A new catalytic spectrophotometric determination of trace bismuth based on its catalytic oxidation of eosine by hydrogen peroxide on heating and in the pH is 4.34 has been developed. 在pH=4.34及加热条件下,基于Bi(Ⅲ)对过氧化氢氧化伊红Y的褪色反应的催化作用,首次提出过氧化氢氧化伊红Y测定痕量铋(Ⅲ)的催化光度法。