【摘要】 目的研究了维生素B12在多壁碳纳米管修饰玻碳电极上的电化学行为与含量测定,以期建立一种直接测定维生素B12的电化学分析方法。方法利用循环伏安法,通过改变缓冲体系、pH值、扫描速度、修饰剂用量等找到维生素B12的最佳测定条件,以便得出最佳测定结果。结果修饰电极对维生素B12有良好的电催化活性,最佳缓冲体系为pH=4.4的醋酸-醋酸钠缓冲体系,最佳的修饰剂用量为20μl。与裸电极相比,多避碳纳米管能显著提高维生素的峰电流,且浓度在0.2×10-4～0.5×10-5 mol/L范围内峰电流与浓度呈良好的线性关系,检出限为1.0×10-7 mol/L。结论多壁碳纳米管修饰玻碳电极对维生素B12有良好的电催化活性,可用于药物制剂中维生素B12的检测。更多还原

【Abstract】 Objective The electrochemical behavior of vitamin B12at a multi-wall carbon nanotube modified glassy electrode was investigated,and a direct electroanalytical method for the determination of vitamin B12was developed..Methods The optimum determination condition was discussed through changing the buffer system,the pH value,the scanning speed,and the amount of modification agent by using cyclic voltammetry(CV).Results The results showed that this modified electrode exhibited an obvious electrocatalytic activity compared with bare electrode;the optimum buffer system was acetic acid-sodiun acetate with pH equal to 4.4,and the optimum amount of modification agent was 20μl.Under the optimized experimental conditions,the peak current and concentration showed a good linear relationship in the range of 0.2×10-4 mol/L～0.5×10-5 mol/L,and the detection limit was 1.0×10-7 mol/L.Conclusion This multi-wall nanotube modified electrode exhibited an obvious electrocatalytic activity,so it can be used for the determination of vitamin B12in pharmaceutical preparations.更多还原