قائمة الطعام
The choice of the method for the determination of selenium in biological samples depends on the form of selenium present in the sample to be analyzed. ... (2004) Simultaneous speciation of inorganic selenium and tellurium by inductively coupled plasma mass spectrometry following selective solid-phase extraction separation. J Anal …
Determination of selenium and tellurium compounds in biological samples by ion chromatography dynamic reaction cell inductively coupled plasma mass spectrometry ... The selenium and tellurium species are extracted from milk powder and rice flour samples by using Protease XIV at 70 degrees C on a water bath …
A colorimetric method for the rapid determination of selenium in 5- to 50-microgram quantities is described. Selenium (IV) and (V) in water solution are reduced by hydrochloric and hydriodic acids, respectively, to elementary selenium which forms a colored complex with the liberated iodine. Excess iodine produced in side reactions combines with ...
Abstract. Selenium and tellurium, like the highly siderophile elements, may constitute key tracers for planetary processes such as formation of the Earth's core and …
Determination of selenium and tellurium concentrations in Pyrenean peridotites (Ariege, France): new insight into S/Se/Te systematics of the upper in mantle samples. Chem. Geol. (2010) K. Marcucci et al. Studies in hydride generation atomic fluorescence determination of selenium and tellurium. Part 2 effect of thiourea and thiols
Spectrophotometric Determination of Iron with 2,6-Pyridinedicarboxylic Acid and 2,4,6-Pyridinetricarboxylic Acid.. Analytical Chemistry 1963, 35 (2), 141-144. …
Determination of selenium and tellurium compounds in biological samples by ion chromatography dynamic reaction cell inductively coupled plasma mass …
Selenium occurs naturally in biological materials that vary from a few parts per billion to a few per cent. Methods for its determination, therefore, cover a wide range of concentrations. As a result there have been developed a number of procedures for selenium analysis. Download to read the full chapter text.
In the late 1990's, the use of selenium (usually with bismuth) as an additive to plumbing brasses to meet no-lead environmental standards became important. The average price for selenium in 2000 was $3.82 per pound. Tellurium is a relatively rare element, in the same chemical family as oxygen, sulfur, selenium, and polonium: oxygen and sulfur ...
Hydrides generated by controlled addition of base stabilized NaBH₄ solution to acid digests are transported directly into a shielded, hydrogen diluted, entrained-air flame for atomic absorption spectrophotometric determination of the individual elements. Analysis of acid digests of foods for As, Se, Sb, and Te was semiautomated. Hydrides generated by …
The chromium(III) interfered with the determination of selenium(IV) at 260 m/^, but not at 360 m/A, The tellurium content of a mixture of selenium (IV) and tellurium (IV) could be determined by subtraction of the absorbance of selenium(IV) thioglycollate, determined as above at 360 m/n, from the total absorbance obtained at 360 mfz when the ...
A novel on-line preconcentration and speciation analysis method for the simultaneous determination of inorganic Se and Te species is presented in this work. The methodology is based on the on-line formation of a hydrophobic ionic liquid (IL) directly in the liquid sample stream of a flow injection system, thus achieving an efficient and rapid …
Determination of selenium and tellurium compounds in biological samples by ion chromatography dynamic reaction cell inductively coupled plasma mass spectrometry. J. Chromatogr. A, 1181 (1) (2008), pp. 60-66, 10.1016/j.chroma.2007.12.065. View PDF View article View in Scopus Google Scholar [9]
Download Citation | Determination of selenium and tellurium compounds in biological samples by ion chromatography dynamic reaction cell inductively coupled plasma mass spectrometry | An ion ...
Whereas for determination of tellurium only the best Sample Analysis choice is IonPac CS10, the IonPac AS5 is more versatile because of its retention characteristics and because the The method developed was applied to the determina- use of weak HC1 mobile phases enables the determina- tion of Te in a ZnCdTe-based semiconductor material. tion of ...
Promising methods have been developed recently for the determination of selenium (Se) and tellurium (Te) in geological materials at ng g −1 and lower levels, using hydride generation-inductively coupled plasma-mass spectrometry. Here we report on a new isotope dilution-hydride generation-inductively coupled plasma-mass spectrometry …
Spectrophotometric determination of trace amounts of selenium in iron and steel with 4-methyl-o-phenylenediamine. Analytica Chimica Acta 1972, 58 (1), 219-222. …
Within this scope, we have developed a high precision analytical method for the simultaneous determination of selenium and tellurium concentrations from a single sample aliquot and for various rock matrices, including ultra-depleted peridotites. The technique employs isotope dilution, thiol cotton fiber (TCF) separation and hydride …
A simple and selective solvent extraction method has been derived for selenium (IV) and tellurium (IV) by sequential mode from each other as well as from other accompanying elements. N-n-octylcyclohexylamine (N- n -OCA) has been used for quantitative extraction of selenium (IV) and tellurium (IV) in dichloromethane (DCM) - xylene solvent mixture. …
The method has been successfully applied in the determination of traces of tellurium and selenium in copper, lead and molybdenum ores, stainless steel and pure copper metal without any additional ...
Consequently, a determination method of selenium and tellurium in gold concentrate was established by inductively coupled plasma atomic emission spectrometry (ICP-AES) with Se 196.090{171} nm and ...
For the determination of selenium 3,3'-diaminobenzidine is used and for tellurium, sym -diphenylthiourea. A minimum of 2 ppm of each element may be determined in silver chloride and 0.3 ppm in ...
Development of alternative methods for the determination of selenium and tellurium in metallurgical materials using modern analytical equipment is an urgent goal. The method of atomic emission ...
The limit of determination is 0.001 percent tellurium, which is equivalent to 0.1 milligram of tellurium when using a 10-gram sample. ... The distillate may be discarded or reserved for selenium determination. Transfer the residual solution containing the tellurium from the distillation flask to the original 400-milliliter beaker, rinse out the ...
Geological reference materials (RMs) with variable compositions and NIST SRM 612 were analysed by isotope dilution mass spectrometry for bulk rock concentrations of chalcogen elements (sulfur, selenium and tellurium), rhenium and platinum‐group elements (PGEs: Ru, Pd, Os, Ir and Pt), including the isotope amount ratios of …
Journal Article: Iodometric determination of selenium and tellurium when they are present simultaneously. Iodometric determination of selenium and tellurium when they are present simultaneously. Full Record; Other Related Research; Authors: Zakharov, V A; Songina, O A; Klyueva, R I
A method for the determination of anti- mony, arsenic, selenium and tin by low pres- sure furnace atomic spectrometry has been established [9-11]. On the basis of these works, a new method for the detemination of anti- mony, arsenic, bismuth, selenium, tellurium and tin has been developed.
No problems have been found in the determination of selenium and tellurium in steel which indicates that these elements are present in their lower oxidation states after the dissolution in aqua regia. For antimony, however, we found systematically too low values even when using the method of additions. In the NBS steel No. 1261, for …
A method has been developed for the determination of traces of arsenic, boron, bismuth, gallium, germanium, phosphorus, lead, antimony, selenium, silicon and tellurium in nickel matrix. The sample was dissolved in HClO 4 (~150 °C) and nickel was settled as crystalline nickelperchlorate [Ni(ClO 4) 2] on cooling.
The temperature-dependent desorption behavior of selenium and tellurium is investigated using a heated quartz crystal microbalance. Prior to heating the quartz crystal microbalance, selenium and tellurium films with varying thickness were deposited using thermal effusion cells in a molecular beam epitaxy system for subsequent determination of temperature …
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