From Big Medical Encyclopedia

FLYuORIMETRYYa (Latin fluor current. a flow + Greek metreo to measure, measure) — the section of a spektrofoto-metriya, to-rogo is included development of methods and devices for quantitative definition of spectral characteristics of fluorescence of bodies of interest into tasks.

Methods and devices for F. (flyuorimetra), differing in high sensitivity and specificity, found application

in a medico-biol. researches during the studying of structure of biomolecules, processes of photosynthesis (see), kinetics of enzymatic reactions (see Kinetics of biological processes), for quantitative and qualitative analysis of various substances. The most widely flyuorimetriche-sky methods use for definition of concentration of substance on intensity of its fluorescence in a sample. Such methods subdivide on direct and indirect. In direct methods concentration of substance is determined by intensity of its own fluorescence (see).

In indirect flyuorimetrichesky methods concentration of substance is determined by intensity of fluorescence of products of interaction of this substance with auxiliary reagents. At the same time there is a formation of fluorescent connection (e.g., amino acids, peptides and proteins can be determined by fluorescence of products of their interaction with flyuoreskaminy; in the similar way define the maintenance of many inorganic ions). Also fluorescent dyes are used. In particular, dyes of an acridic row apply to vital coloring of nuclear chromatin at kariotipichesky researches. At the same time F. it is carried out in microscopes of a special design — mikroflyuorimetra. The method of fluorescent and marked antibodies found various application in biology and medicine in forms of direct and indirect ways of fluorescent coloring. During the use of a direct way fluorescent antibodies contact directly antigens of fabric while during the use of an indirect way they interact with the gamma-globulins (see Immunoglobulins) which earlier contacted these antigens that provides, as a rule, high specificity and test-sensitivity.

Flyuorimetrichesky methods widely apply during the carrying out the titrimetric analysis (a so-called method of the fluorescence titrimetric analysis). In this case use the luminescent indicators changing intensity of a luminescence in a point of equivalence — such, e.g., as metalfluorescent, acid-base, oxidation-reduction, adsorptive and chemiluminescent indicators (see the Luminescence).

By means of flyuorimetrichesky methods of the analysis many connections which are of interest to biology and medicine can be defined. Enter their number organic to - you, alcohols, aldehydes and ketones, amines and amino acids, carbohydrates, coenzymes, cofactors and nucleinic to - you, medicines, pesticides, steroids and vitamins.

Flyuorimetrichesky methods found broad application in enzymology (see). With their help define hydrolases (cholinesterase, lipases, peptidases, phosphatases), dehydrogenases and transaminases, oxidizing enzymes (a xanthineoxidase, peroxidase, monoamine oxidase), etc. Flyuorimetrichesky methods with use of fluorescent dyes find application in medicine, in particular for assessment of permeability of fabric barriers (see. Barrier functions, Permeability) and identification of nek-ry types of malignant tumors.

Ability of many substances and chemical connections to fluorescence at their uv or x-ray radiation (x-ray fluorescence) is used for definition of many toxicants in the environment (in air, the soil, plants and other environments). T. apply to definition in the atmosphere of pyrolysis products of oil (see), acetylene (see), naphthylamines. T. petroleum or stone

coal oils and various organic compounds allows to establish impurity of drinking water. T. use also for definition of vitamins (Bi, B2, etc.) p microorganisms in foodstuff, yeast, urine, other biomaterials.

The way of fluorescent X-ray radiometric definition of heavy metals based on registration of x-ray fluorescence with use of domestic RAGT-8 devices, «Mineral-2», «Mineral-3», «Quantum» is developed. By means of this method perhaps direct definition of many metals (Mg, Cr, Zn, Megapixel, Fe, Those, With, Ni, the SI, As, etc.) in tests without their pretreatment. The error of the analysis does not exceed 2 — 3%. Sensitivity — 0,3 mkg in test. Other metals, and also organic and inorganic pollutants do not prevent definition.

By method F. it is possible to define the main inorganic pollutants in free air (see. Sanitary protection of free air). The scheme of their fluorescent X-ray radiometric definition includes three stages. First of all establish the chemical reaction allowing to record the defined substance in connection with the element determined by a X-ray radiometric method. The subsequent stages — transfer of the formed connection from solution in an insoluble condition and sedimentation of connection on the filter for measurement of x-ray fluorescence. All elements with atomic number from 12 (magnesium) to 83 (bismuth) are almost available to X-ray radiometric definition. Besides, using x-ray fluorescence of antimony, it is possible to determine hydrogen sulfide (after carrying out chemical reaction between the last and mineral butter of a pla lead acetate), sulfuric to - that (sedimentation by barium chloride), ammonia (by reaction with a reactant of Nes-slera), hydrogen chloride and mercaptans (sedimentation by silver nitrate), carbon monoxide (by reaction on the filter with dry iodine pentoxide) etc. The error of definition of these substances makes 3 — 5%.

See also Spectroscopy, the Range ofo volume e tr iya.

Bibliography: In l and d and m and r about in Yu. A. and

Dobretsov G. E. Fluorescent probes in a research of biological membranes, M., 1980; Dmitriyev M. T. and r and about r e in and F. M. Fluorescent X-ray radiometric definition of the main inorganic pollutants in free air, the Gigabyte. and dignity., No. 12, page 52, 1980; Zaydel A. N. Atomic fluorescence analysis, M., 1980; Zakharov I. A. and T and m about-f e e in and V. of II. Luminescent methods

of the analysis, D., 1978; T e p l and c to and I am T. A. Quasiline spectra of a luminescence as method of a research of complex organic mixtures, M., 1971; Toeplitz -

to and I am T. A., Alekseeva T. A. and Valdman M. M. Atlas of kvazili-neychaty luminescent spectrums of aromatic molecules, M., 1978; Hesi-n and A. Ya., etc. Comparative researches of polycyclic aromatic hydrocarbons in objects of the environment surrounding the person, the Gigabyte. and dignity., No. 6, page 39, 1979; Yudenfrend S. Fluorescence analysis in biology and medicine, the lane with English, M., 1965; G u i 1 b and and 1 t G. G. Practical fluorescence, N. Y., 1973;

U den fri en d S. Fluorescence assay in biology and medicine, v. 1—2, N. Y., 1966 — 1970.

P. P. Lidemang; M. T. Dmitriyev,

V. H. Pavlov (gigabyte.).