14C标记的月桂酸盐在淡水勾虾（Hyalella azteca）中的生物富集、代谢及空间分布

对水的生物蓄积性监管评估通常是基于鱼类流水暴露试验得出生物浓缩因子（BCF）。这样的实验需要很多实验动物，而且费时费钱。最近，有人提出了一种替代性的有机中性化合物的测试方法，即用勾虾（Hyalella azteca）进行测试得到BCF值，该值与鱼类 BCF值有很强的相关性。本文研究了离子化合物月桂酸盐在H. azteca中的生物浓缩潜力。 采用流动和半静态的方法对勾虾H. azteca进行1-14C-月桂酸钠暴露实验。由于该化合物的生物降解速度快，需要采用半静态方法，即频繁更换介质，以确保介质浓度稳定。月桂酸盐也可被H. azteca快速代谢。在勾虾组织中测得的总放射性中有很大一部分是不能提取的，这表明矿化月桂酸盐富集在H. azteca的钙化外骨骼中。这在使用14C标记的碳酸盐的进一步研究中得到了证实。以游离脂肪酸计量，月桂酸盐的脂质标准化（5.0%）的勾虾 BCF为8.9。H. azteca的生物浓缩研究结果证实了先前在鱼类中观察到的试验项目的低生物富集潜力。然而，需要测试更多的具有不同性质的有机离子化合物，以评估鱼和勾虾的BCF数据之间是否存在一般相关性。

Bioconcentration, metabolism and spatial distribution of 14C-labelled laurate in the freshwater amphipod Hyalella azteca

Regulatory assessment of the bioaccumulation from water is commonly based on bioconcentration factors (BCF) derived from fish flow-through tests. Such experiments require many laboratory animals and are time-consuming and costly. An alternative test set-up for organic, neutral compounds using the amphipod Hyalella azteca was recently suggested, resulting in BCF values, which show a strong correlation with fish BCF data. In the present study, the bioconcentration potential of the ionic compound laurate was elucidated in H. azteca. The sodium salt of 1-14C laurate was applied to H. azteca in a flow-through and a semi-static approach. Due to rapid biodegradation, a semi-static approach with frequent media replacements was required to ensure stable media concentration. Laurate was also rapidly metabolised by H. azteca. A large proportion of the total radioactivity measured in the amphipod tissue was not extractable suggesting that mineralised laurate was accumulated in the calcified exoskeleton of H. azteca. This was confirmed in a further study using carbonate 14C]. A lipid normalised (5.0 %) Hyalella BCF of 8.9 was calculated for laurate, measured as free fatty acids. The results of the bioconcentration studies with H. azteca confirm the low bioaccumulation potential of the test item previously observed in fish. However, more organic ionic compounds with various properties need to be tested to assess whether a general correlation between fish and Hyalella BCF data exists.