Extraction of polycyclic aromatic hydrocarbons and organochlorine compounds from water: A comparison between solid-phase microextraction and stir bar sorptive extraction

The enrichment of semi-volatile compounds from water using solid-phase microextraction (SPME) and stir bar sorptive extraction (SBSE) was compared. The investigations (analysis of PAHs and organochlorine compounds) were performed to compare SPME-GC/MS and SBSE-thermodesorption-GC/MS. Additionally, SPME fibres and stir bars were desorbed in a small volume of solvent and analysed by HPLC with fluorescence detection. This method was applied to PAHs. SBSE is more robust and under the given conditions (extraction from a 10 mL sample, 1 h exposure time of fibres and stir bars) enables higher recoveries (20.1-97.2%) for the compounds investigated than SPME (recoveries of 6.3-51.6%). Detection limits between 0.1 and 4.5 ng/L were calculated for the SPME-GC/MS combination, whereas the SBSE-GC/MS combination enabled detection limits between 0.05 and 1.0 ng/L. Coupled to HPLC, the detection limits of the PAHs investigated were found to range between 1.0 and 10.0 ng/L (SPME) or between 0.3 and 2.0 ng/L (SBSE). The advantage of SPME is that the procedure can be completely automated, which is not possible when combining SBSE with GC or LC.