高效液相色谱法测定饮料中的咖啡因

Determination of caffeine in beverages by HPLC

目的研究了高效液相色谱法直接测定饮料中咖啡因的新方法。方法采用Hypersil ODS柱,以甲醇+乙酸铵(0.02mol/L)=15+85作流动相,流速1.0m L/min,检测波长207nm,柱温30℃。结果6min内将咖啡因与基体分离,咖啡因含量与峰面积在10～200μg/mL范围呈线性关系,相关系数r=0.9998;回收率范围为97.4%～101.4%。结论该法准确,样品处理简单。

Objeetive To establish a new method for determination of caffeine in beverages by HPLC. Methods The caffeine in beverages was determined by Hypersil ODS column using methanol-0.02 mol/L ammonium aeetae solution （15： 85） as the mobile phase at a flow rate of 1.0 mL/min and detected by VWD at 207 nm. Results Caffeine in mixture was separated within 6 minutes.The standard curve showed a direct linear correlation of the concentration with the peak area. The linear range was 10μg/mL to 200μg/mL（r=-0.9998）. Recovery rate was between 97.4% and 101.4%. Conclusion The method is accurate, simple and suitable for determination of caffeine in beverages.