Preparation method and application of base paper for peracetic acid test strip

Abstract

This invention relates to the field of peracetic acid detection, and addresses the problem of slow color development in peracetic acid test strips by providing a method for preparing the base paper for peracetic acid test strips and its application. The preparation method involves: disintegrating fibers, adding titanium dioxide powder and 0.1-3% (by weight of the fibers) of β-cyclodextrin sulfate, and milling to obtain a pulp with a pulp degree of 20-24°SR; the fibers include hardwood pulp and coconut fiber; filtering and forming the pulp through a forming wire, and drying to obtain the base paper. The application involves using the prepared base paper to make peracetic acid test strips for detecting peracetic acid concentration. This invention, through the selection of optimal fiber raw materials and the addition of β-cyclodextrin sulfate, produces a peracetic acid test strip with sensitive color development.

Description

Technical Field

[0001] This invention relates to the field of peracetic acid detection, and in particular to a method for preparing the base paper for a peracetic acid detection test strip and its application. Background Technology

[0002] With the widespread use of peracetic acid as a novel disinfectant, traditional peracetic acid analysis methods, such as titration, are cumbersome, time-consuming, and require highly skilled personnel, making them unsuitable for some users. However, the concentration of disinfectant used or remaining at a certain level is a crucial aspect to monitor in safe production processes. The emergence of peracetic acid test strips has largely solved this problem. Furthermore, industrial peracetic acid is typically a 18-23% solution containing water, hydrogen peroxide, and acetic acid. Hydrogen peroxide significantly interferes with the determination of peracetic acid.

[0003] Patent CN87106131 discloses a peracetic acid test strip and its preparation method, wherein the ratio of qualitative filter paper to potassium iodide is 1:0.1-0.5, and the pH value is 7-9. In the iodometric determination, these two substances undergo the same reaction, differing only in their reaction rates. Based on this characteristic, the patent employs a method that allows for the separation of the substances by controlling the reaction time, thus enabling the individual determination of peracetic acid content. However, the color development time of this test strip is relatively long, making rapid reading impossible. Therefore, an ideal solution is needed. Summary of the Invention

[0004] To overcome the problem of slow color development in peracetic acid test strips, this invention provides a method for preparing the base paper for peracetic acid test strips and its application. This invention obtains color-sensitive peracetic acid test strips by selecting superior fiber raw materials and adding β-cyclodextrin sulfate, which can develop stable readings within 60 seconds.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for preparing the base paper for a peracetic acid test strip includes the following steps:

[0007] (1) After the fibers are loosened, titanium dioxide powder and β-cyclodextrin sulfate accounting for 0.1-3% of the fiber mass are added, and the pulp is polished to obtain a pulp with a pulp degree of 20-24°SR; the fibers include hardwood pulp and coconut shell fiber;

[0008] (2) The paper is formed by filtering water through a forming mesh and then dried to obtain the base paper.

[0009] Preferably, the fiber contains a mixture of hardwood pulp and coconut shell fiber in a mass ratio of (60-80):(20-40). Hardwood pulp has a denser tissue structure than softwood pulp and contains more impurities. Its lignin content is lower than that of softwood pulp, generally between 20-24%, and its pentosaccharide content is higher, generally between 21-24%. Coconut shell fiber is mainly composed of cellulose, lignin, hemicellulose, and pectin, with cellulose accounting for 46%-63%, lignin 31%-36%, hemicellulose 0.15%-0.25%, pectin 3%-4%, and other impurities, sugars, and minerals. Coconut shell fiber has a high cellulose content and a low hemicellulose content, resulting in excellent mechanical properties, moisture resistance, and heat resistance. Coconut shell fiber is pale yellow, generally 100-450 μm in diameter, 10-25 cm in length, and has a density of 1.12 g / cm³. 3 Coconut shell fibers are long fibers with a multicellular aggregate structure. A bundle of coconut shell fibers contains 30-300 or even more fiber cells and is round in shape. From the perspective of aggregate structure, the crystallized cellulose in coconut shell fibers is helical and potentially contained in amorphous lignin and hemicellulose.

[0010] Preferably, a dispersant and a wet strength agent are added during fiber disintegration. The dispersant is polyacrylamide or vinyl bis-stearamide. The wet strength agent is one of thermosetting urea-formaldehyde resin (UF), melamine-formaldehyde resin (MF), or polyamide-epoxychloropropane resin.

[0011] Preferably, the mass of β-cyclodextrin sulfate is 0.5-1% of the fiber mass.

[0012] Preferably, the amount of titanium dioxide powder used is 0.01-0.1% of the fiber mass.

[0013] Preferably, the base paper has a pore size of 20-40 μm and a porosity of 50-60%.

[0014] The present invention also provides the application of the base paper prepared by the above preparation method, wherein the base paper is soaked in a mixed solution, taken out and dried to obtain peracetic acid test paper.

[0015] Preferably, the base paper is soaked in ethanol and water in sequence, then removed, dried, and then soaked in a mixed solution.

[0016] Preferably, the mixture is an aqueous solution of a colorimetric reagent, a pH buffer, and a dispersant; the colorimetric reagent is a mixture of tetramethylbenzidine sulfate and ferrous salt.

[0017] As a preferred method, the peracetic acid test strip is used as follows: immerse the peracetic acid test strip in the sample to be tested, remove it after 1-10 seconds, and the color will stabilize after 40-60 seconds. Compare the color of the test strip with the standard color chart to read the concentration data of peracetic acid.

[0018] Preferably, the standard colorimetric card is prepared by the following method: a peracetic acid standard solution of known concentration is prepared with water; the peracetic acid test paper described in any of the above-mentioned methods is immersed in the standard solution; after being taken out and the color of the test paper is stabilized, the corresponding standard color is found on the Pantone color chart; thus, the standard color of the peracetic acid standard solution of known concentration is obtained; and a standard colorimetric card of the corresponding known concentration is prepared based on the color value of the standard color corresponding to each known concentration.

[0019] Therefore, the beneficial effects of the present invention are as follows: (1) Using hardwood pulp and coconut fiber as pulp fiber raw materials, the coarse and short hardwood pulp combined with the crystallized spiral cellulose of coconut fiber produces a base paper with many pores that is not easy to collapse, absorbs water quickly, and can retain a large amount of liquid. (2) Adding β-cyclodextrin sulfate during pulping improves the adsorption of the color developer to the base paper and further improves the water absorption performance of the base paper. Under the combined effect, the color development and stabilization time of the test paper is accelerated. Detailed Implementation

[0020] The technical solution of the present invention will be further described below through specific embodiments.

[0021] In this invention, unless otherwise specified, the raw materials and equipment used are commercially available or commonly used in the art. The methods in the embodiments, unless otherwise specified, are conventional methods in the art. Unless otherwise specified, all parts are parts by weight, temperatures are expressed in °C or at ambient temperature, and pressures are at or near atmospheric pressure. Various variations and combinations of reaction conditions (e.g., component concentrations, required solvents, solvent mixtures, temperature, pressure, and other reaction ranges) and conditions that can be used to optimize the purity and yield of the product obtained by the method exist, and only reasonable routine experiments are needed to optimize such method conditions.

[0022] Example

[0023] I. Preparation method of base paper for peracetic acid test strips

[0024] Includes the following steps:

[0025] (1) By weight, 60-80 parts of hardwood pulp and 20-40 parts of coconut shell fiber are dispersed in water, 1-2 parts of dispersant (polyacrylamide or vinyl bis-stearamide) and 1-2 parts of wet strength agent (thermosetting urea-formaldehyde resin, melamine-formaldehyde resin or polyamide epichlorohydrin resin) are added for dissolution, 0.01-0.1% of titanium dioxide powder by fiber weight and 0.1-3% (more preferably 0.5-1%) of β-cyclodextrin sulfate by fiber weight are added, and the pulp is polished to obtain pulp with a pulp degree of 20-24°SR;

[0026] (2) The paper is formed by filtering water through a forming screen and then dried to obtain the base paper. The pore size of the base paper is 20-40 μm, and the porosity is 50-60%.

[0027] II. Application of base paper in the preparation of peracetic acid test strips

[0028] Includes the following steps:

[0029] (1) The raw paper obtained in the first step is soaked in ethanol and water in sequence, and then taken out and dried;

[0030] (2) Soak the base paper in the mixture for 5-10 minutes, take it out, vacuum dry it, cut it to the required size, and paste it on the base plate to obtain the peracetic acid test paper; the mixture is an aqueous solution of colorimetric reagent, pH buffer and dispersant; the colorimetric reagent is a mixture of 0.1-0.5 g / L tetramethylbenzidine sulfate and 10-20 g / L ferrous salt, the pH buffer is a mixture of 5-10 g / L potassium dihydrogen phosphate and 15-35 g / L dipotassium hydrogen phosphate, and the dispersant is 4-15 g / L polyethylene glycol.

[0031] III. Use of Peracetic Acid Test Strips

[0032] Includes the following steps:

[0033] Immerse the peracetic acid test strip prepared in step 2 into the sample to be tested, remove it after 1-10 seconds, remove excess solution, and the color will stabilize after 40-60 seconds. Compare the color of the test strip with the standard colorimetric card to read the concentration data of peracetic acid.

[0034] The standard colorimetric card is prepared by the following method: a peracetic acid standard solution of known concentration is prepared with water; the peracetic acid test paper described in any of the above-mentioned methods is immersed in the standard solution; after it is taken out and the color of the test paper is stabilized, the corresponding standard color is found on the Pantone color chart; thus, the standard color of the peracetic acid standard solution of known concentration is obtained; and a standard colorimetric card of the corresponding known concentration is prepared based on the color value of the standard color corresponding to each known concentration.

[0035] Example 1

[0036] A method for preparing the base paper for a peracetic acid test strip, comprising the following steps:

[0037] (1) By mass, 70 parts of hardwood pulp and 30 parts of coconut fiber are dispersed in water, 1 part of dispersant polyacrylamide and 1 part of wet strength agent thermosetting urea-formaldehyde resin are added for dissolution, and after dissolution, 0.01% of the fiber mass of titanium dioxide powder and 1% of the fiber mass of β-cyclodextrin sulfate (synthesized with sulfur trioxide pyridine complex as sulfate esterification reagent according to existing technology) are added, and the pulp is polished to obtain pulp with a pulp degree of 20-24°SR.

[0038] (2) The paper is formed by filtering water through a forming wire and then dried to obtain the base paper with a basis weight of 85 g / m². 2 .

[0039] The base paper obtained above is used to prepare peracetic acid test strips, and the steps are as follows:

[0040] (1) The base paper was soaked in ethanol and water for 20 minutes in sequence, and then taken out and dried;

[0041] (2) Soak the treated base paper in the mixed solution for 5 minutes, take it out, vacuum dry it, cut it into 6mm×6mm rectangles, and paste it on a PVC base plate to obtain peracetic acid test paper; the mixed solution is an aqueous solution of colorimetric reagent, pH buffer and dispersant; the colorimetric reagent is a mixture of 0.4g / L tetramethylbenzidine sulfate and 15g / L ferrous sulfate, the pH buffer is a mixture of 6g / L potassium dihydrogen phosphate and 20g / L dipotassium hydrogen phosphate, and the dispersant is 10g / L polyethylene glycol.

[0042] The peracetic acid test strip prepared above is used to test for peracetic acid, and the steps are as follows:

[0043] Immerse the peracetic acid test strip in the sample to be tested, remove it after 1 second, absorb off the excess solution, and the color will stabilize after 50 seconds. Compare the color of the test strip with the standard color chart to read the concentration data of peracetic acid.

[0044] The standard colorimetric card is prepared by the following method: Prepare peracetic acid standard solutions with mass concentrations of 0.06%, 0.12%, 0.18%, 0.24%, and 0.30% using water. Immerse any of the peracetic acid test strips described above into the standard solutions, remove them, and after the color of the test strips stabilizes, find the corresponding standard color on the Pantone color chart; thus, obtain the standard color of the peracetic acid standard solution of the known concentration. Based on the color values ​​of the standard colors corresponding to each known concentration, prepare a standard colorimetric card for the corresponding known concentration.

[0045] The test strip is light blue when the concentration is 0.06%, light green when the concentration is 0.12%, light yellow when the concentration reaches 0.18%, and yellow when the concentration reaches 0.24%. The yellow color gradually deepens as the concentration increases.

[0046] Example 2

[0047] A method for preparing the base paper for a peracetic acid test strip, comprising the following steps:

[0048] (1) By weight, 60 parts of hardwood pulp and 40 parts of coconut shell fiber are dispersed in water, 2 parts of dispersant polyacrylamide and 2 parts of wet strength agent thermosetting urea-formaldehyde resin are added for dissolution, and after dissolution, 0.1% of the fiber weight of titanium dioxide powder and 0.5% of the fiber weight of β-cyclodextrin sulfate are added, and the pulp is polished to obtain pulp with a pulp degree of 20-24°SR.

[0049] (2) The paper is formed by filtering water through a forming mesh and then dried to obtain the base paper.

[0050] The base paper obtained above is used to prepare peracetic acid test strips, and the steps are as follows:

[0051] (1) The base paper was soaked in ethanol and water for 20 minutes in sequence, and then taken out and dried;

[0052] (2) Soak the treated base paper in the mixed solution for 10 minutes, take it out, vacuum dry it, cut it into 6mm×6mm rectangles, and paste it on a PVC base plate to obtain peracetic acid test paper; the mixed solution is an aqueous solution of colorimetric reagent, pH buffer and dispersant; the colorimetric reagent is a mixture of 0.1g / L tetramethylbenzidine sulfate and 10g / L ferrous sulfate, the pH buffer is a mixture of 5g / L potassium dihydrogen phosphate and 15g / L dipotassium hydrogen phosphate, and the dispersant is 4g / L polyethylene glycol.

[0053] Example 3

[0054] A method for preparing the base paper for a peracetic acid test strip, comprising the following steps:

[0055] (1) By weight, 80 parts of hardwood pulp and 20 parts of coconut shell fiber are dispersed in water, 1.5 parts of dispersant polyacrylamide and 1.5 parts of wet strength agent thermosetting urea-formaldehyde resin are added for dissolution, and after dissolution, 0.05% of the fiber weight of titanium dioxide powder and 0.1% of the fiber weight of β-cyclodextrin sulfate are added, and the pulp is polished to obtain pulp with a pulp degree of 20-24°SR;

[0056] (2) The paper is formed by filtering water through a forming mesh and then dried to obtain the base paper.

[0057] The base paper obtained above is used to prepare peracetic acid test strips, and the steps are as follows:

[0058] (1) The base paper was soaked in ethanol and water for 20 minutes in sequence, and then taken out and dried;

[0059] (2) Soak the treated base paper in the mixed solution for 5 minutes, take it out, vacuum dry it, cut it into 6mm×6mm rectangles, and paste it on a PVC base plate to obtain peracetic acid test paper; the mixed solution is an aqueous solution of colorimetric reagent, pH buffer and dispersant; the colorimetric reagent is a mixture of 0.5g / L tetramethylbenzidine sulfate and 20g / L ferrous sulfate, the pH buffer is a mixture of 10g / L potassium dihydrogen phosphate and 35g / L dipotassium hydrogen phosphate, and the dispersant is 15g / L polyethylene glycol.

[0060] Example 4

[0061] The difference from Example 1 is that the amount of titanium dioxide powder used during fiber polishing is 0.5% of the fiber mass, which exceeds the preferred range. Specifically:

[0062] A method for preparing the base paper for a peracetic acid test strip, comprising the following steps:

[0063] (1) By mass, 70 parts of hardwood pulp and 30 parts of coconut shell fiber are dispersed in water, 1 part of dispersant polyacrylamide and 1 part of wet strength agent thermosetting urea-formaldehyde resin are added for dissolution, and after dissolution, 0.5% of the fiber mass of titanium dioxide powder and 1% of the fiber mass of β-cyclodextrin sulfate (synthesized with sulfur trioxide pyridine complex as sulfate esterification reagent according to existing technology) are added, and the pulp is polished to obtain pulp with a pulp degree of 20-24°SR.

[0064] (2) The paper is formed by filtering water through a forming mesh and then dried to obtain the base paper.

[0065] The base paper obtained above is used to prepare peracetic acid test strips, and the steps are as follows:

[0066] (1) The base paper was soaked in ethanol and water for 20 minutes in sequence, and then taken out and dried;

[0067] (2) Soak the treated base paper in the mixed solution for 5 minutes, take it out, vacuum dry it, cut it into 6mm×6mm rectangles, and paste it on a PVC base plate to obtain peracetic acid test paper; the mixed solution is an aqueous solution of colorimetric reagent, pH buffer and dispersant; the colorimetric reagent is a mixture of 0.4g / L tetramethylbenzidine sulfate and 15g / L ferrous sulfate, the pH buffer is a mixture of 6g / L potassium dihydrogen phosphate and 20g / L dipotassium hydrogen phosphate, and the dispersant is 10g / L polyethylene glycol.

[0068] Comparative Example

[0069] Comparative Example 1

[0070] The difference from Example 1 is that the fiber used is only hardwood pulp, without coconut shell fiber. Specifically:

[0071] A method for preparing the base paper for a peracetic acid test strip, comprising the following steps:

[0072] (1) Disperse 100 parts of hardwood pulp in water by mass, add 1 part of dispersant polyacrylamide and 1 part of wet strength agent thermosetting urea-formaldehyde resin for dissolution, add 0.01% of titanium dioxide powder by fiber mass and 1% of β-cyclodextrin sulfate by fiber mass (synthesized with sulfur trioxide pyridine complex as sulfate esterification agent according to existing technology), and grind to obtain pulp with pulp degree 20-24°SR;

[0073] (2) The paper is formed by filtering water through a forming mesh and then dried to obtain the base paper.

[0074] The base paper obtained above is used to prepare peracetic acid test strips, and the steps are as follows:

[0075] (1) The base paper was soaked in ethanol and water for 20 minutes in sequence, and then taken out and dried;

[0076] (2) Soak the treated base paper in the mixed solution for 5 minutes, take it out, vacuum dry it, cut it into 6mm×6mm rectangles, and paste it on a PVC base plate to obtain peracetic acid test paper; the mixed solution is an aqueous solution of colorimetric reagent, pH buffer and dispersant; the colorimetric reagent is a mixture of 0.4g / L tetramethylbenzidine sulfate and 15g / L ferrous sulfate, the pH buffer is a mixture of 6g / L potassium dihydrogen phosphate and 20g / L dipotassium hydrogen phosphate, and the dispersant is 10g / L polyethylene glycol.

[0077] Comparative Example 2

[0078] The difference from Example 1 is that ramie fiber is used instead of coconut shell fiber. Specifically:

[0079] A method for preparing the base paper for a peracetic acid test strip, comprising the following steps:

[0080] (1) By mass, 70 parts of hardwood pulp and 30 parts of ramie fiber are dispersed in water, 1 part of dispersant polyacrylamide and 1 part of wet strength agent thermosetting urea-formaldehyde resin are added for dissolution, and after dissolution, 0.01% of the fiber mass of titanium dioxide powder and 1% of the fiber mass of β-cyclodextrin sulfate (synthesized with sulfur trioxide pyridine complex as sulfate esterification reagent according to existing technology) are added, and the pulp is polished to obtain pulp with a pulp degree of 20-24°SR;

[0081] (2) The paper is formed by filtering water through a forming mesh and then dried to obtain the base paper.

[0082] The base paper obtained above is used to prepare peracetic acid test strips, and the steps are as follows:

[0083] (1) The base paper was soaked in ethanol and water for 20 minutes in sequence, and then taken out and dried;

[0084] (2) Soak the treated base paper in the mixed solution for 5 minutes, take it out, vacuum dry it, cut it into 6mm×6mm rectangles, and paste it on a PVC base plate to obtain peracetic acid test paper; the mixed solution is an aqueous solution of colorimetric reagent, pH buffer and dispersant; the colorimetric reagent is a mixture of 0.4g / L tetramethylbenzidine sulfate and 15g / L ferrous sulfate, the pH buffer is a mixture of 6g / L potassium dihydrogen phosphate and 20g / L dipotassium hydrogen phosphate, and the dispersant is 10g / L polyethylene glycol.

[0085] Comparative Example 3

[0086] The difference from Example 1 is that titanium dioxide powder was not added during fiber polishing. Specifically:

[0087] A method for preparing the base paper for a peracetic acid test strip, comprising the following steps:

[0088] (1) By mass, 70 parts of hardwood pulp and 30 parts of coconut shell fiber are dispersed in water, 1 part of dispersant polyacrylamide and 1 part of wet strength agent thermosetting urea-formaldehyde resin are added for dissolution, and after dissolution, 1% of fiber mass of β-cyclodextrin sulfate (synthesized with sulfur trioxide pyridine complex as sulfate esterification agent according to existing technology) is added, and polishing is performed to obtain pulp with a pulp degree of 20-24°SR.

[0089] (2) The paper is formed by filtering water through a forming mesh and then dried to obtain the base paper.

[0090] The base paper obtained above is used to prepare peracetic acid test strips, and the steps are as follows:

[0091] (1) The base paper was soaked in ethanol and water for 20 minutes in sequence, and then taken out and dried;

[0092] (2) Soak the treated base paper in the mixed solution for 5 minutes, take it out, vacuum dry it, cut it into 6mm×6mm rectangles, and paste it on a PVC base plate to obtain peracetic acid test paper; the mixed solution is an aqueous solution of colorimetric reagent, pH buffer and dispersant; the colorimetric reagent is a mixture of 0.4g / L tetramethylbenzidine sulfate and 15g / L ferrous sulfate, the pH buffer is a mixture of 6g / L potassium dihydrogen phosphate and 20g / L dipotassium hydrogen phosphate, and the dispersant is 10g / L polyethylene glycol.

[0093] Comparative Example 4

[0094] The difference from Example 1 is that β-cyclodextrin sulfate was not added during fiber polishing. Specifically:

[0095] A method for preparing the base paper for a peracetic acid test strip, comprising the following steps:

[0096] (1) Disperse 70 parts of hardwood pulp and 30 parts of coconut shell fiber in water by mass, add 1 part of dispersant polyacrylamide and 1 part of wet strength agent thermosetting urea-formaldehyde resin for dissolution, add 0.01% of the fiber mass of titanium dioxide powder after dissolution, and grind to obtain pulp with a pulp degree of 20-24°SR.

[0097] (2) The paper is formed by filtering water through a forming mesh and then dried to obtain the base paper.

[0098] The base paper obtained above is used to prepare peracetic acid test strips, and the steps are as follows:

[0099] (1) The base paper was soaked in ethanol and water for 20 minutes in sequence, and then taken out and dried;

[0100] (2) Soak the treated base paper in the mixed solution for 5 minutes, take it out, vacuum dry it, cut it into 6mm×6mm rectangles, and paste it on a PVC base plate to obtain peracetic acid test paper; the mixed solution is an aqueous solution of colorimetric reagent, pH buffer and dispersant; the colorimetric reagent is a mixture of 0.4g / L tetramethylbenzidine sulfate and 15g / L ferrous sulfate, the pH buffer is a mixture of 6g / L potassium dihydrogen phosphate and 20g / L dipotassium hydrogen phosphate, and the dispersant is 10g / L polyethylene glycol.

[0101] Comparative Example 5

[0102] The difference from Example 1 is that the amount of β-cyclodextrin sulfate used during fiber polishing is 3.5% of the fiber mass, which exceeds the preferred range. Specifically:

[0103] A method for preparing the base paper for a peracetic acid test strip, comprising the following steps:

[0104] (1) By mass, 70 parts of hardwood pulp and 30 parts of coconut shell fiber are dispersed in water, 1 part of dispersant polyacrylamide and 1 part of wet strength agent thermosetting urea-formaldehyde resin are added for dissolution, and after dissolution, 0.01% of titanium dioxide powder by fiber mass and 3.5% of β-cyclodextrin sulfate by fiber mass (synthesized with sulfur trioxide pyridine complex as sulfate esterification reagent according to existing technology) are added, and the pulp is polished to obtain pulp with a pulp degree of 20-24°SR;

[0105] (2) The paper is formed by filtering water through a forming mesh and then dried to obtain the base paper.

[0106] The base paper obtained above is used to prepare peracetic acid test strips, and the steps are as follows:

[0107] (1) The base paper was soaked in ethanol and water for 20 minutes in sequence, and then taken out and dried;

[0108] (2) Soak the treated base paper in the mixed solution for 5 minutes, take it out, vacuum dry it, cut it into 6mm×6mm rectangles, and paste it on a PVC base plate to obtain peracetic acid test paper; the mixed solution is an aqueous solution of colorimetric reagent, pH buffer and dispersant; the colorimetric reagent is a mixture of 0.4g / L tetramethylbenzidine sulfate and 15g / L ferrous sulfate, the pH buffer is a mixture of 6g / L potassium dihydrogen phosphate and 20g / L dipotassium hydrogen phosphate, and the dispersant is 10g / L polyethylene glycol.

[0109] Comparative Example 6

[0110] The difference from Example 1 is that β-cyclodextrin sulfate is replaced with β-cyclodextrin. Specifically:

[0111] A method for preparing the base paper for a peracetic acid test strip, comprising the following steps:

[0112] (1) By mass, 70 parts of hardwood pulp and 30 parts of coconut shell fiber are dispersed in water, 1 part of dispersant polyacrylamide and 1 part of wet strength agent thermosetting urea-formaldehyde resin are added for dissolution, and after dissolution, 0.01% of the fiber mass of titanium dioxide powder and 1% of the fiber mass of β-cyclodextrin are added, and the pulp is polished to obtain pulp with a pulp degree of 20-24°SR.

[0113] (2) The paper is formed by filtering water through a forming mesh and then dried to obtain the base paper.

[0114] The base paper obtained above is used to prepare peracetic acid test strips, and the steps are as follows:

[0115] (1) The base paper was soaked in ethanol and water for 20 minutes in sequence, and then taken out and dried;

[0116] (2) Soak the treated base paper in the mixed solution for 5 minutes, take it out, vacuum dry it, cut it into 6mm×6mm rectangles, and paste it on a PVC base plate to obtain peracetic acid test paper; the mixed solution is an aqueous solution of colorimetric reagent, pH buffer and dispersant; the colorimetric reagent is a mixture of 0.4g / L tetramethylbenzidine sulfate and 15g / L ferrous sulfate, the pH buffer is a mixture of 6g / L potassium dihydrogen phosphate and 20g / L dipotassium hydrogen phosphate, and the dispersant is 10g / L polyethylene glycol.

[0117] Comparative Example 7

[0118] The difference from Example 1 is that β-cyclodextrin sulfate is replaced with carboxymethyl β-cyclodextrin. Specifically:

[0119] A method for preparing the base paper for a peracetic acid test strip, comprising the following steps:

[0120] (1) By mass, 70 parts of hardwood pulp and 30 parts of coconut fiber are dispersed in water, 1 part of dispersant polyacrylamide and 1 part of wet strength agent thermosetting urea-formaldehyde resin are added for dissolution, and after dissolution, 0.01% of titanium dioxide powder by fiber mass and 1% of carboxymethyl β-cyclodextrin by fiber mass are added, and the pulp is polished to obtain pulp with a pulp degree of 20-24°SR.

[0121] (2) The paper is formed by filtering water through a forming mesh and then dried to obtain the base paper.

[0122] The base paper obtained above is used to prepare peracetic acid test strips, and the steps are as follows:

[0123] (1) The base paper was soaked in ethanol and water for 20 minutes in sequence, and then taken out and dried;

[0124] (2) Soak the treated base paper in the mixed solution for 5 minutes, take it out, vacuum dry it, cut it into 6mm×6mm rectangles, and paste it on a PVC base plate to obtain peracetic acid test paper; the mixed solution is an aqueous solution of colorimetric reagent, pH buffer and dispersant; the colorimetric reagent is a mixture of 0.4g / L tetramethylbenzidine sulfate and 15g / L ferrous sulfate, the pH buffer is a mixture of 6g / L potassium dihydrogen phosphate and 20g / L dipotassium hydrogen phosphate, and the dispersant is 10g / L polyethylene glycol.

[0125] Performance testing

[0126] The performance of the peracetic acid test paper prepared in each embodiment and comparative example was tested. The specific test methods were as follows: (1) the capillary absorption height was determined according to GB / T461.1; (2) the air permeability of the paper was determined using a digital air permeability meter. The test conditions were: pressure 13 mmH2O, measuring circle 50 mm. The peracetic acid test paper prepared in each embodiment and comparative example was used to test a 0.18% peracetic acid standard solution. The time from when the test paper was wetted by the sample to when the color stabilized was recorded.

[0127] The results are shown in the table below.

[0128] Capillary suction height (longitudinal) mm / 10min Air permeability μm / Pa*s Color development and stability time (s) Example 1 50 370 46 Example 2 52 364 50 Example 3 54 361 53 Example 4 45 352 60 Comparative Example 2 59 345 97 Comparative Example 5 57 350 65 Comparative Example 6 40 342 86 Comparative Example 7 44 363 78

[0129] As can be seen from the table above, the peracetic acid test strips prepared in each embodiment of the present invention have high sensitivity and fast response time, achieving stable color development and accurate readings within one minute. The capillary absorption height is 45-55 mm / 10 min. Through repeated experiments, the inventors determined that when the capillary absorption height is within this range, the test strip maintains a good absorption rate and the amount of sample absorbed during impregnation, while also maintaining good color development sensitivity. Compared to Example 1, Comparative Example 1, which did not add coconut shell fiber, had test strip strength that was unqualified; Comparative Example 2, which used ramie fiber instead of coconut shell fiber, had test strip performance inferior to Example 1. This is because the crystallized cellulose in coconut shell fiber is spirally embedded in amorphous lignin and hemicellulose, which helps prevent the pores from collapsing after the test strip is formed. Ramie fiber does not have this function. However, coconut shell fiber is pale yellow, requiring the addition of titanium dioxide for whitening even after pulping. Comparative Example 3, which did not add titanium dioxide, had a slightly pale yellow test strip color, making it difficult to distinguish between peracetic acid with a mass concentration of 0.18%-0.24% during testing. Of course, the best effect can only be achieved when the amount of titanium dioxide is controlled within a reasonable range. In Example 4, the amount of titanium dioxide exceeded the preferred range, the air permeability decreased, and the color development and stabilization time was prolonged.

[0130] Comparative Example 4, which did not use β-cyclodextrin sulfate, showed inferior test paper performance compared to Example 1. Cyclodextrin molecules possess a slightly conical, hollow cylindrical three-dimensional ring structure, and cyclodextrin acts as a thickener, improving the strength and toughness of the test paper without the need for additional thickeners. Introducing cyclodextrin into the test paper raw material increases and maintains the porosity between the test paper fibers. Compared to α-cyclodextrin and γ-cyclodextrin, the molecular porosity of β-cyclodextrin is more suitable for this invention. However, Comparative Example 6, using only β-cyclodextrin, showed inferior paper performance compared to Example 1. Because β-cyclodextrin is hydrophilic on the outer edge and hydrophobic on the inner cavity, this invention modifies it into β-cyclodextrin sulfate, transforming it into an ionic cyclodextrin derivative. This improves capillary absorption speed and allows the chromogenic reagent tetramethylbenzidine sulfate to be firmly adsorbed onto the test paper, increasing reaction efficiency and resulting in a significant reduction in colorimetric stability time. Of course, not all ionic cyclodextrin derivatives are effective. Comparative Example 7 used carboxymethyl cyclodextrin, and the performance of the base paper was not as good as in Example 1. It is speculated that the characteristics of the -SO2Na group and the molecular size affected the test paper. In Comparative Example 5, the amount of β-cyclodextrin sulfate exceeded the preferred range. Excessive β-cyclodextrin sulfate can affect the internal structure of the base paper, thereby reducing capillary absorption performance, indicating that the amount of β-cyclodextrin sulfate needs to be controlled within a reasonable range.

[0131] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing a base paper for a peroxoacetic acid test paper, characterized by, Includes the following steps: (1) After the fiber is loosened, titanium dioxide powder and β-cyclodextrin sulfate accounting for 0.1-3% of the fiber mass are added, and the pulp is polished to obtain a pulp with a pulp degree of 20-24°SR; the fiber includes hardwood pulp and coconut shell fiber; (2) The paper is formed by filtering water through a forming wire and then dried to obtain the base paper; Dispersants and wet strength agents are also added during fiber decomposition; The mass ratio of broadleaf wood pulp to coconut shell fiber is (60-80):(20-40); the mass of β-cyclodextrin sulfate is 0.5-1% of the fiber mass; and the mass of titanium dioxide powder is 0.01-0.1% of the fiber mass.

2. The method for preparing a base paper for a peroxoacetic acid test paper according to claim 1, characterized by, The dispersant is polyacrylamide or vinyl bis-stearamide.

3. The method for preparing the base paper of the peracetic acid test strip according to claim 1 or 2, characterized in that, The wet strength agent is one of thermosetting urea-formaldehyde resin, melamine-formaldehyde resin, or polyamide-epoxychloropropane resin.

4. The application of the base paper for a peracetic acid test strip, characterized in that, The base paper prepared by any one of the preparation methods of claims 1-3 is immersed in the mixed solution, taken out and dried to obtain peracetic acid test paper.

5. The application of the base paper for the peracetic acid test strip according to claim 4, characterized in that, The paper is soaked in ethanol and water in sequence, then removed, dried, and then soaked in a mixture.

6. The application of the base paper for the peracetic acid test strip according to claim 4 or 5, characterized in that, The mixture is an aqueous solution of a colorimetric reagent, a pH buffer, and a dispersant; the colorimetric reagent is a mixture of tetramethylbenzidine sulfate and ferrous salt.

7. The application of the base paper for the peracetic acid test strip according to claim 4, characterized in that, The method of using the peracetic acid test strip is as follows: Immerse the peracetic acid test strip in the sample to be tested, remove it after 1-10 seconds, and the color will stabilize after 40-60 seconds. Compare the color of the test strip with the standard color chart to read the concentration data of peracetic acid.

8. The application of the base paper for the peracetic acid test strip according to claim 7, characterized in that, The preparation method of the standard colorimetric card is as follows: prepare a peracetic acid standard solution of known concentration with water, immerse the peracetic acid test paper in the standard solution, take it out, and after the color of the test paper stabilizes, find the corresponding standard color on the Pantone color chart; that is, the standard color of the peracetic acid standard solution of known concentration is obtained. Based on the color value of the standard color corresponding to each known concentration, the corresponding standard colorimetric card of known concentration is prepared.