Anodized zinc wire as a solid-phase microextraction fiber

Abstract

KeyWordsGas ch ro matog rap hy Solid-phase microext faction Zincwire New fi bets Thiophenol and thiol compounds SummaryThe effTciency of anodTzed zinc wire as a new fiber forsolid-phase mTcroextractTon (SPME) has been investigated. Zinc wire was anodTzed by use of dTrect current in a solution of sodium hydroxide at room temperature. The fibers were used for the extractTon of thiophenol, as an example ofthTol compounds, from gaseous samples and from the headspace aqueous samples. The extracted analytes were transferred to a GC injector by use of an (Tn-house-desTgned) SPME syrTnge, whTch enabled easy changTng 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 opti mum conditions one fiberwas used for several identical analyses and relative standard devia tions (RSD) were below 3% (n -6). For fiberto fiber reproducibility RSD was 3.77% (n -6). The fiber is sturdy, inexpensTve, and durable, and can be prepared sTmpl,~ IntroductionOver the past ten years solid-phase microextraction (SPME) has become an attractive alternative to most conventional sampiing techniques and has gained widespread acceptance in many areas [1 5]. This technique integrates easy, rapid, sensitive, and safe sampling, extraction, and concentration with the sample introduction procedure used for GC and HPLC into a single step. SPME uses a small (1 cm) piece of fused silica, on which a liquid phase, similar to a GC stationary phase, has been coated to absorb or adsorb the analytes [5] [28], and Nafion are specialized phases for removal of species such as metal ions, proteins, polar compounds, etc. In recent years research has been directed to the application of new fibers to increase the selectivity, sensitivity, and durability of solid phases. In previous work we developed new fibers consisting of activated charcoal [29,30], anodized aluminum [31], and modified copper wires [32]. These fibers resulted in improvement of one or more of cost, durability, sensitivity, and range of application.Zinc oxide is an interesting metal oxide which can be produced easily. It has considerable adsorptive and catalytic behavior. Zinc oxide catalyses the hydrogenation of carbon dioxide [33] and carboxylic acids [34] to methanol and aldehydes, respectively, and the dehydrogenation of alcohols to aldehydes [35]. In this study a simple and rapid method for preparation of a new fiber consisting of zinc wire coated with zinc oxide (anodized zinc) has been investigated. Because of the considerable adsorptive capacity of ZnO, this wire can be used as an SPME fiber. This should ensure long life, low cost, and desirable selective adsorptive properties for SPME of some organic compounds.Original

Development of Novel Solid-Phase Microextraction Fibers

“…Zhang et al [179] even coupled chemical etching to anodization to prepare a nanowire coating. Similarly, zinc wire and titanium wire were also anodized to prepare ZnO and TiO 2 coatings [180,181]. After TiO 2 coating formed by anodizing, phenyl groups could be subsequently functionalized on TiO 2 for extracting PAHs through π-π stacking effect [182].…”

Progress of Solid‐Phase Microextraction Coatings and Coating Techniques

“…This kind of coating could be used to extract volatile amines, and the detection limit of the method was 0.1-0.3 ng/mL. Similar methods were used to prepare anodized aluminum wire (59), electrochemical anodized zinc wire (60), and copper sulfide wire (61). Farajzadeh et al (62) had prepared three kinds of copper (I) compounds on the surface of copper wire, including copper (I) chloride, copper (I) oxide, and copper (I) sulfide by using the electrochemical method.…”

Sol-gel Titania-Coated Needles for Solid Phase Dynamic Extraction-GC/MS Analysis of Desomorphine and Desocodeine

“…Almost all commercially available SPME fibers are prepared with fused silica fiber, which is fragile and should be handled with care. To overcome this drawback, researchers have developed a number of metal oxide such as Al2O3, 14,15 ZnO, 16 ZrO2 17 and TiO2 18,19 coating in metal supporting wire with different coating techniques. These coating techniques include direct-pasting, 15 electrodeposition, 14,16 chemical oxidation [20][21][22] and sol-gel techniques.…”

“…To overcome this drawback, researchers have developed a number of metal oxide such as Al2O3, 14,15 ZnO, 16 ZrO2 17 and TiO2 18,19 coating in metal supporting wire with different coating techniques. These coating techniques include direct-pasting, 15 electrodeposition, 14,16 chemical oxidation [20][21][22] and sol-gel techniques. [23][24][25][26] The sol-gel process usually involves catalytic hydrolysis of the alkoxide precursors and polycondensation of the hydrolyzed products in the sol solution to form a macromolecular network structure of sol-gel metal oxides.…”