title: Polarographic determination of EDTA in certain pharmaceutical dosage forms.
abstract: A highly sensitive polarographic method was developed for the determination of EDTA added as a preservative in certain pharmaceutical preparations. The method involved chelation with Eu(III) followed by polarographic measurement of the chelate formed. A well-defined cathodic wave was developed in Britton-Robinson buffers over the pH range 2-12. The wave was characterized as being quasi-reversible and diffusion controlled. The current-concentration relationship was found to be rectilinear over the ranges 8-160 and 2-120 micrograms ml-1, using DCt and DPP modes, respectively, with limit of detection of 0.1 microgram ml-1 using the DDP technique. The mechanism of the electrode reaction was verified. The proposed method was applied for the determination of EDTA in certain pharmaceutical dosage forms, and the results obtained were in agreement with those obtained by a reference method.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, University of Mansoura, Egypt.
authors.forename: F
authors.initials: F
authors.lastname: Belal
authors.forename: F A
authors.initials: FA
authors.lastname: Aly
authors.forename: M I
authors.initials: MI
authors.lastname: Walash
authors.forename: A O
authors.initials: AO
authors.lastname: Mesbah
mesh_terms: D002614:Chelating Agents / Q000737:chemistry; D004304:Dosage Forms; D004492:Edetic Acid / Q000032:analysis* / Q000737:chemistry; D005063:Europium / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D011048:Polarography / Q000379:methods*; D011310:Preservatives, Pharmaceutical / Q000032:analysis* / Q000737:chemistry
chemical_list: D002614:Chelating Agents; D004304:Dosage Forms; D011310:Preservatives, Pharmaceutical; D005063:Europium; D004492:Edetic Acid