电化学活化玻碳电极吸附伏安法测定维生素K

Determination of vitamin K by adsorptive voltammetry with a electrochemically activated glassy carbon electrode

维生素K类物质可在经电化学活化的玻碳电极上吸附富集并产生良好的伏安响应,依此建立了吸附伏安法测定维生素K1和K3的方法。在0.1mol/LHCl的支持电解质中,维生素K1在-0.025V左右产生一对氧化还原峰,其峰电流与浓度在1.1×10-6～2.2×10-5mol/L范围内成良好的线性关系,检出限为4.4×10-7mol/L;维生素K3则在+0.059V左右产生一对氧化还原峰,其线性范围为1.8×10-7～3.0×10-5mol/L,检出限为9.1×10-8mol/L。该方法可用于测定药品中的维生素K1和K3。

Vitamin K can be adsorbed and accumulated on an electro-oxidation activated glassy carbon electrode and give the well-defined oxidation-reduction peaks. Based on this, a method for the determination of vitamin K1 and K3 by adsorptive vohammetry was established. In 0.1 mol/L hydrochloric acid solution, a pair of sensitive redox peaks were observed at about - 0.025 V for vitamin K1, and the peak current of vitamin K1 was proportional to its concentration from 1.1 ×10^-6 to 2.2 ×10^-5 mol/L. The detection limit of vitamin K1 was 4.4 ×10^-7 mol/L. The redox peaks of vi- tamin K3 appeared at about ＋ 0.060 V. The peak current showed linear response with its concentration in the range of 1.8 ×10^-7 - 3.0×10^-5 mol/L, and the detection limit was 9.1×10^-8 mol/L. The method can be used for the determination of vitamin K1 and K3 in drug.