Quantitative Determination of Total Alkaloids in Swainsonia salsula with Acid Dye Colorimetry

ZHAO Qing-mei;YU Yong-tao;College of Biological Science and Engineering,Beifang University of Nationalities;Key Laboratory of Fermentation of Brewing Engineering and Biotechnology,State Nationalities Affairs Commission;College of Agronomy,Ningxia University;

Swainsonia salsula;;acid dye colorimetry;;total alkaloids;;matrine

A method was established to quantitatively determine total alkaloids in Swainsonia salsula by acid dye colorimetry.Matrine was used as a control standard and bromothymol blue as dye. The alkaloids from Swainsonia salsula and matrine reacted with bromothymol blue in the buffer solution(p H 7.6). The reaction products were extracted with chloroform. The extract was detected with ultraviolet spectrophotometer. The detection wavelength was 414 nm. The alkaloids of Swainsonia salsula collected from Ningxia province were determined by method mentioned above. The results showed that there was a good linear relationship between the absorbance of the extract and its matrine content ranged from 0.001 7 to 0.013 3 μg / μL. The regression equation established was y=50.549 0x-0.047 7(R2=0.999) with the recovery of matrine of 103.17(RSD=1.70%). The content of total alkaloids in Swainsonia salsula collected from Pinluo,Yanchi and Yinchuan was 0.026%,0.024% and 0.017% respectively. It was a highly sensitive and reproducible method to easily and quantitatively determine the content of total alkaloids in Swainsonia salsula.