Speciative Determination of Dissolved Inorganic Fe(II), Fe(III) and Total Fe in Natural Waters by Coupling Cloud Point Extraction with FAAS

  • Ramazan GÜRKAN University of Cumhuriyet, Faculty of Sciences, Department of Chemistry, TR-58140 Sivas, TURKEY
  • Nail ALTUNAY University of Cumhuriyet, Faculty of Sciences, Department of Chemistry, TR-58140 Sivas, TURKEY

Abstract

A new cloud point extraction (CPE) method for the preconcentration of trace iron speciation in natural waters prior to determination by flame atomic absorption spectrometry (FAAS) was developed in the present study. In this method, Fe(II) sensitively and selectively reacts with Calcon carboxylic acid (CCA) in presence of cetylpyridinium chloride (CPC) yielding a hydrophobic complex at pH 10.5, which is then entrapped in surfactant-rich phase. Total Fe was accurately and reliably determined after the reduction of Fe(III) to Fe(II) with sulfite. The amount of Fe(III) in samples was determined from the difference between total Fe and Fe(II). CPC was used not only as an auxiliary ligand in CPE, but also as sensitivity enhancement agent in FAAS. The nonionic surfactant, polyethylene glycol tert-octylphenyl ether (Triton X-114) was used as an extracting agent. The analytical variables affecting CPE efficiency were investigated in detail. The preconcentration/enhancement factors of 50 and 82 respectively, were obtained for the preconcentration of Fe(II) with 50 mL solution. Under the optimized conditions, the detection limit of Fe(II) in linear range of 0.2-60 µg L-1 was 0.06 µg L-1. The relative standard deviation was 2.7 % (20 µg L-1, N: 5), recoveries for Fe(II) were in range of 99.0-102.0% for all water samples including certified reference materials (CRMs). In order to verify its accuracy, two CRMs were analyzed and the results obtained were statistically in good agreement with the certified values. 

Published
Jun 3, 2013
How to Cite
GÜRKAN, Ramazan; ALTUNAY, Nail. Speciative Determination of Dissolved Inorganic Fe(II), Fe(III) and Total Fe in Natural Waters by Coupling Cloud Point Extraction with FAAS. Pakistan Journal of Analytical & Environmental Chemistry, [S.l.], v. 14, n. 2, p. 12, june 2013. ISSN 2221-5255. Available at: <http://pjaec.pk/index.php/pjaec/article/view/234>. Date accessed: 18 oct. 2017.