Alternaria molds produce a variety of chemically diverse secondary metabolites with potentially adverse effects on human health. However, data on occurrence in food and human exposure is inconsistent for some of these mycotoxins. Membrane filtration is a frequent step in many sample preparation procedures for LC-MS-based methods analyzing food contaminants. Yet, little is known about the possibility of adsorptive phenomena that might result in analyte losses. Thus, we treated a complex extract of Alternaria toxins with several types of syringe filters and unraveled the impact on its chemical composition by LC-MS/MS. We observed significant, and in some cases complete, losses of compounds due to filtration. Particularly, two key Alternaria toxins, alternariol (AOH) and its monomethyl ether (AME), were heavily affected. As a comparison with published food surveys indicating a correlation of the type of filtration used with lower incidence reports in food, our results point at a possible underestimation of AME in past exposure assessment. Also, perylene quinones were greatly affected by filtration, underlining the importance to take this into consideration during analytical method development. Furthermore, we applied the comet assay in HT-29 cells to elucidate the impact of filtration on the genotoxicity of the extract. We observed strong coincidences with the loss of epoxide-carrying metabolites and also an intriguing induction of oxidative DNA damage by yet toxicologically uncharacterized Alternaria toxins. In conclusion, we highlight potential issues with sample filtration and call for a critical re-evaluation of previous food occurrence data in the light of the results at hand.

链霉菌霉菌会产生多种化学上不同的次生代谢产物，对人体健康可能产生不利影响。但是，其中某些霉菌毒素的食物和人体暴露数据不一致。对于基于LC-MS的分析食品污染物的方法，膜过滤是许多样品制备过程中的常见步骤。然而，对于可能导致分析物损失的吸附现象的可能性知之甚少。因此，我们用几种类型的注射器过滤器处理了链格孢菌毒素的复杂提取物，并通过LC-MS / MS揭示了对其化学成分的影响。我们观察到由于过滤而导致的化合物大量损失，在某些情况下甚至完全损失。特别是两个关键的链格孢毒素，交替戊醇（AOH）及其单甲醚（AME）受严重影响。与已发表的食品调查比较表明，所使用的过滤类型与食品中较低的发生率报告具有相关性，我们的结果表明在过去的暴露评估中可能会低估AME。此外，per醌受到过滤的影响很大，强调了在分析方法开发过程中必须考虑到这一点的重要性。此外，我们在HT-29细胞中应用了彗星试验，以阐明过滤对提取物遗传毒性的影响。我们观察到与携带环氧化物的代谢物的丢失以及由毒理学未鉴定的链格孢菌引起的诱人的氧化性DNA损伤诱人的强烈巧合毒素。总之，我们强调了样品过滤的潜在问题，并要求根据现有结果对以前的食物发生数据进行重新评估。