases with RSD lower than 15%. Matrix effect was also evaluated and showed to be less intense for apple juice (-22%) than for apples (-42%). The validated method was applied to 62 samples (apple and apple juice) collected in supermarkets of southern Brazil, during the years 2016 and 2017. Apple samples showed contamination ranging from < LOQ to 757 mu g kg(-1) and apple juice from < LOQ to 1298 mu g L-1.