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1A - Environmental analytical methods (MOP/17) SPME-GC/MS-Method for metabolite scanning of samples from photolysis studies. Geffke, Thomas1, Jens, Lange1, Noack, Udo1, Walter, Bernd2, 1 DR.U.NOACK-LABORATORY, Sarstedt, Niedersachsen, Germany2 THOR GmbH, Speyer, Rheinland-Pfalz, Germany ABSTRACT- Identification of metabolites is an important task in photolysis studies. Usually, radio-labelled substances are preferred to detect degradation products, including all the problems in handling radioactive material. The use of SPME fibres with varying polarity for the extraction of different classes of compounds in combination with GC/MS analysis has shown to be a valuable alternative, because it allows the use of unlabelled substance. The advantages of SPME are the small sample volume, the possibility of multiple extraction steps on the same sample and high sensitivity due to enrichment on the SPME-fibre. Further advantages are easy handling and time-saving sample preparation. The mass spectra of unknown compounds can be compared with library spectra for identification purpose and are giving helpful information for possible structures. Identified compounds and proposals for molecule structures can be verified by additional co-chromatography of reference compounds, if available. These advantages are shown for example by performing photolysis studies on isothiocyanate-compounds which are widely used as biocides. Key words: metabolite, Photolysis, identification, SPME-GC/MS |
