Determination of Ethylenediaminetetraacetic Acid and Nitrilotriacetic Acid as Their Iron(III)-Complexes by Reversed Phase High Performance Liquid Chromatography

Abstract The iron(III) complexes with ethylenediaminetetraacetic acid (EDTA, H4edta) and nitrilotriacetic acid (NTA, H3nta) were separated by the ion-association reversed phase high performance liquid chromatography. The retention behavior of iron(III)–nta complex on the column (4.6 mm i.d., 25 cm long) packed with ZORBAX-ODS was seriously affected by the pH of eluent composed of phosphate buffer solution containing tetrabutylammonium bromide and acetonitrile. A mixture of edta and nta in a synthetic sample solution containing the commonly present metal ions was converted to the corresponding iron(III) complexes and determined successfully by the present method.