RU3644U1 - SAMPLE OF A QUANTITY OF SUBSTANCE FOR GRADING ANALYTICAL INSTRUMENTS AND CONTROL OF ACCURACY OF ANALYSIS BY LABORATORIES - Google Patents

Abstract

A sample of the micro-quantity of a substance for calibrating analytical instruments and controlling the accuracy of analysis by laboratories, made in the form of a sealed ampoule with a substance, characterized in that it is equipped with a capillary placed in the ampoule, and the substance in the form of a solution or dry residue of the solution is enclosed in this capillary.

Description

SAMPLE OF MICRO-QUANTITIES OF SUBSTANCE FOR

GRADING OF ANALYTICAL INSTRUMENTS AND

CONTROL OF ACCURACY OF ANALYSIS

LABORATORIES.

The utility model relates to the field of metrological support of chemicals for analysis methods and can be used by chemical laboratories to calibrate analytical instruments and to control the accuracy of analyzes.

Known composition samples for the calibration of analytical instruments, which are sealed containers (usually glass ampoules) filled with a solution of known concentration / Shaevich A.V. Standard samples for analytical purposes.-M .: Chemistry, 1987.-184s. /

These samples are widely used for metrological support of analytical work. Their advantage is the complete identity of individual copies of the composition samples prepared from one batch of the solution. However, stable samples containing microgram concentrations of substances cannot be manufactured in this way due to the rapid change in their composition due to sorption and chemical reactions occurring on the walls of the vessel. The permissible storage time for such diluted solutions is days or even hours. / Analysis of trace elements // Mater. Symposium (New York, 1955) ed. D. Io and G. Koch. - M.: Publishing. Foreign lit. 1961 /

The concentration of solutions of standard samples, the safety of which is guaranteed for 1 year, is 0.1 mg / cm3 and above.

At the same time, for the calibration of many measuring instruments and for monitoring the accuracy of analyzes, solutions containing microgram concentrations (or quantities) of the dosed substance are needed. Currently, they are obtained by successive dilutions of the initial solution, which not only increases the complexity of the calibration process, but also leads to an increase in the calibration error.

Liquid samples sealed in ampoules are known containing a certain mass of the dosed substance. Under the name standard titres or fixanals, they are widely used with analytical chemistry (see, for example, N.I. Korostelev Reagents and solutions in metallurgical analysis. -M: Metallurgy, 1977.- 400 p., P. 188)

These samples, the closest in combination of features to the claimed utility model, such contain relatively large masses of matter (usually not less than 0.05 grammole). For the above reasons, samples containing trace amounts of a substance are not manufactured.

To achieve the specified technical result, a sample of a micro-quantity of a substance is proposed for calibrating analytical instruments and controlling the accuracy of the analysis by laboratories in the form of a sealed ampoule with a solution of known concentration, characterized in that the metered substance is enclosed in a known microvolume of the solution or solids contained in the ampoule on a solid carrier, for example, in the capillary.

The separation in the claimed model of the functions of the vessel for storing the sample (which is the capillary in the utility model) and the container for protection against external influences (carried out by a sealed ampoule), as well as the use of relatively strong solutions for dosing the substance of microvolumes, allows:

-significantly reduce the area of contact between the walls of the vessel with the solution, which accordingly reduces the effect of sorption and ion exchange processes on the persistence of the solution;

- use the optimal material for the manufacture of the carrier due to the lack of requirements for mechanical strength and the ability to weld, as well as due to its negligible consumption;

-to prevent gas exchange with the external environment, which is possible when using ampoules made of polymer material;

- easy to remove solvent from the capillary due to the small volume of the solution and store in a dry form;

-significantly reduce the mass, dimensions and cost of the sample, due to a sharp reduction in the volume of the solution and ampoule.

The sample, figure 1 is a capillary or carrier of a different form 1, inside of which there is a metered substance 2 in the form of a solution or a dry residue, placed in a sealed ampoule 3.

When a sample is used, the ampoule is opened, the capillary from it is introduced into the vessel for dilution and is mechanically destroyed.

Then, the required amount of solvent is added to the vessel to obtain a solution of the desired concentration.

The advantages of the proposed utility model over the well-known are:

1. Good retention of even microgram quantities of dosed substances due to the very small contact surface of the solution with the walls and the possibility of using materials with optimum inertness for its manufacture;

greatly facilitates shipping and ensures its safety;

3. Low material consumption, which determines a low

product cost;

4. Convenience of using the sample, since there is no need to wash the ampoules, because the metered substance together with the capillary enters the vessel for dilution;

Comparative characteristics of the known and

The proposed sample is shown in the table.

Characterization of samples based on ampoules

Table

As can be seen from the data given in the table when using concentrated dosed solutions and capillaries as vessels for their storage, the contact surface of the solution with the walls of the vessel, and, consequently, their effect on the concentration decreases by two orders of magnitude.

This allows you to dose the amount of the substance two orders of magnitude smaller than that of known samples, while guaranteeing the same sufficiently long duration

storage.

When using capillaries made of materials that are more inert than glass, the dosage amounts can be reduced even more

without deterioration in shelf life. The mass of the proposed model is 30 times less than the known ones.

Claims (1)

A sample of the micro-quantity of a substance for calibrating analytical instruments and controlling the accuracy of analysis by laboratories, made in the form of a sealed ampoule with a substance, characterized in that it is equipped with a capillary placed in the ampoule, and the substance in the form of a solution or dry residue of the solution is enclosed in this capillary.