酮洛芬的伏安行为及吸附缔合平行极谱催化波研究  

Studies on Voltammetric Behavior and Adsorptive/Association Parallel Polarographic Catalytic Wave of Ketoprofen

作　　者：王福民[1] 

机构地区：[1]渭南师范学院化学化工系,渭南714000

出　　处：《化学通报》2007年第2期134-138,共5页Chemistry

基　　金：陕西省教育厅专项科研基金资助项目(03JK216)

摘　　要：采用线性扫描极谱法、循环伏安法及恒电位电解法在NH4Cl-NH3.H2O(pH9.5)缓冲液中研究了酮洛芬(KPF)的伏安行为和极谱催化波的产生机理。结果表明,KPF的羰基首先发生1e-和1H+还原,产生中间体质子化羰基自由基,该自由基再以同样方式进一步还原生成相应的羟基化合物,并伴随有化学反应;引入K2S2O8后,S2O82-作为配位体与吸附在电极表面质子化的KPF形成缔合物,引起峰电位负移,S2O82-及其还原中间产物SO4.-氧化经1e-和1H+还原的KPF羰基自由基,使峰电流显著增加,从而产生了KPF的吸附缔合平行极谱催化波。测得S2O82-氧化KPF质子化羰基自由基的表观速率常数Kf=1.2×104/s。The voltammetric behavior and the production mechanism of polarographic catalytic wave of ketoprofen in ammoniacal buffer medium of pH 9.5 were studied by linear potential scan polarography, cyclic voltammetry and constant potential electrolysis method. The carbonyl group of ketoprofen was first reduced by a 1e^- ,1H^＋ process to produce an intermediate free radical, and the further reduction of the free radical to the corresponding protonated ketoprofen in the same way was accompanied by its chemical reaction. The catalytic wave such characters as the negative shift of the peak potential and the great increase of the peak current in ketoprofen-persulfate system was obtained. Here persulfate as ligand formed an association complex with protonated ketoprofen adsorbed at electrode surface which caused the peak potential of the reduetive wave of ketoprofen to shift negatively. Additionally the great increase of the peak current was due to the persulfate and its reduction species as oxidant oxidized the carbonyl radical of ketoprofen as catalyst in 1 e , 1H ~ reduction. The apparent first-order rate constant Kf of the oxidation reaction of the free radical protonated carbonyl of ketoprofen with persulfate was 1.2 × 10^4/s.

关 键 词：酮洛芬 过硫酸钾 极谱催化波 自由基 

分 类 号：O657.1[理学—分析化学]