柱前衍生化HPLC法测定维U颠茄铝胶囊中维生素U的含量

目的：对维U 颠茄铝胶囊中维生素U 含量测定的方法进行改进，根据维生素U 的特殊结构，建立柱前衍生化HPLC检测法测定其含量。方法：以二硝基氟苯（FDNB）为柱前衍生剂，在碳酸钠- 碳酸氢钠缓冲液（pH 10.0）介质中进行衍生化反应；以HPLC法测定含量，采用Agilent TC-C18（250 mm×4.6 mm，5 μm）色谱柱，以0.01 mol·L^-1 乙酸钠溶液（用乙酸调pH 至6.5）-乙腈（70:30）为流动相，流速1.0mL·min^-1，检测波长360 nm。结果：2 种结构维生素U（氯甲基蛋氨酸和碘甲基蛋氨酸）的衍生产物色谱分离效果均良好，氯甲基蛋氨酸和碘甲基蛋氨酸质量浓度分别在为20.12~201.20 和29.23~292.31 μg·mL^-1 范围内线性关系良好，氯甲基蛋氨酸和碘甲基蛋氨酸的加样回收率分别为97.33%~98.74% 和97.71%~99.24%，RSD（n=6）分别为1.95%~2.52% 和1.85%~2.78%；以本文的柱前衍生化HPLC 法测得的不同厂家的3 批样品中维生素U 含量分别为99.06%、99.73%、100.52%，传统滴定法测得的含量分别为101.07%、102.26%、99.79%，两法结果基本一致。结论：方法学验证结果表明，本文建立的方法可以用于测定维U 颠茄铝胶囊制剂中维生素U 的含量。

Objective:To establish a new analysis method for determination of vitamin U by pre-column derivatization HPLC according to vitamin U special structure,so as to improve the determination method of vitamin U in vitamin U,belladonna and aluminium capsules.Methods:The derivatization reaction is carried out in Na2CO3-NaHCO3 buffer(pH 10.0)medium,with dinitrofluorobenzene(FDNB)as pre-column derivatization, and then analyzed by HPLC.Agilent TC-C18(250 mm×4.6 mm,5 μm)column was adopted,the mobile phase consisted of sodium acetate solution(adjusted to pH 6.5 with acetic acid)-acetonitrile(70:30)at the flow rate of 1.0 mL·min^-1,and the detection wavelength was 360 nm.Results:The derivation products of the two kinds of vitamin U (chlorine methyl methionine and idodine methyl methionine)could be well separated by HPLC.The results showed good relationships between the ranges of 20.12-210.20 μg·mL^-1(chlorine methyl methionine)and 29.23-292.31 μg·mL^-1(idodine methyl methionine).The recoveries for chlorine methyl methionine were 97.33%-98.74% and 97.71%-99.24% for idodine methyl methionine,and RSDs(n=6)were 1.95%-2.52% and 1.85%-2.78%. The vitamin U contents determined by pre-column derivatization HPLC of three samples from different companies were 99.06%,99.73% and 100.52%,while the contents by titration analysis method were 101.07%,102.26% and 99.79%.The results determined by two methods were almost the same.Conclusion:The established method is proved by methodology validation that it can be used for vitamin U determination in vitamin U,belladonna and aluminium capsules.