摘要
采用单扫示波极谱法,VK3在0.1mol/LNaCl底液中,于-0.46V(SCE)处有一良好的二阶导数峰,峰高与浓度在5×10-7~2×10-5mol/L范围内成线性关系,检测限为2.5×10-7mol/L.当pH值小于3.60时,VK3与氢离子作用,于零伏左右有一准可逆的2e-+H+波;当pH值大于3.60时,用低扫速的卷积伏安法观察,可发现VK3有双锋,说明有反应中间体存在,在水合介质中其反应机理是可逆的逐级双电子过程.此外,还对底液中溶解氧的影响进行了讨论.
Vitamin K 3 (menadione) shows a sensitive 2nd order derivative reduction wave with the potential of-0.46V(SCE) in the medium of 0.1mol/L NaCl (pH=4.35) by single sweep oscillopolarography. In the range from 5×10 7 ~2×10 5 mol/L, the peak height of menadione depends linearly on the concentration and the detection limit is 2.5×10 -7 mol/L. Menadione reacts with hydrogen ion at pH<3.60 and produces at about o volt a quasi reversible 2e -+H + wave. In the pH range from 3.60 to 9.26,the electrode process is a reversible multistep charge transfer process. It is proved that there is the reactive intermediate in this pH range by convolution voltammetry. In addition,the effect of dissolved oxygen in this base solution electroreduction of menadione is discussed.
基金
国家自然科学基金
中科院长春应化所电分析开放实验室基金
关键词
维生素K3
溶解氧
卷积伏安法
极谱法
vitamin K 3,dissolved oxygen,convolution voltammetry,oscillopolarography