指示离子Cd^(2+)测定维生素B1的方波极谱法研究

Determination of Vitamin B1 with Indicative Ion Cd^(2+) by Square Wave Polarography

根据Cd2+对维生素B1(VB1)的指示作用,建立了用方波极谱法测定VB1的新方法.在氨-氯化铵缓冲溶液中,VB1不出峰,加入Cd2+后在-0.856 V(vs.SCE)处出现1个固定还原峰,并在-0.360 V(vs.SCE)处可见1个峰高与VB1浓度呈正比的还原峰.依据该还原峰峰高的变化规律可测定VB1的含量.VB1在1.35μg/mL^1.35 mg/mL的范围内有良好的线性关系,检出限可达0.13μg/mL,r为0.999 7.平均加样回收率为99.6%(n=9),RSD为0.9%.利用方法测定营养胶囊中VB1的含量,效果理想,可作为VB1含量的测定方法.

A new method with Cd^2＋ as the indication ion, has been established for the determination of Vitamin B1 by using square polarography. No reduction wave of VB1 appeared in the buffer solution of NH3-NH4Cl. When Cd^2＋ was added to the above solution, the non-electro-active VB1 engendered a new peak at -0.360 V. The height of the peak is directly proportional to the concentration of VB1. The linear range of VB1 was 1.35 μg/mL - 1.35 mg/mL and the determination limit was 0.13 μg/mL, r = 0. 9997. The mean recoveries was 99.6% （n=9）, RSD=0.9%. This method is reliable,accurate and is very suitable for the determination of vitamin B1.