Research on Spectrophotometry for Determination of Total Flavonoids Content in Peanut Hulls

A spectrophotometric method for the determination of total flavonoids in peanut hulls was established by comparing the adaptability,repeatability,stability of three spectrophotometric methods(Mg-HCl,NaNO₂-Al(NO₃)₃-NaOH and AlCl₃ method). The results indicated that the best determination wavelengths for the determination of total flavonoids in peanut hulls were 423,519 and 402 nm,respectively. The repeatability of the three spectrophotometric methods(RSD)was 6.74%,1.32% and 0.96%,respectively. Meanwhile,the AlCl₃ method had the best stability of the sample solution within 60 min. Therefore,the preferred method for determination of total flavonoids in peanut hulls was the AlCl₃ method. The AlCl₃ method was validated by methodology at the wavelength of 402 nm,using luteolin as the reference substance. The results showed that there was a good linear relationship in the ranges of 19.9~100.0 μg/mL,and the correlation coefficient was 0.9997. The recovery of the additional sample was 97%~103%,and the relative standard deviation was 2.36%. The method was simple,rapid,specific,sensitive,reproducible and stable. It was suitable for the determination of total flavonoids in peanut hulls.