Determination of Rutin and Quercetin in Different Tartary Buckwheat Tea and Comparative Study on Their Dissolution Rates

The content of rutin and quercetin in 6 kinds of granulated tartary buckwheat tea and 8 kinds of whole wheat (embryo) tartary buckwheat tea were determined by HPLC, and the dissolution rate of rutin and quercetin in two kinds of tartary buckwheat tea was studied. A Phenomenex C₁₈ column (4.6 mm×250 mm, 5 μm) was used for gradient elution with methanol (A) -0.1% glacial acetic acid (B) as the mobile phase. The flow rate was 1.0 mL·min^-1, and the detection wavelength was 257 nm, and column temperature was 30℃. Under this chromatographic condition, rutin and quercetin were completely separated, and the linear ranges were 0.00362~0.90613 mg·mL^-1 (r=0.9996), 0.01439~0.71947 mg·mL^-1 (r=0.9998), and the average recoveries were 101.99% (RSD 1.71%) and 98.37% (RSD 2.03%). The results showed that the total amount of rutin and quercetin in granulated buckwheat tea was 17.34 mg·g^-1, and quercetin accounted for 89.10%. The total dissolution rate of rutin and quercetin in the brewing solution was 19.41%. The total amount of rutin and quercetin in whole wheat (embryo) buckwheat tea was 11.96 mg·g^-1, of which rutin accounted for 91.39%. The total dissolution rate of rutin and quercetin in the brewing solution was 67.86%. The total dissolution of rutin and quercetin in the brewing solution:Granulated tartary buckwheat teaP<0.01). The cluster analysis of rutin and quercetin in 14 kinds of buckwheat tea and its brewing solution was carried out by SPSS 22.0. It could be divided into two categories:Granulated buckwheat tea and whole wheat (embryo) buckwheat tea.