RU2212029C1 - Way of analysis of liquid biological medium in process of monitoring - Google Patents

Abstract

FIELD: technical physics, study of materials by means of analysis of optical media. SUBSTANCE: invention can be employed for uninterrupted monitoring of composition of liquid biological medium, for instance, in process of hemodialysis, liquid sorption, peritonitial dialysis. Way of analysis consists in preliminary check monitoring of examined medium during which examined medium is sampled, in determination of concentration of components present in medium in each sample, in simultaneous measurement of absorption spectra of each sample. Then boundaries of informative region of spectrum are established in which limits change of absorption spectrum of taken samples is observed. Later absorption spectra of each component present in medium are measured in ultraviolet region of spectrum, components which bands of fundamental absorption fall at informative region are highlighted and dependence of spectral coefficient of extinction on concentration of highlighted components in this zone in range of concentrations of sample is established with due account of interaction of components. Thereupon monitoring of similar process is conducted during which absorption spectra of examined medium in informative region are measured in preset time intervals and concentrations of those components for which spectral characteristics of coefficient of extinction were obtained are computed per each spectrum. EFFECT: increased authenticity of information, widened number of monitored indices of running liquid biological medium, potential for on-line system operation. 2 dwg, 6 tbl

Description

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Claims (1)

A method for analyzing a liquid biological medium during monitoring by electronic absorption spectra in the ultraviolet region of the spectrum, based on the absorption method, characterized in that preliminary control monitoring of the test medium is carried out, during which samples of the test medium are taken, and the concentration of components present in the medium in each sample is determined , the number of samples not less than the number of analyzed components and at the same time measure the absorption spectra of each sample, and then determine the boundaries of inform active region of the spectrum, within which there is a change in the absorption of the samples taken, while the number of wavelengths of the informative region is not less than the number of components, after which the absorption spectra of each of the components present in the medium in the ultraviolet region of the spectrum are measured, the components whose intrinsic absorption bands fall on informative region and determine the dependence of the spectral extinction coefficient on concentration for the selected components in this region in the range of sample concentrations with by taking into account the mutual influence of the components, for which samples are selected in which the concentrations of the selected components changed, the number of samples is not less than the number of selected components, and for each wavelength of the informative region, a system of linear equations is solved, the determinant of which, composed of the concentrations of the selected components in the selected samples, is different from zero, then a similar process is monitored, during which the absorption spectra of the studied medium in the informative region are measured at specified time intervals and for each spectrum, the concentrations of those components for which the spectral characteristics of the extinction coefficient are obtained are calculated, while the concentrations of the components are calculated according to the following dependence:
k $\genfrac{}{}{0ex}{}{\text{Σ}}{\text{λ}}$ = ∑ $\genfrac{}{}{0ex}{}{\text{n}}{\text{j = 1}}$ (C ^j ε ^Σj λ),
where k $\genfrac{}{}{0ex}{}{\text{Σ}}{\text{λ}}$ - spectral absorption coefficient of a layer of unit thickness of the investigated medium containing n-components at a wavelength λ;
ε ^Σj λ is the spectral extinction coefficient of the jth component at a wavelength λ determined during calibration;
C ^j is the concentration of the jth component.

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