Uysal Ulku Dilek, Aturki Zeineb, Raggi Maria Augusta, Fanali Salvatore
Institute of Chemical Methodologies, National Council of Research, Area della Ricerca di Roma 1, Monterotondo Scalo, Rome, Italy.
J Sep Sci. 2009 Apr;32(7):1002-10. doi: 10.1002/jssc.200800634.
In this paper, the simultaneous separation of several polyphenols such as (+)-catechin, (-)-epicatechin, (-)-epigallocatechin, theophylline, caffeine in green and black teas by capillary electrochromatography (CEC) was developed. Several experimental parameters such as stationary phase type, mobile phase composition, buffer and pH, inner diameter of the columns, sample injection, were evaluated to obtain the complete separation of the analysed compounds. Baseline resolution of the studied polyphenols was achieved within 30 min by using a capillary column (id 100 microm) packed with bidentate C(18) particles for 24.5 cm and a mobile phase composed of 5 mM ammonium acetate buffer pH 4 with H(2)O/ACN (80:20, v/v). The applied voltage and the temperature were set at 30 kV and 20 degrees C. Precision, detection and quantification limits, linearity, and accuracy were investigated. A good linearity (R(2) > 0.9992) was achieved over a concentration working range of 2-100 microg/mL for all the analytes. LOD and LOQ were 1 and 2 microg/mL, respectively, for all studied compounds. The CEC method was applied to the analysis of those polyphenols in green and black tea samples after an extraction procedure. Good recovery data from accuracy studies ranged between 90% and 112% for all analytes.
本文建立了采用毛细管电色谱法（CEC）同时分离绿茶和红茶中几种多酚类物质的方法，如（+）-儿茶素、（-）-表儿茶素、（-）-表没食子儿茶素、茶碱、咖啡因。对固定相类型、流动相组成、缓冲液及pH值、柱内径、进样等几个实验参数进行了评估，以实现被分析化合物的完全分离。通过使用内径为100微米、填充双齿C(18)颗粒、长度为24.5厘米的毛细管柱，以及由pH值为4的5 mM醋酸铵缓冲液与水/乙腈（80:20，v/v）组成的流动相，在30分钟内实现了所研究多酚类物质的基线分离。施加电压和温度分别设置为30 kV和20℃。研究了精密度、检测限和定量限、线性和准确度。所有分析物在2-100微克/毫升的浓度工作范围内均具有良好的线性（R(2)>0.9992）。所有研究化合物的检测限和定量限分别为1微克/毫升和2微克/毫升。在经过萃取程序后，将CEC方法应用于绿茶和红茶样品中这些多酚类物质的分析。准确度研究的良好回收率数据在所有分析物中为90%至112%。
