Combination of Dispersive Liquid‐Liquid Microextraction with Flame Atomic Absorption for Determination of Trace Ni and Co in Water Samples and Vitamin B₁₂

Abstract

A dispersive liquid-liquid microextraction method based on the dispersion of 1,2-dichlorobenzene as an extraction solvent into an aqueous phase in the presence of ethanol as a dispersive solvent for the preconcentration of Co 2+ and Ni 2+ ions is discussed. 1-Nitroso 2-naphtol was used as a chelating agent prior to the extraction and the preconcentrated analyte was determined by flame atomic absorption spectrometry. The effect of various experimental parameters including the extraction and dispersive solvent type and volume, pH, amount of the chelating agent, etc. on the microextraction and complex formation was investigated for finding the optimum conditions. The enhancement factors were about 61.9 and 51.8, the calibration graphs were linear in the range of 10-150 mgL -1 and 10-250 mgL -1 with detection limits of 2.42 mgL -1 and 1.59 mgL -1 , and RSD (n = 5) of 3.08% and 2.17% for cobalt and nickel, respectively. The method was successfully applied to the determination of Co and Ni in water and vitamin B 12 .

Vortex Assisted Liquid–Liquid Microextraction Using Triton X‐114 for Ultratrace Cadmium Prior to Analysis

“…A novel modality of LPME technique which is based on a ternary component solvent system like homogeneous liquid-liquid extraction was proposed recently [19][20][21][22][23][24][25][26][27][28]. There are so many advantages of LPME technique like simplicity of operation, quantitative recoveries, good extraction efficiency, high preconcentration factor, rapidity, and low consumption of lethal organic solvent [29][30][31][32].…”

Combination of solid‐phase extraction‐hollow fiber for ultra‐preconcentration of some triazole pesticides followed by gas chromatography‐flame ionization detection

“…The solution to this problem had emerged early with the use of extraction-separation techniques, which offered not only the ability to isolate target analytes from the matrix solution (resulting in reduction, control or even elimination of the interferences originally present), but also the opportunity for pre-concentration and determination of the analytes at very low levels [2]. Several procedures have been developed for the separation and pre-concentration of analytes from aqueous samples, such as liquid-liquid extraction (LLE) [3][4][5], homogeneous liquid-liquid extraction (HLLE) [6][7][8][9], solid-phase extraction (SPE) [10][11][12][13][14][15][16], solid-phase microextraction (SPME) [17][18][19][20][21][22][23][24][25], liquid-phase microextraction (LPME) [26][27][28][29][30][31], stir bar sorptive extraction (SBSE) [32,33] and dispersive liquid-liquid microextraction (DLLME) [34][35][36].…”

Study on Determination of Trace Nickel in Water Samples after Separation/enrichment using Microcrystalline Phenolphthalein Loaded with Chelate

“…There are many methods to separate and enrich Ni(II), such as solvent extraction, 25,26 liquid-liquid extraction, 27 solid phase extraction, [28][29] solvent impregnated resin extraction, 30 cloud point extraction, [31][32] column preconcentration, 33 extraction chromatography, 34 thin-layer chromatography, 35 ion exchange, 36 flotation separation, 37 electrodialysis separation, 38 cation exchange separation, 39 liquid membrane separation, 40 membrane solid phase microextraction, 41 emulsion liquid membrane separation, 42 supported liquid membrane separation, 43,44 chelating resin separation, 45 inner synergistic extraction, 46 polymer inclusion membrane separation, 47 ultrasound-assisted extraction, 48 dispersive liquid-liquid microextraction. 49 The techniques for the enrichment/separation and determination of nickel using microcrystalline naphthalene adsorption system have been re-ported. [50][51][52] Although the results are very satisfactory, this method have some limitations.…”