甘草酸脱色优化工艺研究

Optimization of decoloring technique of glycyrrhizic acid

为甘草酸粉末(D101纯化后)寻求一种最佳脱色工艺。用粉末活性炭对甘草酸粉末的80%乙醇水溶液进行脱色实验,通过单因素及正交实验确定最佳脱色条件。以甘草酸为标准品,采用紫外分光光度法测定甘草酸含量,采用紫外分光光度法测定脱色率。结果显示,粉末活性炭脱色的影响因素依次为:溶液pH>活性炭加入量>脱色温度>脱色时间。甘草酸溶液的最大吸收波长为252nm,在此波长下,通过正交实验确定了脱色的最佳工艺条件,即溶液的pH为6、粉末活性炭的用量为4.5g/100mL乙醇水溶液、温度为80℃、时间为60min。在此工艺条件下,测得成品甘草酸中甘草酸平均含量及平均脱色率分别为95.32%和62.13%。

The study aimed to seek for an optimum technology for decoloring glycyrrhizic acid.The decoloration experiment was conducted on glycyrrhizic acid in 80% alcohol solution by powdered activated carbon and the optimum decoloration condition was confirmed through single factor and orthogonal experiments.With glycyrrhizic acid as standard,the glycyrrhizic acid was determined by anthrone colorimetry and thereducing was determined by UV-spectrophotometry.The results showed that the factors influencing decoloration by active carbon in order were decoloration pHactive carbon dosagedecoloration temperaturetime.The maximum absorption wavelength of coloured matters in extracts was 252nm,under which the optimum technological condition was confirmed through orthogonal experiment,i.e,solution with pH6.0,active carbon dosage of 4.5g/100mL alcohol solution,temperature of 80℃ and time of 60min.Under this technological condition,the determined average content and average decoloration rate of glycyrrhizic acid were 95.32% and 62.13%.