RU1774234C - Fluorometric standard of long-living luminescences - Google Patents

Abstract

The use of solutions containing europium ions in a mixture of heavy (DaO) water and ordinary (H20) water in various component ratios as a fluorimetric standard for long-lived luminescence. 2 tab.

Description

The invention relates to luminescence spectroscopy, in particular to fluorimetric standards

Iso-reference standard for determining the quantum yield and verifying the sensitivity of luminescent devices. As a reference, aqueous solutions of salts of rechvalent cerium are used. The standard has a highly absorbable absorption and luminescence spectra, the maximum in the luminescence spectrum at 350 nm, the high quantum yield of the luminescence characteristics of the luminescence is luminescence temperature in the range of 8 - 80 ° C. The standard is photochemically stable, has short-drying luminescence, the lifetime of the excited state of cerium is 545 nsec.

However, due to the short lifetime of the excited state of cerium, this standard cannot be used as a standard for long-lived luminescence for time-resolved fluoroscopy.

The aim of the invention is to increase the lifetime of the excited state of the fluorimetric standard and thereby enable its use for time-resolved fluorimeters

The goal was achieved by using solutions containing europium ions in a mixture of heavy (D20) and ordinary (H20) water, on the quality of the fluoritic standard of long-lived luminescence.

The fractional content of ordinary water in the mixture is determined from the expression

to

H20

l / r-0.4 9.5

where r is the luminescence lifetime of the determined content

The concentration of europium ions in the standard is chosen based on the required detection sensitivity (the desired concentration range) in accordance with the expression

Ho-tkC,

where 10 is the background luminescence of the solvent,

i is the required luminescence intensity;

C is the concentration of europium ions;

k is the instrument constant

The lifetime of the excited state of europium in a mixture of heavy and ordinary water

vi

4 Yu SO

varies from 0.1 ms at zero content of heavy water in the mixture to 2.5 ms at a content of heavy water of 100%.

By changing the percentage of H.0 and D20 in the mixture, the required luminescence decay time of the standard can be obtained in the range from 0.1 to 2.5 ms. By changing the concentration of eiropi ions in solution, the required luminescence intensity of the standard can be obtained.

Example. To test the properties of the long-lived luminescence standard, a solution of europri trichloride (label) of a concentration of 10 M in a mixture of heavy and ordinary water with a heavy water content of 90% by volume was prepared, which provides a fluorescence lifetime of the label of 0.72 ks; a time of 2.5 ms is provided by 100% DaO.

The spectral and luminescent characteristics of the europium solution were checked on a LS-5B spectrometer (Perkin-Elmer). Europium in a mixture of heavy and ordinary water lumimescistrust with a maximum in the excitation spectrum of 395 im, in the luminescence spectrum - 590 and 615 im.

The standard has temperature stability in the range of 10 - 60 ° C. In the table. Figure 1 shows the experimental data on the study of the temperature stability of three solutions of europri trichloride:

in 100% water, in 99.9% water, in 90% heavy water.

Luminescence intensity of europium trichloride solutions, ed.

The standard has photochemical stability of the luminescence intensity. A solution of europium trichloride in 90% heavy water was irradiated in a quartz cuvette with a 150 W xenon lamp continuously for 6 h; the total dose was 80 J per cm.

The measurement results are presented about table.2.

The standard retains its properties during 9 months of storage in a glass vial in the dark at a constant temperature.

The use of solutions containing europium ions in a mixture of heavy and distilled water as a luminescent standard allows the metrological support of fluorimeters designed to measure and / or indicate long-lived luminescence.

Claims (1)

SUMMARY OF THE INVENTION The use of solutions containing europium ions in a mixture of heavy (D20) and ordinary (NaO) water, as a fluorimetric standard for long-lived luminescence. Table 1 table 2