Separation, preconcentration and measurement of inorganic iron species by cloud point extraction and flow injection flame atomic absorption spectrometry

Abstract

A sensitive and simple method for determination of iron species after separation/preconcentration by cloud point extraction (CPE) has been developed. When the temperature is higher than the cloud point extraction temperature (60 °C), the complexes of iron(II) and iron(III) species with ferron enter the surfactant-rich phase. Total amount of iron in the surfactant-rich phase was analyzed by FI-AAS, whereas, Fe(II) concentration was determined by a spectrophotometric method using mathematical equation to overcome the interference of Fe(III), when they are both present in the same solution. In this way the time-consuming and labor-intensive steps of preoxidation of Fe(II) or reduction of Fe(III) were eliminated. The parameters affecting could point extraction, such as concentrations of ferron and Triton X-114, pH, and equilibrium temperature were systematically investigated. Under the optimum conditions, the calibration curves were linear over the range of 10-250 and 5-150 μg l -1 for 20 and 40 ml preconcentration volume, respectively. The detection limit was 1.7 μg l -1 , and relative standard deviation (RSD) was 2.1% for 20 ml preconcentration volume. The method was applied to the determination of iron species in water samples and total iron in milk. The accuracy was determined by recovery experiment, independent analysis by furnace atomic absorption spectrometry and analysis of certified reference water.

Cloud Point Extraction Spectrophotometric Method for Mutual Determination of Norfloxacin and Iron(III) in Human Serum and Drug Formulations

“…The preconcentration factor obtained was of 83 fold resulted in achieving the limit of detection (LOD) of 3.42 ngmL -1 ( Table 2). Concerning LOD, our findings was 5 fold more better than obtained by Giokas et al, 31 who used CPE-FI-AAS , but about 2 fold less than those obtained by Ohashi et al, 32 and Shakerian et al, 33 whom used CPE-GFAAS and CPE-FI-AAS. The molar absorptivities, Sandell's sensitivities, extraction efficiencies for NOR and Fe(III) were also given in Tables 1 and 2, indicative the proposed method has a good sensitivity and extractability.…”

Development of an Eco-Friendly Method for Iron Extraction and Determination in Pharmaceuticals Using Ciprofloxacin Drug as Chelating agent

“…The cloud point extraction (CPE) combined with any instrumentation can achieve the above-exigent demands and permit to design extraction systems and analyses. Consequently, several methods have been reported for the determination of iron including; CPE, for instance, coupled with flow injection-flame atomic absorption (CPE-FI-FAAS) [9-11], flame atomic absorption(CPE-FAAS) [12][13][14], graphite furnace atomic absorption(CPE-GFAAS) [15] , capillary zone electrophoresis (CPE-CEZ) [16], and Uv-Vis spectrophotometry [17][18]. In all the above-mentioned methods, CPE is based on using commercial organic reagents to form chelate (hydrophobic) with iron at specific pH, apt to interact with surfactant in solution.…”

Development of a dispersive liquid–liquid microextraction method for iron speciation and determination in different water samples

“…Several techniques, such as spectrophotometry [4][5][6][7], atomic absorption spectrometry (AAS) [2,5,[8][9][10], inductively coupled plasma-optical emission spectrometry (ICP-OES) [1,11], ICP-mass spectrometry (MS) [3,12,13], cathodic or anodic stripping Voltammetry [14,15], chromatography [16,17] and spectroscopic sensors [18] have been reported for the determination of Fe or its species.…”