Development of a certified reference material for accurate quantification of patulin in clear apple juice

The potential degradation of patulin in apple juice is a challenge to developing a matrix-related certified reference material (CRM) for accurate quantification of its contamination. This work was aimed to investigate the effects of different anti-browning treatments, i.e. blanching at 90 °C and additions of ascorbic acid, respectively, on the stability of patulin in clear apple juice during storage. A blanching-based processing technology was built to prepare a novel matrix CRM. This homogeneous material proved to be stable at -20 °C for 9 months and at 20 °C for 7 days. The joint certification was performed in eight laboratories by ID-LC-MS/MS. The final certified concentration was 66.3 μg/kg, with the expanded uncertainty of 6.5 μg/kg (k = 2). The developed CRM can be used as an important QC sample for routine detection of patulin in apple juice. This work will serve as a guide to develop other similar matrix CRMs.