Anodized zinc wire as a solid-phase microextraction fiber

The efficiency of anodized zinc wire as a new fiber for solid-phase microextraction (SPME) has been investigated. Zinc wire was anodized by use of direct current in a solution of sodium hydroxide at room temperature. The fibers were used for the extraction of thiophenol, as an example of thiol compounds, from gaseous samples and from the headspace aqueous samples. The extracted analytes were transferred to a GC injector by use of an (in-house-designed) SPME syringe, which enabled easy changing of SPME fibers. The results obtained prove the suitability of anodized zinc wire as a new fiber for extraction and sampling of some organic compounds from these samples. This behavior is most probably because of the porous layer of zinc oxide formed on the metal surface. In this work the optimum conditions were determined for preparation and conditioning of the fibers and extraction of the analytes. Under the optimum conditions one fiber was used for several identical analyses and relative standard deviations (RSD) were below 3% (n = 6). For fiber-to-fiber reproducibility RSD was 3.77% (n = 6). The fiber is sturdy, inexpensive, and durable, and can be prepared simply.