Spectrophotometric Determination of Chromium(III) and Iron(III) by Used of 2-((E)-(1H-benzo[d]imidazol2-yl)diazenyl)-5-((E)-benzylideneimino) phenol;(BIADPI) as Organic Reagent

The azo reagent 2-((E)-(1H-benzo[d]imidazol2-yl)diazenyl)-5-((E)-benzyl ideneimino) phenol (BIADPI) was prepared and examined by using element analysis (C.H.N.), UV-Vis., Mass spectrum, H-1-NMR spectrum and infrared spectra. A sensitive and selective spectrophotometric method is proposed for the rapid determination of iron (III) and chromium(III) using (BIADPI), as spectrophotometer reagent. The reaction between this reagent with chromium (III) and iron (III) is instantaneous at (586,536) nm (lambda(max)) and pH=(7.5,4) to form perpul complexes having a mole ratio 1 : 2 (metal : ligand) for Cr(III) and Fe(III) the absorbance remains stable for over 24 hours. Beer's law is obeyed in the rang of (1-14) mu g. ml-1 and (1-21) mu g. ml(-1) with molar absorptivity (epsilon) = (7.768x10(5), 9.3575x10(5)) L. mol(-1). cm(-1) and a detection limit of (0.275-0.14) mu g. ml(-1) obtained respectively. The precision and accuracy were obtained to be R.S.D%=(0.90.467)%, Re%=(99.1-98.2-)% and E-rel%= (-1.8-0.9)%. The method is successfully employed for the determination of iron(III) in Pharmaceutical preparations (Anemia drugs). The most important interferences were due to Ni(II), Zn(II), Co(II), Cd(II), Cu(II) and Hg(II) and suitable masking agents were used.