黄芩苷对照品2种定值方法比较研究

A comparison study on two measuring methods of baicalin reference substance

目的:分别采用质量平衡法与核磁共振法测定黄芩苷对照品的纯度。方法:采用高效液相色谱法测定色谱杂质,卡尔费休氏法测定水分,炽灼残渣法测定灰分,由质量平衡法计算黄芩苷对照品纯度;同时采用核磁共振法测定其绝对纯度。结果:质量平衡法测得黄芩苷对照品纯度为94.67%,而核磁共振法测得其纯度为97.65%;2种方法测得结果偏差较大。结论:不同杂质响应值的差异及色谱分离能力的限制,都导致质量平衡法在标准物质定值方面具有一定的局限性;核磁共振法具有灵敏度高,精密度好,分析速度快,不受被测物质中杂质影响的优点,为标准物质的定值提供新思路。

Objective： To determine the purity of baicalin reference substance by the mass balance method and the nuclear magnetic resonance（NMR）method.Methods： Chromatogram impurities were determined by HPLC,the moisture content was determined by the Karl Fisher method and the ash content was determined by the residue on ignition method.The purity of baicalin reference substance was calculated by the mass balance method;and it was also determined by the NMR method.Results： The purity of baicalin reference substance was 94.67% as determined by the mass balance method,and 97.65% by the NMR method.The deviation in the purity of baicalin reference substance was evident between the two methods..Conclusion： Inevitable limitations exit due to the different response values between the variable unknown impurities and limited separation of the chromatography while determining the value of reference materials by the mass balance method.The NMR method has such advantage as high sensitivity,good precision,fast analysis speed and not being affected by the impurities of the target object,and can provide a new means for the evaluation of reference materials.