Liquid chromatography-tandem mass spectrometry for the determination of multiple mycotoxins in serum through suspect screening and targeted approaches: Advancing human mycotoxin biomonitoring

Abstract

Human biomonitoring (HBM) is accepted as an effective way to assess human exposure to mycotoxins and to investigate their impact on human health. Ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) has emerged as a powerful tool for the quantitative and qualitative analysis of multiple mycotoxins in various matrices. However, there is a need for selective, sensitive and high-throughput methods using limited sample volumes. Here, the potential of suspect screening and targeted analysis by UHPLC-MS/MS for HBM of multiple mycotoxins in serum samples using an optimized sample pretreatment to ensure the highest coverage and the lowest limit of detection was investigated. A suspect screening method for 144 mycotoxins and metabolites using UHPLC-high-resolution MS/MS followed by data analysis using an in-house library was developed. This library was incorporated into the UNIFI software and contained MS/MS information from the literature as well as retention times determined experimentally (when commercial standards were available) or predicted using the retention time prediction Retip R package (when no commercial standards were available). The suspect screening and targeted methods were validated using pooled human serum spiked with 41 mycotoxins and metabolites standards and applied for HBM of multiple mycotoxins in serum samples from ten Ethiopian adults. In those ten samples, five different mycotoxins were detected using the suspect screening method, including ochratoxin B, for which no standard was available, while seven different mycotoxins were detected using the targeted method. The targeted method excelled in quantitative determination due to the lower limit of quantification for most mycotoxins. In contrast, the screening method, which does not require standards for qualitative analysis, may be particularly suitable for qualitative and semiquantitative determination of a large number of mycotoxins, including metabolites, in a large number of serum samples. In view of the complementarity of the two approaches, the developed suspect screening and targeted methods for mycotoxin analysis can be regarded as promising tools to better understand mycotoxin exposure and their metabolism in humans and address the associated health risks.