定量核磁共振法同时测定复合维生素B片中B1、B2、烟酰胺和泛酸钙

建立了同时测定复合维生素B片中4种有效成分——维生素B1(VB1)、维生素B2(VB2)、烟酰胺和泛酸钙的定量核磁共振氢谱(~1H qNMR)方法.选择延迟时间(D_1)为1.0 s、脉冲宽度(P_1)为3.0μs、采样次数(NS)为500次.以对苯二甲醛为内标,其质子峰δ10.12(2H)为内标峰;溶剂为氘代二甲亚砜(DMSO-d_6).定量峰的化学位移VB1选择δ9.60~9.90(~1H),VB2选择δ11.36(~1H),烟酰胺选择δ9.01(~1H),泛酸钙选择δ0.78(12H).通过标定VB1和泛酸钙对照品的纯度,测定各成分的零截距标准曲线斜率与理论值相符,说明可以直接用绝对定量公式计算其含量.测定各成分的回收率均接近100%,且重复性很好.结果表明该方法准确度高、结果可靠,可用于复合维生素B片中VB1、VB2、烟酰胺和泛酸钙含量的测定.

A Quantitative NMR Method to Analyze Vitamin B1, Vitamin B2, Nicotinamide and Calcium Pantothenate Contents in Compound Vitamin B Tablets

A quantitative1H NMR method was established for analysis of contents of vitamin B1, vitamin B2, nicotinamide and calcium pantothenate in Compound Vitamin B Tablets. The experimental settings were as following: delay time (D1) 1.0 s, pulse width (P1) 3.0μs, number of sampling (NS) 500 times, 1,4-benzenedialdehyde peak atδ10.12 (2H) as the internal standard, and deuterated DMSO-d6 as the solvent. The peaks for quantitative analysis were: vitamin B1 atδ9.60~9.90 (1H), vitamin B2 atδ11.36 (1H), nicotinamide atδ9.01 (1H) and calcium pantothenate atδ0.78 (12H). The slopes of the standard curves obtained for the 4 components were close to theoretically predicted values. Calibration with vitamin B1 and calcium pantothenate reference substances yielded correlation coefficients (r) above 0.999 and recovery ratio near 100%. Finally, the method was applied to 4 real samples, and the results suggested that it is simple to use, accurate and reliable.