Determination of Total Amount of Rare Earth in the New Rare Earth-Chromium-Manganese-Silicon Inoculation by Spectrophotometry

A blue purple coordination complex of rare earth and chlorophosphonazo Ⅲ was formed under the certain acidity.Maximum absorption wavelength of the complex was found at 660nm,Lambert-Beer's law was obeied in the range within 20g of rare earth per 50mL of solution.Linear correlation coefficient is r=0.9996.Spectrophotometric direct determination of total amount of rare earth in the presence of high amounts of chromium and manganese has achieved by this method.This method was easy to operate,higher accuracy,and can meet the needs of the ordinary test.The results of the determinations were obtained by standard addition method,with the recovery more than 98%.