Aflatoxin monitoring in Italian hazelnut products by LC-MS

Hazelnut samples of different origin were collected in different stores of Northern Italy and analysed for aflatoxin (AF) contamination by a sensitive chromatographic method based on a tandem mass spectrometer with electrospray ionization. The effects of two extracting solvent mixtures (methanol/water and acetonitrile/water) and different extraction times were tested and compared in terms of recovery. The analysis showed that 35 out of 93 samples (37.6%) were contaminated by AFs. The incidence of positive samples was higher in the Turkish (66.7%) than in the Italian samples (35.9%). The mean AF contamination was higher (p=0.045, Kruskal-Wallis test) in the Turkish samples (0.33 µg kg-1), compared to the Italian (0.14 µg kg-1) ones. Generally, a low level of AFs contamination was found in the positive samples (0.64 µg kg-1), far below the maximum threshold admitted by the European legislation. AFG1 was the most diffused aflatoxin, found in 19 samples.