胶束电动毛细管色谱法同时测定西洋参中人参皂苷Rg1、Re和Rb1

建立了西洋参中人参皂苷Rg1、Re及Rb1同时分离测定的胶束电动毛细管色谱新方法,以解决西洋参样品中难溶于水的3种人参皂苷的准确定量问题。以40.2 cm(有效长度30 cm)×50 μm的熔融石英毛细管柱为分离柱,分离缓冲液的组成为V(15 mmol/L Na2B4O7+30 mmol/L H3BO3 (pH 9.0)+100 mmol/L十二烷基硫酸钠(SDS)+30 g/L聚乙二醇35000):V(甲醇):V(异丙醇)=2:1:1,于214 nm下检测。详细研究了影响分离的因素。Rg1、Re及Rb1检出限(信噪比(S/N)为3)分别为30、40及30 mg/L,定量限(S/N=9)分别为90、120及90 mg/L,加标回收率为87.4%～95.2%。用该法测定了西洋参标准物质,并与高效液相色谱法的检测结果进行了比对,结果吻合。应用该方法分别测定了中国、加拿大及美国的西洋参,获得满意的结果。

Determination of ginsenosides Rg1, Re and Rb1 in Panax quinquefolium by micellar electrokinetic capillary chromatography

The accurate assay of the three highly hydrophobic ginsenosides Rg1, Re and Rb1 in one injection plays a key role in assessing the quality of Panax quinquefolius. A micellar electrokinetic capillary chromatographic (MEKC) method was therefore developed for the simultaneous determination of ginsenosides Rg1, Re and Rb1 in Panax quinquefolium. The separation was carried out on an uncoated fused-silica capillary with 50 microm i. d. and 30 cm effective length (to the detector). The separation buffer was V (15 mmol/L Na2B4O7 + 30 mmol/L H3BO3 (pH 9.0) + 100 mmol/L dodecyl sulfate sodium salt (SDS) + 30 g/L polyethylene glycol (PEG) 35000): V (methanol): V (iso-propanol) = 2: 1:1. The separation voltage was 30 kV with hydrodynamic injection at 3. 448 kPa for 15 s. The detection wavelength was set at 214 nm. The factors such as the buffer concentration, the content of the organic solvent and buffer additives, which influenced the accurate analysis of ginsenosides, were investigated in detail. The samples were simply extracted twice by methanol-10 mmol/L SDS (1: 1, v/v). The limits of detection (LOD, S/N = 3) for Rg1, Re and Rb1 were 30, 40 and 30 mg/L, respectively. The limits of quantitation (LOQ, S/N = 9) were 90, 120 and 90 mg/L, respectively. The recoveries at the studied concentrations were between 87.4% and 95.2%. The established method was used for the determination of the certified reference material (CRM) of Rg1, Re and Rb1 in Panax quinquefolium. The results were in good agreement with those of the high performance liquid chromatographic (HPLC) method. The samples of Panax quinquefolium from Canada, United States and China were also analyzed separately and satisfactory results were obtained.