A new PVC-activated charcoal fiber coated on silver wire; application in determination of n-alkanes in the headspace of soil samples by SPME-GC.

In this study, a new solid phase microextraction (SPME) fiber based on activated charcoal and polyvinyl chloride (PVC) coated on silver wire is presented. This fiber is very mechanically and thermally stable. Unlike commercial fiber, which is coated on fused silica, this fiber has a metallic base to which the coating adheres very strongly. On the other hand, producing this fiber is very fast, and can be completed in less than 30 min. This compares favorably with the time to make a fiber based on fused silica, which may last several days, due to many steps, such as conditioning in HCl, drying, deactivation, impregnation with a binder and coating. Also, this fiber is stable up to 250 degrees C. It has been successfully used for the analysis of n-alkanes in the gaseous phase and headspace of soil samples after optimization of the experimental parameters by capillary gas chromatography. The relatively high capacity of the sorbent allows 20-30% of the analytes to be transferred to a separative system during first extraction.