Swiss Centre for Applied Ecotoxicology, Eawag-EPFL, Überlandstrasse 133, 8600, Dübendorf, Switzerland.
Anal Bioanal Chem. 2019 Apr;411(10):2057-2069. doi: 10.1007/s00216-019-01628-1. Epub 2019 Feb 8.
Ecotoxicological screening of surface waters can involve multiple analyses using multiple bioassay and chemical analytical methods that require enriched samples to reach low concentrations. Such broad screening of the same sample necessitates sufficient sample volume-typically several liters-to produce a sufficient amount of enriched sample. Often, this is achieved by performing parallel solid-phase extractions (SPE) where extracts are combined into a pool-this is a laborious process. In this study, we first validated our existing SPE method for the chemical recovery of an extended set of compounds. We spiked four estrogenic compounds and 11 herbicides to samples from independent rivers (1 L) and wastewater treatment plant effluents (0.5 L). Then, we investigated the effect of increased sample loading of the SPE cartridges on both chemical and biological recoveries by comparing the validated volumes with four times larger sample volumes (i.e., 4 L river water and 2 L effluent). Samples were analyzed by LC-MS/MS and three bioassays: an estrogen receptor transactivation assay (ERα-CALUX), the combined algae test, and a bacterial bioluminescence inhibition assay. Our existing SPE method was found to be suitable for enriching the extended set of estrogens and herbicides in river water and effluents with near to perfect chemical recoveries (~ 100%), except for the herbicide metribuzin (46 ± 19%). In the large volume river and effluent samples, the biological activities and concentrations of the spiked compounds were between 87 and 104% of those measured with the lower sample loading, which is adequate. In addition, the ratio between the large and original volume SPE method for the non-target endpoint (bacterial bioluminescence inhibition) was acceptable (on average 82 ± 9%). Results indicate that our current water extraction method can be applied to up to four times larger sample volumes, resulting in four times more extract volumes, without significant reductions in recoveries for the tested estrogens and herbicides. Graphical abstract ᅟ.
地表水的生态毒理学筛选可能需要使用多种生物测定和化学分析方法进行多项分析，这些方法需要富集样品以达到低浓度。对同一样品进行如此广泛的筛选需要足够的样品量-通常为数升-以产生足够量的富集样品。通常，这是通过并行固相萃取 (SPE) 来实现的，其中提取物被合并到一个池中-这是一个繁琐的过程。在这项研究中，我们首先验证了我们现有的 SPE 方法，用于化学回收一组合成化合物。我们向来自独立河流 (1 L) 和废水处理厂废水 (0.5 L) 的样品中添加了四种雌激素化合物和 11 种除草剂。然后，我们通过比较经过验证的体积与四倍大的样品体积 (即 4 L 河水和 2 L 废水) ，研究了 SPE 小柱上样品负载增加对化学和生物回收率的影响。样品通过 LC-MS/MS 和三种生物测定法进行分析：雌激素受体转导测定法 (ERα-CALUX)、组合藻类试验和细菌生物发光抑制测定法。我们现有的 SPE 方法被发现适用于在河水和废水中富集扩展的雌激素和除草剂组合，化学回收率接近完美 (~100%)，除了除草剂甲磺隆 (46 ± 19%)。在大体积河水和废水中，添加化合物的生物活性和浓度与较低样品负载测量值相比在 87%至 104%之间，这是足够的。此外，非靶向终点 (细菌生物发光抑制) 的大体积和原始体积 SPE 方法之间的比例是可接受的 (平均为 82 ± 9%)。结果表明，我们目前的水提取方法可应用于多达四倍大的样品体积，从而产生四倍多的提取物体积，而测试的雌激素和除草剂回收率没有显著降低。
