摘要：
通过2台高压恒流泵、1台紫外检测器、1个手动进样阀、1个高压切换阀和2根色谱柱组建了二维液相色谱系统,建立了在线富集测定银杏叶提取物(EGB)及其制剂中微量银杏酸的方法.第一维色谱柱为富集柱,采用ZORBAX Eclipse Plus-C18(2.1 mmx12.5mm,5μm),流动相为甲醇-水-三氟乙酸混合液(体积比80:20:0.01),流速为0.25 mL/min,可实现300μL样品的富集,有效降低了基体干扰.第二维色谱柱为分析柱,采用ZORBAX Eclipse Plus-C18(2.1 mmx150mm,5 μm),流动相为甲醇-水-三氟乙酸混合液(体积比90: 10:0.01),流速为0.25 miymin,可有效分离银杏酸.使用紫外检测器在310 nm处检测,可实现对银杏酸的准确定量.研究了试样的溶剂对富集效果的影响,当试样溶剂与第一维流动相一致时可获得较好的富集效果.该方法对试样中5种银杏酸在0.200-100.0 mg/kg范围内具有良好的线性关系,相关系数均大于0.998,检出限达0.02～0.06 mg/kg.对实际样品测定结果的相对标准偏差均不大于5.0％,在5、 10 mg/kg加标水平下,加标回收率为94.0％～101.3％.%A method of two-dimensional liquid chromatography with online enrichment was established for the determination of trace ginkgolic acids in Ginkgo biloba extract(EGB) and their preparations. The liquid chromatography system was composed of two LC pumps, an UV detector, a manual sampling valve, a switching valve and two columns. The ginkgolic acids were enriched on the first dimensional column of ZORB AX Eclipse Plus-C18 (2.1 mm x 12. 5 mm, 5μm) using a methanol-water-trifluoroacetic acid mixture (80:20:0.01) as mobile phase at a flow rate of 0.25 mL/min, then separated on the second dimensional column of ZORBAX Eclipse Plus-C18(2.1 mm x 150 mm, 5 μm) using a methanol-water-trifluoroacetic acid mixture (90:10-0.01) as mobile phase at a flow rate of 0.25 mL/min, finally detected with a UV detector at 310 nm. The effects of sample solvent and sample volume on the enrichment were investigated. When the sample solvent was consistent with the first dimension mobile phase, the enrichment on 300 μL sample could be achieved. There existed good linear responses for 5 kinds of ginkgolic acids in the range of 0.200-100.0 mg/kg, with correlation coefficients greater than 0.998 and detection limits of 0.02-0.06 mg/kg. The recoveries at two spiked levels of 5 mg/kg and 10 mg/kg were between 94.0％ and 101.3％ with relative standard deviations not more than 5.0％.
