Method of quantitative determination of methane-fullerenes in reaction mix by uv-spectroscopy method
FIELD: measurement equipment.
SUBSTANCE: invention relates to the method of quantitative determination of methane- fullerene of various level of replacement in reaction mix using UV-spectroscopy method consisting in reading of UV-spectra, plotting of calibration curves using the values of the second derivative of the spectrum, finding from them of the linear regression equations. Meanwhile for preparation of models of the studied compounds with various levels of replacement the organic solvents are used, UV-spectra are recorded in a wide interval of concentration, the linear regression equations for determination of the content of mono-replaced methane- fullerenes h=1.23×10-4c+0.01×10-5, di-replaced h=1.54×10-4c+0.20×10-5, three-replaced h=2.31×10-4c+0.30×10-5 tetra-replaced h=4.00×10-4c+0.32×10-5 then when determining methane-fullerenes with various levels of replacement in a reaction mix the analysed samples are selected from the reaction mix, UV-spectra are read, the curves are plotted on the basis of values of the second derivative of the spectrum, the respective value h is substituted in the respective linear regression equation and the concentration of methane-fullerenes in the analysed mix is calculated.
EFFECT: present invention allows to determine quantitatively the composition of complex reaction mixes of isomeric compounds consisting of two and more components in a wide range of concentration without their separation from a reaction mix with a possibility of the subsequent performing of the process before pre-planned ratio of ingredients.
2 cl, 5 tbl, 8 ex, 2 dwg
The invention relates to methods of quantitative determination of complex reaction mixtures, in particular methanofullerenes different degrees of substitution the method of UV spectroscopy. The invention can find application in the study of the structure fullerensoderzhashchikh macromolecular compounds, where on the basis of UV spectra is the most correctly sets out all the possible types of occurrences of C60in the polymer chain (Torx, fullerene in the primary circuit, the fullerene at the ends of the macromolecule, etc.).
Known quantitative method of finding the production of a commercial mixture of m-cresol containing o-, n-isomers of cresol, 2,4-, 2,5-, 2,6-carbonaceous carbolic acid o-ethylphenol (patent GB 760729 from 16.12.1953. The removal of the IR and UV spectra were carried out in the gas phase at 200°C, and was determined in a mixture only m-cresol with an accuracy of 0.3 to 3.0% and the error rate of the device in this method is 2%. This technique with sufficient accuracy the content is only one component in the mixture, and analyzed multiple connections it unusable. In addition, the recording of the UV spectra in the gas phase is very difficult due to the fact that not all organic matter can be transferred into the gas phase without decomposition.
The closest to the proposed invention is a method of determining in a mixture number of cefoperazone and sulbactam, was�audica in the removal of UV-spectra, graphic find first and second derivative spectra (Journal of Pharmaceuticul & Biomedicul Analysis, 1994, V. 12, No. 5. p.653-657). However, in the aforementioned method, the recording of the spectra is carried out only in water, and this greatly narrows the range of analytes that dissolve only in polar and nonpolar organic solvents. By this method it is possible to measure the concentrations of two compounds, which are procured on the production, and the authors are just preparing solutions of different concentrations.
The aim of the invention is to provide a method for the quantitative determination of complex reaction mixtures of isomeric compounds consisting of two or more components, in a wide range of concentrations without isolation from the reaction mixture with the possibility of the process to pre-planned ratios of ingredients.
This object is achieved in that the determination of complex reaction mixtures is performed in two stages. The first phase is removed and treated with UV spectra allocated methanofullerenes, distinguished by the type and number of substituents. On the basis of the second derivative UV spectra are constructed calibration graphs, which are determined by the linear regression equation. In the second phase are synthesized methanofullerene different stephenathome, removed their spectra and was found in the first stage equations of the linear regression corresponding to the type of substitution, determined by the number of substituted methanofullerenes.
The first stage is implemented as follows. Originally synthesized five complex mixtures methanofullerenes differ in the number of substituents in the core of C60. Mixture in a chromatographic column was divided into components depending on the number of substituents in the fullerene, i.e. allocated to individual connections. Then prepared solutions in organic solvents (chlorinated benzenes, chlorinated hydrocarbons, toluene, acetonitrile): randomly selected 5 or 6 concentrations in the range of 10-4-10-6mol/l (feasible it is designated intervals, as at larger than 10-4mol/l concentrations of the height of the characteristic peaks of above-scale optical absorption, and at concentrations less than 10-6mol/l, the height of the characteristic peaks is at the level of measurement error of the spectrophotometer), and each of methanofullerenes. Recorded UV spectra of all samples. Recording of the spectra was carried out at room temperature in the wavelength range from 190 to 1100 nm, but most characteristic is an interval of 250-400 nm, slit width of 2.0 nm, using a quartz cuvette with a thickness of 1 see EPA�, that the absorption spectra of the mixture methanofullerenes different degrees of substitution consists of a number of overlapping bands, the determination of the number of derivatives methanofullerenes is a difficult task. The highest selectivity of spectrophotometric analysis is achieved in the transition to the second derivative UV spectra, i.e. in the study of concentration dependencies of d2A/dλ2=f(λ). Testing different values of Δλ revealed that step-by-step coefficient Δλ=40 shows the best selectivity, high sensitivity and adequate signal-to-noise ratio for the experimental work.
The dependencies of d2A/dλ2-f(λ) (Fig.1) was measured corresponding to h1(monosubstituted methanofullerene), h2(disubstituted), etc. of the amplitude between the minimum and the maximum of d2A/dλ2at all concentrations, which are further used to construct a calibration graph (Fig.2). On the basis of a calibration curve based on the concentration of mono-, di -, etc. substituted methanofullerene from the second derivative to find the linear regression coefficients needed to calculate the molar concentrations of methanofullerenes. The parameters of linear regression for concentration dependencies of the optical density and d2A/dλ2presented in table 1.
|The parameters of linear regression for concentration dependencies of d2A/dλ2|
|Adduct||λ, nm||The linear equation||R||Sr×103|
The second stage is implemented with specific examples of implementation of the method of quantitative determination methanofullerenes in the reaction mixture in different solvents.
Example 1. To a solution of 0.1 g (0.14 mmol) of fullerene C60in 30 ml of toluene was added 0.069 g (0.2 mmol) CBr4, 0.033 ml (0.18 mmol) of galliavola ester of malonic acid and 0.32 ml (0.21 mmol) of diazabicyclo[4.2.0]undec-7-Jena (DBU). The reaction mixture was stirred under inert atmosphere at room temperature for 1.5 h, then was filtered, the filtrate was washed with 5% HCl solution, dried over MgSO4that was evaporated. The residue was separated separated by column chromatography on SiO2, eluent - toluene. Got 0.040 g (~32 wt.%) monosubstituted, 0.02 g (~14%) disubstituted, 0.015 g (~8%) and trisubstituted 0.01 g (~5%) tetramaster products. Spectroscopic analysis of the reaction mixture showed, with 35.2 wt.%) monosubstituted, (15,9%) disubstituted, (8,8%) and trisubstituted (6,3%) tetramaster products.
Example 2. Analogously to example 1, except that the process time is 4 hours. After the division separated by column chromatography on SiO2(toluene) received: (12 wt.%) monosubstituted, (36%) disubstituted, 0.015 g (24%) and trisubstituted (15%) tetramaster products. Spectroscopic analysis of the reaction mixture showed (14.3 wt.%) monosubstituted, (37,0%) disubstituted, (25,8%) and trisubstituted (18,2%) tetramaster products table.2). For the evaluation of the results of the quantitative analysis of mixtures methanofullerenes compared them with data HPLC (conditions chromatographic analysis: chromatographic system Shimadzu LC-20" with spectrophotometric diagnosticum detector (Japan); detection was carried out at a wavelength of 280 nm, used column Exsil Silica 250×4.6 mm, 5 μm, mobile phase was used eluent composition of hexane:toluene:isopropyl alcohol=97:2:1, the feed rate of the mobile phase was 1 ml/min.
|Comparison of methods for the quantitative determination of a mixture methanofullerenes in toluene|
|The number of deputies||Example 1 (1.5 hours)||Example 2 (4 hours)|
|Column chromatography on SiO2wt.%||HPLC, wt.%||UV-spectroscopy, wt.%||Column chromatography on SiO2wt.%||HPLC, wt.%||UV-spectroscopy, wt.%|
Example 3. Analogously to example 1, but the solvent used chloroform (chlorinated hydrocarbon), the process time is 1.5 hours. The results of the analysis of the reaction mixture are presented in table.3.
Example 4. Analogously to example 1, but the solvent used chloroform (chlorinated hydrocarbon), the process time is 4 hours. The results of the analysis of the reaction mixture are presented in table.3.
|Comparison of methods for the quantitative determination of a mixture IU�anapolitanos in chloroform|
|Number||Example 3 (1.5 hours)||Example 4 (4 hours)|
|Vice||Column chromatography on SiO2wt.%||HPLC, wt.%||UV-spectroscopy, wt.%||Column chromatography on SiO2wt.%||HPLC, wt.%||UV-spectroscopy, wt.%|
|di-||10,0||13,2||13,2||40,1||of 40.8||of 40.8|
Example 5. Analogously to example 1, but the solvent used acetonitrile, the process time is 1.5 hours. The results of the analysis of the reaction of CME�and presented in table.4.
Example 6. Analogously to example 1, but the solvent used acetonitrile, the process time is 4 hours. The results of the analysis of the reaction mixture are presented in table.4.
|Comparison of methods for the quantitative determination of a mixture methanofullerenes in acetonitrile|
|The number of deputies||Example 5 (1.5 hours)||Example 6 (4 hours)|
|Column chromatography on SiO2wt.%||HPLC, wt.%||UV-spectroscopy, wt.%||Column chromatography on SiO2wt.%||HPLC, wt.%||UV-spectroscopy, wt.%|
Example 7. Analogously to example 1, but the solvent used o-dichlorobenzene (chlorinated benzene) (chlorinated benzene), the process time is 1.5 hours. The results of the analysis of the reaction mixture are presented in table.5.
Example 8. Analogously to example 1, but the solvent used o-dichlorobenzene (chlorinated benzene), the process time is 4 hours. The results of the analysis of the reaction mixture are presented in table.5.
|Comparison of methods for the quantitative determination of a mixture methanofullerenes in o-dichlorobenzene|
|The number of deputies||Example 7 (1.5 hours)||Example 8 (4 hours)|
|Column chromatography on SiO2wt.%||HPLC, wt.%||UV-spectroscopy, wt.%||Column chromatography on SiO2wt.%||HPLC, wt.%||UV-spectroscopy, wt.%|
The accuracy of quantitative measurement of various methanofullerenes in mixture using UV-spectroscopy and HPLC are well correlated and comparable among them. However, in the case of HPLC selection mixture allentow to separate methanofullerenes very time consuming and for the implementation of the method requires very expensive equipment.
Thus, quantification of various methanofullerenes in complex mixtures by UV-spectroscopy with high accuracy and in a short time to ascertain the concentration of two or more components without interrupting the process. With the use of UV spectroscopy can be: a) to investigate the reaction kinetics of education methanofullerene based on the C60b) to bring the reaction to the planned concentration of the desired isomer in the reaction mixture, i.e. in General to control the process.
1. A method for quantifying methanofullerenes different degrees of substitution in the reaction mixture by UV-spectroscopy, which consists in the removal of UV-spectra, the construction of calibration graphs based on the values of W�Roy derivative spectrum finding them linear regression equations, characterized in that for the preparation of samples of the investigated compounds of various degrees of substitution of organic solvents are used, the recording of the UV spectra is produced in a wide range of concentrations, the linear regression equation for the determination of monosubstituted methanofullerenes h=1,23×10-4c+0,01×10-5, disubstituted h=1,54×10-4c+0,20×10-5, trisubstituted h=2,31×10-4c+0,30×10-5, terazosina h=4,00×10-4c+0,32×10-5then when you define methanofullerenes different degrees of substitution in the reaction mixture is sampled analyzed samples from the reaction mixture, removal of the UV spectra of the plot is based on the values of the second derivative spectrum, the substitution of the appropriate value of h in the corresponding linear regression equation and calculating the concentration methanofullerenes in the analyzed mixture.
2. A method for quantifying methanofullerenes different degrees of substitution in the reaction mixture by UV spectroscopy according to claim 1, characterized in that as the organic solvent used chlorinated benzenes, chlorinated hydrocarbons, toluene, acetonitrile, recording UV spectra is performed in a concentration range from 10-4-10-6mol/l, wherein the designated number�number of components in a mixture of two or more.
SUBSTANCE: invention relates to monitoring of the environment and biological objects aimed at identification of the content of metal ions in liquid media with the application of photochromic compounds. In the method of spectrophotometric identification of metal ions in liquid media with an application of photochromic compounds of class of chromenes due to formation of complexes between the photoinduced merocyanine form of the said compounds and metal ions as chromenes used are such bischromenes as: 2,2,11,11-tetrakis(4-methoxyphenylphenyl)dioxa(1,12)triphenylene, 2,2,8,8-tetrakis(4-methoxyphenyl)dioxa(1,7)chrysene, 3,3,11,11-tetra-(4-methoxyphenyl)-3,11-dihydro-4,10-dioxadibenzo[a,h]anthracene, 3,3,10,10-tetra-(4-methoxyphenyl)-3,10-dihydro-411-dioxadibenzo[a,h]anthracene.
EFFECT: increased selectivity of identification is achieved.
24 ex, 1 tbl, 6 dwg
SUBSTANCE: solutions of an analyte (bendazole) and a comparison sample are prepared. The solvent used to prepare the test solutions is 0.1M hydrochloric acid solution. The comparison sample used is benzoic acid or phenolphthalein. Optical density of the analyte (bendazole) solution and the comparison sample is measured on a spectrophotometer with analytical wavelength of 270 nm. The results are calculated using a formula by entering a calculation factor of 0.181 into said formula when determining using benzoic acid and 0.293 when determining using phenolphthalein.
EFFECT: method increases reproducibility of measurement results, reduces cost, labour input, analytical error and enables unification of the analysis method.
SUBSTANCE: invention relates to biotechnology and a method of producing continuous lines of living cells and use thereof. The disclosed method involves irradiating said living cells with a UV light dose of about 20 mJ/cm2 to about 300 mJ/cm2, at a wavelength between about 100 nm and about 400 nm, for about 30 s to 5 min and collecting cells that are capable of proliferation after at least 20 passages. The obtained cell lines are deposited in ECACC under numbers 08020602, 08020603 and 08020604 and can be used to produce viruses or gene products.
EFFECT: invention facilitates recombinant expression of biomolecules.
23 cl, 4 dwg, 1 tbl, 6 ex
SUBSTANCE: method for measuring in situ an oral agent applied from a dental care product on a substrate containing: (a) contacting the substrate and the oral agent for applying some oral agent on the substrate with the substrate being coated with saliva, and (b) analysing the substrate with the use of a probe being a part of a toothbrush and applied for infrared spectroscopy (IRS) or ultraviolet spectroscopy (UVS); a wave length used at the stage b) is specific for the above oral agent; a reference signal of the dental care product without the oral agent is deducted from an analysis result to calculate the amount of the oral agent.
EFFECT: method can be applied for the purpose of the monitoring of the patient's dental health or the fast and effective screening or analysis of compositions to be used for applying the oral active substances onto the dental surface.
16 cl, 15 dwg, 2 ex
SUBSTANCE: to extract caffeine from an aqueous solution, a water-salt solution of caffeine with pH 11.0±1.0 is prepared using saturated potassium carbonate solution as a salting-out agent; caffeine is extracted until establishment of phase equilibrium for 7-10 minutes with a solution of a solvotropic reagent in ethyl alcohol with concentration of 0.85-0.90 mol/dm3 with volume ratio of the water-salt solution of caffeine to the extractant of 5:1; the water-salt phase is separated from the organic phase and analysed by UV spectrophotometry at wavelength of 272 nm. Concentration of caffeine in the aqueous solution is determined from a calibrated curve.
EFFECT: method enables to achieve high coefficient of distribution of caffeine with one-fold extraction with a solution of a solvotropic reagent in ethyl alcohol, and virtually complete extraction of caffeine from the water-salt solution.
SUBSTANCE: three samples of a letter are obtained and analysed, one of which is extracted with a solvent and subjected to UV spectrophotometry right away; the second is analysed 30 days layer; the third is analysed 60 days after analysing the first sample; the second and third samples are extracted and subjected to UV spectrophotometry in the same conditions as the first sample; quantitative comparison of the results of UV spectrophotometry of the three samples is carried out based on the ratio of optical densities in the region of peaks (330-1100 nm) of dyes per unit length of the line of each sample in intervals of 1 and 2 months to obtain the behaviour of ageing of the manuscript, wherein ageing takes place in "natural" conditions with optimally permissible temperature, relative humidity and air speed in accordance with GOST 30494-96.
EFFECT: simplicity, high accuracy, guaranteed reproducibility and high reliability of determining ageing.
SUBSTANCE: described is method of quantitative determination of metronidazole by spectrophotometry of determined substance and standard sample of comparison, and as solvent for preparing determined solution applied is 0.1M solution of hydrochloric acid, spectrophotometry is carried out at wave length 276 nm, as sample for comparison applied is benzoic acid or phenolphthalein and calculation is carried out by formula.
EFFECT: method makes it possible to increase repeatability of determination results, reduce cost, labour consumption, analysis error, standardise analysis methods.
SUBSTANCE: device for determining overall unsaturation of organic compounds has an oxygen or air dosing unit, an electrodischarge ozoniser, a bubbling reactor, a spectrophotometric ozone analyser. The spectrophotometric analyser has two photosensors fitted with operational amplifiers. One of the photosensors is designed to detect concentration of ozone at the output of the ozoniser, and the second is designed to detect ozone concentration at the output of the bubbling reactor. In the absence of ozone, voltage signals from both photosensors are equal and after operational amplifiers, said voltage has a value V0. The device also has a unit for stabilising ozone concentration consisting of said photosensor fitted at the output of the ozoniser, a comparator which compares the voltage signal at the output of the operational amplifier connected to said photosensor with a given value Vc, and a latching transistor controlled by the comparator and connected in the power supply circuit of the ozoniser.
EFFECT: stability of ozone concentration, high measurement accuracy and wider measurement range during analysis using an ozone-air and an ozone-oxygen mixture.
2 cl, 1 dwg
SUBSTANCE: invention refers to a method of analysing oligosaccharides being components of low molecular weight heparins and very low molecular weight heparins in blood plasma. A method of analysing β-unsaturated oligosaccharides in blood plasma. Application of the method for quantitative analysis of enoxaparin, octaparin, bemiparin or tinsaparin. Application of the method for quantitative analysis of octasaccharides (versions).
EFFECT: more adequate oligosaccharide analysis.
15 cl, 2 dwg, 2 tbl, 2 ex
SUBSTANCE: solutions of a substance to be determined and a reference sample are prepared. 0.1 M sodium hydroxide is used as a solvent for preparing the analysed solutions. Potassium chromate or potassium ferricyanide is used as a reference sample. The optical density of the solution of the analysed substance and the reference sample of potassium chromate or potassium ferricyanide is measured by a spectrophotometre at wave length 264 or 298 nm respectively. The results are calculated by formula with an introduced conversion factor.
EFFECT: higher reproducibility of results of determination and reduced analytical error.
FIELD: medicine, pharmacy, analytical pharmaceutical chemistry.
SUBSTANCE: invention proposes a method for simultaneous determination of composition of multicomponent medicinal preparations by reversed HPLC method with ultraviolet detector. Method is used in carrying out analysis of preparations comprising the following drugs: (1) paracetamol, propifenazone, caffeine, phenobarbital, codeine phosphate; or (2) paracetamol, ascorbic acid, codeine phosphate, phenylephrine hydrochloride, chlorphenylamine maleate; or (3) paracetamol, theophylline, caffeine, phenobarbital, ephedrine hydrochloride; or (4) codeine phosphate, nipagin, nipazol for a single stage in linear gradient regimen wherein the composition of mobile phase changes from phosphate buffer solution with pH 3.0 to its mixture with acetonitrile taken in the volume ratio = 1:1. Invention provides the complete separation of peaks of all analyzed and interfering substances and to obtain precise quantitative results.
EFFECT: improved assay method.
2 cl, 17 dwg, 16 tbl, 6 ex
FIELD: organic chemistry, possible use when determining total organic pollution of surface, underground, drinking and industrial waters, and also for determining total amount of volatile compounds in these waters.
SUBSTANCE: in accordance to method for determining total organic pollution of water, a sample of water with organic pollution is taken, subjected to effect of ultraviolet radiation, in process of this effect, light absorption coefficient is measured, content of soluble iron is determined by means of chemical analysis and, if iron content does not exceed 0,15 mg/dm3, content of common organic carbon is calculated using formula C=k/a [%dm3/mg], where C - content of common organic carbon, mg/dm3; k - light absorption coefficient, %; a - experimentally calculated proportionality coefficient, characterizing connection between light absorption coefficient and content of common organic carbon at volumetric concentration of sample, having light absorption coefficient above 25% and content of soluble iron not above 0,15 mg/dm3.
EFFECT: simplification of realization, high objectivity of evaluation, high precision of measurements.
3 tbl, 1 dwg
FIELD: analytical chemistry.
SUBSTANCE: invention relates to method for quantitative determination of thiotriazoline and pyracetam in complex drugs by high performance chromatography, wherein silicagel with grafted 3-(chlorodimethyl)-propyl-N-dodecylcarbamate having particle size of 5 mum is used as sorbent; and degassed 0.05 M aqueous solution of potassium dihydrophosphate is used as mobile phase. Mobile phase velocity is 1 ml/min, and column temperature is 30°C. Method of present invention makes it possible to determine content of two abovementioned active ingredients simultaneously.
EFFECT: simplified process of sample preparation.
3 ex, 3 tbl
FIELD: measuring engineering.
SUBSTANCE: device comprises the source of ultraviolet radiation, pickups of ultraviolet radiation arranged in the liquid at various distances from the source, and appliance for cleaning.
EFFECT: enhanced precision and simplified design.
SUBSTANCE: invention refers to medicine and can be used in analytical laboratories for standardisation and quality assurance of medical products. Solutions of defined substance and the standard reference solution are prepared. The 0.1 M sodium hydroxide solution is used as a dissolvent for preparation of a defined solution, and as the standard reference solution - potassium chromate. Measure optical density of a defined solution and reference potassium chromate solution using spectrophotometer. Calculation of results is performed under the formula entering recalculation factor in it.
EFFECT: allows increasing reproducibility of results of definition, sensitivity of the analysis, reducing labour input, an analysis error, excluding use of toxic reactants and unifying analysis techniques.
SUBSTANCE: invention refers to medicine and can be used in analytical laboratories for standardisation and quality assurance of medical products. The method involves preparing solutions of defined substance and the standard reference solution. Clear water and 0.1 M sodium hydroxide solution are used as a dissolvent for preparation of a defined solution, nickel chloride being used as the standard reference solution. The method further includes measuring optical density of a defined solution and reference nickel chloride solution using spectrophotometer; calculating results from the formula and entering recalculation factor therein.
EFFECT: increased sensitivity of the analysis and reproducibility of results; reduced toxicity, labour input, and analytical error.
SUBSTANCE: invention relates to the field of medicine and can be used in control and analytic laboratories for standardisation and control of medication quality. Solutions of substance to be determined and comparison sample are prepared. As solvent for preparation of tested solutions 0.1 M solution of hydrochloric acid is used. As comparison sample phenolphthalein or benzoic acid is used. Optical density of solution of substance to be determined and comparison sample of phenolphthalein or benzoic acid are measured by spectrophotometer. Calculation of results is carried out by formula by introducing to it scaling factor. The method allows for increasing sensitivity of analysis, reproducibility of results of determination, reducing toxicity, labour-intensiveness and analysis error, unifying analysis technique.
EFFECT: increase in analysis sensitivity and reproducibility of results of determination, unification of analysis technique.
SUBSTANCE: present invention refers to analytical chemistry and can be used for quantative determination of methionine in water solutions by spectrophotmetric method. The method includes the preparation of standard methionine solutions, determination of optical density at characteristic wavelength, plotting of the calibration function for standard methionine solutions (optical density against concentrations at characteristic wavelength), determination in the analysed methionine solution of the optical density and methionine concentration according to optical density at characteristic wavelength using the calibration function. The determination of the characteristic wavelength is implemented in ultraviolet spectral region according to the differential absorption in coordinates λ=f(ΔA) whereat ΔA=Afollowing-Aprevious.
EFFECT: enhancing of determination reliability, accuracy and selectivity as well as simplifying and time decrease of the determination.
SUBSTANCE: method of determining quality of Iceland spar crystals for making polarisers involves measurement of the optical density spectrum of the crystal in the wavelength range from 220 to 400 nm in plane-polarised light. The electric vector of the plane-polarised light is parallel to the optical axis of the crystal. At least two opposite faces of the crystal, parallel to its optical axis, are polished, and the optical axis of the crystal is perpendicular to the incident light. The positions of maximums of the absorption band are determined, as well as the corresponding optical density values, and the quality class of the crystalline material is determined as follows: 1st class - not above 0.31 cm-1, 2nd class - not above 0.35 cm-1, 3rd category - not above 0.45 cm-1.
EFFECT: more accurate control of light absorption of crystalline material for making polarisers.
5 dwg, 1 tbl, 1 ex
SUBSTANCE: solution of substance to be defined and a sample solution for comparison are prepared. As a diluent for the preparation of the test solutions 0.1 M solution of hydrochloric acid is used. As a sample for comparison yellow dimethyl is used. Optical density of solution of substance to be defined and of yellow dimethyl sample for comparison are measured by spectrophotometer at a wavelength of 318 nm. The results are calculated according to the formula with a conversion coefficient.
EFFECT: improving of results reproducibility; reducing of cost, complexity and analysis errors.