The effect of surface active compounds on chemical processes occurring in aquatic environments

Use of non-ionic surfactant solutions for the extraction and preconcentration of phenolic compounds in water prior to their HPLC-UV detection

A simple and rapid HPLC method with spectrophotometric detection to determine phenolic compounds in water, including the 11 priority phenolic pollutants, is described. As they are present in low concentrations, an extraction and preconcentration step is necessary prior to their determination. A methodology based on the cloud point phenomenon is applied using the non-ionic surfactant oligoethylene glycol monoalkyl ether (Genapol X-080) as extractant. The optimum conditions for the extraction and preconcentration of phenolic derivatives have been established and detection limits lower than 10 micrograms L-1 were obtained for all studied compounds. The method has been applied to their determination in sea water and depurated waste water samples.

Surfactants and complexing agents: new tasks for specimen banking?

Surfactants and complexing agents are chemical products that are released into the environment in large amounts after being used in cleaning processes, mineral flotation, pesticide formulations, etc. Although these compounds are largely degraded during sewage treatment in industrialized countries, significant amounts will be found in sediments or sewage sludges. Furthermore, large concentrations of these compounds can be found in small rivers and brooks in the vicinity of outfalls of sewage treatment plants. Since these compounds can be expected to alter the organic matrix of the soil (surfactants) or to remobilize heavy metals from soils or sediments (complexing agents), their occurrence in the environment and their effects have to be investigated to estimate their long-term risk potential. This could be a new task for specimen banking. To this end, (a) sensitive and specific detection methods for surfactants and complexing agents have to be developed at concentrations relevant to environmental occurrence, and (b) the effect of surfactants and complexing agents on the distribution of organic and inorganic pollutants in environmental compartments has to be investigated. Preliminary investigations show significant synergistic or antagonistic effects of various surfactants on the adsorption of pollutants at clay minerals.