NaFoMat Group, Applied Physic Department, University of Santiago de Compostela. Campus Vida, 15782, Santiago de Compostela, Spain.
Department of Biology, CESAM (Centro de Estudos Do Ambiente e Do Mar), University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
Ecotoxicol Environ Saf. 2019 Nov 30;184:109580. doi: 10.1016/j.ecoenv.2019.109580. Epub 2019 Sep 4.
Ionic Liquids (ILs) are generically regarded as environmentally "harmless" and thus, assumed as "non-toxic". However, due to the endless design possibilities, their ecotoxicological profile is still poorly known. An accurate knowledge on the toxicity of a substance is required, under the scope of environmental regulation worldwide, before their application and commercialization. Knowledge on the relationship between the chemical structure and toxic effects is essential for the future design of more biocompatible solvents. Focusing on the use of ILs as base lubricants, lubricant additives, or even as potential working fluids for absorption heat pumps, the knowledge on its environmental impact is of great importance, due to the possibility of spills. In this specific context, four analogues of glycine-betaine-based ILs (AGB-ILs) and four glycine-betaine based ILs (GB-ILs) were synthesized and characterized. Their ecotoxicity was assessed using representatives of two trophic levels in aquatic ecosystems, the bacteria Allivibrio fischeri (commonly used as a screening test organism) and the microalgae Raphidocelis subcapitata (as an alternative test organism that has been proven very sensitive to several IL families). The microalgae were more sensitive than the bacteria, hence, following a precautionary principle, we recommend considering the toxicity towards microalgae as an indicator in future studies regarding the focused ILs. Although four of the studied ILs were derived from a natural amino acid, all were considered hazardous for the aquatic environment, disproving the primary theory that all ILs derived from natural compounds are benign. Furthermore, the modification in the structure of anion and the cation can lead to the increase of toxicity.
离子液体（ILs）通常被认为对环境“无害”，因此被认为是“无毒的”。然而，由于设计的可能性无穷无尽，它们的生态毒性特征仍然知之甚少。在全球环境法规的范围内，在应用和商业化之前，需要对一种物质的毒性有准确的了解。在未来设计更具生物相容性的溶剂时，了解化学结构与毒性效应之间的关系至关重要。关注 ILs 作为基础润滑剂、润滑剂添加剂，甚至作为吸收式热泵的潜在工作流体的用途，由于可能发生泄漏，因此了解其对环境的影响非常重要。在这种特定的情况下，合成并表征了四种甘氨酸甜菜碱基离子液体（AGB-ILs）和四种甘氨酸甜菜碱基离子液体（GB-ILs）的类似物。使用水生生态系统中两个营养级别的代表，即细菌发光杆菌（通常用作筛选测试生物）和微藻莱茵衣藻（作为已被证明对几种 IL 家族非常敏感的替代测试生物）来评估它们的生态毒性。微藻比细菌更敏感，因此，根据预防原则，我们建议在未来针对重点 ILs 的研究中，将对微藻的毒性视为指示物。尽管研究中的四种 ILs 都源自天然氨基酸，但它们都被认为对水生环境有害，这否定了所有源自天然化合物的 ILs 都是良性的主要理论。此外，阴离子和阳离子结构的修饰会导致毒性增加。
