催化褪色光度法测定痕量钡  

Catalytic Spectrophotometric Determination of Trace Barium Based on the Decoloration Reaction of Erichrome Black T and Dodecylbenzene Sulfonic Sodium

作　　者：刘佳铭[1] 马同森[2] 

机构地区：[1]漳州师范学院化学系,漳州363000 [2]河南大学化学化工学院,开封475001

出　　处：《分析化学》1999年第10期1215-1218,共4页Chinese Journal of Analytical Chemistry

摘　　要：Ba^(2+)能在pH5弱酸性介质中催化十二烷基苯磺酸钠(DBS)对铬黑T(EBT)的褪色反应.详细研究了动力学条件,确立了测定钡的最适宜催化动力学条件.表观摩尔吸光系数ε_(620)=3.0×10~6L·mol^(-1)·cm^(-1),校正曲线方程为log(A_o/A)=0.006260+0.008704C_(Ba^2)+(μg/L);线性范围0～16μg/L(r=0.9991);检出限4.0×10^(-11)g/mL.该催化反应属一级反应,活化能E为142.53kJ/mol;速率常数k为3.15×10^(-2)/s.所建立方法用于水样中痕量Ba^(2+)的测定,结果与AAS法相符.Barium ion can catalyze the decolorization reaction of Erichrome Black T and dodecylbenzene solfonic sodium in a pH 5 of weak acid medium. The condition of kinetics has been studied in detail andthe optimum condition of catalytic kinetic determination of barium was established. The apparent molarabsorptivity . The equation of calibration curve is log+0.008704CBa3+(Ug/L) with the linear range of 0～16μg/L( r= 0. 9991) , the detection limit forbarium is 4.0×10-11 g/mL. This catalytic reaction is a first order reaction and its activation energy E is142.53 kJ/mol, rate constant K is 3.15×10-2/s. The method has been applied to the determination oftrace Ba( E ) in water samples, the results were in agreement with those given by AAS method.

关 键 词：钡 铬黑T DBS 动力学光度法 测定 

分 类 号：O614.233[理学—无机化学]