Development and validation of an LC-MS/MS method for the simultaneous determination of citrinin and ochratoxin a in a variety of feed and foodstuffs.

An ultra-performance liquid chromatography-electrospray tandem mass spectrometry (UPLC-ESI+/--MS/MS) method for the simultaneous analysis of citrinin (CIT) and ochratoxin A (OTA) in feed (chicken and pig) and food (cereal-based products, fruit, vegetable juices, nuts, seeds, herbs, spices, vegetarian and soy products, alcoholic beverages, baby food products and food supplements) was developed. The mycotoxins were extracted from these matrices using a QuEChERS-based extraction method without any further clean-up step. The samples were 5-fold concentrated. Final extracts were analyzed using a UPLC-MS/MS system and chromatographic separation was achieved by applying a gradient elution for a total run time of 10 min. Mycotoxins were quantified using an internal calibration via analyte/13C-labeled internal standard ratio. The developed method was validated according to the criteria described in Commission Regulation No. 401/2006/EC and Commission Decision No. 2002/657/EC. Specificity, linearity, apparent recovery, limit of detection and quantification, intraday and interday precision, measurement uncertainty, matrix effect, and extraction efficiency were the parameters studied. Finally, 90 Belgian chicken and pig feed samples were analyzed, revealing the simultaneous presence of CIT (<LOQ - 3.90 μg/kg) and OTA (<LOQ - 5.60 μg/kg) in more than 50% of these products.