高效液相色谱法检测人血浆中咖啡因及其3种去甲基代谢产物

Determination of Caffeine and Its Three Demethylated Metabolites in Human Plasma by High Performance Liquid Chromatography

以８氯茶碱作为内标，利用高效液相色谱同时测定人血浆中咖啡因及其３种去甲基代谢产物—副黄嘌呤、可可碱和茶碱的方法。这４种物质可以在一个固定相柱子上（ＳｐｈｅｒｉｓｏｒｂＣ１８，５μｍ，４６ｍｍ×２５０ｍｍ）被同时分离；流动相为甲醇：０１ｍｏｌ／Ｌ磷酸二氢钠（３０：７０）（Ｖ／Ｖ）；流速：０８ｍｌ／ｍｉｎ；紫外检测器，波长２７４ｎｍ。实验表明这４种物质的最小检出量均在７５ｎｇ／ｍｌ，并具有较好的线性、重复性及较高回收率。

Serum concentrations of caffeine (CA) and its three major demethylated metabolites (theobromine,TB;paraxanthine,PX;theophylline,TP) were measured by high performance liquid chromatography (HPLC) in healthy subject after oral CA loading.8 chlorotheophylline was used as internal standard and CA,TB,PX and TP in plasma were extracted by dichloromethane.The four substances were seperated on a reversed phase column (Spherisorb C 18 ,4 6mm×250mm,5μm),monitored at Uv 274nm.The results indicated that the accuracy and reproducibility of the method were sufficient as metabolic probe for measuring the activity of CYP1A2 in vitro.