In situ Preconcentration Method for Iron(II) in Environmental Water Samples Using Solid Phase Extraction Followed by Spectrophotometry Determination

• DOI: 10.2116/analsci.13.231
• Publication Date: 2007-12-21T04:39:16Z
• Authors: Minora Okumura; Yasushi Seike; Kaoru Fujinaga; Kazunori Hirao
• Keywords: Solid phase extraction; Spectrophotometry; Hydrochloric acid; Cationic polymerization

A simple and rapid method for in situ preconcentration of iron(II) in environmental water samples has been developed, based on solid phase extraction using Sep-Pak C18 cartridges. Iron(II) in water samples, which was taken into a graduated syringe to prevent oxidation of iron(II) by air, was converted into a colored cationic complex with ferrozine (C 20 H 12 N 4 O 6 S 2 Na 2 ) at pH 4.5 immediately after sample collection. The iron(II)-ferrozine complex was adsorbed on Sep-Pak C18 as an ion-pair with acetate ion. The complex was stable on Sep-Pak C18 for at least 3 weeks. The adsorbed complex was eluted with a mixture of acetone and 0.1 M hydrochloric acid. The color intensity due to the complex was measured at 562 nm. The proposed method is applicable to brackish and sea waters as well as fresh water.