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 ...
Read More
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.
Fereshteh Heydari; Majid Ramezani; Nasim Bayat; Maryam Ghalenoei
Volume 4, Issue 2 , September 2017, , Pages 42-49
Abstract
A novel switchable-hydrophilicity solvent based liquid phase microextraction (SHS-LPME) coupled with flame atomic absorption spectrometry has been applied for preconcentration and extraction of Ag(I). In this study, Triethylamine (TEA) was selected as switchable solvent. The Ag (I)-1-(2-pyridylazo)-2-naphthol ...
Read More
A novel switchable-hydrophilicity solvent based liquid phase microextraction (SHS-LPME) coupled with flame atomic absorption spectrometry has been applied for preconcentration and extraction of Ag(I). In this study, Triethylamine (TEA) was selected as switchable solvent. The Ag (I)-1-(2-pyridylazo)-2-naphthol complex was extracted into organic phase by converting the protonated carbonate (P-TEA-C) to TEA. The experimental conditions were optimized using Plackett–Burman and Box–Behnken design methods. Under the optimum conditions, the detection limit, relative standard deviation and the enrichment factor were 0.35 μg L-1, 1.4% and 68, respectively. The calibration graph was linear over the range 2 to 500 μg L-1 with correlation coefficient of 0.997. The proposed method was successfully applied to determine of trace silver in water samples.
Majid Haji Hosseini; Mohammad Reza Rezaei; Mohammad Rezaee; Peyman Asaadi; Khatereh Ashtari
Volume 1, Issue 1 , March 2014, , Pages 20-28
Abstract
This study propose a new analytical protocol for the determination of benzene, xylene, toluene and styrene in water samples using homogeneous liquid-liquid microextraction via flotation assistance (HLLME-FA) technique followed by gas chromatography-mass spectrometry (GC-MS). In this research, a special ...
Read More
This study propose a new analytical protocol for the determination of benzene, xylene, toluene and styrene in water samples using homogeneous liquid-liquid microextraction via flotation assistance (HLLME-FA) technique followed by gas chromatography-mass spectrometry (GC-MS). In this research, a special extraction cell was designed to facilitate collection of the low-density solvent extraction. No centrifugation was required in this procedure. The water sample solution was added into the extraction cell which contained an appropriate mixture of extraction and homogeneous solvents. By using air flotation, the organic solvent was collected at the conical part of the designed cell. The effects of different variables on the efficiency of the extraction were studied simultaneously using experimental design. Response surface methodology was applied to investigation the optimum conditions of each variable. Using optimized variables in the extraction process, for all target analytes, the detection limits, the precisions and the linearity of the method were found in the range of 0.8-8.2 ng mL-1, 3.09-7.96% (RSD, n=4) and 1-100 ng mL-1, respectively. The headspace method was used for the accuracy of comparison. The performance of the method was evaluated for extraction and determination of analytes in water samples and satisfactory results were obtained (RSD ≤10.06 %).
