摘要
以硝酸作氧化剂,将非电活性的维生素E氧化为具有电活性的醌型化合物-生育酚红,采用循环伏安法研究了生育酚红在碳糊电极上的电化学行为,探讨了阳离子表面活性剂的增敏效果、电极反应机理和表面活性剂的增敏机制。试验结果表明:在乙醇-硝酸(69+31)电解质溶液中,在一定量的阳离子表面活性剂十八烷基三甲基氯化铵存在时,生育酚红在碳糊电极上,具有一对可逆的氧化还原峰,峰电位差为30 mV,维生素E的浓度在1.6×10^(-8)～4.0×10^(-6)mol·L^(-1)范围内与其峰电流呈线性关系,检出限(3S/N)为4.0×10^(-9)mol·L^(-1)。该阳极溶出伏安法应用于分析维生素E药品,回收率在92.9%～110.2%之间。
The non-electroactive vitamin E was transformed into electroactive quinoid compound-tocopherol with conc. HNO3 as oxidant. The electrochemical behavior of tocopherol at carbon paste electrode was studied by cyclic voltammetry. The effect and mechanism of enhancement of sensitivity by cationic surfactant, and mechanism of the electrode reaction, were discussed. It was found that in a mixture of ethanol and HNO3 （69＋31）, a pair of reversible oxidation peak and reduction peak of quinoid was obtained at the presence of cationic surfactant OTAC, with potential difference of oxidation peak and reduction peak attained to the value of 30inV. Linear relationship between values of peak current and concentration of vitamin E was found in the range from 1. 6×10 ^-8mol·L^-1 to 4. 0× 10^-6mol·L^-1, with detection limit （3S/N） of 4. 0 × 10^-9mol·L^-1. The proposed anodic stripping voltammetric method was applied to the analysis of vitamin E capsules, giving values of recovery in the range of 92. 9% -- 110. 2%.
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
2009年第8期885-888,共4页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
