液相微萃取对中药中低丰度有效成分桂皮酸及其衍生物的浓缩富集及色谱分析

目的利用液相微萃取/后萃取-高效液相色谱法(HPLC)对中药中低丰度有效成分桂皮酸及衍生物进行定性鉴别及含量测定,探讨欲萃物浓度、供相体积与富集倍数之间的关系。方法正庚醇为萃取溶剂,供相为2.0×10-4mol/LHCl,接收相为0.008mol/LNaOH,1800r/min转速下,萃取60min后进行HPLC分析。结果桂皮酸、对羟基桂皮酸、对甲氧基桂皮酸的线性范围可达6个数量级,检测限分别为0.2,0.08,0.2pg/ml。精密度:日内RSD<10.6%,日间RSD<11.9%,回收率为94.7%～101.3%,92.1%～105.9%。结论该方法操作简单,分析物的富集倍数达到近100倍,对常规前处理方法难以分析的低丰度微量、痕量成分的分析具有重要的意义。

Concentration, enrichment and chromatographic analysis of cinnamic acid and its derivatives, a group of lowto-moderately abundant active ingredients in traditional Chinese medicine, by liquid-phase microextraction

Objective To qualitatively identify and determine the contents of low-to-moderate cinnamic acid and its dericatives, a group of low-to-moderately abundant active ingredients in traditional Chinese medicine, by liquid-phase microextraction and post-extraction high performance liquid chromatography （HPLC）, so as to explore the relationships among concentrations of extracted agent, donor phase volume and enrichment factor. Methods Polyvinylidene difluoride fiber was used as solvent carrier, at a donor phase of 2.0×10^-4 mol/L HCl and an acceptor phase of 0.008 mol/L NaOH. After extracting for 60 min at 1800 r/min rotary speed, HPLC was performed. Results The linear ranges of cinnamic acid, p-hydroxycinnamic acid and p-methoxy cinnamic acid were up to the sixth power, with limits of detection （LODs） respectively at 0.2 pg/ml, 0.08 pg/ml and 0.2 pg/ml. The intra-day RSD was less than 10.6%, inter-day RSD less than 11.9%, and recovery rates being 94.7%～101.3% and 92.1%～105.9%. Conclusion The method was easy to use, and the enrichment factor of extracted agents were up to nearly 100-folds. A great significance was shown with this method for analysis of low-abundant, trace-quantity components that are difficult to analyzed with conventional pre-treatment approaches.