Quantitation of enniatins in biological samples of Wistar rats after oral administration by LC-MS/MS

The emerging Fusarium mycotoxins enniatins (ENNs) have diverse biological properties, mainly due to their ionophoric activity, and represent a potential risk to human and animal health since they are commonly found in food and feed. In vivo toxicity studies are scarce and limited to the major mycotoxins. Until now, any method for the simultaneous analysis of these compounds in plasma, serum and feces from rat has been reported. A method for the extraction and determination of ENNs A, A1, B and B1 from Wistar rat samples by liquid chromatography tandem mass spectrometry has been developed. The method was successfully validated with satisfactory recoveries (70-106%), good intraday (<10%) and interday (<20%) precision, expressed as relative standard deviation, and good linearity between limits of quantitation (LOQ) and 100 times LOQ. Limits of detection (LOD) and LOQ were ≤1 and ≤10 ng/ml, respectively. The validated method was applied for the analysis of biological Wistar rat samples that were administered a mixture of ENNs containing 1.19, 2.16, 1.03 and 1.41 mg/kg body weight of ENN A, A1, B and B1, respectively. Blood, urine and feces samples collected every 2 h during the 8-h duration of the experiment were analyzed. The administered dose of the mixture of ENNs did not cause observable adverse effects on the animals. ENNs concentrations detected in serum and urine were below LOQs. The four ENNs were detected in feces reaching the maximum concentration at 6 h after administration.