分光光度法测定Fe(Ⅲ)-二甲酚橙显色反应的研究

SPECTROPHOTOMETRY METHOD FOR COLOR REACTION OF Fe(Ⅲ)- WITH XYLENOL ORANGE(XO)

在 5× 10 -2 mol·L-1HCl溶液中 ,二甲酚橙与Fe(Ⅲ )生成紫红色络合物 ,其最大吸收波长位于5 6 0nm处 ,表观摩尔吸光系数ε =2 .0× 10 4L·mol-1·cm-1.Fe(Ⅲ )含量在 0～ 2 .4mg·L-1范围内符合Beer定律 .用于水样中微量铁 (Ⅲ )的测定 。

In the solution of 5×10^(-2) mol·L^(-1)HCl, the reaction of xylenol orange(XO) and Fe(Ⅲ) could form a purple coordination compound with maximum absorption at 560 nm. The molar absorption coefficient is (2.0×10~4 )L ·mol^(-1)· cm^(-1).Beer’s law is obeyed in the concentration range of 0～2.4 mg·L^(-1) for Fe(Ⅲ) .It’s a suitable way for testing quantity of Fe(Ⅲ) in the sample of water.