Abstrait

Investigation of charge transfer complex formation between Fe(III) and 2,6-dihydroxy benzoic acid and its applications for spectrophotometric determination of iron in aqueous media

Mohammad Saeid Hosseini, Sara Madarshahian

On the basis of affinity of Fe(III) ions toward functional groups of 2,6- dihydroxy benzoic acid (2,6-DHB), a charge transfer complex (CT) is formed between Fe(III) ion and 2,6-DHB in acidic media. The stoichiometry and stability constant of the complex was determined using both mole ratio and Job’s methods. It was established a 1:1 complex was formed and the stability constant obtained fromboth themethod,mole ratio: 2.550.14105 and Job: 2.700.12105 is in agreement with together. This method was used for spectrophotometric determination of Fe(III) in aqueous media. The dynamic range and detection limit (DL) were 1.210-5 to 3.610-4M and 1.510-6M, respectively. The relative standard deviation (RSD) was found to be 0.76%in the replicate treatments (n=7) with 1.610-4MFe(III). The accuracy of the method was confirmed using a certified reference material (CRM) and it was applied satisfactorily for determination of iron in amultivitamin-multimineral tablet and variouswater samples.