Validation of a UPLC-MS/MS Method for Multi-Matrix Biomonitoring of Alternaria Toxins in Humans

Mycotoxins, natural toxins produced by fungi, contaminate nearly 80% of global food crops. Alternaria mycotoxins, including alternariol (AOH), alternariol monomethylether (AME), and tenuazonic acid (TeA), present a health concern due to their prevalence in various plants and fruits. Exposure to these toxins exceeds the threshold of toxicological concern in some European populations, especially infants and toddlers. Despite this, regulatory standards for Alternaria toxins remain absent. The lack of toxicokinetic parameters, reference levels, and sensitive detection methods complicates risk assessment and highlights the necessity for advanced biomonitoring (HBM) techniques. This study addresses these challenges by developing and validating ultra-high performance liquid chromatography method coupled with tandem mass spectrometry to quantify AOH, AME, TeA, and their conjugates in multiple biological matrices. The validated method demonstrates robust linearity, precision, recovery (94–111%), and sensitivity across urine (LOD < 0.053 ng/mL), capillary blood (LOD < 0.029 ng/mL), and feces (LOD < 0.424 ng/g), with significantly lower LOD for TeA compared to existing methodologies. The application of minimally invasive microsampling techniques for the blood collection enhances the potential for large-scale HBM studies. These advancements represent a step toward comprehensive HBM and exposure risk assessments for Alternaria toxins, facilitating the generation of data for regulatory authorities.