酸性染料比色法测定巴豆中总生物碱的含量

Determination of total alkaloids in Croton tiglium by acid dye colorimetry

目的建立巴豆中总生物碱含量的测定方法,对不同产地的巴豆总生物碱质量分数进行比较研究。方法以木兰花碱作为对照品,采用酸性染料比色法测定巴豆中总生物碱质量分数。结果酸性染料法的显色条件为加pH 6.0缓冲液至8 mL,加溴麝香草酚蓝3.5 mL,振摇3 min,静置40 min,三氯甲烷8mL萃取,测定波长为420 nm,在0.024 6～0.147 3 mg范围内线性关系良好(r=0.999 5),平均回收率99.0%,RSD为2.75%。结论本含量测定方法操作简单,灵敏度高,准确性、重复性好,可用于巴豆中总生物碱的含量测定。

Objective To establish a method for the assay of the total alkaloids in Croton tiglium,and investigate the contents from different origins.Methods Acidic dye colorimetry was used for the determination of total alkaloids in Croton tiglium with magnoflorine as reference substance.Results Acid dye colorimetric conditions were as follows： pH6.0 buffer to 8.0 mL,adding 3.5 mL bromothymol blue,extracting with 8 mL chloroform,shaking out for 3 minutes,stewing for at least 40 min,then determining at the wavelength of 420 nm.The concentration of magnoflorine showed good linearity within the range of 0.024 6-0.147 3 mg,r=0.999 5,and the average recovery ratio was 99.0% with RSD of 2.75%.Conclusion This method is simple,highly sensitive,accurate and reproducible,which can be used for determination of the total alkaloids in Croton tiglium.