Bartels Peter, von Tümpling Wolf
UFZ, Helmholtz Centre for Environmental Research - UFZ, Department River Ecology, Brueckstrasse 3a, D-39114 Magdeburg, Germany.
Sci Total Environ. 2007 Mar 1;374(1):143-55. doi: 10.1016/j.scitotenv.2006.11.039. Epub 2007 Jan 25.
Diclofenac can be detected in surface water of many rivers with human impacts worldwide. The observed decrease of the diclofenac concentration in waters and the formation of its photochemical transformation products under the impact of natural irradiation during one to 16 days are explained in this article. In semi-natural laboratory tests and in a field experiment it could be shown, that sunlight stimulates the decomposition of diclofenac in surface waters. During one day intensive solar radiation in middle European summer diclofenac decomposes in the surface layer of the water (0 to 5 cm) up to 83%, determined in laboratory exposition experiments. After two weeks in a field experiment, the diclofenac was not detectable anymore in the water surface layer (limit of quantification: 5 ng/L). At a water depth of 50 cm, within two weeks 96% of the initial concentration was degraded, while in 100 cm depth 2/3 of the initial diclofenac concentration remained. With the decomposition, stable and meta-stable photolysis products were formed and observed by UV detection. Beyond that the chemical structure of these products were determined. Three transformation products, that were not described in the literature so far, were identified and quantified with GC-MS.
在全球受到人类活动影响的许多河流表层水中都能检测到双氯芬酸。本文解释了在自然光照影响下，水体中双氯芬酸浓度在1至16天内的下降情况及其光化学转化产物的形成。在半自然实验室试验和野外实验中发现，阳光能促进地表水层中双氯芬酸的分解。在中欧夏季一天的强烈太阳辐射下，通过实验室暴露实验测定，双氯芬酸在水表层（0至5厘米）的分解率高达83%。在野外实验进行两周后，水表层已检测不到双氯芬酸（定量限：5纳克/升）。在水深50厘米处，两周内初始浓度的96%被降解，而在100厘米深处，初始双氯芬酸浓度仍有三分之二留存。随着双氯芬酸的分解，通过紫外检测观察到了稳定和亚稳定的光解产物。此外，还确定了这些产物的化学结构。通过气相色谱 - 质谱联用仪（GC-MS）鉴定并定量了三种迄今文献中未描述的转化产物。
