Use of triolent filled semipermeable membranes for detection and monitoring of environmentally relevant organic chemicals
This paper presents two different applications of a sampling-extraction device. The system is a polyethilene membrane filled with 1 g of Triolein (1,2,3-Tri[cis-9-octadecenoyl]glicerol), the main constituent of fish lipids. The membranes were used to detect and monitor the presence of musk xilene in a river. Results were compared with those obtained from the analysis of water, sewages and fish samples. In a second study the use of the membrane was combined with the Daphnia magna toxicity test to provide a detection system for lipophilic toxic chemicals. The survey of musk xilene indicated the presence of the chemical in fish (between 1 and 19.5 mg/kg), in an urban sewage (3.6 μg/l) and a river sample (0.2 μg/l). However the membranes concentrated the chemical several orders of magnitude, allowing the detection in areas with water levels below the detection level and the confirmation and identification of the chemical by gas chromatography-mass spectrometry. In the second study, toxicities for Daphnia magna (up to 70% for the total (volatile and non volatile) chemicals, and up to 100% for non-volatile chemicals after an additional concentration step) were observed although the chemicals were not identified by GC-MS. Both results show that screening toxicity-based methods as the one provided by triolein membranes- ecotoxicity tests combinations are appropiate to detect non-polar organic compounds in the aquatic environment.