The standard method of determining tannin was used to analyze intensive sulfitation tannin extract and the results showed there was only 3.

• 应用鞣质测定的标准方法对重度亚硫酸化改性栲胶进行分析；其鞣质含量仅为3.；2%25；而鞣质的定性试验却表明滤液中仍存在大量的鞣质。