The influence of atomic number on the complex formation constants by visible spectrophotometric method

The influence of atomic number on the complex formation constants and it's application by visible spectrophotometric method has been carried out. The complex compound have been made of Y, Nd, Sm and Gd with alizarin red sulfonic in the mole fraction range of 0.20 - 0.53 and pH range of 3.5 - 5. The optimum condition of complex formation was found in the mole fraction range of 0.30 - 0.53, range of pH 3.75 - 5, and the total concentration was 0.00030 M. It was found that the formation constant (β) of alizarin red S. complex by continued variation and matrix disintegration techniques were β : (7.00 ± 0.64).109 of complex 39γ,β : (4.09±0.34).108 of 60Nd, β : (7.26 ± 0.42).108 of 62Sm and β : (8.38 ± 0.70).108 of 64Gd. It can be concluded that the atomic number of Nd is bigger than Sm which is bigger than Gd. The atomic number of Y is the smallest. (39) and the complex formation constant is a biggest. The complex compound can be used for sample analysis with limit detection of Y : 2.2 .10-5 M, Nd : 2.9 .10-5 M, Sm : 2.6 .10-5 M and Gd : 2.4 .10-5 M. The sensitivity of analysis are Y>Gd>Sm>Nd. The Y2O3 sample of product result from xenotime sand contains Y2O3 : 98.96 ± 1.40 % and in the filtrate (product of monazite sand) contains Nd : 0.27 ± 0.002 M