Photodegradation of the pharmaceutical drug diclofenac in a lake: Pathway, field measurements, and mathematical modeling
作者:Thomas Poiger、Hans-Rudolf Buser、Markus D. Müller
DOI:10.1002/etc.5620200205
日期:2001.2
profiles of diclofenac were measured in Lake Greifensee (Switzerland) under mixed (February/December) and stratified (July) lake conditions. The concentrations ranged from 1 to 12 ng/L and were lower in summer than in winter, especially near the lake surface, pointing to an efficient elimination of diclofenac by photodegradation in the lake. Laboratory experiments confirmed the rapid photodegradation of diclofenac
在混合(2 月/12 月)和分层(7 月)湖泊条件下,在格莱芬湖(瑞士)测量了双氯芬酸的垂直浓度分布。浓度范围为 1 至 12 ng/L,夏季低于冬季,尤其是在湖面附近,表明湖中光降解可有效消除双氯芬酸。实验室实验证实,当暴露在阳光下时,双氯芬酸在水中的快速光降解。一级反应速率根据实际太阳辐射(半衰期,tau = 0.2-1.7 h)随季节变化。最初的光产物是 8-氯咔唑-1-乙酸,它的光降解速度甚至比母体化合物还要快。Carbazole-1-乙酸,之前报道的主要光产物,仅在 H 源(如甲醇)存在下形成。在没有氢源和空气的情况下,形成羟基咔唑-1-乙酸。然而,在空气中没有观察到羟基咔唑-1-乙酸,因此,在类似于湖中的条件下,可能是因为它快速进一步的光氧化。使用一维湖泊模型的计算机模拟将实际太阳辐射和湖泊冲洗数据考虑在内,证实光解是格莱芬湖中双氯芬酸的主要消除途径。这些计算进一步表明,光产物