Luminescent method of determining terbium. RU patent 2506569.
 Measuring method in real time mode of film thickness of coating not containing chrome on surface of strip steel / 2498215Method involves the following stages: stage 1 - two chemical substances soluble in water are chosen, which contain P, Ca, Ti, Ba or Sr and do not react with liquid for application of a coating not containing chrome; stage 2: two chemical substances soluble in water and chosen at stage 1 are added to the liquid for application of the coating not containing chrome and mixed till they are homogeneous; after that, a reference sample of the coating film is made; stage 3: emission from an instrument for determination of film thickness in an independent mode is used for excitation of two chemical substances soluble in water in order to obtain characteristic spectra of two chemical substances soluble in water, and therefore, determination of film thickness of the reference sample coating; coating film thickness determined at use of a chemical substance soluble in water, which has intensive characteristic spectrum, is accepted as actual film thickness, while the coating film thickness determined at use of the chemical substance soluble in water, which has weak characteristic spectrum, is accepted as measured thickness of film; difference between actual film thickness and measured film thickness is accepted as thickness correction value; operations for obtaining thickness correction values are performed for many times, which correspond to measured film thicknesses; as a result of approximation of values of thickness correction and measured film thickness, an equation of correlation function between measured film thickness and value of thickness correction is obtained; stage 4 - chemical substance that is soluble in water and that has weak characteristic spectrum is added to liquid for application of the coating not containing chrome, and emission from the instrument for determination in real time mode of the coating film thickness is used for excitation of substance and therefore to obtain the measured film thickness; after that, expression of correlation function is used to obtain thickness correction value, and finally, based on the measured film thickness and the thickness correction value, actual thickness of the coating film is obtained. |
 Method of monitoring degree of crosslinking polyethylene / 2492451Test and reference samples are alternately placed in a chamber isolated from light, cooled with liquid nitrogen, luminescence of polyethylene is actuated using a source of ultraviolet radiation, which is registered by a photodetector and according to the value of photoresponse of the test and reference samples respectively, the degree of crosslinking is determined. |
 Measuring device for determining at least one blood sample parameter / 2468355Invention relates to a measuring device for determining at least one parameter of a blood sample, with a flow-through measuring cell (1), in which there is at least one luminescence-optical sensor element (ST, SO, SG), which can be brought into contact with the blood sample, and at least one light source (4) for exciting the luminescence-optical sensor element and at least one photodetector (6) for receiving the luminescence radiation emitted by the luminescence-optical sensor element. The light source (4) and the photodetector (6) are located on opposite sides (7) and (8) of the flow-through measuring cell (1). According to the invention, at least one luminescence-optical sensor element (ST, SO, SG) is placed on an excitation side (7) of the flow-through measuring cell (1), which faces the light source (4). The light source (4) emits excitation radiation of wavelength less than 600 nm, while the luminescence radiation of the sensor elements (ST, SO, SG) lies in a wavelength range greater than 600 nm. |
 Method of determining charge carrier concentration profile in semiconductor quantum-dimensional structure / 2464548Method of determining charge carrier concentration profile in a semiconductor quantum-dimensional structure involves measuring the luminescence spectrum at a low excitation level. The excitation level is then raised until there is energy shift of the emission line from recombination of quantum-dimensional, spatially confined charge carriers and the charge carrier concentration profile is determined from the value of the shift of the emission line using a self-consistent solution of Schrodinger and Poisson equations. |
 Apparatus for monitoring impurities in waste water / 2460993Apparatus for monitoring impurities has a sealed removable optical flow cell placed in a light-proof housing with a built-in photodetector. The apparatus includes a gas and analysed liquid mixer, having a common wall with the optical flow cell. A hole for overflow of liquid is made in the common wall. The mixer has two diaphragms with given pore size and two stop cocks. The light-proof housing in which the optical cell is placed has one photodetector, a tap for outlet of the analysed liquid and is connected by flexible light guides to a light source. The gas and analysed liquid mixer is made from light-proof material and has separate nozzles for inlet of liquid and gas. The gas and analysed liquid mixer is provided with removable diaphragms which allow passage of particles of a dispersed phase with a given degree of dispersion. The gas and analysed liquid mixer is also provided with stop cocks for controlling gas pressure and outlet of coarsely dispersed particles from the zone of the mixer. |
 Method of measuring brightness and colour temperature of surface in region of action of laser radiation and apparatus for realising said method / 2460992In the invention, narrow spectral bands for detecting thermal radiation of a surface lie in the reflection spectral band of galvano scanner mirrors on both sides of the laser band in the immediate vicinity thereof. The apparatus for measuring brightness and colour temperature of a surface in the region of action of laser radiation has a galvano scanner with a F-teta lens and a 2-channel optical pyrometer with a lens. The apparatus additionally includes a rotating mirror with a narrow reflection spectral band on the laser wavelength and 100% reflection coefficient, optically connected to the laser and the 2-channel optical pyrometre with a lens. The apparatus additionally includes a rotating mirror with a central elliptical region with a 100% reflecting coating at the laser wavelength. |
 Apparatus for investigating luminescent properties of material with spatial micro- or nano-scale resolution (versions) / 2454657Apparatus for investigating luminescent properties of material with spatial micro- and nano-scale resolution includes an object table for accommodating sample material, a first source for exposure of the analysed region of the material, a laser light source, a luminescence detector and a clock unit. The first exposure source is in form of an electron source, and the clock unit delays the effect of laser light on each analysed region of the material relative the time at which that region is exposed to electron radiation. The apparatus includes a scanning unit which is in form of apparatus which exposes each analysed region of the sample of the material to electron radiation and laser light. |
 Estimation of tissue modification with application of fibre optic device / 2445041Invention relates to medicine, namely, to spectroscopic method of defining in real time ablation speed in cardiac tissue in-vivo. For this purpose probe irradiation with wavelengths of near-wave infrared range (NIR) are directed at cardiac tissue in-vivo in such a way, that probe irradiation interacts with cardiac tissue to form spectrum of reverse dispersed irradiation. Spectrum contains intensity dependence on wavelength on said wavelength range. Then ablation irradiation is directed at cardiac tissue. Inclination of said spectrum is measured. Stage of ablation irradiation direction is carried out simultaneously with stage of inclination measurement. Speed of tissue ablation is determined, proceeding from said slope. |
 Brillouin reflectometer / 2444001Reflectometer has a pulsed laser connected to a detecting element in form of a first piece of optical fibre through a first apparatus of enabling reception of backscattered radiation. A second piece of optical fibre is connected to the output of the first apparatus. A second apparatus can enable emission of continuous laser radiation into the second piece of optical fibre in a direction opposite the direction of propagation of the radiation scattered in the detecting element. A photodetector is connected by its input to the output of the second apparatus for enabling reception of scattered radiation and is connected to an information processing unit. A laser frequency control unit is connected to the information processing unit and can stabilise the frequency of one of the lasers and change the frequency of the other laser. |
 Method for creating reference gages for non-destructive spectral methods of measuring impurity concentration in crystals / 2442143FIELD: chemistry. SUBSTANCE: according to the method, the roentgenofluorescence intensity of the analytic line is measured in the tested sample (crystal) and the roentgenofluorescence intensity of the same line is measured in working mixture containing a known amount of the measured element. A calibration chart is built and the absolute concentration of the impurities in the sample. At the same time spectral measurements of the sample are carried out, their results are compared with the results of roentgenofluorescence measurement and a reference gage is acquired for future use in impurity spectral analysis in industrial-scale production of the crystals. EFFECT: creation of reference gages (reference crystal samples) while retaining measurement accuracy for controlled crystal properties. 4 dwg |
 Method of obtaining mesoporous nanosized cerium dioxide powder (versions) / 2506228Invention relates to chemical industry, to production of nanosized powders of metal oxides for fine-grained ceramics of broad spectrum. Method of obtaining cerium dioxide powder includes stages: obtaining water 0.05M solution of cerium nitrate or cerium acetate, using Ce(NO3)3·6H2O or Ce(CH3COO)3·H2O, obtaining alcohol solution of stabiliser of sol of organic N-containing compound: N,N-dimethyloctylamine, tetraethylammonium hydroxide or monoethanolamine with concentration 0.45-3.30M, 0.37M and 0.016M, obtaining sol in water-organic system by combination of composed solutions, evaporation of water-organic system, formation of gel and thermal processing of gel in the interval of temperatures 95-500°C by step-by-step schedule, with application as sol stabilser of one of the following low-molecular organic N-containing compounds (N): N,N-dimethyloctylamine, tetraethylammonium hydroxide or monoethanolamine in form of alcohol solution with molar ratio N/metal, equal 1-20. |
 Method of obtaining calcium-doped lanthanum manganite / 2505485Calcium-doped lanthanum manganite is obtained by reaction from lanthanum, manganese and calcium oxides by their grinding, first annealing in air at 1350±50°C, cooling to room temperature, re-grinding and pressing obtained material in tablets, its re-annealing in air at 1350±50°C, further annealing in oxygen and cooling to room temperature, with obtaining samples with composition La1-xCaxMn1-zO3, in which selected calcium concentration is 0.05<x<0.22, selected manganese concentration is 0<z≤0.05, first annealing in air is carried out for 12 hours, second re-annealing in air is carried out for 4 hours, annealing in oxygen is carried out at T=650±20°C for 50 hours, and further cooling to room temperature is carried out in air at rate not lower than 10°C/min. |
 Method of processing phosphogypsum / 2504593Method of processing phosphogypsum involves step-by-step agitation sulphuric-acid leaching of rare-earth metals and phosphorus while feeding sulphuric acid to the head step, using the obtained leaching solution of the head step at subsequent leaching steps, separating the undissolved residue from pulp of a tail step and washing with water, treating the leaching solution of the tail step to obtain a mother solution, using the mother solution and the washing solution for leaching. Leaching of the rare-earth metals and phosphorus at the second and subsequent steps is carried out from a mixture of phosphogypsum and the leached pulp from the previous step. Sulphuric acid is fed to the head leaching step in an amount which enables to extract rare-earth metals and phosphorus into the solution at the head step and subsequent steps at pH values at the tail leaching step not higher than pH at the onset of precipitation of rare-earth metal phosphates. The tail step for leaching rare-earth metals and phosphorus is carried out while simultaneously treating the leaching solution by extracting rare-earth metals by sorption with a cationite. The rare-earth metal-saturated cationite is separated from the mother pulp and taken for producing a rare-earth metal concentrate. A portion of the mother solution is pre-purified from phosphorus by precipitation thereof with a basic calcium compound. The obtained phosphorus-containing precipitate is fed for recycling. |
 Method of obtaining complex yttrium, barium and copper oxide / 2503621Invention can be applied in microelectronics. To obtaining complex yttrium, barium and copper oxide YBa2Cu3O7-δ, from water solution, which contains yttrium, barium and copper nitrates, combined sorption of yttrium, barium, copper in given molar ratio Y:Ba:Cu = 1:2:3 is carried out at the stage of sorption from the said solution on carboxyl cationite KB-4p-2. After that, obtained material is dried and subjected to successive heating at temperature 110 - for 2 h, at 250°C - for 2 h, at 450°C - for 5 h, at 600°C - for 3 h, at 850°C - for 6 h and after that for 1 hour in oxygen atmosphere. |
 Method of obtaining stabilised water sol of nanocrystalline cerium dioxide, doped with gadolinium / 2503620Invention relates to technologies of nanomaterials production for obtaining of oxide fuel elements, thin coatings, films, which have high ionic conductivity. Method includes preparation of water solution of cerium and gadolinium salts, in which total concentration of rare earth elements constitutes 0.005÷0.02 mole per litre of water, and molar ratio of Ce:Gd constitutes from 19:1 to 4:1, addition of anion-exchange resin in OH-form to obtained solution until pH 9.0÷10.0 is reached, separation of formed colloidal solution from anion-exchange resin by filtering, hydrothermal processing at 120÷210°C for 1.5÷4 h and cooling to room temperature. Obtained unstable sol of nanocrystalline cerium dioxide, doped with gadolinium, is additionally stabilised with salt of polybasic acid (citric or polyacrylic) with molar ratio of rare earth elements in acid, equal 1:1÷4, and following slow drop-by-drop addition of ammonia water solution until pH 7÷8 is obtained. |
 Complex processing of coal combustion flue ash / 2502568Invention relates to processing of wastes, particularly, to ash-and-slag wastes of thermal electric power stations. Coal combustion ash is placed in reaction zone to add carbon sorbent thereto in amount of 10-25 kg per ton of ash. Then, it is processed by the mix of ammonium fluoride and sulfuric acid, heated to 120-125°C and held thereat for 30-40 minutes. Tetrafluorosilane resulted from said processing is absorbed by ammonium fluoride. Solution of ammonium hydroxide is introduced into that of ammonium tetrafluorosilicate to precipitation of silicon dioxide. Then, concentrated sulfuric acid in double surplus is added to aluminium residue, held at 250°C for 1.5 h and processed by water. Solid residue is calcined at 800°C. |
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Method of production of rare-earth element fluorosulphide powders / 2500502 Invention relates to inorganic chemistry, particularly to production of powders to be used in laser technology and optical instrument making. Proposed method comprises preparation of blend and its thermal treatment. Said blend is prepared from the powder of sesquialteral rare-earth element sulphides with particle size of 1-30 mcm and powder of rare-earth element trifluorides with particle size of 10-70 nm at molar ratio of 1:1.Thermal treatment of the blend is conducted at 650-800 °C for 20-30 minutes in atmosphere of argon, sulfiding gases H2S+CS2 and fluoridiser gases C2F4, CF4 obtained in Teflon pyrolysis. |
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Method of obtaining complex scandium chloride and alkali metal / 2497755 Invention relates to inorganic chemistry and deals with method of obtaining complex scandium chloride and alkali metal. Metallic scandium is mixed with lead dichloride and salt of alkali metal. Obtained charge is placed into crucible with inert atmosphere, heated to reaction temperature in presence of metallic lead and kept at temperature, exceeding melting temperature of mixture of salts by 50-100°, for 10-30 minutes. Metallic scandium is applied in compact form in from of pieces. As salt of alkali metal, metals chlorides are applied. In initial charge mixture of chloride salts of alkali metals is applied. |
 Method of producing powder of solid solutions of lanthanum, neodymium, praseodymium and samarium oxysulphides / 2496718Invention relates to inorganic chemistry and specifically to a method of producing powder of solid solutions of rare-earth oxysulphides for making ceramic articles, phosphors and laser materials. The method of producing powder of solid solutions of lanthanum, neodymium, praseodymium and samarium oxysulphides involves preparing a mixture of given mass of weighted forms of rare-earth oxides dissolved in nitric acid, precipitating rare-earth sulphates from the obtained solution using concentrated sulphuric acid, evaporating the formed suspension on air at 70 - 90°C to a dry state, grinding and calcining at 600°C for 1.5 hours, further grinding to a fine state and treating in a hydrogen stream with gas feed rate of 6 eq/h with respect to the weight of rare-earth sulphates at the following temperatures and duration of heat treatment: 600°C - 10 hours, 700°C - 5 hours and 850°C - 1 hour. |
 Molybdate-based inorganic pigment / 2492198Invention can be used in paint-and-varnish industry, in making plastic, ceramics and construction materials. The molybdate-based pigment, which contains cerium and an alkali-earth metal, is a complex molybdate with a scheelite structure of the composition Ca1-3/2XCexMoO4, where 0.10≥x≥0.02. |
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Method for production of cerium dioxide having high specific surface / 2243940 Invention relates to simplified method for production of cerium dioxide having high specific surface useful for catalyst preparation. Method includes blending of (mass %) cerium carbonate 44-58; ammonia acetate 25-34; and water 14-25. Obtained mixture is dried in air and baked at 7000C. |
FIELD: chemistry.
SUBSTANCE: invention relates to analytical chemistry and specifically to a method for luminescent determination of terbium. The method involves converting terbium into a luminescent compound with an organic reagent. The reagent used is 1,2-dioxybenzene-3,5-disulphonic acid (DBSA) and ethylenediaminetetraacetic acid (EDTA) is added to the solution of the luminescent complex of terbium with DBSA in ratio Tb:DBSA:EDTA=1:1:1 at pH=12.0-13.0.
EFFECT: invention increases sensitivity, selectivity and accuracy of analysis.
1 ex
The invention relates to the field of analytical chemistry - methods luminescence determination of terbium, and can be used to determine trace amounts of terbium in the analysis of a mixture of oxides of rare earth elements in natural waters.
Known methods luminescence determination of terbium complex with organic reagents with namedialog (1-ethyl-7-methyl-4-one-1,8-naftopidil-3-carboxylic acid, L-α-methyl-β-(3,4-dioksifenil) alanine, in complexes with derivatives pyrazolone [Nespolehliv, Lionnel, Lasovskaya O.N., Sveltlana. Spectrophotometric and fluorescent methods for the determination of lanthanides. - Kiev: Naukova Dumka, 1989. - S].
The closest in technical essence and the achieved result is the way the luminescence determination of terbium with the use of 1,2-deoxy-3,5-disulfonate [Poluektov NS, Alkaev L.A., Tishchenko M.A., Ukr. Analyte. Chemistry. - 1970. - V.25. No. 12. - S].
The disadvantage of this method of determination of terbium is the quenching of luminescence of terbium in the presence of REE with incomplete 4f shell, lack of sensitivity, selectivity and stability in time of standing and radiation.
The objective of the invention is the determination of terbium in the background of a mixture of other REE, no influence of other REE with incomplete 4f shell, the lower limit of detection, increasing the ustoichivosti luminescence determination of terbium in time standing and radiation.
The result is achieved that as complexing agents use organic reagent (R) - 1,2-dioxobenzo-3,5-disulfonate (DBSK) and the solution luminescense complex compounds of terbium with DBSK poured a solution of ethylenediaminetetraacetic acid (EDTA) in the ratio b:DBSK:EDTA=1:1:1, then 10%solution of KOH create pH(12-13)±0,1.
The resulting compound of terbium with organic reagent DBSK in the presence of EDTA when irradiated with ultraviolet light mercury lamps SVD-120A gives an intense green luminescence color, stable in time standing at λTb=546 nm.
The solution of a complex of terbium with DBSK in the presence of EDTA increases selectivity of the analytical definitions, by the addition of one molecule of EDTA. In solutions of the complexes there is no influence of foreign elements into luminescense ion that is related to the presence in the molecule of the complex is only one metal ion and the absence of polymerization. The influence of EDTA on the complex of terbium helps to improve the sensitivity, reproducibility and allows the determination of terbium via a calibration curve and by comparing with standard samples.
Example. Determination of terbium in a mixture of oxides of rare-earth elements in natural waters.
For the preparation of solutions of chlorides of lanthanides their oxides before artelino calcined for one hour in a muffle furnace at a temperature of 650-700°C and cooled in a desiccator. A portion of the oxides of the lanthanides, according to the calculations of the concentration of 1·10-2M, treated with hydrochloric acid and N2O2and then the solution is evaporated. The dry residue is dissolved in distilled water. Solutions with lower concentrations of REE prepare appropriate dilution. The concentration of a standard solution of terbium chloride control chelatometric method. The titration is carried out in the presence of urotropine, is used as an indicator arsenazo I. When determining the content of terbium ions in the mixture of oxides of rare earth working devices slit width is chosen small and the same when working with standard samples and analyzed solutions.
The solution DBSK concentration of 10-5M prepare an appropriate dilution of a more concentrated aqueous solution.
The EDTA concentration of 10-5M is prepared by dissolving the sodium salt in distilled water. Appropriate dilutions prepare a solution of lesser concentration. The acidity of the environment create a 10%solution of KOH to pH=(12-13)±0,1. The pH of the solutions is carried out using universal ionomer EV-74 with a glass electrode calibrated with standard buffer solutions. For determination of terbium in the REE oxides used the calibration method and additives.
The excite luminescence ultravioleta the first light mercury lamps SVD-120A, located in the illuminator OI-18A, equipped with a quartz condenser and filter UFS-1,2. For registration of luminescence spectra were used fluorescent installation, equipped with a spectrometer DFS-24 recorder PSC-4. The intensity of the luminescence of the complexes were recorded at λ=546 nm. Largest peaks in the luminescence of solutions samples and samples with additives was calculated content of terbium in the analyzed sample. The receiver served the photomultiplier PMT-79.
The proposed method allows to determine the terbium in a mixture of REE oxides, natural water with a detection limit of n·10-11g/ml, bypassing methods of concentration. Compared with the known method it does not influence other REE on the intensity of the luminescence of terbium complex with DBSK and EDTA when defining it in different objects (λ=546 nm; pH=(12,0-13,0)±0.1; composition b:DBSK:Desk=1:1:1, if CTB=2·10-5MDBSK=CAdd=5·10-5; tarticle=1.5 hours; solutions of the complexes are stable for tregion=10 min).
Fluorescent detection method terbium, including translating it into luminescense connection with organic reagent, wherein the organic reagent is used 1,2-dioxobenzo-3,5-disulfonate and luminescense compound is poured ethylenediaminetetraacetic acid, presleduyumie ratio of components:
Tb:DBSK:EDTA=1:1:1 at pH=12,0-13,0.