Spectrophotometric determination of lanthanum, thorium and iron(III) with chromotropic acid azo dyes of the pyridine series.
Highly sensitive methods for the determination of lan thanum, thorium and iron(III) have been developed with the sodium salts of 2-(pyridyl-2-azo)chromotropic acid, 2-(pyridyl-3-azo)chromotropic acid and 2-(2-carboxypyridyl-3-azo)chromotropic acid. Optimum concentration ranges are of the order 1-20 ppm. The effect of diverse ions (cations and anions) including those of rare-earths are reported. The nature of the complexes has been investigated and values for the instability constants are given.
Majumdar
A K
AK
Department of Inorganic and Analytical Chemistry, Jadavpur University, Calcutta-32, India.
Chatterjee
A B
AB