Silicate measurement reagent, measurement kit, and measurement method

Abstract

A silicate measurement reagent, a measurement kit, and a measurement method. The measurement reagent comprises a reagent 1, a reagent 2, and a reagent 3; the reagent 1 comprises a strongly acidic reagent and a weighting agent, and the mass ratio of the strongly acidic reagent to the weighting agent is (1-10):(2-10); the reagent 2 comprises molybdate and water, and the mass-to-volume ratio (g:mL) of molybdate to water is (1-50):(1-50); the reagent 3 comprises a masking agent, a reducing agent and water, and the mass-to-volume ratio (g:g:ml) of the masking agent to the reducing agent to water is (2-30):(10-50):(1-100). The measurement reagent has no special environmental requirements and no special three-waste pollution, and has low cost, the measurement steps are simple, no interference and more accurate measurement are achieved, the color development time is short, and the mobility is strong.

Description

A detection reagent, detection kit and detection method for silicate Technical Field

[0001] The present invention belongs to the technical field of materials, and in particular relates to a silicate detection reagent, a detection kit and a detection method. Background Art

[0002] Nearly all industrial production processes require water, and water quality has varying impacts on both the process and the product. Silicon content in water is a commonly measured parameter; excessive levels not only increase scale formation but also increase scale hardness. Exceeding the specified concentration of silica in circulating cooling water can easily lead to pipe blockages and even serious accidents. To prevent these accidents, real-time monitoring of the silicon content in industrial water is essential. Excessive silicon content requires silicon removal treatment.

[0003] There are many methods for detecting silicate, including gravimetric, titration, and spectrophotometric methods. Gravimetric methods generally include the double hydrochloric acid evaporation and dehydration method, the single hydrochloric acid evaporation and dehydration method, the chlorination method, the polyethylene oxide coagulation gravimetric method, and the animal gel coagulation gravimetric method. Titration is widely used to determine silica in cement, metallurgy, new inorganic materials, glass products, and their raw materials. Spectrophotometry is widely used in the water quality testing industry. Silicon and phosphate react with molybdate in an acidic environment to form yellow silicomolybdate and heteropolyacid complexes. The addition of citric acid destroys the phosphorus-containing complexes, leaving only the yellow silicon-containing compounds for quantitative determination. High silicon content results in a darker yellow color, the color depth of which is proportional to the effective silicon concentration and conforms to the Lambert-Beer law within a certain range, making it suitable for colorimetric determination. However, this method requires specialized equipment, is costly, cumbersome, requires high professional expertise, and is difficult to use in emergency situations, limiting its application in rapid testing. In order to make up for the shortcomings of the above-mentioned detection, a rapid, accurate, easy-to-carry, simple-to-operate and quick silicate detection kit has been developed in recent years.

[0004] Existing silicate detection kits are all based on the reaction principle of silicomolybdenum yellow or silicomolybdenum blue. In an acidic solution, silicic acid and ammonium molybdate generate yellow silicomolybdenum heteropoly acid (silicomolybdenum yellow method), which is then masked with oxalic acid and reduced to a silicomolybdenum blue complex (silicomolybdenum blue method) with ascorbic acid. Its color depth is proportional to the concentration of effective silicon and conforms to the Lambert-Beer law within a certain range, so that it can be measured by colorimetry. However, in actual operation, it is found that these test kits generally have a high false positive ratio and cannot eliminate the interference of elements such as arsenic and phosphorus. Therefore, improving the measurement sensitivity of the test kit and eliminating the interference of other elements is a key problem that needs to be solved at present. In addition, currently commercially available silicate detection kits or silicate detection test strips all require multi-step operation, are not suitable for field operations, have a short reagent storage period, and are not easy to preserve for a long time. Therefore, it is urgent to improve the assay method of existing silicate.

[0005] Chinese patent publication number CN115931757A provides a reagent combination for silicate determination, a preparation method thereof, and a silicate determination method. These methods utilize non-hazardous raw materials, reducing reagent costs and improving laboratory safety. However, their drawback is that they cannot eliminate interference from elements such as arsenic and phosphorus.

[0006] The Chinese patent with publication number CN114371165A shields the interference of high chroma and reducing substances in high-interference wastewaters such as domestic sewage, landfill leachate, or sewage with excessively high concentrations that can be diluted by providing acidification steps, oxidation steps, and color development steps. However, these are pre-treatment steps for sewage and do not improve the molybdenum blue color development method, nor can they eliminate the interference of elements such as arsenic and phosphorus.

[0007] Summary of the Invention

[0008] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide a detection reagent, a detection kit and a detection method for silicate.

[0009] In one aspect, the present invention provides a silicate detection reagent, comprising reagent 1, reagent 2, and reagent 3;

[0010] The reagent 1 includes a strong acidic reagent and a weighting agent, and the mass ratio of the strong acidic reagent to the weighting agent is (1-10):(2-10);

[0011] The reagent 2 includes molybdate and water, and the mass volume ratio (g:mL) of the molybdate to water is (1-50):(1-50);

[0012] The reagent 3 includes a masking agent, a reducing agent and water, and the mass volume ratio (g:g:mL) of the masking agent, the reducing agent and the water is (2-30):(10-50):(1-100).

[0013] Furthermore, the strong acidic agent is selected from a mixture of one or more of sulfamic acid, citric acid, glycolic acid, benzenesulfonic acid, substituted benzenesulfonic acid, and trichloroacetic acid;

[0014] The molybdate includes one or more of sodium molybdate, ammonium molybdate and potassium molybdate;

[0015] The masking agent includes one or more of citric acid, oxalic acid, tartaric acid, and EDTA;

[0016] The reducing agent includes one or more of ferrous sulfate, ascorbic acid, and tin chloride;

[0017] The weighting agent includes one or more of sodium chloride, sodium sulfate, and potassium sulfate.

[0018] Furthermore, the substituent of the substituted benzenesulfonic acid is selected from C1-C4 alkyl, chlorine, bromine or iodine;

[0019] Preferably, the substituted benzenesulfonic acid includes o-C1-C4 alkylbenzenesulfonic acid, m-C1-C4 alkylbenzenesulfonic acid, p-C1-C4 alkylbenzenesulfonic acid, o-chlorobenzenesulfonic acid, m-chlorobenzenesulfonic acid, p-chlorobenzenesulfonic acid, o-bromobenzenesulfonic acid, m-bromobenzenesulfonic acid, and p-bromobenzenesulfonic acid;

[0020] Preferably, the substituted benzenesulfonic acid is selected from p-toluenesulfonic acid.

[0021] Further, the strong acidic agent is selected from sulfamic acid;

[0022] The molybdate is selected from ammonium molybdate;

[0023] The masking agent is selected from oxalic acid;

[0024] The reducing agent is selected from ascorbic acid;

[0025] The weighting agent is selected from sodium chloride.

[0026] Another aspect of the present invention provides a silicate detection kit, which comprises the above-mentioned detection reagent.

[0027] Furthermore, the kit also includes a standard colorimetric card.

[0028] Another aspect of the present invention provides a method for preparing the above-mentioned detection kit, comprising the steps of:

[0029] Prepare reagent 1: Grind the strong acid reagent and weighting agent thoroughly according to the ratio. The mixed components after grinding should be able to pass through an 80-mesh standard sieve. After packaging, vacuum or seal with inert gas.

[0030] Prepare reagent 2: Dissolve molybdate in water according to the ratio;

[0031] Prepare reagent 3: Dissolve the masking agent and reducing agent in water according to the ratio.

[0032] Furthermore, the reagent 1 is packaged into 0.1 to 0.5 g per tube.

[0033] Furthermore, the preparation method also includes the preparation of a standard colorimetric card: using a silica stock solution to prepare silicate 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 to 5 ml of various silicate standard solutions, adding them to the reagent 1 respectively, shaking well, then adding 1 to 5 drops of reagent 2, shaking well, then adding 1 to 5 drops of reagent 3, shaking well, and coloring for 1 to 5 minutes to obtain a standard colorimetric card.

[0034] The present invention also provides a method for detecting silicate, which adopts the above-mentioned detection kit for detection, comprising the steps of: adding 1 to 5 mL of a water sample to be tested to reagent 1, shaking well, then adding 1 to 5 drops of reagent 2, shaking well, then adding 1 to 5 drops of reagent 3, shaking well, developing color for 1 to 5 minutes, and comparing with a standard colorimetric card to determine the concentration of silicate in the water sample to be tested.

[0035] The test kit of the present invention should be stored in a cool, dry place, preferably below 26°C. If the temperature is above 25°C, unused test strips should be stored in the refrigerator in a fresh-keeping layer and packaged in a light-proof and moisture-proof container. The test kit of the present invention has an effective shelf life of approximately one year.

[0036] The beneficial effects of the present invention are:

[0037] 1. The silicate detection method of the present invention is based on the molybdenum blue method. It is a fast and flexible silicate rapid detection method that does not require instruments and equipment and has low production and use costs. The kit of the present invention has no special environmental requirements, no special three wastes pollution, low cost, simple detection steps and no interference, and the determination is more accurate, the color development time is short and the mobility is strong. Compared with traditional methods or other determination forms, the present invention is more convenient to use 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 inexpensive. It has a wide range of applications and can be used to determine the silicate content in water bodies such as chemical wastewater, surface water, urban sewage recycling-landscape environment water and urban miscellaneous water, especially in the monitoring of environmental silicate.

[0038] 2. The silicate detection kit of the present invention reduces the interference of phosphorus by controlling the acidity and reducing the amount of acid added. When used for silicate detection in water samples, it has strong anti-interference ability, a short detection time of only 5 minutes, and is easy to operate. In addition, the kit is small in size and can be carried around. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG1 is a standard colorimetric card for the detection kit of the present invention;

[0040] FIG2 is the color development result of Example 1;

[0041] FIG3 is the color development result of Example 2;

[0042] FIG4 is the color development result of Example 3;

[0043] FIG5 is the color development result of Example 4. DETAILED DESCRIPTION

[0044] To more clearly understand the present invention, the present invention is further described with reference to the following examples and accompanying drawings. The examples are intended to illustrate the present invention only and are not intended to limit the present invention in any way. In the examples, all raw materials and reagents are commercially available. Experimental methods without specific conditions are conventional methods and conditions well known in the art, or according to the conditions recommended by the instrument manufacturer.

[0045] This embodiment provides a silicate detection kit, which includes reagent 1, reagent 2, reagent 3 and a standard colorimetric card. Reagent 1 includes a strong acid reagent and a weighting agent, and the mass ratio of the strong acid reagent to the weighting agent is (1-10): (2-10); reagent 2 includes molybdate and water, and the mass volume ratio of the molybdate to water (g: mL) is (1-50): (1-50); reagent 3 includes a masking agent, a reducing agent and water, and the mass volume ratio of the masking agent, reducing agent and water (g: g: mL) is (2-30): (10-50): (1-100). The preparation method is as follows:

[0046] Prepare Reagent 1: Grind the strong acidic reagent and the weighting agent thoroughly according to the ratio. The ground mixture can pass through an 80-mesh standard sieve. After packaging, vacuum or seal with inert gas. Preferably, package Reagent 1 into 0.1-0.5g per tube.

[0047] Prepare reagent 2: Dissolve molybdate in water according to the ratio;

[0048] Prepare reagent 3: Dissolve the masking agent and reducing agent in water according to the ratio.

[0049] Preparation of standard colorimetric card: Use silica stock solution to prepare silicate 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 1-5 ml of each silicate standard solution and add it to Reagent 1. Shake well. Then add 1-5 drops of Reagent 2. Shake well. Then add 1-5 drops of Reagent 3. Shake well. After color development for 1-5 minutes, a standard colorimetric card is prepared. If silicate is present in the water, a blue-green color will appear. The depth of the color is related to the silicate concentration in the water. Compare it with the standard colorimetric card to determine the silicate concentration in the water sample.

[0050] Wherein, the strong acidic reagent is selected from a mixture of one or more of sulfamic acid, citric acid, glycolic acid, benzenesulfonic acid, substituted benzenesulfonic acid, and trichloroacetic acid; preferably, the substituent of the substituted benzenesulfonic acid is selected from C1-C4 alkyl, chlorine, bromine or iodine; preferably, the substituted benzenesulfonic acid includes o-C1-C4 alkylbenzenesulfonic acid, m-C1-C4 alkylbenzenesulfonic acid, p-C1-C4 alkylbenzenesulfonic acid, o-chlorobenzenesulfonic acid, m-chlorobenzenesulfonic acid, p-chlorobenzenesulfonic acid, o-bromobenzenesulfonic acid, m-bromobenzenesulfonic acid, and p-bromobenzenesulfonic acid; preferably, the substituted benzenesulfonic acid is selected from p-toluenesulfonic acid.

[0051] The molybdate includes one or more of sodium molybdate, ammonium molybdate and potassium molybdate.

[0052] The masking agent includes one or more of citric acid, oxalic acid, tartaric acid, and EDTA.

[0053] The reducing agent includes one or more of ferrous sulfate, ascorbic acid, and tin chloride.

[0054] The weighting agent includes one or more of sodium chloride, sodium sulfate, and potassium sulfate. The addition of the weighting agent facilitates the weighing of the powder.

[0055] Example 1

[0056] This embodiment provides a silicate detection kit, which includes reagent 1, reagent 2, reagent 3 and a standard colorimetric card.

[0057] Prepare Reagent 1: Add 2 g of aminosulfonic acid and 8 g of sodium chloride to a mortar and pestle. Grind thoroughly until all the raw materials pass through an 80-mesh standard sieve. Then divide the mixture into 0.2 g tubes and seal them with vacuum or inert gas.

[0058] Prepare reagent 2: Dissolve 0.5 g of ammonium molybdate in 5 mL of water.

[0059] Prepare reagent 3: Dissolve 1 g of oxalic acid and 4 g of ascorbic acid in 10 mL of water.

[0060] Silicate standard solutions with concentrations of 0 mg / L, 0.1 mg / L, 0.2 mg / L, 0.5 mg / L, 1 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 were prepared using silica stock solution. 1-5 ml of each silicate standard solution was added to reagent 1, shaken well, and then 1-5 drops of reagent 2 were added, shaken well, and then 1-5 drops of reagent 3 were added, shaken well, and color was developed for 1-5 minutes to prepare a standard colorimetric card. If silicate is present in the water, a blue-green color will appear, and the depth of the color is related to the concentration of silicate in the water.

[0061] The prepared standard colorimetric card is shown in FIG1 , and the color development result is shown in FIG2 .

[0062] Example 2

[0063] This embodiment provides a detection kit, which includes reagent 1, reagent 2, and reagent 3.

[0064] Prepare Reagent 1: Add 2 g of aminosulfonic acid and 8 g of sodium chloride to a mortar and pestle. Grind thoroughly until all the raw materials pass through an 80-mesh standard sieve. Then divide the mixture into 0.2 g tubes and seal them with vacuum or inert gas.

[0065] Prepare reagent 2: Dissolve 0.5 g of ammonium molybdate in 5 mL of water.

[0066] Prepare reagent 3: Dissolve 4 g of ascorbic acid in 10 mL of water.

[0067] Sodium dihydrogen phosphate stock solution was used to prepare phosphate standard solutions at concentrations of 0 mg / L, 0.5 mg / L, 1 mg / L, 2 mg / L, 4 mg / L, 8 mg / L, 15 mg / L, 30 mg / L, 60 mg / L, 120 mg / L, and 250 mg / L. 1-5 ml of each phosphate standard solution was added to Reagent 1 and shaken well. Then, 1-5 drops of Reagent 2 were added, shaken well, and then 1-5 drops of Reagent 3 were added, shaken well, and color was developed for 1-5 minutes. The results are shown in Figure 3. This indicates that without the addition of a masking agent, the kit cannot eliminate interference from elements such as phosphorus.

[0068] Example 3

[0069] This embodiment provides a detection kit, which includes reagent 1, reagent 2, and reagent 3.

[0070] Prepare Reagent 1: Add 2 g of aminosulfonic acid and 8 g of sodium chloride to a mortar and pestle. Grind thoroughly until all the raw materials pass through an 80-mesh standard sieve. Then divide the mixture into 0.2 g tubes and seal them with vacuum or inert gas.

[0071] Prepare reagent 2: Dissolve 0.5 g of ammonium molybdate in 5 mL of water.

[0072] Prepare reagent 3: Dissolve 1 g of oxalic acid and 4 g of ascorbic acid in 10 mL of water.

[0073] Sodium dihydrogen phosphate stock solution was used to prepare phosphate standard solutions with concentrations of 0 mg / L, 0.1 mg / L, 0.2 mg / L, 0.5 mg / L, 1 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, and 500 mg / L. 1-5 ml of each phosphate standard solution was added to Reagent 1 and shaken. Then, 1-5 drops of Reagent 3 were added and shaken. Then, 1-5 drops of Reagent 2 were added and shaken. After color development for 1-5 minutes, the results are shown in Figure 4. Changing the order of adding the reagents could not eliminate the interference of elements such as phosphorus.

[0074] Example 4

[0075] This embodiment provides a detection kit, which includes reagent 1, reagent 2, and reagent 3.

[0076] Prepare reagent 1: Add 0.1 M hydrochloric acid solution to each tube.

[0077] Prepare reagent 2: Dissolve 0.5 g of ammonium molybdate in 5 mL of water.

[0078] Prepare reagent 3: Dissolve 1 g of oxalic acid and 4 g of ascorbic acid in 10 mL of water.

[0079] Detection: Silicate standard solutions of varying concentrations were prepared using silica stock solution. 1-5 ml of each silicate standard solution was added to Reagent 1, shaken well, followed by 1-5 drops of Reagent 2, shaken well, and then 1-5 drops of Reagent 3, shaken well. After color development for 1-5 minutes, the results are shown in Figure 5. This indicates that other acids can also meet the requirements, but sulfuric acid, hydrochloric acid, and other liquid acids are highly corrosive and difficult to transport, so liquid acids are not used in this invention.

[0080] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A detection reagent for silicate radicals, characterized in that, The detection reagent includes Reagent 1, Reagent 2, and Reagent 3; Reagent 1 includes a strong acid reagent and a weighting agent, and the mass ratio of the strong acid reagent to the weighting agent is (1 - 10):(2 - 10); Reagent 2 includes molybdate and water, and the mass - to - volume ratio (g:mL) of the molybdate to water is (1 - 50):(1 - 50); Reagent 3 includes a masking agent, a reducing agent, and water, and the mass - to - volume ratio (g:g:mL) of the masking agent, the reducing agent to water is (2 - 30):(10 - 50):(1 - 100).

2. The detection reagent according to claim 1, wherein, The strong acid reagent is selected from one or a mixture of more than one of sulfamic acid, citric acid, glycolic acid, benzenesulfonic acid, substituted benzenesulfonic acid, trichloroacetic acid; The molybdate includes one or more of sodium molybdate, ammonium molybdate, potassium molybdate; The masking agent includes one or more of citric acid, oxalic acid, tartaric acid, EDTA; The reducing agent includes one or more of ferrous sulfate, ascorbic acid, stannous chloride; The weighting agent includes one or more of sodium chloride, sodium sulfate, potassium sulfate; 3. The detection reagent according to claim 2, wherein The substituent of the substituted benzenesulfonic acid is selected from C1 - C4 alkyl, chlorine, bromine, or iodine.

4. The detection reagent according to claim 2, wherein The substituted benzenesulfonic acid includes o - C1 - C4 alkylbenzenesulfonic acid, m - C1 - C4 alkylbenzenesulfonic acid, p - C1 - C4 alkylbenzenesulfonic acid, o - chlorobenzenesulfonic acid, m - chlorobenzenesulfonic acid, p - chlorobenzenesulfonic acid, o - bromobenzenesulfonic acid, m - bromobenzenesulfonic acid, p - bromobenzenesulfonic acid; The substituted benzenesulfonic acid is selected from p - toluenesulfonic acid.

5. The detection reagent according to claim 1, wherein The strong acid reagent is selected from sulfamic acid; The molybdate is selected from ammonium molybdate; The masking agent is selected from oxalic acid; The reducing agent is selected from ascorbic acid; The weighting agent is selected from sodium chloride.

6. A detection kit for silicate radicals, characterized in that, The kit includes the detection reagent described in claim 1.

7. The detection kit according to claim 6, characterized in that, The kit further includes a standard colorimetric card.

8. The preparation method of the detection kit according to claim 6, characterized in that, Including steps: Preparing Reagent 1: According to the ratio described in claim 1, the strong acid reagent and the weighting agent are fully ground, and the ground mixed components can pass through an 80 - mesh standard sieve. After sub - packaging, it is sealed by vacuum pumping or passing an inert gas; Preparing Reagent 2: According to the ratio described in claim 1, the molybdate is dissolved in water; Preparing Reagent 3: According to the ratio described in claim 1, the masking agent and the reducing agent are dissolved in water.

9. The preparation method according to claim 8, characterized in that, Reagent 1 is sub - packaged into 0.1 - 0.5 g per tube.

10. The preparation method according to claim 8, characterized in that, The preparation method further includes the preparation of a standard colorimetric card: Using a silica stock solution, prepare silicate 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, 1000 mg / L. Take 1 - 5 ml of each silicate standard solution, add them to Reagent 1 described in claim 7 respectively, shake well, then add 1 - 5 drops of Reagent 2, shake well, then add 1 - 5 drops of Reagent 3, shake well. After color development for 1 - 5 min, the standard colorimetric card is prepared.

11. A method for detecting silicate radicals, characterized in that, Detection is carried out using the detection kit described in claim 6, including the steps of: adding 1-5 mL of the water sample to be tested into reagent 1, shaking well, then adding 1-5 drops of reagent 2, shaking well, then adding 1-5 drops of reagent 3, shaking well, after color development for 1-5 minutes, comparing with the standard colorimetric card to determine the concentration of silicate in the water sample to be tested.

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