SPECTROPHOTOMETRIC STUDY OF EQUILIBRIA COMPLEXATION OF COPPER(II), ZINC(II), AND IRON(III) WITH 4-(1H-1,2,4-TRIAZOLYL-3-AZO)-2-METHYLRESORCINOL AND MULTICOMPONENT ANALYSIS DETERMINATION IN DRUGS

Spectrophotometric study of Cu(II), Zn(II), and Fe(III) with 4-(1H-1,2 ,4-triazolyl-3-azo) -2-methylresorcinol (H(3)L) and numerical analysis of data using a general least-squares program LETAGROP-SPEFO yields c omplexes ZnH(2)L, ZnHL, Zn(HL)(2), CuH(2)L, CU(HL)(2), FeH(2)L, FeH(2) L(OH)1 and Fe(HL)(2) (charges omitted). The equilibria have been studi ed at I(NaNO3) = 0.25 mol dm(-3), 25 degrees C in 40 % methanol. Condi tions for multicomponent spefo analysis were found, the determination is optimal at pH approximate to 9, with a good sensitivity, i.e. numer ical values of molar absorptivity values epsilon(i)/(dm(3) mol(-1) cm( -1)) 78400, 39500, and 47800 for Zn(II), Cu(II), and Fe(III), respecti vely. The reagent was used for the determination of these elements in drugs.