Application of Human Biomonitoring to Assess Human Exposure to Mycotoxins and their Modified Forms

Total mycotoxins exposure in humans could be estimated by the combined measures of urinary free mycotoxins, phase I metabolites and their glucuronides and/or sulphates derivatives. The predigestion of urine with ?-glucuronidase/sulfatase enzymes deconjugate the glucuronides and sulphates derivatives to form free mycotoxins and phase I metabolites, thus reducing the number of analytes (mycotoxin biomarkers) to be measured. It has been demonstrated that foods can be frequently contaminated by mixtures of mycotoxins and their modified forms. These last can be hydrolysed in the gut to form the parent mycotoxins. Therefore the analysis of urine for multi-biomarker is a powerful approach to identify the type and the number of mycotoxins ingested by each individual. Moreover, the urinary concentrations of mycotoxin biomarkers can be used to estimate the probable daily intake of those mycotoxins for which human excretion rate is available. We have developed an highly sensitive multi-biomarker LC-MS/MS method based on predigestion of urine with ?-glucuronidase/sulfatase enzymes and SPE/immunoaffinity concentration and cleanup for the determination of urinary biomarkers of deoxynivalenol (DON), zearalenone (ZEA), aflatoxin B1 (AFB1), fumonisin B1 (FB1), and ochratoxin A (OTA). These are the main mycotoxins frequently co-occurring in food/beverage worldwide and are mainly produced by Fusarium graminearum (DON, ZEA), Aspergillus flavus and A. parasiticus (AFB1), F. verticillioides and F. proliferatum (FB1), Penicillium verrucosum and A. carbonarius (OTA). Our method was used to analyse 356 human urines collected in Italy, South Africa and Sweden and allowed the identification of mycotoxins mostly ingested in each country as well as the probable daily intake of each mycotoxin.