Determination of priority organic substances in surface water containing suspended particulate matter by disk solid phase extraction ; Bestimmung von prioritären organischen Substanzen in schwebstoffhaltigen Oberflächenwasser mittels Festphasenextraktionsscheiben

The European Water Framework Directive (WFD, Directive 2000/60/EC) requires an extensive monitoring of surface water on priority and priority hazardous substances mentioned in Directive 2008/105/EC. Many of these substances can sorb strongly on suspended particulate matter (SPM) due to their hydrophobic character. Therefore, the so called whole water sample, the water sample including solid matter, has to be investigated. The usually used sample preparation methods, such as liquid-liquid extraction (LLE) or solid phase extraction (SPE), are affected by SPM by the formation of emulsions, insufficient extraction of particle-bound analytes or plugging. Consequently, SPM and water sample are often separated, e.g., by filtration, and analysed separately. This approach is associated with a high expenditure of time and work. An alternative may be the use of SPE disks. They have an enhanced diameter compared to SPE cartridges and therefore tend less to plugging. Therefore, an extraction of the whole water sample may become possible in one step. After a first extensive investigation of the occurrence of residual water and its effects in disk SPE to reduce analytical interferences, a multi-component trace analysis of 54 organic xenobiotics in surface water by SPE disk/gas chromatography-mass spectrometry (GC-MS) was developed and validated considering the requirements of the WFD and its following directives. The developed procedure allows the determination of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs) and other pesticides in 1 L water containing up to 1000 mg SPM/sample. The SPE disk sample preparation is combined with two GC-MS methods, differing only in their injection modes to cover a large concentration range. This large concentration range is due to the high number of investigated analytes and the targeted limits of quantification (LOQs), which are associated with the environmental quality standard (EQS) values. ...