Spectrophotometric and potentiometric studies of some lanthanide chelates with O-chloro-Schaffer acid azo-dye

ABSTRACT

The complication of O-chloro-schaffer acid azo-dye with some lanthanides; namely, La, Pr, Nd, Sm, Eu, Gd, Er, Yb, and Lu, were studied. Lanthanides formed chelated complexes of different lambda max with orthochloro-schaffer acid azo-dye at different pH values. The composition [MR, MR2 and MR3] of the chelates investigated was established spectrophotometrically by the continuous variation of molar ratio, slope ratio, and straight line methods and by the conductometric titration method. For photometric determination of lanthanides with this reagent Sandell's sensitivity, Beer's Law were also determined. The Bjerrum and Calvin potentiometric titration technique was employed to determine the stepwise formation constants