RU2215284C2 - Method for express-evaluation of substances on solid surfaces - Google Patents

Abstract

FIELD: analytical methods. SUBSTANCE: at least one reagent is applied on surface to be examined with the aid of air sol device, first reagent being dihydroxyxanthene dye solution in polar organic solvent at pH 1-3 and second one aqueous acetic acid solution. More particularly, 70:1 mixture of 0.3- 0.6% eosin BA or floxin acetonic solution and aqueous hydrochloric acid solution is used as first reagent. EFFECT: enabled express-evaluation without use of supplementary equipment. 3 cl, 4 tbl

Description

 The invention relates to analytical chemistry and indication, in particular to a colorimetric method for detecting biological agents on solid surfaces.

 The invention can be used in methods for determining biological agents on various surfaces in a domestic environment, as well as for carrying out an appropriate set of sanitary-hygienic measures.

A known method of detecting biological agents using a dropper with an indicator solution (2.5% solution of ninhydrin in a 50% solution of DMSO containing 0.025% sodium borohydride) and an indicator ticket (chromatographic paper brand "C" without impregnation) [B. IN. Buyanov. Group identification of pathogens of infectious diseases in environmental objects. -M., 1999]. 1-2 drops of the analyzed liquid are applied to the indicator ticket and 1-2 drops of the wetting reagent are added to it from a special dropper. Using a thermostat, the indicator ticket is heated to a temperature of 90 ^o C. In the case of the presence of protein-containing substances in the sample, a blue-blue color is observed on a white background.

The disadvantages of this method are:
- use of a dropper with a reagent perishable in air;
- contact of the operator with the infected surface when using indicator tickets to detect biological agents on the surfaces;
- small survey area;
- the use of additional equipment (thermostat);
- significant detection time (5-10 min).

 A known method of rapid detection of substances on solid surfaces, including applying a reagent to the test surface using an aerosol package and visual control of the surface color change [Patent 2117935 for the invention, "Method for determining the presence of asymmetric dimethylhydrazine". Priority invention: December 9, 1997]. The method is not intended to detect biological agents and allows you to determine the presence of asymmetric dimethylhydrazine (UDMH) by indicating on the surfaces, moreover, contacting is carried out on the surface by spraying the reagent using an aerosol package made in the form of a sealed enclosure filled with the reagent with a spray head, and as reagents use solutions of cobalt (II) chloride, nitrate or sulfate in water.

 The technical problem to which the present invention is directed is the rapid detection of biological agents on solid surfaces, which does not require the use of additional equipment and direct contact of the operator with the infected surface.

 The solution of the technical problem in the method of rapid detection of substances, including applying a reagent to the test surface using aerosol packaging and visual control of the surface color change, is carried out by using as a reagent a solution of a dioxixanthene dye derivative in a polar organic solvent at pH 1-3.

 Technical essence of the proposal. A large number of analytical reagents for protein were tested as possible indicator formulations providing an indication effect at room temperature. The results are shown in table 4. As follows from the data in Table 4, of all the tested reagents, the instant analytical effect is caused only by indicator compositions based on the indicator of bromocresol green and derivatives of dioxixanthene dye: BA eosin and phloxin.

 However, in the case of using the indicator of bromocresol green, a similar, indicative effect is caused by tap (rain) water. This is unacceptable.

 Example 1

 Detection of biological agents using an aerosol package filled as a solution of a dioxixanthene dye derivative in a polar organic solvent with a mixture of 0.3 ... 0.6% (wt.) Solution of BA eosin or phloxin in acetone and 0.75% (wt.) an aqueous solution of hydrogen chloride in a ratio of 70: 1.

 Eosin BA or phloxin in high concentrations does not dissolve in acetone, and this leads to cost overrun of reagent. Acetone was chosen as the polar organic solvent based on ensuring good mixing (mutual dissolution) with aqueous solutions of protein-containing substances. This concentration of an aqueous solution of hydrogen chloride is selected from the need to discolor the reagent, which reduces the background color of the indicator formulation when applied to an uninfected surface. A significant excess of an aqueous solution of hydrogen chloride causes a more rapid destruction of the indicator formulation during storage.

To detect biological agents on various surfaces:
1) open the front of the spray device, bring the aerosol package at a distance of 20-25 cm from the surface to be controlled, taking into account the direction and speed of the wind;
2) spray the indicator solution repeatedly pressing the lever of the spray device of the aerosol package with the index finger;
3) the presence of an indicator effect (the appearance of dark crimson spots on a light crimson background) indicates the presence of biological agents on the surface.

 Table 1 shows the experimental data on the indication effects on various surfaces when using aerosol packages for the rapid detection of biological agents.

 As follows from the table. 1, an analytical reagent based on eosin BA or phloxin does not lead to the appearance of a false indication effect on various surfaces.

 In the table. 2 shows experimental data illustrating the specificity (selectivity) of the proposed analytical method.

 As follows from the data in Table 2, other protein-containing products can cause a similar indication effect. Sodium bicarbonate causes the appearance of raspberry-orange spots, disappearing after 30 seconds.

 To increase the visibility of the indicator effect, after applying the indicator formulation, a 3. ..5% solution of acetic acid is additionally applied to the test surface using another aerosol package. The summary results of the sensitivity assessment are given in Table 3. The data given in the table indicate that most bacterial strains cause the appearance of an indication effect, while the surface treatment with acetic acid, the indication effect is noticeably enhanced.

 Thus, based on the presented data, the claimed method for the determination of biological agents can be used for their express detection on surfaces.

 The relatively high specificity of the used analytical reagent testifies to the high promise of using the proposed method for the rapid detection of biological agents using aerosol containers for use in domestic conditions, as well as for carrying out the corresponding complex of sanitary and hygienic measures.

Claims (3)

 1. The method of rapid detection of substances on solid surfaces, including applying at least one reagent to the test surface using an aerosol package and visual control of the color change of the surface, characterized in that the first reagent is a solution of a derivative of dioxixanthene dye in a polar organic solvent at pH 1-3, and as a second reagent - an aqueous solution of acetic acid.  2. The method for the rapid detection of substances on solid surfaces according to claim 1, characterized in that a mixture of 0.3-0.6 wt.% Is used as a solution of a dioxixanthene dye derivative in a polar organic solvent. % solution of eosin BA or phloxin in acetone and 0.75 wt. % aqueous solution of hydrogen chloride in a ratio of 70: 1.  3. The method of rapid detection of substances on solid surfaces according to claim 1, characterized in that after applying the first reagent to the test surface to increase the visibility of the analytical effect using aerosol packaging apply 3-5 wt. % solution of acetic acid.

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