Simultaneous determination of four aflatoxins and ochratoxin A in ginger after inoculation with fungi by ultra-fast liquid chromatography-tandem mass spectrometry

BACKGROUND Aflatoxins (AFs) and ochratoxin A (OTA) have been detected frequently in food, agricultural products and traditional Chinese medicines, and their presence poses serious health and economic problems worldwide. Ginger can easily be polluted with mycotoxins. In this study, ginger samples were cultivated for 15 days after inoculation with fungi and were prepared based on ultrasound-assisted solid–liquid extraction using methanol/water followed by immunoaffinity column clean-up and analysed by ultra-fast liquid chromatography–tandem mass spectrometry (UFLC-MS/MS) for AFs and OTA. RESULTS The limits of detection and quantification of AFs and OTA were 0.04–0.30 µg mL−1 and 0.125–1.0 µg mL−1, respectively. The recoveries were 82.0–100.2%. After 15 days' cultivation, no macroscopic mildew was found in ginger. But, the content of AFB1 expressed an increasing trend in ginger, peel [less than the limit of quantification (LOQ)] to the innermost layer (51.86 µ mL−1 ), AFB2 was only detected in the innermost layer at the level of 0.87 µ mL−1. A small amount (