在pH 6.8的B-R缓冲介质中,芦丁在264 nm和379 nm波长处有两个强度不等的吸收峰,两个峰的吸光度之和与芦丁浓度呈线性关系,据此提出了应用双波长叠加分光光度法测定样品中微量芦丁的方法,芦丁的质量浓度在0.336~50.4 mg·L-1范围内符合比耳定律.表观摩尔吸光率达4.37×104L·mol-1·cm-1,比单波长法提高了81.7%.方法的检出限(3S/N)为0.112 mg·L-1.应用此方法测定了复方芦丁片剂及槐米中芦丁的含量,用标准加入法测得此方法的回收率在95.8%~107.1%之间,测定值的相对标准偏差(n=6)在1.3%~1.7%之间.

In a B-R buffer medium of pH 6.8,two absorption peaks at the wavelength of 264 nm and 379 nm were observed in the absorption spectrum of rutin. By applying the measurement mode of “absorbance addition at 2 wavelengths”,i.e.,by taking the sum of values of absorbances at 264 nm and 379 nm,linear relationship between the values of sum of absorbance and mass concentration of rutin was obtained in the range of 0.336-50.4 mg·L-1. The apparent molar absorptivity of 4.37×104L·mol-1·cm-1 was obtained under this condition,which is 81.7% higher than that obtained under the conventional single wavelength measurement mode. Detection limit (3S/N) of the proposed method was found to be 0.112 mg·L-1. Samples of rutin compound tablets and flos sophorae were analyzed by this method and recovery was tested by standard addition method,giving values of recovery in the range of 95.8% to 107.1% and RSD′s (n=6) in the range from 1.3% to 1.7%.