Kvasnicka Frantisek, Voldrich Michal, Vyhnálek Josef
Department of Food Preservation and Meat Technology, Institute of Chemical Technology Prague, Technická 3, 166 28 Prague 6, Czech Republic.
J Chromatogr A. 2007 Oct 26;1169(1-2):239-42. doi: 10.1016/j.chroma.2007.08.074. Epub 2007 Sep 5.
An on-line coupled capillary isotachophoresis-capillary zone electrophoresis method for the determination of glycyrrhizin in liqueurs is described. The optimised electrolyte system was 5 mM HCl+11 mM epsilon-aminocaproic acid+0.05% hydroxyethylcellulose+30% methanol (leading electrolyte), 5 mM caproic acid+30% methanol (terminating electrolyte) and 20 mM caproic acid+10 mM histidine+0.1% hydroxyethylcellulose+30% methanol (background electrolyte). Method characteristics, i.e., linearity (20-500 ng/ml), accuracy (recovery 99+/-4%), intra-assay repeatability (2%), intermediate repeatability (3.8%) and detection limit (8 ng/ml) were determined. Speed of analysis, low laboriousness, high sensitivity and low-running cost are the typical attributes of the capillary isotachophoresis-capillary zone electrophoresis method. Developed method was successfully applied to analysis of liqueurs with liquorice extract and some foods (sweets and food supplements) containing liquorice. Found levels of glycyrrhizin in liqueurs, sweets and food supplements varied between 1-16 mg/l, 850-1050 mg/kg and 1.6-1.8 g/kg, respectively.
描述了一种用于测定利口酒中甘草酸的在线耦合毛细管等速电泳 - 毛细管区带电泳方法。优化后的电解质系统为5 mM盐酸 + 11 mM ε-氨基己酸 + 0.05%羟乙基纤维素 + 30%甲醇（前导电解质）、5 mM己酸 + 30%甲醇（终止电解质）和20 mM己酸 + 10 mM组氨酸 + 0.1%羟乙基纤维素 + 30%甲醇（背景电解质）。测定了方法特性，即线性（20 - 500 ng/ml）、准确度（回收率99±4%）、批内重复性（2%）、中间精密度（3.8%）和检测限（8 ng/ml）。分析速度快、劳动强度低、灵敏度高和运行成本低是毛细管等速电泳 - 毛细管区带电泳方法的典型特点。所开发的方法成功应用于含甘草提取物的利口酒以及一些含甘草的食品（糖果和食品补充剂）的分析。在利口酒、糖果和食品补充剂中测得的甘草酸含量分别在1 - 16 mg/l、850 - 1050 mg/kg和1.6 - 1.8 g/kg之间。
