Department of Analytical Chemistry, Faculty of Chemistry, Complutense University of Madrid, Ciudad Universitaria, 28040 Madrid, Spain.
Talanta. 2012 Jan 30;89:169-77. doi: 10.1016/j.talanta.2011.12.011. Epub 2011 Dec 24.
Bioaccumulation and possible transformation of methylmercury and selenite has been checked on a 72 h-cycle of bioaccumulation and depuration using larvae from zebrafish. The larvae were exposed to methylmercury and selenite at concentrations of 1% and 0.1% of their LC(50) values. Quantitative extraction of methylmercury and selenite from exposed larvae was achieved by using ultrasonic probe-assisted extraction (USP), thus reducing extraction time and solvent consumption. Extracted species collected at different exposure times were characterized and quantified by liquid chromatography coupled to ICP-MS. Bioconcentration factors (BCFs) were estimated by two procedures: (i) as the ratio of the contaminant concentration in larvae and exposure media (BCF(48 h)) and (ii) fitting contaminant concentration in larvae to bioaccumulation models that describe uptake and depuration processes (BCF(k)). The BCFs obtained for methylmercury were 5000 and 2333 for larvae exposed to 1 μg L(-1) and 10 μg L(-1), respectively; while for selenite the BCF was 74 for larvae exposed to 10 μg L(-1). The good correlation between the BCFs found and those previously reported in the literature shows the proposed method as a good and promising alternative to the OECD Bioconcentration Test 305. Actually, the use of zebrafish larvae reduces the bioaccumulation test time from forty two (OECD Bioconcentration Test 305) to three days. In addition, potential biotransformation of both methylmercury and selenite was evaluated by LC-ICP-MS. For this purpose, a method for species extraction in small size samples by using ultrasonic probe sonication was developed.
采用斑马鱼幼鱼进行了 72 小时生物蓄积和净化周期的生物蓄积和可能的转化实验，检测了甲基汞和亚硒酸盐的生物蓄积和可能的转化。将幼鱼暴露于浓度为其 LC（50）值的 1%和 0.1%的甲基汞和亚硒酸盐中。通过使用超声探针辅助提取（USP），从暴露的幼鱼中定量提取甲基汞和亚硒酸盐，从而减少了提取时间和溶剂消耗。通过将收集到的不同暴露时间的提取物种进行特征描述和通过液相色谱与 ICP-MS 进行定量分析。通过两种方法估计生物浓缩因子（BCF）：（i）污染物浓度与幼虫和暴露介质的比值（BCF（48 h）），以及（ii）拟合幼虫中污染物浓度的生物蓄积模型，这些模型描述了吸收和净化过程（BCF（k））。暴露于 1μg L（-1）和 10μg L（-1）甲基汞的幼虫的 BCF 分别为 5000 和 2333；而暴露于 10μg L（-1）亚硒酸盐的幼虫的 BCF 为 74。发现的 BCF 与文献中先前报道的 BCF 之间的良好相关性表明，该方法是 OECD 生物浓缩测试 305 的良好替代方法。实际上，使用斑马鱼幼鱼将生物蓄积测试时间从四十（OECD 生物浓缩测试 305）减少到三天。此外，还通过 LC-ICP-MS 评估了甲基汞和亚硒酸盐的潜在生物转化。为此，开发了一种使用超声探针超声处理从小型样品中提取物种的方法。
