RU2460998C1 - Method of determining polyhexamethylene guanidine hydrochloride - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method involves reaction of reactants followed by analysis of the obtained products. According to the invention, the reactant used is a colloidal solution of gold nanoparticles in water. After reaction, the obtained product (gold nanoparticles and aggregates thereof) are concentrated on foamed polyurethane and the concentrate is analysed.

EFFECT: high reliability and simple analysis.

3 cl, 5 ex

Description

The invention relates to a method for determining polyhexamethylene guanidine hydrochloride (Biopag, which is part of disinfectants) using the processes of aggregation of gold nanoparticles for the analysis of different types of water.

A known method for determining Biopag by capillary electrophoresis with spectrophotometric detection at 200 nm. The method allows to determine polyhexamethylene guanidine hydrochloride in the presence of hexamethylene diamine and guanidine hydrochloride with a detection limit of 2 μg / ml [Rudnev A.V. Determination of polyhexamethylene guanidine by capillary electrophoresis. / A.V. Rudnev, T.G. Dzherayan // Journal. Analit. Chemistry. - 2006. - T.61. - No. 10 - S.1086-1089]. However, the sensitivity of this method is insufficient, since in drinking water Biopag must be determined at the level of 0.1 μg / ml. In addition, the implementation of this method involves the use of expensive equipment.

A known method of potentiometric determination of Biopag and some other polycations using ion-selective electrodes with a membrane that includes a defined polycation and various organic and inorganic counterions. The method allows to achieve good selectivity of determination [Chmilenko F.A. Potentiometric sensors for determining water-soluble polyelectrolytes. / F.A. Chmilenko, I.V. Korobova, O.V. Mikulenko // Zh. Analit. Chemistry. - 2008. - T.63. - No. 6 - S.645-650]. However, the sensitivity of the described method (the lower limit of the determined contents at the level of 5 μg / ml) is still insufficient to control the content of Biopag in water.

A known method for the determination of cationic surfactants, which include Biopag, using the processes of aggregation of gold nanoparticles in solution. The determined components were cationic surfactants, which are alkyl trimethylammonium bromides. As a reagent used gold nanoparticles obtained by the nitrate method. Detection was carried out visually, by changing the color of the solutions. [Kuong C.-L. Semi-quantitative determination of cationic surfactants in aqueous solutions using gold nanoparticles as reporter probes. / C.-L. Kuong, W.-Y. Chen, Y.-C. Chen // Anal. Bioanal. Chem. - 2007. - V.387. - P.2091-2099]. However, the method is suitable only for the semi-quantitative determination of cationic surfactants and does not allow quantitative analysis. The disadvantage of this method is the inability to achieve high sensitivity due to the natural limitations of the eye's perception of color changes in dilute aqueous solutions.

The closest analogue to the proposed one is a method for determining Biopag by photometry of its ionic associates with eosin. At pH> 5, eosin forms ionic associates with Biopag, absorbing at 540 nm. For their solubilization syntanol is added to the mixture [Krengold S.U. Determination of N, N-bis (3-aminopropyl) dodecylamine, cationic surfactants and polyhexamethylene guanidine in disinfectants. / S.U. Kreingold, K.A. Shestakov // Disinfection business. - 2004. - No. 1. - S.31-33]. The method is suitable for determining Biopag in disinfectants. However, the lower limit of the determined contents of the method lies at the level of 1 μg / ml, which is not enough to determine Biopag at the MPC level in waters.

The technical task of the invention is the development of a simple, safe and cheap method for determining polyhexamethylene guanidine hydrochloride (Biopag) to control its content in different types of waters.

The problem was solved by the present invention. In the method for determining polyhexamethylene guanidine hydrochloride, including its interaction with reagents, followed by analysis of the obtained products, according to the invention, a colloidal solution of gold nanoparticles in water is used as a reagent, and after interaction, the resulting product, including gold nanoparticles and their aggregates, is concentrated on polyurethane foam and analyzed concentrate.

In this case, the analysis of the concentrate is preferably carried out using a spectrophotometer directly in the matrix of polyurethane foam.

Signal registration is preferably carried out using a mini-spectrophotometer - Eye-One monitor calibrator (Ai Van).

Thus, to solve the technical problem, a method is proposed that uses the aggregation of gold nanoparticles obtained by the citrate method under the influence of Biopag, followed by sorption of products on polyurethane foam and registration of the analytical signal in the PUF matrix using a mini-spectrophotometer - Eye-One Pro monitor calibrator . The method allows to determine Biopag in the concentration range of 0.05-0.2 μg / ml, the relative standard deviation is 0.05 (for 0.1 μg / ml). The correctness of the determination was verified by analyzing different types of water: tap, mineral, and swimming pool water, as well as analyzing the Bior-1 disinfectant.

Example 1 of the construction of the calibration graph

To construct a calibration curve, 0.25 to 0.2 ml of a 5 μg / ml aqueous solution of Biopag was added to the shaking vessels containing 0.2 ml of a 0.25 M EDTA solution and 0.5 ml of 0.1 M NaOH, deionized water to 3.5 ml and 1.5 ml of a solution of gold nanoparticles (88 μg / ml) obtained by the citrate method were added. The solutions were intensively mixed, after which 1 tablet of PUF was immediately introduced (diameter ~ 16 mm, height ~ 5 mm, m = 0.02 g), squeezed them with a glass rod to remove air bubbles and shook the vessels on a mechanical shaker for 15 minutes. After that, the tablets were removed, dried with filter paper, and diffuse reflection was measured at 530 nm using a mini-spectrophotometer - Eye-One Pro monitor calibrator.

Example 2 of using a mini-spectrophotometer - Eye-One Pro monitor calibrator for measuring the diffuse reflection of PUF samples with gold nanoparticles

For measurements, the Eye-One Pro mini spectrophotometer was connected to the computer’s USB port, in Windows, the Eye-One Share program attached to the mini spectrophotometer was launched and the device was calibrated using the white backing included in the standard kit. After that, the samples were measured, and the data obtained as an array of diffuse reflection coefficients for various wavelengths were exported to Excel. For each diffuse reflection coefficient obtained using Eye-One Pro, the corresponding value of the Kubelka-Munk function F was calculated, which linearly depends on the content of nanoparticles in the PUF phase and is related to the diffuse reflection coefficient as follows:

where R is the diffuse reflection coefficient.

The advantages of the proposed device in this use case compared to traditionally used spectrophotometers and diffuse reflectance spectrometers include low cost, affordability, ease of use and compactness.

Example 3 Biopag definitions in a sample of tap water or swimming pool water

Tap water was purified from chlorine by settling for a day. After that, the Biopag standard solution was added to it to a final concentration of 0.23 μg / ml. The solution was thoroughly mixed. An aliquot of the obtained 2.2 ml artificial sample was added to a solution containing 0.2 ml of a 0.25 M EDTA solution and 0.5 ml of 0.1 M NaOH, and mixed. Then, we acted, as in the construction of the calibration dependence (example 1). Thus, it was found that the calcium, magnesium, chloride and sulfate ions present in real amounts in the waters of this type do not affect the correct determination of Biopag by the proposed method.

Example 4 definition of Biopag in mineral water

Mineral water was purified from excess carbon dioxide by sedimentation during the day. Then they acted as described in Example 3. It was shown that hydrocarbonate, chloride, sulfate ions, as well as potassium and sodium ions present in mineral water in 1000-fold amounts in relation to Biopag do not affect the correct determination of Biopag by the proposed method .

Example 5 determination of Biopag in a disinfectant preparation "Bior-1"

An aliquot of 0.5 ml of the Bior-1 preparation was transferred to a 100 ml volumetric flask, the flask was brought to the mark with deionized water and the solution was stirred. An aliquot of 0.5 ml of the resulting solution was transferred to another 100 ml volumetric flask, made up to the mark with deionized water and the solution was stirred. An aliquot of 0.1 ml of the solution thus obtained was introduced into a shaking flask containing 0.2 ml of 0.25 M EDTA solution and 0.5 ml of 0.1 M NaOH, the contents were mixed. Then they acted as described in example 1. The correct determination of the content of Biopag in the preparation "Bior-1" by the proposed method is confirmed by comparison with the passport data.

Claims (3)

1. A method for determining polyhexamethylene guanidine hydrochloride, including its interaction with reagents followed by analysis of the products obtained, characterized in that the colloidal solution of gold nanoparticles in water is used as a reagent, and after the reaction, the resulting product, including gold nanoparticles and their aggregates, is concentrated on polyurethane foam and analyze the concentrate. 2. The method according to claim 1, characterized in that the analysis of the concentrate is carried out using a spectrophotometer directly in the matrix of polyurethane foam. 3. The method according to claim 2, characterized in that the signal is recorded using a mini spectrophotometer - monitor calibrator Ai van.