【摘要】 基于pH=9.0的NH3-NH4Cl缓冲液中与T= 40℃的条件下,Co(II) 催化过氧化氢氧化茜素红的褪色反应,建立了催化过氧化氢氧化茜素红褪色光度法测定痕量Co(II)新方法,对测量波长、试剂浓度、反应温度、反应时间及共存离子的干扰等条件进行探讨和选择.该催化褪色反应的速率常数k = 2.70?0-4S-1,表观活化能E = 96.79 KJ/mol.Co(II)含量在0.50~5.2礸/L范围内符合比尔定律,其线性回归方程为 ㏒(A0/ Ai)=0.0138C Co(II) (礸/L)–0.0003,r = 0.9994,检出限为0.33礸/L(3 Sb/k, n = 11 ).本方法已成功用于叶绿素钴盐样品中Co(II)含量的测定,回收率为102.1~102.6%.更多还原

【Abstract】 A new catalytic spectrophotometric determination of trace Co(II) based on its catalytic oxidation of alizarin red with hydrogen peroxide in the presence of NH3-NH4Cl (pH 9.0)medium and at 40 ℃ has been proposed,and the optimum reaction conditions, such as wavelength and reagent concentration and reaction temperature and reaction time and disturb ion were tested. The apparent activation energy E of this discoloration reaction is96.79KJ/mol and the rate constant k is2.70?0-4 s-1. The Beer抯 law is obeyed in the concentration range of 0.50 ~ 5.2礸/L Co(II) with the detection limit 0.33礸/L(3 Sb/k, n = 11 ) .The regression equation of calibration graph is ㏒(A0/ Ai)=0.0138C Co(II)(礸/L)-0.0003, and the correlation coeffecient is 0.9993. This method has been applied to the analysis of chlorophyll Co(II) salt, the recoveries were reasonable for the analysis of cobalt, in range of 102.1~102.6%.更多还原