Rocks,minerals, soils

Analytical and Bioanalytical Chemistry -     

Rocks, minerals, soils

AbstractsParticular products and fields of application

Rocks, minerals, soils     

2.3 Rocks, minerals, soils

Abstracts2 Particular products and fields of application

     

2.3 Rocks, minerals, soils

Abstracts2 Particular products and fields of application

2.3 Rocks, minerals, soils     

2.3 Rocks, minerals, soils

Abstracts2. Particular products and fields of application

2.3 Rocks, minerals, soils     

2.3 Rocks, minerals, soils

Abstracts2 Particular products and fields of application

2.3 Rocks, minerals, soils     

The spectrographic determination of trace elements in rocks,minerals and soils

Summary The total content of trace elements in rocks, minerals and soils is determined by a semi-quantitativecathode layer arc spectrographic technique. For more accurate determinationsa variable internal standard technique, in which the trace element contents are compared with that of iron, is employed. This method is combined with a chemical concentration for the analysis of extracts of soils and plant materials. The chemical concentration technique involves the use of 8-hydroxyquinoline, tannic acid and thionalide, and gives recovery of microgram quantities of most trace elements, rejecting at the same time the alkalis, alkaline earths and phosphate.

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Zusammenfassung Der Gesamtgehalt von Spurenelementen in Gesteinen, Mineralien und Bodenproben wird nach einem halbquantitativen Verfahren bestimmt; hiezu werden die Proben in gehöhlten, als Kathoden geschalteten Elektroden im Bogenstrom verbrannt. Für genauere Bestimmungen wird nach einem abgeänderten Verfahren der quantitativen Spektralanalyse die Menge des Spurenelementes der Probe in Bezug auf ihren Eisengehalt ermittelt. Diese Methode ist mit einer chemischen Anreicherung für die Untersuchung von Bodenextrakten und Pflanzenmaterial kombiniert. Die Technik der chemischen Anreicherung beruht auf der Verwendung von 8-Oxichinolin, Gerbsäure und Thionalid; auf diese Weise lassen sich Mikrogramme der meisten Spurenelemente ermitteln, bei gleichzeitiger Abscheidung der Alkalien, Erdalkalien und Phosphate.

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Résumé La teneur globale des traces d'éléments dans les roches, les minéraux et les sols, est déterminée par une technique semi-quantitative, spectrographique d'arc à couche cathodique. Pour les dosages plus précis, on emploie une technique à étalon interne variable dans laquelle les teneurs en traces sont comparées à celles du fer. Cette méthode est combinée avec une concentration chimique pour l'analyse des extraits de sols et de végétaux. La technique de concentration chimique comporte l'emploi d'oxine, d'acide tannique et de thionalide et permet de récupérer des quantités de l'ordre du microgramme de la plupart des éléments en traces, ce qui élimine simultanément les alcalins, les alcalino-terreux et les phosphates.

     

The determination of stable scandium in plants,animals, sediments,sands, soils,rocks and minerals by neutron-activation analysis

A method is described for the determination of stable scandium in samples of plants, animals, sediments, soils, rocks and minerals. The samples and comparator standards were irradiated in a neutron flux of 5·10¹² n/cm²/sec for 4 h and dissolved and the scandium quantitatively precipitated from 2N nitric acid as scandium phytate; contaminants were rinsed from the precipitate with nitric and hydrochloric acids. The limit of detection was 0.005μg(±10% at the 95% confidence level). The activated ⁴⁶Sc was counted by γ-spectrometry.     

Surfactant-mediated extraction of iron and its spectrophotometric determination in rocks, minerals, soils, stream sediments and water samples

An extraction spectrophotometric method for iron determination in rocks, minerals, soils, stream sediments and water samples has been developed. At pH 3-4, iron (III) forms a 1:2:1 ternary complex with thiocyanate and cetyltrimethylammonium bromide (Fe/SCN/CTAB) which is extracted into ethyl acetate. The readily formed purple complex is suitable for extraction spectrophotometric determination of iron in rocks and related materials from submicrogram to milligram levels. The method is free from any interference due to commonly associated ions present in the matrices of rock samples. The present method is at least fourfold more sensitive (ε=3.2×10⁴ l mol⁻¹ cm⁻¹) than the conventional thiocyanate method and, in addition to the enhanced sensitivity and selectivity, it has got definite advantages over the corresponding binary thiocyanate system in terms of substantial improvement in the stability of the complex formed and broadening of Beer's law adherence range (0-6.0 mg/l). The method has been applied to a number of geological and hydrogeochemical samples for the determination of iron and the results obtained have been found to be favourably comparable with those obtained from the standard methods.     

Simultaneous TG,DTG, DTA and EGA technique for the determination of carbonate,sulphate, pyrite and organic material in minerals,soils and rocks

A simultaneous TG, DTG, DTA and EGA method was developed for the determination of carbonate, sulphate, pyrite and organic material in minerals. The method is based on the selective direct determination of SO₃ and CO₂ evolved from the heated sample, and on the indirect determination of H₂O. The thermogas-titrimetric adapter of the derivatograph collects the liberated gases (CO₂, SO₃, SO₂) quantitatively, absorbs them in water, and titrates them continuously and automatically with NaOH titrant. The changes in the volume of titrant consumed are recorded as a function of the temperature. In two parallel examinations, one titration is performed at pH 4, and the other at pH 9.3. The former measurement yields only the amount of SO₃ (SO₂), while the latter gives the joint amount of SO₃ (SO₂) and CO₂.

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Zusammenfassung Autoren entwickelten eine Methode zur simultanen TG, DTG, DTA und EGA zur Bestimmung von Karbonaten, Sulfaten Pyrit und organischem Material in Mineralen. Die Methode basiert auf der selektiven direkten Bestimmung des beim Erhitzen der Probe entwickelten SO₃ bzw. CO₂ und der indirekten Bestimmung von Wasser. Die in Freiheit gesetzten Gase (CO₂, SO₃, SO₂) werden im gastitrimetrischen Adapter des Derivatographen gesammelt, in Wasser absorbiert und kontinuierlich und automatisch mit NaOH titriert. Das Volumen der verbrauchten Titrierflüssigkeit wird in Abhängigkeit von der Temperatur registriert. In zwei Parallelversuchen wird eine Titration bei pH 4, die andere bei pH 9.3 ausgeführt. Die erstere Messung ergibt nur die Menge an SO₃ (SO₂), während bei der letzteren die Gesamtmenge an SO₃ (SO₂) und CO₂ erhalten wird.

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, , ( ) , , . SO₃ CO₂, , . - (CO₂, SO₃, SO₂), . ë . : pH=4, - pH=9.3. SO₃(SO₂), — SO₃(SO₂) CO₂.

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The authors thank Prof. E. Pungor for valuable discussions, and Mrs. M. Kiss and Miss I. Fábián for their technical assistance.     

Competitive sorption between glyphosate and inorganic phosphate on clay minerals and low organic matter soils

Inorganic phosphate may influence the adsorption of glyphosate to soilsurface sites. It has been postulated that glyphosate sorption is dominatedby the phosphoric acid moiety, therefore, inorganic phosphate could competewith glyphosate for surface sorption sites. We examine sorption of glyphosatein low organic carbon systems where clay minerals dominate the available adsorptionsites using ³²P-labeled phosphate and ¹⁴C-labeled glyphosateto track sorption. We found glyphosate sorption strongly dependent on phosphateadditions. Isotherms were generally of the L type, which is consistent witha limited number of surface sites. Most sorption on whole soils could be accountedfor by sorption observed on model clays of the same mineral type as foundin the soils.     

Studies on distribution of radionuclides and behavior of clay minerals in the soils of river environs

Journal of Radioanalytical and Nuclear Chemistry - In the present investigation, the activity concentrations of radionuclides in the soils of Cauvery river environs were measured using HPGe gamma...