Speciation of Fe(II) and Fe(III) by using dispersive liquid-liquid microextraction and flame atomic absorption spectrometry

Abstract

Um método de extração de Fe(III) em amostras de água prévio à determinação espectrométrica foi desenvolvido. Microextração dispersiva líquido-líquido (DLLME) foi usada com sucesso como método de preparação de amostras para espectrometria de absorção atômica por chama (FAAS). Na abordagem proposta, 8-hidroxiquinolina (oxina) foi usada como agente quelante, clorofórmio e metanol foram selecionados como solventes extrator e dispersivo, respectivamente. Alguns fatores influenciando a eficiência da extração de Fe(III) e sua subsequente determinação foram estudados e otimizados, incluindo: tipo e volume de solventes extrator e dispersor, pH da solução da amostra, concentração do agente quelante e tempo de extração. Nas condições otimizadas, o fator de enriquecimento deste método para Fe(III) foi 462. O limite de detecção para Fe(III) foi 4,5 ng mL -1 , e o desvio padrão relativo (RSD) 1,4% (n = 5, c = 400 ng mL -1).An extraction method for Fe(III) from water sample before spectrometric determination was developed. Dispersive liquid-liquid microextraction (DLLME) technique was successfully used as sample preparation method for flame atomic absorption spectrometry (FAAS). In the proposed approach, 8-hydroxy quinoline (oxine) was used as chelating agent, chloroform and methanol were selected as extraction and dispersive solvents, respectively. Some factors influencing the extraction efficiency of Fe(III) and its subsequent determination were studied and optimized, including: type and volume of extraction and dispersive solvents, pH of sample solution, concentration of the chelating agent and extraction time. Under the optimized conditions, the enrichment factor of this method for Fe(III) was 462. The limit of detection for Fe(III) was 4.5 ng mL -1 , and the relative standard deviation (RSD) 1.4% (n = 5, c = 400 ng mL -1 ).

Determination of trace levels of iron in serum samples of hepatitis B and C patients using dispersive liquid–liquid microextraction

“…As can be seen, the present method shows a good detection limit and precision and a good enhancement factor. 16,[42][43][44][45][46][47][48][49][50] 3.8. Applications…”

Separation and Speciation of Iron Ions by Using Colorimetric Hydrogels

“…However, Fe 2+ ion concentration of the solutions, including both of Fe 3+ and Fe 2+ ions, was determined with a UV-Vis spectrophotometer (PG T80+) (λ max : 512 nm) by using 1,10-phenanthroline (Aldrich, 99%) (19,46). 1 H and 13 C-NMR spectra were recorded on a Bruker-300 spectroscope using DMSO-d 6 as the solvent and tetramethylsilane (TMS) as the internal reference. The surface morphology of the hydrogels was examined using SEM.…”

“…Iron at high concentrations may cause various health problems. Therefore, many studies have been conducted in recent times on determination, measurement, separation and speciation of iron ion species (Fe 2+ /Fe 3+ ) (12,13). The simplest way to determine whether or not iron ions are present in a liquid sample is to use a sensor (5,14).…”

Atomic spectrometry update. Elemental speciation review

“…49 A method involving the DMLLE of Fe species from water samples has been devised. 50 Iron III was selectively extracted as the complex with 8-hydroxyquinoline into chloroform with methanol as the dispersive solvent. For a sample volume of 5 mL the extraction efficiency was critically dependent on the extractant solvent volume, ranging from 0% at 150 mL to 100% at 200 mL to 50% at 250 mL.…”