QUANTITATIVE DETERMINATION OF TOTAL FLAVONOIDS IN CITRUS PEEL BY ULTRAVIOLET SPECTROPHOTOMETRY

Did establish a method which acted rutin as standard sample to measure determination of total flavonoids in citrus peel. Meanwhile, the contents of the total flavonoids in citrus peel that disposed through different conditions were measured and compared and analyzed by using the ultraviolet-visible spectrophotometry with three methods. The results showed that, of the three methods, the concentration of the total flavonoids was the highest by using the Al(NO3)3 (345 nm), and the coloration method with direct measurement (270 nm) and AlCl3 (415 nm) took the second and the third place. The method of assaying the total flavonoids was determined by the ultraviolet-visible spectrophotometry with AlCl3 (275 nm) system after being studied by HPLC. The regression equation was Y=28.891X+0.000 2 with a relation coefficient r=1, the average recovery was 99.3 %, RSD =1.84 % (n=5). The average content of the total flavonoids in non-isolating fat and ultrasonic treatment citrus peel was 3.09 %. This method was easily operated and accurate and reproducible,it could be a feasible way for measuring the total flavonoids in citrus peel.