Abstract
Globally, rivers are contaminated by a diverse range of organic micropollutants originating from waste water effluents or surface runoff in urban and agricultural areas. In rivers, suspended particulate matter (SPM), which can be constituted by a high proportion of organic material and fine mineral particles, sorbs many of these organic micropollutants and thus influences their distribution and residence times. Furthermore, benthic organisms, which live and feed in freshly deposited sediments, may be at increased risk of exposure to SPM-associated organic micropollutants. Efficient methods for the analysis of organic micropollutants in river SPM are therefore required for studying the distribution of these pollutants in space and time as well as the potential exposure of benthic organisms. In recent years, the "quick, easy, cheap, effective, rugged and safe" (QuEChERS) sample preparation methodology has gained increasing popularity for the analysis of organic micropollutants in environmental samples, including soils and sediments. In this study, we compared four extraction methods based on the QuEChERS methodology for their performance when combined with high-performance liquid chromatography tandem mass spectrometry analysis. As a result, a simple formate-buffered extraction method for the analysis of 104 selected organic pollutants, including pesticides and pharmaceuticals, in river SPM was developed and validated. The validated method was sensitive, with a median method limit of quantification of 1.0 ng/g. The method was applied to investigate the spatial and temporal distribution of the selected pollutants in SPM samples collected in the French-German border river, Lauter, which is an important regional refuge for biodiversity.