scholarly journals Emulsification liquid–liquid microextraction method based on a deep eutectic solvent for separation and preconcentration of lead from environmental water samples

2018 ◽  
Vol 19 (3) ◽  
pp. 864-870 ◽  
Author(s):  
Cennet Karadaş ◽  
Derya Kara

Abstract In this paper, a novel emulsification liquid–liquid microextraction method based on deep eutectic solvents (DESs) for the preconcentration of lead from water samples and its determination by flame atomic absorption spectrometry is described. Purpurin was used as complexing ligand and the Pb(II)-purpurin complexes were extracted and preconcentrated from the aqueous phase using a choline chloride/2-chlorophenol (at a 1:2 molar ratio) based DES as a water-miscible extraction solvent and tetrahydrofuran as an emulsifier solvent. Some analytical parameters affecting the extraction yield were investigated and optimized. Using a 20 mL aqueous sample, the limit of detection and preconcentration factor of the method were 5.93 μg L−1 and 20, respectively. The accuracy of the method was assessed through the analysis of certified reference surface water (SPS-SW2 Batch 127) and spiked water samples. The certified and obtained values were statistically in good agreement at 95% confidence level. The recovery values of spiked water samples were between 102% and 105%.

2010 ◽  
Vol 8 (3) ◽  
pp. 617-625 ◽  
Author(s):  
Hossein Abdolmohammad-Zadeh ◽  
Elnaz Ebrahimzadeh

AbstractA rapid dispersive liquid-liquid micro-extraction (DLLME) methodology based on the application of 1-hexylpyridinium hexafluorophosphate [C6py][PF6] ionic liquid (IL) as an extractant solvent was applied for the pre-concentration of trace levels of cobalt prior to determination by flame atomic absorption spectrometry (FAAS). 1-Phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) was employed as a chelator forming a Co-PMBP complex to extract cobalt ions from aqueous solution into the fine droplets of [C6py][PF6]. Some effective factors that influence the micro-extraction efficiency include the pH, the PMBP concentration, the amount of ionic liquid, the ionic strength, the temperature and the centrifugation time which were investigated and optimized. In the optimum experimental conditions, the limit of detection (3s) and the enrichment factor were 0.70 µg L−1 and 60, respectively. The relative standard deviation (RSD) for six replicate determinations of 50 µg L−1 Co was 2.36%. The calibration graph using the pre-concentration system was linear at levels 2–166 µg L−1 with a correlation coefficient of 0.9982. The applicability of the proposed method was evaluated by the determination of trace amounts of cobalt in several water samples.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Mohammad Reza Jamali ◽  
Mohammad Gholinezhad ◽  
Saiedeh Balarostaghi ◽  
Reyhaneh Rahnama ◽  
Seyed Hojjat Allah Rahimi

A new, simple, and versatile cloud-point extraction (CPE) methodology has been developed for the separation and preconcentration of cobalt. The cobalt ions in the initial aqueous solution were complexed with 4-Benzylpiperidinedithiocarbamate, and Triton X-114 was added as surfactant. Dilution of the surfactant-rich phase with acidified ethanol was performed after phase separation, and the cobalt content was measured by flame atomic absorption spectrometry. The main factors affecting CPE procedure, such as pH, concentration of ligand, amount of Triton X-114, equilibrium temperature, and incubation time were investigated and optimized. Under the optimal conditions, the limit of detection (LOD) for cobalt was 0.5 μg L-1, with sensitivity enhancement factor (EF) of 67. Calibration curve was linear in the range of 2–150 μg L-1, and relative standard deviation was 3.2% (c=100 μg L-1;n=10). The proposed method was applied to the determination of trace cobalt in real water samples with satisfactory analytical results.


2014 ◽  
Vol 2 (1) ◽  
Author(s):  
C. Bosch Ojeda ◽  
F. Sánchez Rojas

AbstractDispersive liquid-liquid microextraction (DLLME) was applied to the separation and preconcentration of Cd(II) and Co(II) from water and food samples. The influence of the following analytical parameters on the quantitative recoveries of cadmium and cobalt were investigated: pH, extraction solvent volume, dispersing solvent volume and type, and concentration of chelating agent. Under the optimized conditions, the detection limits were 2 μg L


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