Disinfectants

Abstract

To provide a disinfectant that does not require on-site preparation, ensuring stable storage and distribution.SOLUTION: A disinfectant contains an aqueous solution containing hypochlorous acid and nitrogen compounds.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to disinfectants. [Background technology]

[0002] Currently, alcohol-based disinfectants such as ethanol and chlorine-based disinfectants such as sodium hypochlorite are used as disinfectants.

[0003] In addition, due to the COVID-19 epidemic, various studies have been conducted on the effectiveness of weakly acidic hypochlorous acid water against viruses (Non-Patent Document 1). Hypochlorous acid (HClO) is a compound that produces hypochlorite ions (ClO - Weakly acidic hypochlorous acid water is a solution prepared at pH 5-6, which has a high proportion of undissociated HClO, which has a high bactericidal effect. Weakly acidic hypochlorous acid water with a pH of 5-6 has a high abundance of HClO, which has a high bactericidal effect.

[0004] Chloramines are also known to have bactericidal and virus inactivating properties. Chloramines are produced by the reaction of ammonia and hypochlorous acid. For this reason, a solution of hypochlorous acid and ammonia is used. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Yu Miyaoka et al., Virus Research, 297, 198383 (2021) Summary of the Invention [Problem to be solved by the invention]

[0006] However, the ammonia in the aqueous solution of hypochlorous acid is unstable and cannot be mixed in advance. Therefore, the disinfectant is prepared by mixing hypochlorous acid and ammonia at the site of disinfection. It is complicated to prepare such a two-liquid type disinfectant at the site of disinfection, and it is costly to store and distribute the materials for preparation. Therefore, there is a demand for a disinfectant that does not need to be prepared at the site of disinfection and can be stably stored and distributed. [Means for solving the problem]

[0007] The gist of the present invention is as follows. (1) A disinfectant containing an aqueous solution of hypochlorous acid and a nitrogen compound. (2) The disinfectant described in (1) above, wherein the nitrogen compound is inorganic nitrogen. (3) The disinfectant described in (1) above, wherein the nitrogen compound is nitrate nitrogen. (4) The disinfectant according to any one of (1) to (3) above, wherein the hypochlorous acid is sodium hypochlorite. (5) The disinfectant according to any one of (1) to (4) above, which is a composition for virus inactivation and / or sterilization. (6) A disinfection method comprising reacting a disinfectant comprising an aqueous solution containing hypochlorous acid and a nitrogen compound with organic matter containing viruses, bacteria, or both. Effect of the Invention

[0008] According to the present invention, it is possible to provide a disinfectant that does not require preparation at the disinfection site and can be stably stored and distributed. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a graph showing the results (virus infectivity) of the virus inactivation test in Examples 1 to 3 and Comparative Examples 1 and 2. [Diagram 2] FIG. 2 is a schematic diagram showing the procedure of the plaque assay for measuring the viral infectivity, which is the amount of remaining virus. [Diagram 3]FIG. 3 is a graph showing inorganic nitrogen concentration and pH for each available chlorine concentration when a sodium hypochlorite solution and inorganic nitrogen are mixed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present disclosure is directed to a disinfectant comprising an aqueous solution comprising hypochlorous acid and a nitrogenous compound.

[0011] The disinfectant of the present disclosure (hereinafter also referred to as the present disinfectant) is a one-liquid type aqueous solution in which hypochlorous acid is mixed with a nitrogen compound, and does not require preparation at the disinfection site, and can be stably stored and distributed. The present disinfectant can be used as it is to act on viruses and bacteria during disinfection, and can exhibit excellent disinfection effects. In this specification, disinfection means virus inactivation and / or sterilization.

[0012] That is, the present disinfectant can be used for inactivating viruses and / or killing bacteria by acting on them through addition, etc. In this application, inactivation means reduction in infectivity.

[0013] The aqueous solution containing hypochlorous acid and a nitrogen compound can be an aqueous solution of hypochlorous acid containing a nitrogen compound. The hypochlorous acid and the nitrogen compound can exist as ions in the aqueous solution. When an aqueous solution of hypochlorous acid containing a nitrogen compound is applied to organic matter containing viruses and bacteria, the organic matter is oxidized to generate aldehydes, organic acids, and nitrogen. . raw The aldehydes formed by this synthesis can be used to convert nitrate nitrogen (NO 3 - -N) is reduced to nitrite nitrogen (NO 2 - -N) and ammonium nitrogen (NH 4 + In addition, the organic matter is reduced by the organic acid produced to produce ammonium nitrogen (NH 4 +The resulting ammonium nitrogen can then react with hypochlorous acid in the aqueous solution to produce chloramines, in a complex reaction.

[0014] The present disinfectant preferably has a pH of 5 to 9, more preferably 7 to 8. In the present disinfectant, within the above preferred pH range, both the disinfecting effect of hypochlorous acid and the ease of generating chloramines can be achieved.

[0015] Carbon dioxide gas can be used to adjust the pH of this disinfectant. By blowing carbon dioxide gas into this disinfectant, the pH is adjusted to about 5-6 before the carbon dioxide gas escapes, making it possible to obtain a stronger disinfecting effect of hypochlorous acid, and as the carbon dioxide gas escapes, the pH changes to about 7-8, making it easier to generate chloramine, and the disinfecting effect of chloramine can also be obtained. In the aqueous solution of the disinfectant, hypochlorous acid exists as HClO at a pH of about 7.5 or less, and as ClO at a pH of about 8 or more. - It can exist as:

[0016] Chloramines have bactericidal and virus inactivating properties, so this disinfectant can achieve a greater disinfecting effect than hypochlorous acid alone. Therefore, this disinfectant can inactivate and / or kill more types of viruses than conventional disinfectants. This disinfectant can also inactivate enveloped viruses such as Pseudomonas syringae phage φ6 (NBRC105899), which is a bacterium (Pseudomonas syringae) (NBRC14084) infected with bacteriophage φ6, and non-enveloped viruses. Without being bound by theory, it is believed that this disinfectant can achieve a greater disinfecting effect because chloramines are generated in the vicinity of organic matter containing viruses and bacteria. Chloramines are generated by the reaction of ammonia and hypochlorous acid, and at pH 5 or higher, monochloramine (NH 2 Cl), dichloramine (NHCl) at pH 3-5 2 ), and trichloramine (NCl) at pH 3 or less.3 ) can be generated.

[0017] The organic matter includes viruses and / or bacteria, but may also include organic matter such as sebum.

[0018] In order to enhance the disinfection effect, the hypochlorous acid and nitrogen compounds in the disinfectant solution can be contained at a preferred concentration.The hypochlorous acid in the disinfectant solution has a disinfection effect, and the generated chloramines also have a disinfection effect, so it is preferable that the hypochlorous acid itself has a disinfection effect and the generated chloramines have a disinfection effect at a concentration that can add the disinfection effect.The disinfectant solution can be prepared by mixing a hypochlorous acid aqueous solution of a predetermined concentration with a solution of a nitrogen compound such as nitric acid of a predetermined concentration.

[0019] While ammonium nitrogen and monochloramine are unstable, nitrate nitrogen (nitric acid) can exist stably even in hypochlorous acid. By allowing nitrate nitrogen to coexist with hypochlorous acid water, organic matter can be oxidized during use to produce chloramines, which have the effect of inactivating viruses.

[0020] Therefore, the disinfectant of the present invention is not a two-liquid type that is mixed and used to act on viruses and bacteria when used, but a one-liquid type that is used to act on viruses and bacteria as it is when used. The disinfectant can be used as a composition for inactivating viruses and / or killing bacteria, and can have a disinfecting effect when mixed with viruses and bacteria. In the present application, inactivation means that the infectivity is reduced.

[0021] The nitrogen compound is preferably inorganic nitrogen, more preferably nitrate nitrogen. Nitrate can exist stably in hypochlorous acid, so nitrate nitrogen is more preferable. The inorganic nitrogen concentration in the aqueous solution can affect the bactericidal action and / or virus inactivation action.

[0022] Nitrite nitrogen (NO 2 - -N) and nitrate nitrogen (NO 3 -The concentration of NO in aqueous solution can be measured by naphthylethylenediamine spectrophotometry. 2 - -N and NO 3 - Regarding the concentration of -N, simultaneous quantification of anions by ion chromatography is considered, but NO 2 - If the concentration is low, the previous Cl - The peak of Cl may affect the quantification. - Since there is a lot of NO in hypochlorous acid water, 2 - It is difficult to quantify, but it can be determined by naphthylethylenediamine absorptiometry.

[0023] Nitrous acid reacts with sulfanilamide to form a diazonium ion. The diazonium ion combines with naphthylethylenediamine to produce an azo dye (a pink to red compound). Nitric acid can be indirectly measured by naphthylethylenediamine spectrophotometry after reduction to nitrous acid. A cadmium-copper reduction column can be used to reduce nitric acid to nitrous acid.

[0024] Chloramines (NH 2 The concentration of chloramine (NH Cl-N) can be measured by the indophenol blue method. The indophenol blue method is a method for quantifying the amount of chloramine by measuring the absorbance of N-(p-hydroxyphenyl)-p-quinoneimine (indophenol blue) produced when monochloramine reacts with phenol. The concentration of chloramine (NH Cl-N) can be measured by the indophenol blue method. The indophenol blue method is a method for quantifying the amount of chloramine (NH Cl-N) by measuring the absorbance of N-(p-hydroxyphenyl)-p-quinoneimine (indophenol blue) produced when monochloramine reacts with phenol. 2 It is possible to measure the concentration of Cl-N.

[0025] Ammonium nitrogen (NH 4 + The concentration of -N) can be measured by adding only phenol to the aqueous solution without adding sodium hypochlorite solution.

[0026] The disinfecting effect of this disinfectant can be evaluated by measuring the virus infectivity, which is the amount of remaining virus. Figure 2 shows a schematic diagram of the plaque method procedure.

[0027] This disinfectant can be prepared by mixing a hypochlorous acid aqueous solution with a nitrogen compound such as a nitric acid aqueous solution. For example, the disinfectant can be prepared by diluting and mixing the nitrogen compound and the hypochlorous acid aqueous solution so that the effective chlorine concentration is 10 to 100 ppm for an inorganic nitrogen concentration of 10 ppm. The inorganic nitrogen concentration in the prepared aqueous solution can be measured by the above method. The pH of the prepared aqueous solution can be measured using a pH meter.

[0028] After preparing the present disinfectant, the pH can be adjusted using carbon dioxide gas. By blowing carbon dioxide gas into the present disinfectant to dissolve it, the pH can be adjusted to preferably about 5 to 6, and the disinfecting effect of hypochlorous acid can be more potently obtained. Thereafter, as the carbon dioxide gas escapes, the pH can be changed to about 7 to 8, promoting the production of chloramines.

[0029] The hypochlorous acid in the hypochlorous acid aqueous solution is preferably generated from sodium hypochlorite, potassium hypochlorite, or calcium hypochlorite. Calcium hypochlorite (white powder) is solid and can be distributed and can dissolve relatively slowly. Hypochlorous acid may also be generated directly by electrolysis.

[0030] The present disclosure is also directed to a method of disinfection comprising reacting organic matter, including viruses, bacteria, or both, with a disinfectant comprising an aqueous solution including hypochlorous acid and a nitrogen compound.

[0031] The disinfection method preferably comprises the following reaction: Reacting a composition comprising an aqueous solution containing hypochlorous acid and a nitrogen compound with organic matter including viruses, bacteria, or both to produce aldehydes and / or organic acids; (A) generating ammonia by reducing coexisting nitrate nitrogen with the aldehydes, (B) generating ammonia by reducing the organic matter with the organic acid, or (C) generating ammonia by both (A) and (B), reacting said ammonia with said hypochlorous acid to produce chloramines. EXAMPLES

[0032] Example 1 For an effective chlorine concentration of 20 ppm in sodium hypochlorite, the inorganic nitrogen is nitrate nitrogen (NO 3 - An aqueous solution was prepared so that the concentration of N was 5 ppm.

[0033] A virus suspension was prepared using Pseudomonas syringae phage φ6 (NBRC105899), which was prepared by infecting bacteria (Pseudomonas syringae) (NBRC14084) with bacteriophage φ6.

[0034] (Virus inactivation test) The prepared aqueous solution (900 μL) was added to the virus suspension (100 μL) and allowed to stand at room temperature. After 5 minutes, the virus infectivity (amount of remaining virus) was measured by the plaque method shown in FIG. 2.

[0035] Example 2 For an effective chlorine concentration of 20 ppm in sodium hypochlorite, the inorganic nitrogen is nitrate nitrogen (NO 2 - A virus inactivation test was carried out in the same manner as in Example 1, except that the aqueous solution was prepared so that the concentration of -N was 5 ppm.

[0036] Example 3 For an effective chlorine concentration of 20 ppm for sodium hypochlorite, ammonium nitrogen (NH 4 + A virus inactivation test was carried out in the same manner as in Example 1, except that the aqueous solution was prepared so that the concentration of -N was 5 ppm.

[0037] Comparative Example 1 A virus inactivation test was carried out in the same manner as in Example 1, except that only phosphate buffer solution (PBS) was used.

[0038] Comparative Example 2 A virus inactivation test was carried out in the same manner as in Example 1, except that only an aqueous sodium hypochlorite solution having an effective chlorine concentration of 20 ppm was used.

[0039] Example 4 For an effective chlorine concentration of 20 ppm for sodium hypochlorite, ammonium nitrogen (NH 4 + A virus inactivation test was carried out in the same manner as in Example 1, except that the aqueous solution was prepared so that the concentration of -N was 1 ppm.

[0040] Example 5 For an effective chlorine concentration of 20 ppm for sodium hypochlorite, ammonium nitrogen (NH 4 + A virus inactivation test was carried out in the same manner as in Example 1, except that the aqueous solution was prepared so that the concentration of -N was 2 ppm.

[0041] Example 6 For an effective chlorine concentration of 20 ppm for sodium hypochlorite, ammonium nitrogen (NH 4 + A virus inactivation test was carried out in the same manner as in Example 1, except that the aqueous solution was prepared so that the concentration of -N was 10 ppm.

[0042] The inorganic nitrogen concentrations of the aqueous solutions prepared in the Examples and Comparative Examples were measured by naphthylethylenediamine absorptiometry and indophenol blue method.

[0043] (Virus inactivation test evaluation) FIG. 1 shows the results (virus infectivity) of the virus inactivation test in Examples 1 to 3 and Comparative Examples 1 and 2. In contrast to Comparative Example 1, in Comparative Example 2, in which only sodium hypochlorite (effective chlorine concentration 20 ppm) was used, the virus was hardly reduced. On the other hand, the solution in which nitrate nitrogen in Example 1 and ammonium nitrogen in Example 3 were mixed was able to reduce the number of plaques. The solution in which nitrite nitrogen was mixed in Example 2 was unable to reduce the number of plaques, but this is thought to be because nitrite was unstable and did not oxidize organic matter.

[0044] (Evaluation of the impact of ammonium nitrogen concentration) The virus inactivation tests carried out in Examples 3 to 6 were compared. Table 1 shows the relationship between the monochloramine concentration and the virus reduction rate depending on the concentration of ammonium nitrogen in a mixed solution of sodium hypochlorite (effective chlorine concentration 20 ppm) and ammonium nitrogen. The virus reduction rate was calculated from the ratio of the virus infectivity obtained in each example to the virus infectivity in Comparative Example 1.

[0045] [Table 1]

[0046] NaClO and NH 4 + -N produces monochloramine (NH 2 Cl) is produced, and monochloramine (NH 2 The higher the Cl) concentration, the higher the virus reduction rate, and it can be seen that monochloramine is more effective at inactivating viruses, i.e., its antiviral activity increases. This result suggests that monochloramine effectively acts on the virus.

[0047] When the inorganic nitrogen concentration was measured after adding an aqueous solution of sodium hypochlorite and nitrate nitrogen to a virus suspension, it was confirmed that a small amount of ammonium nitrogen was produced. By mixing with the virus suspension, an oxidation-reduction reaction of organic matter occurs, reducing nitrate nitrogen to ammonium nitrogen, and when ammonium nitrogen is produced, it is highly likely that chloramines (e.g. monochloramine) are also produced, and it is believed that chloramines contributed to the inactivation of the virus.

[0048] (Analysis of inorganic nitrogen in the presence of hypochlorous acid) Figure 3 shows the inorganic nitrogen concentration and pH for each available chlorine concentration when sodium hypochlorite solution and inorganic nitrogen are mixed. In Figure 3(a), the starting form of nitrogen is nitrate nitrogen (NO 3 ― -N), and in Figure 3(b), the starting form of nitrogen is nitrite nitrogen (NO 2 ― ―N), and in Figure 3(c), the starting form is ammonium nitrogen (NH 4 + -N).

[0049] When nitrate nitrogen was mixed with a sodium hypochlorite solution, as shown in Figure 3(a), nitrate nitrogen did not change even in the presence of hypochlorous acid and remained stable.

[0050] When nitrite nitrogen was mixed with sodium hypochlorite solution, the proportion of nitrite nitrogen oxidized to nitrate nitrogen increased as the available chlorine concentration was increased, as shown in Figure 3(b).

[0051] In Figures 3(a) and 3(b), the total amount of inorganic nitrogen measured was about 10 ppm, which was the set value. It was found that inorganic nitrogen could be quantified even in the presence of hypochlorous acid under conditions of 10 ppm inorganic nitrogen and 100 ppm available chlorine concentration.

[0052] When ammonium nitrogen and sodium hypochlorite solution were mixed, as shown in Figure 3(c), the total amount of inorganic nitrogen was about 10 ppm, which was almost the same as the set value, up to an available chlorine concentration of about 50 ppm, but when the available chlorine concentration was 60 ppm or more, the total amount of inorganic nitrogen and monochloramine measured tended to decrease. As the available chlorine concentration increases, the Cl / N ratio increases, and the following reaction proceeds. NH 2 Cl+HOCl→NHCl 2 +H 2 O NHCl 2 +HOCl → NCl 3 +H 2 O

[0053] In addition, the produced dichloramine decomposes via the following reaction: 2N HCl 2 +OH - →N 2 ↑+HOCl+2H + +3Cl - 2N HCl 2 +OH - →N 2 O↑+3H++4Cl -

[0054] At effective chlorine concentrations of 60 ppm or more, the dichloramine produced is N 2 Gas and N 2 It is believed that the inorganic nitrogen concentration in the solution decreased due to decomposition into O gas.

[0055] The amount of nitrate nitrogen produced gradually increased when the available chlorine concentration was between 60 ppm and 100 ppm. In particular, when the available chlorine concentration was between 80 ppm and 100 ppm, the pH was about 5 to 6, so the proportion of hypochlorous acid present as undissociated HClO increased, and the amount of nitrate nitrogen produced also increased.

Claims

1. Bubbling carbon dioxide gas into a disinfectant containing an aqueous solution containing hypochlorous acid and nitrate nitrogen; and The method includes reacting the disinfectant containing the carbon dioxide gas with organic matter containing viruses, bacteria, or both to produce aldehydes and / or organic acids, (A) reducing the nitrate nitrogen with the aldehydes to generate ammonium nitrogen; (B) reducing the organic matter with the organic acid to produce ammonium nitrogen; or (C) Producing ammonium nitrogen by both (A) and (B); and reacting the ammonium nitrogen with the hypochlorous acid to generate chloramines; Further comprising: The disinfectant contains the hypochlorous acid in a ratio such that the effective chlorine concentration is 10 to 100 ppm relative to the nitrate nitrogen concentration of 10 ppm. Disinfection method.

2. 2. The disinfection method of claim 1, wherein the hypochlorous acid is generated from sodium hypochlorite.

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