Multi-compound methods for the detection of pharmaceutical residues in various waters applying solid phase extraction (SPE) and gas chromatography with mass spectrometric (GC-MS) detection

This paper describes two highly sensitive analytical methods for the unambiguous determination of pharmaceutical residues and related polar contaminants in environmental water samples. Both analytical methods use solid phase extraction (SPE), chemical derivatization, and detection of the analytes by capillary gas chromatography-mass spectrometry (GC-MS) with selected ion monitoring (SIM). Using the two methods, a total of 19 pharmaceuticals and 7 related polar contaminants, most of them pesticides, can be detected and quantified down to the low ng/L range in sewage, surface, ground, and drinking water. Recoveries between 70 and 110% and standard deviations of less than 15% were determined for 21 analytes when applying the analytical method that uses pentafluorobenzyl bromide (PFBBr) for derivatization. The second method, which employs N-(t-butyldimethylsilyl)-N-methyltrifluoroacet-amide (MTBSTFA) for derivatization was found to be slightly less sensitive and reproducible but it also permitted the analysis of several other environmentally important compounds such as the antiepileptic drugs carbamazepine or primidone. From spiking experiments, limits of detection (LODs) between less than 1 and 10 ng/L and limits of quantification (LOQs) between 1 and 40 ng/L were calculated