HPLC法测定减肥茶中非法添加的咖啡因含量

Determination of the Illegally Added Contents of Caffeine in Diet Tea by HPLC

目的 探究市场上常见的五种减肥茶中的咖啡因含量。并和相应质量的茶叶中所含咖啡冈的鞋进行比较，以验证减肥茶中是否非法添加咖啡因。并对减肥茶中的咖啡因含量提供规定限度参考。方法色谱柱为Inertsil ODS-SPC18柱（250rnm＊4．6mm，5μm），流动相为甲醇：水（19：81）流速为1．0mL／min，柱温为40℃，用紫外检测器在274nm波长下测定。结果咖啡因线性范围为20．12-201．20gg／mL（r=0．9999）保留时间为9．304min，平均回收率101．82％，RSD为1.32％。结论本方法快速、简便、准确，重现性好，可作为控制减肥茶中咖啡因含量的方法。

Objective To establish a HPLC method for diet tea with illegally added caffeine. Method Chromatographic column is Inertsil ODS-SP C18（5 μm 250 nm·4.6 nm, 5 μm）, the flow rate is 1.0 mL/min, the column temperature is 40℃, PDA FID determine on the 274 nm. Result The linear range of caffeine is 20.12-201.20 μg/mL （r=0.9999）, holding time is 9.304 rain. The average recoveries（n=8） is101.833 % （RSD=1.32 %）. Conclusion This method is rapid, simple and accurate, reproducible and can be used as a method for determination of the content of the illegally added caffeine in diet tea.