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Sorption of the mixed-ligand complexes of europium(III) with thenoyltrifluoroacetone (TTA) and 1,10-phenanthroline (Phen) on polyurethane foam (PUF) has been studied by a luminescence method. The optimum conditions of sorption have been found. The sorbate composition on PUF has been determined (the Eu:TTA:Phen ratio was 1:3:1). Luminescence spectra of the europium complexes in solution and on PUF...
Sodium di-n-propyldithiophosphinate has been proposed as a reagent to improve the sorption properties of activated carbon. The conditions for sorption concentration and separation of bismuth from aqueous solutions were studied. Possibilities for desorption and subsequent determination of bismuth by atomic emission spectroscopy with inductively-coupled plasma were shown.
A simple and rapid preconcentration technique, based on collecting trace nitrite on a membrane filter and dissolving the membrane filter in an organic solvent, has been applied to its spectrophotometric determination in water. At pH 2.0, nitrous acid diazotizes with p-aminoacetophenone, which is then coupled with N-(1-naphthyl)-ethylenediamine, at the same pH. The azo dye formed is collected on a...
The phosphine oxide Cyanex 921 (tri-n-octylphosphine oxide) was found to be a very efficient extractant for gold from aurocyanide aqueous solutions. A system comprising a microcolumn packed with this new reagent was developed for the separation and enrichment of gold. Because of the high selectivity of the developed system it is possible to analyze gold in the presence of an excess of other metals...
This paper describes an improvement in detection capability of microwave plasma torch atomic emission spectrometry by using a flow-injection on-line column preconcentration system. The analytical performances of Cd, Cu, Mn and Zn were studied. The analytes were preconcentrated with a thiol resin. The preconcentration period, the pH of the sample solution and the HCl concentration in the eluant were...
A biological organism (chitosan) was utilized to preconcentrate lead ions from tap water. This preconcentration was achieved by mixing 0.8 ml of chitosan slurry with 10-50 ml of lead-containing solution and subsequently separating by centrifugation. The chitosan paste was then dissolved in 1 ml of 0.2% nitric acid and analysed by graphite furnace atomic absorption spectrometry. The extraction efficiency...
A procedure for the preconcentration and determination of lead in vegetable and biological samples was developed in the continuous mode coupled to a flame atomic absorption spectrometer. Lead is quantitatively preconcentrated in acetic buffer as its diethyldithiocarbamate chelate onto a C-18 minicolumn, placed in the loop of a proportional injector, eluted by a stream of methyl isobutyl ketone and...
Trace quantities of zirconium were preconcentrated on a series of chelating resins. The experimental conditions for preconcentration such as pH, time and metal ion concentration were optimized for the batch processes. Continuous flow manifolds were developed for the on-line preconcentration of zirconium using microcolumns containing chelating resins. Calibration plots were obtained with correlation...
A combined method for the preconcentration and selective spectrophotometric determination of both valencies of iron, i.e., Fe(II) and Fe(III), down to 0.4 μg l -1 has been developed. Iron(III) from synthetic and natural water samples has been concentrated on a melamine-formaldehyde resin at pH 5; iron(II) was not retained under identical conditions. The oxidized iron was concentrated...
Two preconcentration methods has been developed for simultaneous determination of zirconium and hafnium by energy dispersive X-ray fluorescence (EDXRF). The first method is a liquid-solid extraction procedure with the use of an anionic exchange resin modified with xylenol orange. The second is a precipitation procedure carried out in the presence of lanthanum. Both methods permit significant enhancement...
The preconcentration and recovery of lead and cadmium traces at ng 1 -1 level were evaluated in standard solutions and natural aqueous samples using a FIAS (Flow Injection Atomic Spectrometry) apparatus. The method is based on retention of the complex formed between Pb or Cd and 1,2-dihydroxy-3,5-benzendisulphonic acid (Tiron) on a macroporous anion-exchange resin. The recovery of the...
A simple technique has been developed for preconcentration of gaseous trace organic compounds on solid sorbents, followed by gas chromatography. The sorbent is packed in a cartridge prepared from a syringe needle placed in the gas chromatographic injector and the analytes previously adsorbed are thermally desorbed at the injector temperature and then directly swept by the carrier gas into the column...
This paper presents a method whereby trace elements are adsorbed in NH 4 Cl-NH 3 medium on activated carbon and then determined by microwave plasma torch atomic emission spectrometry (MPT-AES). The working conditions (including microwave forward power, gas flow rate, NH 3 -NH 4 Cl concentration in the sample solution, HCl concentration in the eluant, sample introduction...
Results obtained from a preliminary investigation of the performance of a flat sheet membrane desolvator (FSMD) utilizing dual hydrophobic polypropylene membranes with an average pore size of 0.05 μm and a 50 ± 5 μm thickness are reported. The membranes have a desolvation area of 241 cm 2 . The volume-to-surface area ratio is 0.3 cm. Using the FSMD with an ultrasonic nebulizer (USN), aqueous...
A very stable chelating resin matrix was synthesized by covalently linking o-vanillinthiosemicarbazone (oVTSC) with the benzene ring of the polystyrene-divinylbenzene resin Amberlite XAD-2 through a -N=N- group. The resin was used successfully for the separation and preconcentration of copper(II), zinc(II) and lead(II) prior to their determination by atomic absorption spectrophotometry. The total...
Cellulose phosphate (CELLPHOS) was studied as a collector for analytical preconcentration of traces of Cd(II), Cr(III), Cu(II) and Ni(II) from aqueous sample solution. It has been proved that using chromatographic columns packed with CELLPHOS for preconcentration and 1.0 mol 1 - HCl for elution the adsorbed analytes are quantitatively enriched. An enrichment factor of 20 (100 ml sample,...
A procedure is developed for determination of As, Co, Se, Cr, Pb, Zn, Cu, Mn, Cd, Sb, and Sn in water by ICP-AES analysis of alcohol eluates after pre-concentration of the samples. The pre-concentration is performed on a sodium diethyldithiocarbamate supported soft polyurethane foam. The sorbed elements are subsequently eluted with 1-propanol and the alcohol eluates are analysed by ICP-AES. A eight-fold...
A new concentration method of rhodium using Mg-W cell-electrodeposition has been developed. The method was combined with electrothermal atomic absorption spectrometry (ETAAS) with a tungsten tube atomizer. The optimal immersing time was 120 s. The most suitable pH for rhodium electrodeposition was 1.0. Under optimal conditions, the detection limit of rhodium by the ETAAS with the preconcentration...
A highly selective, sensitive, and fairly rapid and economical differential pulse polarographic (DPP) method has been reported for the determination of trace amounts of vanadium and molybdenum in standard alloys and various environmental samples. The morpholine-4-carbodithioates of these metals were retained (>99% recovery) quantitatively on microcrystalline naphthalene in the pH range 4.5-6.9...
Low capacity adsorbents, based on iminodiacetic acid and a crosslinked agarose, Novarose™, have been synthesised for the enrichment of metal ions. Test ions Cu 2+ with high, and Cd 2+ with a moderate affinity for the sorbent were selected. The study includes the effect of specific capacity and matrix composition on the rate of uptake and recovery of these ions. Using a column packed...
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