Study on quantitative determination of total flavonoids in citrus peel by colorimetry

Flavonoids had been widely studied in natural products because of their several bioactivities to human body.The paper compared three detection methods,which are direct method,aluminum nitrate method and aluminum chloride method,and confirmed that aluminum chloride method had the best result for quantitative determination of total flavonoids in citrus peel.If the determination wavelength was 275 nm,the standard sample was rutin and the concentration of analyte was within the range of 0.0077-0.0385 mg/ml,the results showed a good linear relationship(R2=1) between absorbance and the concentration of analyte,with the correlation coefficient R2 of 1.The average recovery of this method was 99.3% with RSD of 1.84%(n=5).The stability,precision and repetition of this method were very good.The average total flavonoids content of non-isolating fat and ultrasonic treatment citrus peel was 3.09%.This method is easily operated,accurate and reproducible.