维生素B_1在磷酸盐介质中的极谱吸附波及应用

An Adsorptive Polarographic Wave of Vitamin B_1 in Phosphate Buffer and Its Analytical Application

在 p H6 .6的 Na H2 PO4 - Na2 HPO4 缓冲溶液中 ,维生素 B1 在单扫描极谱上于 - 1.5 V(vs.SCE)产生一个灵敏的吸附还原峰 ,维生素 B1 的含量在 7× 10 - 8～ 1× 10 - 5mol/ L范围内与波高有线性关系 (r=0 .999) .运用该法测定了维生素 B1 药片和复合维生素 B药片中维生素 B1 的含量 ,结果令人满意 .机理研究表明 :该极谱波是由吸附在滴汞电极表面的维生素 B1 还原产生的 。

A sensitive polarographic reduction wave of vitamin B 1 with E p =-1.5 V (vs,SCE) has been observed by using single sweep polarography in NaH 2PO 4-Na 2HPO 4 buffer solution(pH 6.6).The peak height is linearly proportional to the concentration of vitamin B 1 in the range of 7×10 -8~1×10 -5 mol/L. The method has been used to determine the vitamin B 1 in the pharmaceutical tablets with satisfactory results. The mechanism study has showed that the polarographic wave is attributed to the reduction of vitamin B 1 strongly adsorbed on DME surface and the electrode reaction is a two-electron irreversible process.