A UPLC-MS/MS method was developed and validated for the determination of aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2) and ochratoxin A (OTA) in raw coffee samples. Mycotoxins were extracted using a modified QuEChERS method with little sample preparation excluding clean-up and enrichment procedures. Linearity was demonstrated for the five mycotoxins in the range 0.125-20 µg/kg. This method shows negligible matrix effect for individual concentrations, thus allowing the use of an external standard procedure. Limits of quantification (LOQ) ranged from 0.45 to 1 μg/kg. Recoveries between 63% and 89% were achieved. The intra- and inter-day precisions were lower than 15%. The applicability of the method was demonstrated, taking into account fitness for purpose, with simplicity, reliability, low costs and environmental friendliness. The results show that 3 out of 4 samples were contaminated with OTA.
Keywords: Aflatoxins; UPLC-MS/MS; ochratoxin A; raw coffee beans.