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.

链格孢霉菌产生多种化学成分多样的次生代谢物，对人类健康具有潜在的不利影响。然而，关于其中一些霉菌毒素在食品中和人类暴露中的数据并不一致。膜过滤是基于 LC-MS 的食品污染物分析方法的许多样品制备过程中的常见步骤。然而，人们对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造成的化合物损失显着，在某些情况下甚至是完全损失。特别是，两种主要的链格孢毒素，链格孢醇（AOH）及其单甲醚（AME），受到严重影响。与已发表的食品调查相比，表明所用过滤类型与食品中较低发病率报告之间存在相关性，我们的结果表明，过去的暴露评估中 AME 可能被低估。此外，苝醌受过滤的影响很大，这强调了在分析方法开发过程中考虑这一点的重要性。此外，我们在 HT-29 细胞中应用彗星测定来阐明过滤对提取物遗传毒性的影响。我们观察到携带环氧化物的代谢物的损失与毒理学上尚未表征的链格孢毒素引起的氧化 DNA 损伤的有趣诱导有很强的一致性。总之，我们强调了样品过滤的潜在问题，并呼吁根据现有结果对之前的食品发生数据进行严格的重新评估。