Collect. Czech. Chem. Commun. 1983, 48, 471-476

5-Methyl-1,3,4-thiadiazolyl-(2-azo-6)-3,4-dimethylphenol as new analytical reagent

Juan Cacho, Cristina Nerin and Laura Ruberte

Department of Analytical Chemistry, University of Zaragoza, Zaragoza, Spain


A synthesis of the new reagent 5-methyl-1,3,4-thiadiazolyl-(2-azo-6)-3,4-dimethylphenol (MTDADF) is described. The dissociation constant of the OH group is determined by spectrophotometry (pKa = 7.88 ± 0.05). the reaction of MTDADF with Ni(II) is quantitatively studied. Beer's law is obeyed of 0-2.4 ppm of Ni(II), the optimum range being 0.4 to 2.0 ppm, as deduced from a Ringbom graph. The stoichiometry of the complex corresponds to the ML2 type. Many other ions interfere seriously in the determination of Ni(II).