Reyhaneh Rahnama; Saideh Fatemeh Shafeii Darabi; Mohammad Reza Jamali
Abstract
This work presents a fast, feasible, and sensitive method for the preconcentration and separation of cobalt in various real samples through the use of deep eutectic solvent-based dispersive liquid-liquid microextraction (DES-DLLME) in which deep eutectic solvent, methanol, and 1-(2-pyridylazo)-2-naphthole ...
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This work presents a fast, feasible, and sensitive method for the preconcentration and separation of cobalt in various real samples through the use of deep eutectic solvent-based dispersive liquid-liquid microextraction (DES-DLLME) in which deep eutectic solvent, methanol, and 1-(2-pyridylazo)-2-naphthole (PAN) were employed as extraction solvent, dispersive solvent, and complexing agent, respectively. Co concentration was measured by flame atomic absorption spectrometer. Effective parameters which may influence the extraction efficiencies (like type and volume of the dispersive and extraction solvent, pH, PAN concentration, and salt concentration) were examined and the optimal values were determined. The use of optimal conditions resulted in a limit of detection equal to 1.5 μg/L with a preconcentration factor of 40. RSD value, after measuring 20.0 μg/L of cobalt for 10 times, resulted in a value of 3.0 %. The methodʼ s accuracy and applicability were assessed through the evaluation of Co content in water certified reference materials and different agricultural and water specimen.
Soleyman Bahar; Bahare Babamiri
Volume 1, Issue 2 , September 2014, , Pages 115-120
Abstract
In this work, a procedure for preconcentration of cobalt using dispersive liquid–liquid microextraction (DLLME) with the reagent 1-Nitroso 2-naphtol as complexing reagent was developed. At pH 4, Co(II) was complexed with 1-nitroso 2-naphtol and extracted into the fine droplets formed when mixing ...
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In this work, a procedure for preconcentration of cobalt using dispersive liquid–liquid microextraction (DLLME) with the reagent 1-Nitroso 2-naphtol as complexing reagent was developed. At pH 4, Co(II) was complexed with 1-nitroso 2-naphtol and extracted into the fine droplets formed when mixing chloroform (extraction solvent), ethanol (disperser solvent) and the sample solution. After extraction, the phases are separated and cobalt ion was determined in the enriched phase by flame atomic absorption spectrometry (FAAS). Under the optimum conditions, the enrichment factor 57.22 was obtained. The detection limit of the method was 3.76 ng mL-1 and the relative standard deviation (RSD) for eight replicate mrasurements of 0.05 µg mL-1 Co (II) was 2.3 %. The results to the determination of Co(II) in environmental water samples (tap water, well water, mineral water), egg yolk and hair have demonstrated the applicability of the proposed method.
