分光光度法快速测定铸铁及钢中稀土总量

Fast Determination of the Total Amount of Rare Earth in Cast Iron and Steel by Spectrophotometry

试样以稀硝酸溶解后，铁、钛元素严重干扰稀土的测定。可用草酸配位掩蔽消除之，钛高时可用草酸、过氧化氢联合掩蔽Fe、Ti等，从而消除干扰。在0．7～1．8pH酸性介质中，稀土可与偶氮氯膦-mA形成蓝色配位络合物，蓝色配位络合物的强度与稀土含量成正比例关系，借此可以用直接偶氮氯膦-mA光度法快速测定稀土总量，测定结果令人满意的。

After the sample was dissolved with dilute nitric acid, the elements of iron and titanium gravely disturb the determination of rare earth. Oxalic acid can be used to coordinate, mask and remove them. When titanium is high, oxalic acid and hydrogen peroxide Can be jointly used to mask elements like Fe and Ti, thus removing their disturbance. In acidic medium of 0. 7 - 1.8 pH, rare earth and azochlorphosphon-mA can form blue coordination complex and the intensity of the blue coordination complex is in direct proportion to the content of rare earth, based on which the azochlorphophon-mA photometric method can be used to fast determine the total amount of rare earth, the result being satisfactory.