摘要
研究了当Twen80存在时,非水溶性meso四(4溴苯基)卟啉(TBrPP)与镉络合显色反应的条件Cd与TBrPP形成络合物的摩尔组成比为1∶1,表观摩尔吸光系数为4.5×105l·mol-1·cm-1,Cd含量在0~0.36μg·ml-1内有较好的线性关系,线性回归方程A=0.00034+0.161C,相关系数r=0.9997,稳定常数为2.6×107用于烟草样中痕量镉的测定,与AAS值进行比较,获得了令人满意的结果.
The color reaction of Cd(II) with mesoTetra(4Bromophenyl)porphyrin (TBrPP) has been studied in the presence of Tween80 at pH9.0~11.2. The apparent molar absorptivity is 4.5×105l·mol-1·cm-1 measured at maximum absorption 436nm. The molar ratio of TBrPP to Cd(II) is 1∶1. Beer's law is obeyed for Cd(II) in the range of 0~0.36μg·ml-1. The linear equation is A=0.00034 + 0.161C,r=0.9997. The stabilization constant of the complex is 2.6×107. This method has been applied to determine cadmium in tobacco with satisfactory results compared with AAS data.
关键词
烟草
卟啉
镉
分光光度
tobacco, cadmium, porphyrin, spectrophotometry