固相萃取/定量核磁共振波谱法测定乳增宁胶囊中的淫羊藿苷

Determination of Icariin in Ruzengning Capsule by Solid Phase Extraction/Quantitative Nuclear Magnetic Resonance Spectroscopy

建立了固相萃取(SPE)/定量核磁共振波谱(q NMR)无标样测定乳增宁胶囊中有效成分淫羊藿苷含量的方法。样品用10%乙醇室温下超声提取,以HC-C18型SPE柱对提取液进行浓缩除杂后,用q NMR测定淫羊藿苷的含量。考察了超声时间、SPE样品前处理条件以及定量核磁共振实验条件对定量结果的影响。选择氘代二甲基亚砜为溶剂,2,3,5-三碘苯甲酸为内标,并用基准试剂邻苯二甲酸氢钾对其进行标定。选择脉冲宽度P1=14.1μs,扫描次数NS=256为q NMR定量淫羊藿苷的实验条件。淫羊藿苷的定量峰为δ7.9(2',6'-H,d,2H)。结果显示,所建方法的日内精密度RSD为0.43%,日间精密度RSD为0.75%,淫羊藿苷与2,3,5-三碘苯甲酸峰面积比与质量比的零截距标准曲线的线性相关系数为0.999 9,且斜率与理论值相符。该法测定淫羊藿苷的LOD为0.122 mg/g;LOQ为0.368 mg/g。样品经SPE预处理后淫羊藿苷的回收率为99.8%~103.0%。可在不用对照品的情况下对乳增宁胶囊中淫羊藿苷的含量进行测定。

The quantitative nuclear magnetic resonance spectroscopy （qNMR ）method for the determination of icariin in Ruzengning capsule was established based on solid phase extraction （SPE ）.The sample powder in capsule was ultrasonically extracted using 10 % alcohol as solvent at room temperature.The extraction solution was enriched and cleaned with an HC-C 18 SPE cartridge.The effects of ultrasonic extraction and SPE,qNMR experimental conditions were investigated.The qNMR experiment conditions were selected as follows：using deuterated DMSO as solvent,2,3,5-triiodobenzoate as internal standard,a P1 （pulse width ）of 14.1 μs,and a NS （number of scan ）of 256.The 1H NMR peak of δ 7.9 （2 ,6 -H,d,2H ）of icariin was chosen as the quantitative peak.Method validation was performed with the intra-day RSD of 0.43 % and the inter-day RSD of 0.75 % .The linear correlation coefficient （ r ）was 0.999 9 between the peak area ratio and mass ratio of icariin to internal standard.LOD was 0.122 mg/g and LOQ was 0.368 mg/g.The recoveries of the SPE-qNMR were in the range of 99.8 % -103.0 % .The result showed that the method was stable,accurate and reliabile.With no need of icariin standard,the method was applied in the determination of icariin in 3 batches of real Ruzengning capsule.