COLORIMETRIC DETECTION AND ESTIMATION OF CERIUM

Quadrivalent cerium gives a bright yellow colour with benzidine in hydrochloric acid solution. 0.03\(\gamma\) of the element can be detected on a spot-plate. Trivalent rare earths, Th, Cu, Be, Mg, alkaline earths, Zn. Al, Bi, \(UO_2^{++}\), Mn, Ni,\(NO_3^{'}\), \(PO_4^{''}\), CI', F’, MoO4", As3O4", in moderate amounts do not interfere ; but, vanadate and chromate cause interference even in small quantities. The reagent may also be adopted for the colorimetric estimation of cerium