A new selective SPME fiber for some n-alkanes and its use for headspace sampling of aqueous samples

This contribution presents a new porous solid phase microextraction (SPME) fiber based on cellulose acetate and polyvinyl chloride (PVC) coated on a metallic base. The proposed fiber is selective for n-alkanes higher than C-10, especially for C-12-C-15. PVC acts as a binder and surface modifier of the fiber. Fiber preparation can be completed in less than 15 min. High capacity, chemical, thermal, and mechanical durability, low cost, and no occurrence of additional peaks in chromatograms are further advantages of the proposed fiber. The relative standard deviations obtained from a single fiber are less than 9% for all analytes. The fiber-to-fiber reproducibility is better than 18%. After optimizing experimental conditions such as fiber composition, extraction time, desorption temperature, solution volume, salting out effect, etc. the fiber can be used for sampling from the headspace of aqueous solutions containing n-alkanes (C-10-C-20) in the mug/L concentration range. Detection limits of 50-150 mug/L are obtained on use of capillary gas chromatographic separation and flame ionization detection. The microextraction procedure is rapid and equilibration takes less than 20 min.