A capillary electrophoresis (CE) method combined with online and offline enrichment for improving the detection sensitivity of chondroitin sulfate (CS) is established. The online enrichment method is based on the field-amplified sample stacking and large volume electrokinetic injection, and offline enrichment is based on the association between cetyltrimethylammonium chloride and CS. Experimental parameters affecting CE method such as the type and pH of background electrolyte, the injection mode and time and the steps of offline enrichment were optimized. Under optimum conditions, the calibration plot between CS concentration and peak area was linear in the range of 1 ~ 100 μg/mL. The enrichment factor was 130 times and the limit of detection was 50 ng/mL. The average recovery was 103.5% and the relative standard deviation of peak area was <2.0%. The method was successfully applied to the quantitative analysis of CS in drugs.

中文翻译：

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离线选择性萃取与在线富集相结合，通过毛细管电泳对硫酸软骨素进行灵敏分析。

建立了毛细管电泳与在线和离线富集相结合的方法，以提高硫酸软骨素（CS）的检测灵敏度。在线富集方法基于现场放大的样品堆叠和大体积电动进样，离线富集基于十六烷基三甲基氯化铵与CS的缔合。优化了影响CE方法的实验参数，例如背景电解质的类型和pH，进样方式和时间以及离线富集的步骤。在最佳条件下，CS浓度与峰面积之间的校准曲线在1〜100μg/ mL范围内呈线性关系。富集因子为130倍，检出限为50 ng / mL。平均回收率为103.5％，峰面积的相对标准偏差<2。0％。该方法已成功应用于药物中CS的定量分析。