Optical and chromaticity characteristics of Arsenazo III complexes of rare-earth elements

Optimal conditions for the complexation of La, Nd, Sm, Tb, Dy, Gd, Ho, Er, and Yb ions with Arsenate III were found, and molar absorptivities of the c omplexes were calculated. Chromaticity characteristics of the complexes wer e determined. The coefficients of calibration plot equations and molar coef ficients of chromaticity functions were calculated for the concentration ra nge 10-50 mug of rare-earth element per 25 mL of solution. It was demonstra ted that the use of the most sensitive chromaticity functions increases the sensitivity of the reaction by 1.5-2 orders of magnitude compared to the p hotometric method.