催化H_2O_2氧化伊红Y褪色光度法测定痕量铋(Ⅲ)

Catalytic Spectrophotometry for the Determination of Trace Bismuth Based on Oxidizing Decoloration Reaction of Eosine by Hydrogen Peroxide

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。所提方法灵敏度高，表观摩尔吸光系数ε５１４．８＝３．６×１０８Ｌ·ｍｏｌ－１·ｃｍ－１，检出限为２．０×１０－１４ｇ／ｍＬ；工作曲线的回归方程ΔＡ＝－０．００１３＋１．７６２５ＣＢｉ３＋（μｇ／Ｌ）；相关系数ｒ＝０．９９９５。本方法简便、快捷，成功地用于人发样和水样中痕量铋（Ⅲ）的测定，同时也讨论了催化褪色反应机理。

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.The method has high sensitivity,the molar absorptivityε514.8 being 3.6×108 L·mol-1·cm-1,and the detection limit being 2.0×10-14g/mL.The regression equation of calibration graph isΔA=-0.0013+1.7625 CBi3+ (μg/L)and the correlation coeffecient is 0.9995. The method was rapid,simple,and it has been applied for the determination of bismuth in human hair and water samples.The mechanism of the catalytic determination was also discussed.