Solvent bar microextraction

In this work, a new and simple microextraction method termed solvent bar microextraction (SBME) was developed. In this method, the organic extractant solvent (1-octanol) was confined within a short length of a hollow fiber membrane (sealed at both ends) that was placed in a stirred aqueous sample solution. Tumbling of the extraction device within the sample solution facilitated extraction. Pentachlorobenzene (PCB) and hexachlorobenzene (HCB) were used as model compounds to investigate the extraction performance. Analysis was cartied out by gas chromatography/electron capture detection. This new method provided very high enrichment (similar to110-fold for PCB and similar to70-fold for HCB) in 10 min and good reproducibility (< 4%, n = 6). Since the hollow fiber membrane was sealed, it could be used for extraction from dirty samples, such soil slurries. This novel microextraction method was compared with single-drop microextraction and static hollow fiber membrane microextraction in which the extractant solvent was also held within a hollow fiber but with the latter fixed to a syringe needle (i.e., there was no tumbling effect). Comparison between SBME and conventional solid-phase microextraction in a soil slurry sample was also investigated.