Surfactants and Nanobiotechnology Department, Institute of Advanced Chemistry of Catalonia, IQAC-CSIC, Jordi Girona 18-26, 08034, Barcelona, Spain.
Laboratory of Microbiocides Chemistry, Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89b, 61-614, Poznań, Poland.
J Hazard Mater. 2019 Jun 5;371:108-114. doi: 10.1016/j.jhazmat.2019.03.005. Epub 2019 Mar 1.
New cleavable oligomeric cationic surfactants containing ester groups susceptible to hydrolysis between the hydrocarbon tails and the hydrophilic moiety have been synthesized and their biodegradability and aquatic toxicity examined. Aerobic biodegradability was evaluated by applying a standard method for ready biodegradability, the CO Headspace test. Aquatic toxicity was assessed by means of the acute toxicity test with Daphnia. Cleavable oligomeric cationic surfactants undergo a significant biodegradation extent (31-52%) as compared to dimeric surfactants without ester groups that showed null degradation in previous works. However, they do not attain the threshold of ultimate degradation required (60%) to be classed as easily biodegradable chemicals. On the other hand, the introduction of cleavable groups in the surfactant hydrophobic chains reduces the toxic effects on the microorganisms responsible for degradation observed for conventional alkyl ammonium dimeric surfactants. Acute toxicity values of betainate cationic oligomeric surfactants to Daphnia magna, IC-48 h, varies from 1.5 to 50 mg/L. Aquatic toxicity of oligomeric cationic surfactants depends on their hydrophobicity and increases regularly with the alkyl chain length. However, whether the surfactant is a dimeric or a trimeric betaine ester does not affect their acute toxicity to crustacean.
已经合成了含有酯基的可裂解低聚阳离子表面活性剂，这些酯基易在烃尾和亲水部分之间发生水解，并对其生物降解性和水生毒性进行了研究。采用标准的好氧生物降解性测定方法——CO 顶空测试法评估了有氧生物降解性。通过急性毒性试验（用大型蚤进行）评估了水生毒性。与之前研究中没有酯基的二聚表面活性剂相比，可裂解低聚阳离子表面活性剂具有显著的生物降解程度（31-52%）。然而，它们并未达到作为易生物降解化学品所需的最终降解阈值（60%）。另一方面，在表面活性剂疏水链中引入可裂解基团会降低对负责降解的微生物的毒性影响，这在传统的烷基铵二聚表面活性剂中是观察不到的。季铵盐低聚阳离子表面活性剂对大型蚤的急性毒性值（IC-48h）为 1.5 至 50mg/L。低聚阳离子表面活性剂的水生毒性取决于其疏水性，并随烷基链长度的增加而规律增加。然而，表面活性剂是二聚还是三聚甜菜碱酯并不会影响其对甲壳类动物的急性毒性。
