GC测定风油精中薄荷脑含量的实验教学设计

A Teaching Experiment on GC Analysis of the Menthol in Essential Ealm

设计用GC测定风油精中薄荷脑含量的药物分析实验。用乙酸乙酯为溶剂提取样品,HP25毛细管柱（530μm×30 m,1μm）及氢火焰离子化检测器;载气为高纯氮,载气流速2 mL/m in,进样口和检测器温度均为250℃。标准曲线方程为A=0.008C-0.028 6（R^2=0.999 9,n=5）,在0.375-6 g/L线性关系良好。高（6 g/L）、中（1.5 g/L）、低（0.375 g/L）3个浓度的日内、日间变异均〈3%;3个浓度的加样回收率依次为99.10%、104.52%、97.30%;最低检测浓度为0.25 g/L。筛选出了合适的处理样品的溶剂和最佳的GC分离条件,考查了方法的精密度和回收率,最终确定了稳定的实验条件。

To design the experiment for determining the menthol in essential ealm by gas chromatography,HP25（530 μm×30 m,1 μm） cap illary column was used to the gas chromatography seperation at the same time using flame ionization detector.N2（99.999%） was the carrier gas and was kept 2 mL/min during the run.The temperature of injector and detector was both 250 ℃.The results show that the standard curve is A=0.008C-0.028 6（R^2=0.999 9,n=5）,the method shows good linearity over the range of 0.375～6 g/L.The average recoveries are 99.10% （6 g/L） ,104.52% （ 1.5 g/L） ,97.30% （0. 375 g/L）, respectively, and within day and between day variation 〈5%. The limit of detection is 0. 25 g/L. It developed the most probable solvent used to dilute the sample, found the best GC isolation method, and in the end,a stable method is established.