Reliable and sensitive analytical platform to assess dietary exposure of pigs to mycotoxins and explore potential urinary biomarkers

A reliable and sensitive analytical platform is proposed for the assessment of pig exposure to mycotoxins through the consumption of commercial feed. A total of 48 naturally contaminated feed and 55 urine samples collected from eight Spanish farms were analyzed using a fast and simple methodology based on solid-liquid extraction (SLE) or liquid-liquid extraction (LLE) and dispersive liquid-liquid microextraction (DLLME). High-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) was used for the targeted analysis of 27 mycotoxins from different families in both matrices achieving limits of quantification in a range of 0.019-73.5 ng g^-1 in feed and 0.011-31.7 ng mL^-1 in urine. All feed samples showed contamination with at least 7 mycotoxins. Enniatins (A, A1, B and B1) and beauvericin were quantified in 100 % of feed samples. ENNB, tenuazonic acid (TeA) and deoxynivalenol (DON) were the mycotoxins with the highest mean total concentrations (1.0 ± 1.9 μg g^-1, 155 ± 209 ng g^-1 and 81 ± 94 ng g^-1, respectively). In urine samples, DON, TeA, ENNB1 and ENNA were the most prevalent mycotoxins; and TeA, fumonisin B1 and alternariol had the highest mean total concentration (133 ± 199 ng mg^-1, 0.43 ± 1.3 μg mg^-1 and 0.29 ± 1.3 μg mg^-1 creatinine, respectively). Statistical tests revealed the correlation of DON and TeA occurrence in feed and urine. Untargeted analysis by HPLC coupled to quadrupole-time-of-flight mass spectrometer (Q-TOF-MS) yielded some urinary biomarkers of mycotoxin exposure and other relevant compounds such as certain antibiotic residues in urine.