显色剂偶氮胂Ⅲ直接吸光光度法测定微量镧

Spectrophotometric Determination of Microamont of Lanthanum with Arsenazo

研究了显色剂偶氮胂III与镧的显色反应,在0.020mol·L-1的盐酸介质中,试剂与镧生成绿色络合物,其最大吸收波长为650nm,摩尔吸光吸数为3.14×104L·mol-1·cm-1,该方法灵敏度高,常见金属离子允许量大,选择性好。在0.040～0.80μg·mL-1范围内符合比耳定律,其线性回归方程为A=0.2371cLa(III)(μg·mL-1)+0.00191,相关系数r=0.9995。

In this paper , spectrophotometric determination of lanthanum with Arsenazo in HCl medium has been described. The molar absorptivity of the complex is 3.14×10~4 L·mol^(-1)·cm^(-1) ,the method is high sensitivity and selectivity and Beer 's law is obeyed in the range of 0.040～0.80 μg·mL^(-1) for lanthanum. Line regression equation :A=0.237 1c_(Lg)(III)( μg·mL^(-1)) +(0.001 91,) correlation coefficient r=0.999 5.