Environment and Climate Change Canada, Aquatic Contaminants Research Division, 105 McGill St., 8th floor, Montréal, Québec, H2Y 2E7, Canada.
Faculté de Pharmacie, Université de Montréal, Plateforme de biopharmacieC.P. 6128, succ. Centre-ville, Montréal, Québec, H3C 3J7, Canada.
Environ Sci Pollut Res Int. 2022 Jun;29(30):45303-45313. doi: 10.1007/s11356-022-19064-7. Epub 2022 Feb 10.
Aquatic organisms are continuously exposed to emerging contaminants coming from urban effluents of wastewater treatment plants. The contamination of surface water by those effluents poses a number of environmental risks, and pharmaceuticals are part of this class of effluent contaminants. Various classes of pharmaceuticals are not treated by wastewater treatment plants and anticancer drugs are part of them. The chemotherapy drug methotrexate (MTX) is an emerging contaminant and its growing use with the increase in cancer cases worldwide raises potential risk to aquatic organisms exposed to effluent discharges. However, chemical analyses in exposed freshwater aquatic organisms for ecotoxicological studies are rarely available and no studies have been done yet to accompany ecotoxicological data of exposed filter-feeding organisms. The purpose of this study was to develop a specific and sensitive analytical LC-MS/MS method for the quantification of methotrexate uptake in mussels exposed at different concentrations of the drug. A solid/liquid extraction followed by solid phase extraction (SPE) using an MCX phase purification scheme was optimized. The optimal recovery of 65% and matrix effect of 38% allowed to achieve a limit of quantification of 0.25 ng g, with an accuracy of 99-106%, a precision of no more than 3% RSD, and linearity ranging from 0.25 to 25 ng g. This methodology was tested with mussels exposed for 96 h at different concentrations (4 to 100 µg L) of MTX. The data revealed tissue uptake at concentrations ranging from 0 to 2.53 ng g. This suggests that this drug has low uptake potential and this methodology could be used to examine tissue levels of this drug in organisms continuously exposed to urban pollution.
水生生物不断暴露于城市废水处理厂废水中新兴的污染物中。这些废水对地表水的污染带来了许多环境风险，而药品是这类废水污染物的一部分。各种类别的药品都未被废水处理厂处理，而抗癌药物就是其中之一。化疗药物甲氨蝶呤（MTX）是一种新兴的污染物，随着全球癌症病例的增加，其使用量不断增加，对暴露于废水排放中的水生生物构成了潜在风险。然而，用于生态毒理学研究的暴露于淡水水生生物中的化学分析很少，并且尚未对暴露于滤食性生物的生态毒理学数据进行研究。本研究旨在开发一种特定且灵敏的 LC-MS/MS 分析方法，用于定量测定暴露于不同浓度药物的贻贝中甲氨蝶呤的摄取量。优化了固相/液相萃取，然后使用 MCX 相纯化方案进行固相萃取（SPE）。优化后的回收率为 65%，基质效应为 38%，可实现定量限为 0.25ng/g，准确度为 99-106%，精密度不超过 3%RSD，线性范围为 0.25-25ng/g。该方法学已用于研究在不同浓度（4 至 100µg/L）的 MTX 下暴露 96 小时的贻贝。数据显示在 0 至 2.53ng/g 的浓度范围内存在组织摄取。这表明该药物的摄取潜力较低，该方法学可用于检查连续暴露于城市污染的生物组织中的该药物的水平。
