Aflatoxin M1 contamination of raw cow's milk in five regions of Kosovo during 2016.

During February and August 2016 (winter and summer season), 192 samples of raw bulk tank milk have been collected from small dairy farms in five different regions of Kosova (Prishtina, Prizren, Peja, Mitrovica, and Gjilan). These samples were analyzed for aflatoxin M1 (AFM1) contamination level by ultra-high performance liquid chromatography coupled with electrospray ionization triple quadrupole tandem mass spectrometry (UHPLC-ESI-MS/MS). The limit of quantification for AFM1 was 0.02 μg/L and recovery at 0.1-0.5 μg/L was 90-95% (coefficient of variation 15-25%). A total of 74 milk samples (38%) were found to be contaminated with AFM1 and 11 samples (5.7%) slightly exceeded the European Union maximum level of 0.05 μg/L. The maximum AFM1 level was at 0.082 μg/L. There was no relevant difference between summer and winter with regard to AFM1 frequency and levels. Although the frequency of AFM1-positive samples varied between regions, from 7% (Prishtina) to 53% (Prizren), only minor regional differences were observed with regard to average and maximum toxin levels. The high percentage of milk samples which were non-compliant with AFM1 maximum levels indicates that efforts to reduce the contamination levels of aflatoxin B1 in cows feed in Kosovo are necessary.