The thermal behavior of rutin extracted from the buds of Sophora japonica L. by different methods and conditions have been investigated using TG and DTG. The results showed that every sample had
different mass loss, curve shape, and peak location related to varied extraction technology. The TG-DTG characteristics of
the rutin sample extracted by alkali-dissolution and acid-sedimentation with the solution adjusted to pH 9 and simply borax
as stabilizer were highly similar to that of standard rutin, with the maximal purity determined by spectrophotometry. Therefore,
the TG-DTG patterns could be served to characterize rutin extracted from the buds of Sophora japonica L.