高效毛细管电泳法测定胭脂虫提取物中胭脂红酸

建立高效毛细管电泳法(HPCE)测定胭脂虫提取物中胭脂红酸含量的方法以含5% 乙腈、5% 乙二醇的40mmol/LNa2HPO4-Na2B4O7·10H2O 混合缓冲液(pH9.434)为背景电解质，60cm × 75μm 未涂层毛细管柱为分离泳道，分离电压20kV，0.5psi × 10s 压力进样，柱温25℃，检测波长239nm，此条件下，采用峰面积内标法定量；在选定的电泳条件下，胭脂红酸质量浓度在50～500mg/L 范围内线性关系良好，线性相关系数R=0.9958，加标回收率为100.86%，方法检出限(RSN=3)为5.00μg/mL。本方法测定胭脂红酸含量试剂用量少，简便、快速、准确，可应用于实际生产中胭脂红酸的测定。

Determination of Carminic Acid Content in Cochineal Extract by High Performance Capillary Electrophoresis

A method for determining the content of carminic acid in cochineal extract was established using high performance capillary electrophoresis (HPCE). All experiments were carried out on an uncoated capillary column (60 cm × 75 μm, i.d.) under 20 kV and 0.5 psi × 10 s injection pressure at 25 ℃. The detection wavelength was set at 239 nm. Internal calibration method was used for quantification. Under all selected conditions, a good linear relationship of carminic acid was observed over the range of 50 to 500 mg/L, with a linear correlation coefficient of 0.9958. The average recovery rate of carminic acid in 7 parallel cochineal extracts spiked at a level was 100.86% and the detection limit was 5.00 μg/mL. This method is simple, rapid, accurate and can provide a reference for actual production.