title: Electrosorption-enhanced solid-phase microextraction of trace anions using a platinum plate coated with single-walled carbon nanotubes.
abstract: A platinum plate coated with single-walled carbon nanotubes (SWCNTs@Pt) was prepared by means of electrophoretic deposition. Using the SWCNTs@Pt plate, an electrosorption-enhanced solid-phase microextraction (EE-SPME) technique was proposed for the extraction of trace anions in water, described as follows: a positive potential was applied to the SWCNTs@Pt plate to extract F(-), Cl(-), Br(-), NO(3)(-) and SO(4)(2-) from water using electrosorption, and then a negative potential was applied to the plate placed in ultra-pure water for the desorption of the absorbed anions, and finally the desorbed anions were analyzed using ion chromatography (IC). The EE-SPME parameters, including extraction potential and time as well as desorption potential and time, were investigated. An analytical method based on the above procedures, i.e., EE-SPME-IC, was established and used for the analysis of trace anions in water. The results showed that the application of potential on the SWCNTs@Pt plate significantly enhanced the ion extraction efficiency, and an enrichment factor of 15-38 was achieved. The SWCNTs@Pt plate could be used more than 50 times without significant decay. The linear range, the limit of detection (S/N=3), the limit of quantification (S/N=10) and repeatability (n=7) of our EE-SPME-IC method were 1.0-150.0 μg/L, 0.06-0.26 μg/L, 0.19-0.85 μg/L and 2.1-8.0%, respectively. The proposed method was successfully applied for the analysis of trace anions in deionized water, and acceptable recoveries between 65.3 and 121.1% were obtained for the spiked deionized water samples.
authors: State Key Laboratory of Marine Environmental Science, Environmental Science Research Center, Xiamen University, Xiamen 361005, China. liql@xmu.edu.cn
authors: Quanlong
authors: Q
authors: Li
authors: Yujing
authors: Y
authors: Ding
authors: Dongxing
authors: D
authors: Yuan
mesh_terms: D000838:Anions / Q000032:analysis / Q000302:isolation & purification*; D004586:Electrophoresis; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D052617:Solid Phase Microextraction / Q000379:methods*; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D000838:Anions; D037742:Nanotubes, Carbon; D014867:Water; D010984:Platinum