Sources of nitrogen heterocyclic PAHs (N-HETs) along a riverine course.

For the first time the occurrence of 26 nitrogen heterocyclic polyaromatic hydrocarbons (N-HETs) and the antiepileptic drug carbamazepine (CBZ) as a marker for anthropogenic influence was determined in an entire river system and its influents. Besides the investigation of diurnal and annual variations in concentrations, dilution and load calculations, the aims were to facilitate transferability to other rivers by identifying sources of the different substances. To create a sufficient database over 180 aqueous samples from the River Fuhse (Lower Saxony, Germany), its catchment area, effluents of municipal and industrial wastewater treatment plants (WWTPs) and rainwater were analyzed. Typical substances found in background water samples and rain samples were quinoline and isoquinoline, whereas 1-/3-methylisoquinoline were traced back to an industrial WWTP. Due to similar concentration levels in the effluents of municipal WWTPs, their impact on the river correlated with their nominal loads. In municipal WWTP effluents CBZ (cmedian=1693ngL-1), 2-methylquinoline (cmedian=64ngL-1), and acridine (cmedian=62ngL-1) prevailed. Although the occurrence of N-HETs at contaminated sites is a widely discussed scientific topic, this study showed that the investigated site was a source with only small volumetric contribution to N-HET concentrations in the adjacent river. In total the River Fuhse discharges 20kga-1 N-HETs and 21kga-1 CBZ into the receiving river.

Development and application of a simultaneous SPE-method for polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, heterocyclic PAHs (NSO-HET) and phenols in aqueous samples from German Rivers and the North Sea.

Polycyclic aromatic hydrocarbons (PAHs), heterocyclic PAHs (NSO-HETs), alkylated PAHs and phenols are known as the prevailing contaminants in groundwater at tar contaminated sites. Besides these local sources, the concentrations and the distribution in particular of NSO-HETs in environmental samples, such as rivers, have received notably less attention. To investigate their occurrence in river basins two sensitive analytical methods for the simultaneous extraction of 86 substances including NSO-HETs, classical EPA-PAHs, alkylated PAHs and phenols were developed: liquid-liquid extraction for the whole water phase and solid phase extraction for the dissolved water phase only. Solely GC-MS or additionally LC-MSMS for fractionated basic nitrogen heterocycles (N-HETs) were used for quantification. Limits of quantification were in the low ngL(-1) range. Concentrations were determined in 29 aqueous samples from 8 relatively large rivers located in Lower Saxony (Germany) and the North Sea. NSO-HETs had comparable or even higher sum concentrations than EPA-PAHs. N-HETs, especially acridine and quinolines with concentrations of up to 20ngL(-1) per substance, were predominant.