The Prut River, the second longest tributary of the Danube river, was investigated for a wide range of anthropogenic organic pollutants to fill the data gap on environmental contamination in eastern European surface waters. In this study, the occurrence of a wide range of organic pollutants was measured along the transboundary Prut River, between Sculeni and Branza in 2010-2012. Using two different analytical methods, gas chromatography coupled to mass spectrometry and liquid chromatography coupled to high-resolution mass spectrometry, over 300 compounds were screened for and 88 compounds were determined in the Prut River. In general, the chemicals occurred at low levels. At the last sampling site upstream of the confluence with the Danube river at Branza, the highest average concentrations (≥ 100 ng L-1) were determined for the artificial sweetener acesulfame, the pharmaceuticals metformin, 4-acetamidoantipyrene, and 4,4,5,8-tetramethylchroman-2-ol, the antioxidants 2,4-di-tert-butylphenol, 3-tert-butyl-4-hydroxyanisol, and 3,5-di-tert-butyl-4-hydroxy-toluene, the personal care products HHCB (galaxolide), 4-phenyl-benzophenone, and octyl dimethyl-p-aminobenzoic acid, the industrial chemical diphenylsulfone, and the sterol cholesterol. Low concentrations of agricultural pesticides occurred in the catchment. At Branza, the total accumulated load of all measured compounds was calculated to be almost 19 kg day-1. In comparison to the Rhine River, the loads in the Prut, determined with same LC-HRMS method for the same set of analytes, were two orders of magnitude lower. Discharge of wastewater without proper treatment from the city of Iasi in the Jijia catchment (Romania) as well as from the city of Cahul (Moldova) revealed a distinct increase in concentrations and loads in the Prut at Frasinesti and Branza. Thus, an implementation of wastewater treatment capacities in the Prut River basin would considerably reduce the loads of micropollutants from urban point sources.
Keywords: GC-MS; LC-HRMS; Organic pollutants; Prut River catchment; River monitoring; Target screening.