分光光度法测定仙鹤草总酚含量的方法研究

摘要

Objective To propose a method to determine the total polyphenols in agrimonia pilosa ledeb. Methods Folin-Ciocalteus reagent and gallic acid as the standard were used to determine the total polyphenols in agrimonia pilosa ledeb by the spectrophotometry. 0. 5mL of Folin-Ciocalteus reagent and 1. 7mL of 20% Na2CO3 solution were added into lOmL volumetric flask which contained the certain amounts of agrimonia pilosa ledeb sample. The reaction continued of 90 min at room temperature, and then determined absorption value at 660nm and 760nm. Results The mass concentrations of polyphenols in the interval of 0 ~ 10. 4 mg/L were linearly related to the absorption values. The standard curve at 760nm was y = 0. 091 %x +0. 012 9, R =0. 999 3 and the recovery of total polyphenols was 98. 4% ~ 99. 8%. The standard curve at 660nm was y = 0. 084 Ix - 0. 002 6, R1 = 0. 999 7 and the recovery of total polyphenols was 101. 2% ~ 101. 9% . Conclusion It showed good precision, repeatability and recovery to determine total polyphenols both at 760 nm and 660nm. This research provided a reference for quantitative analysis total polyphenols of agrimonia pilosa ledeb.%目的 建立测定仙鹤草中总酚含量的测定方法.方法 通过可见分光光度法,以没食子酸为标准品,采用FolinCiocalteus试剂,在装有仙鹤草样品的10mL容量瓶中,依次加入Folin-Ciocalteus试剂0.5mL,20％ Na2 C031.7mL,在室温条件下放置90min,然后在波长760nm和660nm测定吸光度.结果 总多酚浓度在0～10.4 mg/L与吸光度有良好的线性关系.760nm时的回归方程为y =0.091.8x +0.012.9,R2 =0.999 3,加标回收率为98.4％～99.8％；660nm时的回归方程为y=0.084 7x-0.002 6,R2=0.999 7,加标回收率为101.2％ ～ 101.9％.结论 在760nm和660nm 2个波长处测定的结果,都具有良好的精密度、重复性和回收率,可以作为测定仙鹤草多酚定量分析的参考方法.