A quantification and confirmation method of patulin in apple juice by GC/MS

A sensitive and selective method for quantification and confirmation of patulin in apple juice by GC/MS was developed. By this method, patulin was precisely determined and confirmed down to the level of 1 and 5 microg/kg in samples, respectively. Patulin was extracted with ethyl acetate from a sample and then hexane was added to the concentrated extract solution. Significant amounts of insoluble impurities were filtered off, followed by further clean-up by solid-phase extraction with combined silica gel and Florisil cartridges. The filtration step in a low-polarity condition was very effective to remove the impurities in the sample extract solution. The eluate from the cartridges was evaporated to dryness under reduced pressure and patulin was determined and confirmed by GC/MS after derivatization with 2.5% N,O-bis(trimethylsilyl)trifluoroacetamide ethyl acetate solution. Patulin was determined in the selected ion monitoring mode (m/z 226) and confirmed in the SCAN mode (m/z 40-340). The recovery from apple juice spiked with 10-500 microg/kg ranged from 93.4 to 100%. The limits of detection and quantification were 0.1 (S/N = 3) and 1 microg/kg (S/N = 30) of patulin in samples, respectively. Levels down to 5 microg/kg of patulin in sample were readily confirmed.