Preconcentration Of Trace Elements Research Articles

Preconcentration of trace elements for neutron activation analysis using activable tracers

Use of an enriched isotope as an activable tracer is proposed for the preconcentration of trace elements in neutron activation analysis. As a test of this method, contents of cadmium in various biological standard samples were determined by addition of an enriched116Cd tracer in the preconcentration step followed by neutron irradiation and γ-ray spectrometry. The principle, advantage, and limitations of the method are also discussed.

Solvent extraction-electrothermal atomic-absorption analysis

The review discusses the problems of rational combination of solvent-extraction separation and preconcentration of trace elements with their determination by electrothermal atomic-absorption spectrometry.

Preconcentration of trace elements in natural water with cellulose piperazinedithiocarboxylate and determination by neutron activation analysis

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPreconcentration of trace elements in natural water with cellulose piperazinedithiocarboxylate and determination by neutron activation analysisSakingo. Imai, Motoho. Muroi, Akira. Hamaguchi, and Mutsuo. KoyamaCite this: Anal. Chem. 1983, 55, 8, 1215–1219Publication Date (Print):July 1, 1983Publication History Published online1 May 2002Published inissue 1 July 1983https://doi.org/10.1021/ac00259a008RIGHTS & PERMISSIONSArticle Views50Altmetric-Citations20LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (652 KB) Get e-Alerts Get e-Alerts

Direct preconcentration of trace elements in aqueous solutions on macroreticular acrylic ester resin

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDirect preconcentration of trace elements in aqueous solutions on macroreticular acrylic ester resinAlfio. Corsini, Solomon. Chiang, and Robert. DiFrusciaCite this: Anal. Chem. 1982, 54, 8, 1433–1435Publication Date (Print):July 1, 1982Publication History Published online1 May 2002Published inissue 1 July 1982https://doi.org/10.1021/ac00245a039RIGHTS & PERMISSIONSArticle Views50Altmetric-Citations14LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (413 KB) Get e-Alerts Get e-Alerts

Dibenzylammonium and sodium dibenzyldithiocarbamates as precipitants for preconcentration of trace elements in water for analysis by energy dispersive x-ray fluorescence

Precipitation with combined dibenzylammonium dibenzyldithiocarbamate and sodium dibenzyldithiocarbamate at pH 5.0 can be used to separate 22 trace elements from water. Membrane filtration of the precipitate yielded a thin sample, suitable for analysis by energy dispersive X-ray fluorescence spectrometry. Alkalis, alkaline earths, lanthanides, and halides were not precipitated, permitting a clean separation of trace elements from the macro constituents of drinking water and drinking water supplies. Methods are given for preparation of reagents of higher purity than previously described.

Preconcentration of trace elements from seawater with silica-immobilized 8-hydroxyquinoline

Preconcentration of trace elements from seawater with silica-immobilized 8-hydroxyquinoline

Preparation of Chemically Modified Cellulose Exchangers and Their Use for the Preconcentration of Trace Elements

Preparation of Chemically Modified Cellulose Exchangers and Their Use for the Preconcentration of Trace Elements

Preconcentration of trace elements in sea water by complexation with 8-hydroxyquinoline and adsorption on C18 bonded silica gel

Preconcentration of trace elements in sea water by complexation with 8-hydroxyquinoline and adsorption on C18 bonded silica gel

Preparation of Chemically Modified Cellulose Exchangers and their use for the Preconcentration of Trace Elements

I. INTRODUCTION Analytical chemistry at trace levels frequently requires special techniques and precautions to avoid systematic errors. Preconcentration of the analyte elements is one of these special steps that can be favorably applied to the sample prior to analysis.

Hybrid methods of analysis. Plenary lecture

Methods of separation and determination are usually combined and their combinations are diverse. The separation and determination stages are not often connected closely, but in a number of instances the properties of a separation product (concentrate) have a significant effect on the determination. Such a combination is not a simple sum of separation and determination techniques; sometimes virtually new methods arise. An example is the combination of solvent extraction and flame atomic-absorption spectrophotometry (if the extract is introduced directly into the flame). There is a tendency to carry out the separation and determination in the same device (gas chromatography, high-performance liquid chromatography). In gas chromatography a group of analytical methods was developed that were hybrids of separation and determination techniques.New methods of such a type have been developed in this and in other laboratories. These methods include a combination of solvent extraction pre-concentration and spark-source mass spectrometry. Trace elements from a sample are collected on high-purity alumina after separation of the matrix by solvent extraction; the alumina is then analysed by mass spectrometry. Copper oxide has been used as a collector for the determination of trace amounts of noble metals. Other hybrid methods have been suggested that are based on combinations of solvent extraction with polarography and spectrochemical analysis. Organic chelate-forming reagents, which are free radicals, have been used in a combination of separation and electron-spin resonance spectroscopy; this allows the latter technique to be made a universal analytical technique and the sensitivity to be increased. High-performance liquid chromatography can be used for inorganic analysis in combination with solvent extraction. Some new reagents have been proposed for the group pre-concentration of trace elements.

Preconcentration of trace elements from pure manganese and manganese compounds with activated carbon as collector

A method is described for separation of traces of Bi, Cd, Co, Cu, Fe, In, Ni. Pb, Tl, and Zn from pure manganese and manganese compounds and their determination by flame a.a.s. After the metal or manganese dioxide samples have been dissolved in acid (and manganese salts in water) the trace elements are compleed with potassium xanthogenate. The solution is then filtered through a small filter paper covered with activated carbon, whereby complex compounds are separated from the matrix. When the charcoal is treated with acid, a trace concentrate is obtained which is nearly free of manganese. The detection limits for the analysis of 10-g samples of manganese metal are <0.5 p.p.m., and for 30-g samples of MnCl2-4H2O are ⩽ 0.1 p.p.m. The relative standard deviation, in general,is lower than 5%.

The use of a chelating resin column for preconcentration of trace elements from sea-water in their determination by neutron-activation analysis

A Chelex-100 resin column has been employed for the preliminary concentration of trace elements in water samples before their determination by neutron-activation analysis. The column, filled with a 1:1 mixture of the resin (50–100 mesh) and Pyrex glass powder of the same mesh-size, is shown to maintain a constant flow-rate and give reproducible results. By a combination of preconcentration and neutron-activation analysis it is possible to determine Ba, Ca, Cd, Ce, Co, Cr, Cu, Fe, La, Mg, Mn, Sc, U, V and Zn in sea-water and/or fresh water simultaneously at the parts per milliard level.

Separation techniques used in radiochemical procedures

After summarising the techniques available generally in analytical chemistry for the separation and pre-concentration of trace elements, reasons are given why some of these procedures have achieved greater prominence in particular radiochemical separations. Examples of contemporary practice and current trends in a wide variety of radiochemical separation problems are then illustrated by reference to papers that have appeared in recent literature.

Plasticized open-cell polyurethane foam as a universal matrix for organic reagents in trace element preconcentration : Part III. Collection of cobalt traces on 1-nitroso-2-naphthol and diethyldithiocarbamate foams

The preparation of 1-nitroso-2-naphthol and diethylammonium diethyldithiocarbamate foams is described. The effect of pH, plasticizer and shaking time on the collection efficiency of cobalt(II) on these reagent foams has been investigated. The collection of various concentrations of cobalt(II) on the proposed reagent foams packed in columns is quantitative at flow-rates of 5–6 ml cm -2 min -1.

Plasticized open-cell polyurethane foam as a universal matrix for organic reagents in trace element preconcentration : Part II. Collection of mercury traces on dithizone and diethyldithiocarbamate foams

The analytical suitability of zinc dithizonate foam for the collection and preconcentration of traces of mercury(II) has been examined. The effect of pH, plasticizer and chelating agent concentration on the collection rate of mercury has been critically investigated. The capacity for mercury(II) of a TBP-plasticized zinc dithizonate foam at pH 6 is 23.4 μeq g −1. The effect of plasticizer on the rate of recovery of mercury with sodium thiosulphate solution is also discussed. The preparation of zinc diethyldithiocarbonate foam is described. Traces of mercury(II) can also be collected rapidly and quantitavely by this foam.

Plasticized open-cell polyurethane foam as a universal matrix for organic reagents in trace element preconcentration: Part I. Collection of silver traces on dithizone foam

The preparation of plasticized foam containing dithizone or zinc dithizonate is described. The foam was used successfully for the rapid and quantitative collection of trace amounts of silver in batch and column experiments. The preconcentration of small amounts of silver from dilute aqueous solutions was found to be possible. The effects of different plasticizers, pH of the aqueous phase, and dithizone concentration in the foam, on the collection rate of silver were critically investigated.

Radioactivation analysis of aluminium, vanadium, copper, molybdenum, zinc and uranium in natural water samples using organic coprecipitants

A method is described for the determination of trace metal ions, V, Al, Cu, Mo Zn, and U, in natural water samples by neutron activation analysis, using organic coprecipitation as a preconcentration method. The preconcentration of trace elements was accomplished by converting the dissolved trace metal ions into the oxine chelates atpH 5.2 and extraction of the chelates witho-phenylphenol which is a liquid above 56 °C and solidifies at room temperature. After cooling the extraction system, the fine particles of the organic phase were collected on a millipore filter and the precipitate was air-dried in a clean environment. The solid extract was wrapped up in a sheet of clean polyethylene and subjected to neutron irradiation in a reactor for less than 10 min at a thermal flux of 2·1013 n·cm−2·sec−1. γ-Ray spectrometry by a coaxial Ge(Li) detector connected to a 1024-channel PHA was performed on the irradiated sample without further chemical separation, and thus the ppb level concentration of the elements in natural water samples could be determined. The fundamental study of the collection of the trace elements is also described.

Preconcentration of trace elements by aluminium hydroxide

Coprecipitation of traces of cobalt, zinc, chromium, ruthenium and mercury with freshly precipitated aluminium hydroxide has been investigated by a radiotracer method. Investigations were performed over a wide range of pH. The results indicate that traces of cobalt, zinc and chromium could be almost completely coprecipitated between pH 6 and 10. On the other hand coprecipitation yield for ruthenium in this pH range do not exceed 95%, which is believed to be the consequence of the various physicochemical states of ruthenium. The coprecipitation yields for mercury are very low as a consequence of the presence of non-ionized HgCl2.

Atomic Absorption Spectrophotometry in Water Analysis

Abstract The application of AAS to the analysis of major and certain trace elements in fresh and natural waters has been discussed. Sodium, potassium, calcium and magnesium were determined either directly or after dilution with deionized water. Pre-concentration of trace elements by simple evaporation was found to be satisfactory and compared favorably with other concentration techniques. The ranges of various elements commonly encountered in the fresh waters of India are given.

Atomic absorption spectrophotometry in water analysis.

Abstract The application of AAS to the analysis of major and certain trace elements in fresh and natural waters has been discussed. Sodium, potassium, calcium and magnesium were determined either directly or after dilution with deionized water. Pre-concentration of trace elements by simple evaporation was found to be satisfactory and compared favorably with other concentration techniques. The ranges of various elements commonly encountered in the fresh waters of India are given.