Amberlite XAD-4 Impregnated With a New Pentadentate Schiff base: a Chelating Collector for Separation and Preconcentration of Trace Amounts of Gallium (III) and Indium (III) (original) (raw)
Related papers
Acta Chimica Slovenica
A new solid-phase extraction method for separation and preconcentration of trace amounts of Ga(III) and In(III) in bio-logical and water samples is proposed. The procedure is based on the adsorption of Ga(III) and In(III) ions on a column of Amberlite XAD-4 resin loaded with newly-synthesized pentadentate naphthol-derivative Schiff base 1-{[(6-{[(E)-1-(2-hydroxy-1-naphthyl)methylidene]amino}-2-pyridyl)imino]methyl}-2-naphthol (HMPN) prior to their determination by flame atomic absorption spectrometry (FAAS). The optimum pH values for quantitative sorption of Ga(III) and In(III) are 4.5–6.0 and 4.5–8.0, respectively, and their desorptions can be achieved by using 5 mL of 0.5 M HNO 3 . The sorption capacities of the resin for Ga(III) and In(III) were 1.27 and 1.45 mg g –1 , respectively. The enrichment factor for preconcentration of Ga(III) and In(III) was found to be 200. The precision of the method, evaluated as the relative stan-dard deviation obtained by analyzing a series of ten ...
International Agrophysics, 2019
The simultaneous determination of Ga(III) and In(III) in environmental water samples was described. The procedure was based on adsorptive stripping voltammetry using an in situ plated bismuth film electrode as a working electrode. In order to obtain low detection limits and satisfactory separations of gallium and indium peaks on the voltammogram, cupferron was used as a complexing agent. The optimum composition of the supporting electrolyte was found to be: 0.1 mol l-1 acetate buffer (pH=5.0), 2 × 10-4 mol l-1 cupferron, 2 × 10-4 mol l-1 Bi(III), optimal voltammetric parameters were found to be: accumulation potential-0.9 V, accumulation time 60 s. The linear range of Ga(III) as well as In(III) was observed over a concentration range from 2.5 × 10-8 mol l-1 to 1.5 × 10-6 mol l-1. The method was satisfactorily applied to the simultaneous quantification of gallium and indium in environmental water samples. This facilitated a promising application of the recommended procedure for monitoring the environment, which is necessary to evaluate the soil-plant system. K e y w o r d s: gallium(III), indium(III), trace analysis, environmental water samples
The Analyst, 2000
Thiosalicylic acid (TSA)-modified Amberlite XAD-2 (AXAD-2) was synthesized by coupling TSA with the support matrix AXAD-2 through an azo spacer. The resulting chelating resin was characterized by elemental analyses, thermogravimetric analysis (TGA) and infrared spectra. The newly designed resin quantitatively sorbs Cd II , Co II , Cu II , Fe III , Ni II and Zn II at pH 3.5-7.0 when the flow rate is maintained between 2 and 4 ml min 21 . The HCl or HNO 3 (2 mol l 21 ) instantaneously elutes all the metal ions. The sorption capacity is 197.5, 106.9, 214.0, 66.2, 309.9 and 47.4 mmol g 21 of the resin for cadmium, cobalt, copper, iron, nickel and zinc, respectively, whereas their preconcentration factor is between 180-400. The breakthrough volume of HCl or HNO 3 for elution of these metal ions was found to be 4-8 ml. The limit of detection (LOD) for Cd II , Co II , Cu II , Fe III , Ni II and Zn II was 0.48, 0.20, 4.05, 0.98, 1.28 and 3.94 mg l 21 , respectively, and the limit of quantification (LOQ) was found to be 0.51, 0.29, 4.49, 1.43, 1.58 and 4.46 mg l 21 , respectively. The loading half time, t 1/2 , for the cations was found to be less than 2.0 min, except for nickel for which the value was 13.1 min. The determination of each of these six cations is possible in the presence of other five, if their concentration is up to 4 times. All six metals were determined in river water (RSD ≈ 0.7-7.7%) and tap water samples (RSD ≈ 0.3-5.7%). The estimation of Co was made in the samples of multivitamin tablets (RSD < 2.3%). The results agree with those quoted by manufacturers.
Mikrochimica Acta, 2001
Pyrogallol is covalently linked with the benzene ring of Amberlite XAD-2, through an azo (–N=N–) spacer group and the resulting new polymer characterized by elemental analyses, thermogravimetric analysis (TGA) and infrared (IR) spectra. It has been used for separation and preconcentration of Cu(II), Cd(II), Co(II), Ni(II), Pb(II), Zn(II), Mn(II), Fe(III) and U(VI) prior to their determination by flame atomic absorption spectrometry (FAAS) or fluorimetry (for U(VI) only). The pH ranges for quantitative sorption are 5.5–6.5, 5.5–7.5, 5.5–7.0, 5.5–7.0, 5.5–6.5, 5.5–6.5, 5.5–8.0, 5.5–6.2 and 5.5–6.2, respectively, for the nine metal ions, which can be desorbed (recovery 90–99%) with 4 mol L−1 HNO3 or HCl. The sorption capacity of the resin has been found to be in the range 4.10 to 6.71 mg of metal g−1 of dry resin. The loading half time (t1/2) was ≤3.3 min for all the metal ions. The effects of NaF, NaCl, NaNO3, Na2SO4, and Na3PO4 on the sorption of these metal ions (0.2 µg mL−1) are reported. The Ca(II) and Mg(II) are tolerable up to a concentration level of 40–400 and 25–240 µg mL−1, respectively. The enrichment factor for Cu(II), Cd(II), Co(II), Ni(II), Pb(II), Zn(II), Mn(II), Fe(III) and U(VI) has been found to be 65, 40, 65, 120, 25, 160, 120, 140, and 70 (concentration level 2–25 ng mL−1), respectively. The limit of detection for these nine metal ions is 5.0, 1.3, 5.0, 4.0, 25.0, 0.5, 1.0, 2.0 and 1.0 ng mL−1, respectively. After enrichment on the present matrix, the flame AAS method has been applied to determine these metal ions (except U) in river water samples (RSD ≤ 7%) and well water (RSD ≤ 8%). Uranium present in well water samples has been enriched on the present matrix and determined by a fluorimetric method (RSD ≤ 6%). The cobalt present in pharmaceutical vitamin tablets was also preconcentrated with the aid of the present chelating resin and determined by FAAS to be 1.93 µg g−1 (RSD ∼4%).
Amberlite XAD-4 resin (AXAD-4) has been functionalized by coupling it through an sNdNs group with 1-(2-pyridylazo)-2-naphthol (PAN). The resulting chelating resin, PAN-AXAD-4, has been characterized by using elemental and thermogravimetric analysis, infrared spectra, water regain value, and hydrogen ion capacity. The sorption capacity was found to be (285, 145, 135, 85, and 76) µmol · g -1 for Zn(II), Co(II), Ni(II), Cu(II), and Pb(II), respectively. The kinetics was studied at different temperatures, and the corresponding rate constants were also determined. All the metals could be eluted with 5 mL of HNO 3 resulting in a high preconcentration factor of 300 to 500. The detection limits were found to be (0.65, 0.80, 0.85, 0.95, and 1.40) µg · L -1 for Zn(II), Co(II), Ni(II), Cu(II), and Pb(II), respectively. The validity of the method was checked by analyzing standard reference materials and performing recovery studies. The analytical utility of the PAN-AXAD-4 for preconcentration and determination of metal ions was explored by analyzing river, canal, sewage, tap water, multivitamin formulation, and infant milk substitute by direct as well as the standard addition method.
2003
A sensitive and selective flow injection time-based method for on-line preconcentration/separation and determination of gallium by flame atomic absorption spectrometry at trace levels was developed. The on-line formed gallium chloride complex is sorbed onto a polyether-type polyurethane foam mini-column, followed by on-line quantitative elution with isobutyl methyl ketone and direct introduction into the flame pneumatic nebulizer of the atomic absorption spectrometer. All chemical and flow variables of the system as well as the possible interferences were studied. The manner of strong HCl solutions propulsion was investigated and established using a combination of two displacement bottles. For 90 s preconcentration time, a sample frequency of 28 h (1 , an enhancement factor of 40, a detection limit of 6 mg l (1 and a precision expressed as relative standard deviation (s r ) of 3.3% (at 1.00 mg l (1 ) were achieved. The calibration curve is linear over the concentration range 0.02 Á/3.00 mg l (1 . The accuracy of the developed method was sufficient and evaluated by the analysis of a silicon Á/aluminum alloy standard reference material. Finally, it was successfully applied to gallium determination in commercial aluminum alloys, natural waters and urine. #