Roman Mark C
Tampa Bay Analytical Research, 13160 56th Ct, Suite 606, Clearwater, FL 33760, USA.
J AOAC Int. 2013 Sep-Oct;96(5):933-41. doi: 10.5740/jaoacint.10-488.
A rapid method has been developed to quantify seven catechins and caffeine in green tea (Camillia sinensis) raw material and powdered extract, and dietary supplements containing green tea extract. The method utilizes RP HPLC with a phenyl-based stationary phase and gradient elution. Detection is by UV absorbance. The total run time, including column re-equilibration, is 13 min. Single-laboratory validation (SLV) has been performed on the method to determine the repeatability, accuracy, selectivity, LOD, LOQ, ruggedness, and linearity for (+)-catechin, (-)-epicatechin, (-)-epicatechin gallate, (-)-epigallocatechin, (-)-gallocatechin gallate, (-)-epigallocatechin gallate, and (+)-gallocatechin, as well as caffeine. Repeatability precision and recovery results met AOAC guidelines for SLV studies for all catechins and caffeine down to a level of approximately 20 mg/g. Finished products containing high concentrations of minerals require the use of EDTA to prevent decomposition of the catechins.
已开发出一种快速方法，用于定量绿茶（茶树）原料、粉状提取物以及含绿茶提取物的膳食补充剂中的七种儿茶素和咖啡因。该方法采用带有苯基固定相和梯度洗脱的反相高效液相色谱法。通过紫外吸光度进行检测。包括柱重新平衡在内的总运行时间为13分钟。已对该方法进行单实验室验证（SLV），以确定（+）-儿茶素、（-）-表儿茶素、（-）-表儿茶素没食子酸酯、（-）-表没食子儿茶素、（-）-没食子儿茶素没食子酸酯、（-）-表没食子儿茶素没食子酸酯、（+）-没食子儿茶素以及咖啡因的重复性、准确性、选择性、检测限、定量限、耐用性和线性。对于所有儿茶素和咖啡因，重复性精密度和回收率结果符合AOAC单实验室验证研究指南，最低可达约20 mg/g的水平。含有高浓度矿物质的成品需要使用乙二胺四乙酸来防止儿茶素分解。
