Confirmation of patulin and 5-hydroxymethylfurfural in apple juice by gas chromatography/mass spectrometry

Abstract

A gas chromatographic/mass spectrometric (GC/MS) method was developed for the confirmation of patulin and 5-hydroxymethylfurfural (HMF) extracted from apple juice. The extraction is based on the official AOAC method for liquid chromatographic analysis. Juice extracts are quickly and easily derivatized with bis(trimethylsilyl)trifluoracetamide under mild conditions, and the trimethylsilyl ethers of the analytes are stable for at least several hours. The analytes are determined by GC/MS using an electron-impact source and selected ion monitoring of characteristic ions. For both analytes, the interassay differences between base-peak ratios for samples and standards were all <7.1% (absolute). The presence of patulin was confirmed at fortification levels of about 30-400 μg/L and naturally occurring levels of about 80-400 μg/L. The presence of HMF was also confirmed at levels ≤2 mg/L. The proposed mass spectral fragmentation pathways of the analytes are presented.