Kit for detecting trace nitrite, detection system and related method therefor

Abstract

A kit for detecting trace nitrite, a detection system and a related method. The kit comprises a nitrite detection reagent, the nitrite detection reagent comprising the following component raw materials in parts by mass: 0.5-50.0 parts of sulfanilic acid, 0.1-20.0 parts of hydrochloride naphthodiamide, 10.0-90.0% of a weighting agent, 1.0-60.0 parts of a masking agent and 0-10.0 parts of an accelerator. Compared with conventional methods or other measurement forms, the kit, the detection system and the related method offer more convenient use, easy formulation, safe and simple operation and low cost, and do not require specialized technicians for measurement. Reagents used in the kit are all common chemical reagents, which are safe, reliable and low in price.

Description

A kit for detecting trace nitrite, a detection system and related methods Technical Field

[0001] The present invention relates to the field of material technology, and in particular to a kit for detecting trace nitrite, a detection system and related methods. Background Art

[0002] Nitrite is a highly toxic substance, and detecting the presence of nitrite in water is of great significance. If nitrite in water enters the human blood circulation, it can oxidize normal hemoglobin (ferric hemoglobin) into methemoglobin, causing hemoglobin to lose its ability to transport oxygen in the body and cause human poisoning. In addition, nitrite can react with secondary amines to generate carcinogenic nitrosamines, so detecting nitrite in water is of special significance and value. In addition, nitrite is easily affected by microorganisms in water and is very unstable. Based on this characteristic, the detection of nitrite content in water should be carried out on-site, that is, water samples should be taken and tested immediately at any time to detect the true situation of the water samples on site.

[0003] In recent years, numerous methods for determining nitrite have been reported both domestically and internationally, including spectrophotometry, polarography, flow injection, fluorescence, ion chromatography, and potentiometry. These methods offer advantages such as high sensitivity and accuracy, but they also suffer from high reagent consumption, short shelf life of colorants, and cumbersome and time-consuming procedures, making them suitable only for laboratory use. Furthermore, the need for instrumentation and specialized testing hinders widespread adoption and on-site determination, limiting their application in rapid testing.

[0004] In view of the current prevalence and severity of nitrite residues, there is an urgent need for a convenient, fast, easy-to-operate and low-cost nitrite detection kit, which is not only conducive to on-site determination by ordinary people, but also can be used as a basic judgment by quality inspection agencies.

[0005] Summary of the Invention

[0006] In order to solve the above technical problems, the present invention provides a kit for detecting trace nitrite, a detection system and related methods.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] The first aspect of the present invention provides a kit for detecting trace nitrite, which includes a nitrite detection reagent, which includes the following component raw materials in parts by mass: 0.5 to 50.0 parts of p-aminobenzenesulfonic acid, 0.1 to 20.0 parts of naphthylethylenediamine hydrochloride, 10.0 to 90.0% of a weighting agent, 1.0 to 60.0 parts of a masking agent, and 0 to 10.0 parts of an accelerating agent.

[0009] Preferably, the weighting agent includes at least one of sodium chloride, sodium sulfate, and potassium sulfate.

[0010] Preferably, the masking agent includes at least one of potassium sodium tartrate, citric acid, oxalic acid, tartaric acid, EDTA, and EDTA-Na.

[0011] Preferably, the speed increasing agent is at least one of manganese sulfate and manganese chloride.

[0012] Preferably, the kit is stored in a cool and dry place at a temperature below 26°C.

[0013] The second aspect of the present invention provides a method for preparing the kit for detecting trace nitrite, comprising the following steps: taking the raw materials of each component according to a ratio, fully grinding the raw materials of each component until they can pass through an 80-mesh standard sieve, then packaging them into 0.1g to 0.5g tubes, and then vacuuming or sealing with an inert gas to obtain the kit for detecting trace nitrite.

[0014] The third aspect of the present invention provides the use of the above-mentioned kit for detecting trace nitrite in the field of water quality detection of chemical wastewater, surface water, urban wastewater recycling, landscape water and urban miscellaneous water.

[0015] A fourth aspect of the present invention provides a trace nitrite detection system, which includes the above-mentioned kit for detecting trace nitrite and a standard colorimetric card; wherein the standard colorimetric card is prepared by the following steps: using a 1000 mg / L nitrite stock solution to prepare nitrite standard solutions with concentrations of 0 mg / L, 2.0 mg / L, 5.0 mg / L, 10.0 mg / L, 20 mg / L, 50 mg / L, 100 mg / L, 200 mg / L, 500 mg / L, and 1000 mg / L, taking 1 mL to 5 mL of each of the nitrite standard solutions, adding solid reagents respectively, shaking well, and coloring for 1 to 5 minutes until the color is basically stable, thereby obtaining a standard colorimetric card.

[0016] The fifth aspect of the present invention provides an application method of the trace nitrite detection system, comprising: adding 1 mL to 5 mL of the water sample to be tested to the kit for detecting trace nitrite, shaking well, and comparing the pink color depth of the kit with the standard colorimetric card to determine the concentration of nitrite in the water sample to be tested.

[0017] A sixth aspect of the present invention provides the application of the above-mentioned trace nitrite detection system in the field of water quality detection of chemical wastewater, surface water, urban wastewater recycling, landscape water and urban miscellaneous water.

[0018] Compared with the existing technology, the technical solution provided by the present invention has at least the following advantages:

[0019] The present invention provides a rapid and flexible nitrite detection test kit and determination method that does not require any instruments or equipment and has low production and use costs. The detection principle of the detection kit for nitrite in water provided by the present invention is as follows: nitrite undergoes a diazotization reaction with p-aminobenzenesulfonic acid under acidic conditions to generate a diazonium salt, and this diazonium salt undergoes a coupling reaction with a naphthylethylenediamine hydrochloride reagent to generate a purple-red azo compound. The depth of its color is proportional to the nitrite content in the sample solution and can be determined visually by colorimetry. The kit does not require special environmental requirements, can be stored for a long time and remain stable, is free of special three wastes pollution, is low in cost, has simple detection steps without interference, and is more accurate in determination, with a short color development time and strong portability. Compared with traditional methods or other determination forms, the present invention is more convenient to use, easy to prepare, safe and simple to operate, low in cost, and does not require specialized technicians to perform the determination. The reagents used in the present invention are all common chemical reagents, which are safe, reliable and low in price. It has a wide range of applications and can be used to determine the nitrite content in water bodies such as chemical wastewater, surface water, urban sewage recycling - landscape water and urban miscellaneous water, especially in the monitoring of environmental nitrite.

[0020] The device has the advantages of 1) water sample testing can be completed in just 5 minutes; 2) simple operation; 3) easy to carry, the size of a noodle, and can be carried around; 4) strong anti-interference ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG1 is a standard colorimetric card provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The inventors discovered that Chinese Patent Publication No. CN1191468C discloses an apparatus for measuring nitrite in water, specifically a rapid colorimetric nitrite measurement tube comprising a vacuum glass tube of uniform cross-section. However, a disadvantage of the vacuum glass tube is that the test solution contained within the tube has a relatively short retention time.

[0023] Chinese patent publication number CN100487436C discloses a rapid nitrite assay kit and its application, addressing issues such as the instrument-intensive, labor-intensive nature of nitrite testing and its unsuitability for on-site determination. However, the kit requires a reaction column containing enrichment material, making the process relatively cumbersome. Furthermore, the reagents are all liquid, resulting in a short shelf life.

[0024] Chinese patent publication number CN109827921A discloses a nitrite content determination reagent tablet. This tablet structure improves and addresses some of the shortcomings and issues of methods using liquid reagents. However, tableting requires weighing two powders separately, which is a cumbersome process.

[0025] It can be seen that currently available nitrite detection kits or nitrite detection test strips require multiple steps, for example, are not suitable for field work, and the reagents have a short shelf life and are not easy to store for a long time. Therefore, there is an urgent need to improve the determination method of nitrite.

[0026] In view of this, the first aspect of the present invention provides a kit for detecting trace nitrite, the kit comprising a nitrite detection reagent, the nitrite detection reagent comprising the following component raw materials in parts by mass: 0.5 to 50.0 parts of p-aminobenzenesulfonic acid, 0.1 to 20.0 parts of naphthylethylenediamine hydrochloride, 10.0 to 90.0% weighting agent, 1.0 to 60.0 parts of masking agent, and 0 to 10.0 parts of speed increasing agent.

[0027] The second aspect of the present invention provides a method for preparing the kit for detecting trace nitrite, comprising the following steps: taking the raw materials of each component according to a ratio, fully grinding the raw materials of each component until they can pass through an 80-mesh standard sieve, then packaging them into 0.1g to 0.5g tubes, and then vacuuming or sealing with an inert gas to obtain the kit for detecting trace nitrite.

[0028] The third aspect of the present invention provides the use of the above-mentioned kit for detecting trace nitrite in the field of water quality detection of chemical wastewater, surface water, urban wastewater recycling, landscape water and urban miscellaneous water.

[0029] A fourth aspect of the present invention provides a trace nitrite detection system, which includes the above-mentioned kit for detecting trace nitrite and a standard colorimetric card; wherein the standard colorimetric card is prepared by the following steps: using a 1000 mg / L nitrite stock solution to prepare nitrite standard solutions with concentrations of 0 mg / L, 2.0 mg / L, 5.0 mg / L, 10.0 mg / L, 20 mg / L, 50 mg / L, 100 mg / L, 200 mg / L, 500 mg / L, and 1000 mg / L, taking 1 mL to 5 mL of each of the nitrite standard solutions, adding solid reagents respectively, shaking, and coloring for 1 to 5 minutes until the color is basically stable, to obtain a standard colorimetric card.

[0030] The fifth aspect of the present invention provides an application method of the trace nitrite detection system, comprising: adding 1 mL to 5 mL of the water sample to be tested to the kit for detecting trace nitrite, shaking well, and comparing the pink color depth of the kit with the standard colorimetric card to determine the concentration of nitrite in the water sample to be tested.

[0031] A sixth aspect of the present invention provides the application of the above-mentioned trace nitrite detection system in the field of water quality detection of chemical wastewater, surface water, urban wastewater recycling, landscape water and urban miscellaneous water.

[0032] The present invention is described in detail below with reference to specific embodiments.

[0033] The kit for detecting trace nitrite comprises a nitrite detection reagent, which specifically comprises the following raw materials: 0.5g to 50.0g of p-aminobenzenesulfonic acid, 0.1g to 20.0g of naphthylethylenediamine hydrochloride, 10.0g to 90.0g of a weighting agent, 1.0g to 60.0g of a masking agent, and 0 to 10.0g of an accelerating agent.

[0034] Wherein, the weighting agent includes at least one of sodium chloride, sodium sulfate and potassium sulfate.

[0035] The masking agent includes at least one of potassium sodium tartrate, citric acid, oxalic acid, tartaric acid, EDTA, and EDTA-Na.

[0036] The speed increasing agent is at least one of manganese sulfate and manganese chloride.

[0037] Example:

[0038] Recipe 1: Prepare the raw materials in the following proportions: 25.0g p-aminobenzenesulfonic acid, 10.0g naphthylethylenediamine hydrochloride, 50.0g sodium sulfate, and 30.0g oxalic acid.

[0039] Recipe 2: Prepare the raw materials in the following proportions: 0.5 g p-aminobenzenesulfonic acid, 0.1 g naphthylethylenediamine hydrochloride, 10.0 g sodium chloride, 1.0 g citric acid, and 10.0 g manganese sulfate.

[0040] Recipe 3: Prepare the raw materials in the following proportions: 50.0 g of p-aminobenzenesulfonic acid, 20.0 g of naphthylethylenediamine hydrochloride, 90.0 g of a mixture of sodium sulfate and potassium sulfate, 60.0 g of a mixture of EDTA-Na and tartaric acid, and 5.0 g of manganese chloride.

[0041] Choose any recipe, add the materials shown in the recipe into a mortar, grind thoroughly until all the raw materials can pass through an 80-mesh standard sieve, then package into 0.1-0.5 g per tube, and vacuum or seal with inert gas.

[0042] Add the above materials into a mortar and grind them thoroughly until all the raw materials can pass through an 80-mesh standard sieve. Then package them into tubes of 0.1 to 0.5 grams each and vacuum-pack them or seal them with inert gas.

[0043] Preparation of standard colorimetric card: Use nitrite stock solution (1000 mg / L) to prepare nitrite standard solutions with concentrations of 0 mg / L, 2.0 mg / L, 5.0 mg / L, 10.0 mg / L, 20 mg / L, 50 mg / L, 100 mg / L, 200 mg / L, 500 mg / L, and 1000 mg / L. Take 1 to 5 mL of various nitrite standard solutions, add solid reagents respectively, shake well, and color for 1 to 5 minutes until the color is basically stable to prepare a standard colorimetric card, as shown in Figure 1. It can be seen that as the concentration of the nitrite standard solution increases, the color gradually darkens from pink to purple, and then to orange.

[0044] When water quality testing is required, add 1 to 5 mL of the water sample to be tested into the reagent and shake well (1 to 5 minutes). If nitrite exists in the water, pink will appear. The depth of the color is related to the concentration of nitrite in the water.

[0045] In summary, the detection principle of the detection kit for nitrite in water provided by the present invention is: nitrite undergoes a diazotization reaction with p-aminobenzenesulfonic acid under acidic conditions to generate a diazonium salt, and this diazonium salt undergoes a coupling reaction with a naphthylethylenediamine hydrochloride reagent to generate a purple-red azo compound. The depth of its color is proportional to the nitrite content in the sample liquid and can be determined by visual colorimetry. The present invention includes a nitrite rapid detection reagent and a preparation method thereof, a nitrite rapid test kit and a nitrite rapid determination method. The present invention is characterized by being independent of instruments, low cost, convenient, fast, and flexible. This method has the advantages of being smart and stable, simple in actual operation, and having few laboratory environmental pollution advantages and is therefore widely used.

[0046] Those skilled in the art will appreciate that the above-described embodiments are specific examples for implementing the present application, and that in actual applications, various changes in form and detail may be made thereto without departing from the spirit and scope of the present application. Any person skilled in the art may make changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be subject to the scope defined in the claims.

Claims

1. A kit for detecting trace nitrite, characterized in that: The kit includes a nitrite detection reagent, and the nitrite detection reagent includes the following component raw materials in parts by mass: 0.5 to 50.0 parts of p-aminobenzenesulfonic acid, 0.1 to 20.0 parts of naphthylethylenediamine hydrochloride, 10.0 to 90.0% of a weighting agent, 1.0 to 60.0 parts of a masking agent, and 0 to 10.0 parts of a speed increasing agent.

2. The kit for detecting trace nitrite according to claim 1, characterized in that: The weighting agent includes at least one of sodium chloride, sodium sulfate and potassium sulfate.

3. The kit for detecting trace nitrite according to claim 1, characterized in that: The masking agent includes at least one of potassium sodium tartrate, citric acid, oxalic acid, tartaric acid, EDTA, and EDTA-Na.

4. The kit for detecting trace nitrite according to claim 1, characterized in that: The speed increasing agent is at least one of manganese sulfate and manganese chloride.

5. The kit for detecting trace nitrite according to claim 1, characterized in that: The test kit should be stored in a cool and dry place at a temperature below 26°C.

6. The method for preparing a kit for detecting trace nitrite according to any one of claims 1 to 5, characterized in that: The following steps are involved: The raw materials of each component are taken according to the ratio, and the raw materials of each component are fully ground until they can pass through an 80-mesh standard sieve, and then packaged into 0.1g to 0.5g tubes, and then vacuumed or sealed with inert gas to obtain the kit for detecting trace nitrite.

7. Application of the kit for detecting trace nitrite as claimed in any one of claims 1 to 5 in the field of water quality detection of chemical wastewater, surface water, urban sewage recycling, landscape water and urban miscellaneous water.

8. A trace nitrite detection system, characterized in that: The system comprises a kit for detecting trace nitrite as claimed in any one of claims 1 to 5, and a standard colorimetric card; The standard colorimetric card is prepared by the following steps: using 1000 mg / L nitrite stock solution to prepare nitrite standard solutions with concentrations of 0 mg / L, 2.0 mg / L, 5.0 mg / L, 10.0 mg / L, 20 mg / L, 50 mg / L, 100 mg / L, 200 mg / L, 500 mg / L and 1000 mg / L respectively, taking 1 mL to 5 mL of various nitrite standard solutions, adding solid reagents respectively, shaking well, and coloring for 1 to 5 minutes until the color is basically stable, so as to obtain a standard colorimetric card.

9. The application method of the trace nitrite detection system according to claim 8, characterized in that: include: Add 1 mL to 5 mL of the water sample to be tested into the kit for detecting trace nitrite, shake well, and compare the pink color depth of the kit with the standard colorimetric card to determine the concentration of nitrite in the water sample to be tested.

10. Application of the trace nitrite detection system as claimed in claim 8 in the field of water quality detection of chemical wastewater, surface water, urban wastewater recycling, landscape water and urban miscellaneous water.

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