左氧氟沙星在膨胀石墨电极上的吸附伏安行为及其测定  

Adsorption voltammetric behavior and determination of levofloxacin at expanded graphite electrode

作　　者：梁耀东[1] 李弯弯[1] 贺拥军[1] 

机构地区：[1]西安科技大学化学与化工学院,陕西西安710054

出　　处：《西安科技大学学报》2015年第2期242-247,共6页Journal of Xi’an University of Science and Technology

基　　金：陕西省教育厅专项基金项目(2009JQ2010);西安科技大学培育基金项目(XKBO200635)

摘　　要：利用膨胀石墨电极在正电位区域残余电流低、基线平稳的特点,采用循环伏安法、差分脉冲伏安法和紫外可见分光光度法,研究了左氧氟沙星在膨胀石墨电极上的伏安行为,并建立了测定左氧氟沙星的新方法。在0.2 mol·L^-1KH2PO4-Na2HPO4（p H=5.29）的缓冲溶液中,左氧氟沙星在＋1.0 V（vs.SCE）处有一灵敏的不可逆氧化峰,采用差分脉冲伏安法对左氧氟沙星进行检测。在优化的实验条件下,峰电流与左氧氟沙星浓度在7.0×10^-8-2.0×10^-5mol·L^-1范围内呈线性关系,检出限为3×10^-8mol·L^-1（s/n=3）,对1.0×10-6mol·L^-1左氧氟沙星平行测定11次的相对标准偏差为2.2%.方法选择性好、灵敏度高,用于胶囊中左氧氟沙星含量的测定,回收率在96%-105%之间。结果表明,左氧氟沙星在膨胀石墨电极表面发生了吸附控制的两电子、两质子不可逆氧化过程。Expanded graphite electrodes are of characteristics of low background currents and flat measure baseline over a range of the large positive potentials in aqueous solution. The voltammetric behavior of levofloxacin at expanded graphite electrode was investigated by cyclic voltammetry,differential potential voltammetry and ultraviolet-visible spectroscopy,and a new method for the determination of levofloxacin was proposed. A sensitive oxidation peak of levofloxacin in 0. 2 mol L^- 1KH2PO4- Na2HPO4（ p H5. 29） buffer was obtained at ＋ 1. 0 V（ vs. SCE）,the content of levofloxacin was measured by differential potential voltammetry. Under the optimized condition,the oxidation peak current varied linearly with the concentration of levofloxacin in the range from 7. 0 × 108 to 2. 0 × 10^5 mol L^- 1,and the detection limit was 3 × 10^8 mol L^- 1（ s/n = 3）,the relative standard deviation of eleven measurements was 2. 2 %for 1. 0 × 10^6 mol L^- 1levofloxacin. The method has fairly good selectivity and high sensitivity,and has been applied to the determination of levofloxacin in the capsules with the recoveries within 96 and105%. The results showed that the oxidation of levofloxacin was an adsorption-controlled irreversible two-electron and two-proton process.

关 键 词：膨胀石墨电极 左氧氟沙星 差分脉冲吸附伏安法 

分 类 号：O632[理学—高分子化学]