Spectrophotometric studies on Ce [III], Th [IV], UO2 [VI] and VO [IV] complexes with 6,7-dihydroxy-4-methylcoumarin

The complexes of Ce [III], Th [IV], UO2 [VI] and VO [IV] with 6, 7-dihydroxy-4 methylcoumarin are investigated using spectrophotometric methods. The optimum conditions favoring the formation of their colored complexes are critically evaluated. The studies reveal that 1: 1, 1: 2 and 1: 3 [M: L] complexes are formed in solution. The stability constants of the different complexes are calculated. The effect of diverse ions is investigated. A spectrophotometric method for the determination of the named metal ions is represented also a photometric titration method using EDTA as titrant is also given. The proposed method is applicable to the ppm range the metal ions with high accuracy and precession

Spectrophotometric studies on the Al, Ga and in chelates with 5- [2-hydroxy-5-sulphophenylazo] -8-quinolinol

Trivalent ions of Al, Ga and In form colored complexes with 5 - [2-, hydroxy - 5-8 sulphaphenylazo] -8- quinolinol. The complexes were used satisfactorily for the photometric determination of the metal ions. The optimum conditions for the formation of the complexes were extensively investigated. Universal buffers of pH 6.6, 4.5 and 6.60 were used for Al, Ga and In respectively. The stoichiometry of the formed complexes and their stability constants were determined spectrophotometrically. The interference of many metal ions in the determination was also investigated. Beer's law is obeyed up to 0.67, 1.7 and 3.44 ppm metal ion. A Spectrophotometric titration of Ga with EDTA proved to be successful