A dry-chemical test paper for detecting iodine ions in urine and a preparation method and application thereof

Abstract

The application provides a dry-chemical test paper for detecting iodine ions in urine and a preparation method and application thereof, and belongs to the technical field of urine iodine detection reagents. The urine iodine dry-chemical test paper comprises a urine iodine test paper, a urine treatment substrate bag and a standard colorimetric bag; the urine iodine test paper comprises a magnetic white sheet and a reagent module, the reagent module is attached to one end of the magnetic white sheet, the reagent module is obtained by drying and shearing filter paper impregnated with A solution and B solution; the urine treatment substrate bag is composed of a package loaded with a urine treatment substrate, the urine treatment substrate is composed of activated carbon and a treatment reagent; the standard colorimetric bag comprises an iodine ion standard solution and a standard colorimetric card; the A solution comprises a buffer, an oxidizing agent and a stabilizer; and the B solution comprises a chromogenic agent and an organic solvent. Compared with the iodine catalytic arsenic cerium oxidation-reduction method, the application is more green, non-toxic, more operable, convenient to use, accurate in detection, fast in speed, low in cost and suitable for wide range of applications.

Description

Technical Field

[0001] This invention relates to the field of urine iodine detection reagents, and in particular to a dry chemical test strip for detecting iodine ions in urine, its preparation method, and its application. Background Technology

[0002] Iodine is an essential trace element for the synthesis of thyroid hormones in the human body. Insufficient or excessive iodine intake can affect thyroid function, causing thyroid damage and leading to thyroid diseases. Iodine deficiency in pregnant women, in particular, can cause brain damage in the fetus and infant, resulting in irreversible intellectual disability and psychomotor dysfunction. Therefore, monitoring iodine levels in the human body is of great significance. The kidneys are the main excretory organs for iodine; 90% of the body's iodine is excreted through urine. Urinary iodine levels can assess the body's iodine nutritional status. Clinically, urinary iodine levels are measured to determine the body's iodine content and guide iodine intake accordingly.

[0003] Previous reports on the detection of urinary iodine have included arsenic-cerium catalytic spectrophotometry, inductively coupled plasma chromatography-mass spectrometry (ICP-MS), and chemiluminescence immunoassay. Studies have found that the arsenic-cerium catalytic spectrophotometry method uses heavy metals, which is environmentally unfriendly; ICP-MS requires specialized digestion equipment; and chemiluminescence immunoassay requires large-scale automated analytical instruments. These methods are not only costly and time-consuming, but also complex to operate, making them unsuitable for widespread application in primary healthcare facilities.

[0004] Dry chemical test strips are a commonly used detection carrier in clinical practice. Compared to reagent kits, they have a longer shelf life and are easier to carry, store, and transport. Therefore, it is essential to overcome the shortcomings of previous urinary iodine detection technologies and develop a dry chemical test strip for detecting iodine ions in urine that is simple to operate, highly accurate, fast, convenient to use, low in cost, and suitable for widespread application. Summary of the Invention

[0005] The purpose of this invention is to provide a dry chemical test strip for detecting urinary iodine that is simple to operate, highly accurate, and convenient to use, as well as its preparation method and application.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides a dry chemical test strip for detecting iodide ions in urine, comprising urine iodide test strip, urine treatment matrix package and standard colorimetric card package;

[0008] The urine iodine test strip comprises a magnetic white sheet and a reagent module, with the reagent module attached to one end of the magnetic white sheet; the reagent module is made by drying and cutting filter paper impregnated with solution A and solution B.

[0009] The urine treatment matrix package consists of a package containing a urine treatment matrix, which is composed of activated carbon and treatment reagents.

[0010] The standard colorimetric card package includes an iodide ion standard solution and a standard colorimetric card;

[0011] Solution A contains a buffer solution, an oxidizing agent, and a stabilizer;

[0012] Solution B contains a colorimetric reagent and an organic solvent.

[0013] This invention provides a method for preparing dry chemical test strips for detecting iodide ions in urine, comprising the following steps:

[0014] 1) Preparation of urine iodine test strips: Filter paper is soaked in solution A and dried, then soaked in solution B and dried, and cut into strips to obtain reagent modules; one side of the reagent modules is pasted onto a magnetic white sheet, and then the magnetic white sheet is cut into strips to obtain urine iodine test strip packs;

[0015] 2) Preparation of urine treatment matrix package: Activated carbon and treatment reagents are mixed in pure water, the filtrate is filtered off after precipitation, the filter cake is collected, and the filter cake is baked until dry to obtain urine treatment matrix; the urine treatment matrix is ​​added to packaging, vacuumed and sealed to obtain urine treatment matrix package;

[0016] 3) Preparation of standard colorimetric card pack: Preparation of iodide ion standard solution: Take iodide ion standard substance, add artificial urine, and prepare iodide ion standard solutions of various concentrations for later use; Preparation of standard colorimetric card: Take iodide ion standard solution, add urine treatment matrix, shake well, filter, and prepare iodide ion test solutions of various concentrations; Immerse urine iodine test paper into iodide ion test solutions of various concentrations respectively, take it out, time the reaction, read the value, and use the concentration of iodide ion test solution and the corresponding endpoint color of urine iodine test paper as color standard to obtain standard colorimetric card.

[0017] Furthermore, in the preparation steps of the urinary iodine test strip:

[0018] Solution A contains a buffer solution, an oxidizing agent, and a stabilizer;

[0019] Furthermore, the buffer solution comprises one or more of the following: tris(hydroxymethyl)aminomethane hydrochloride buffer solution, potassium dihydrogen phosphate-disodium hydrogen phosphate buffer solution, disodium hydrogen phosphate-sodium hydroxide buffer solution, citrate-sodium citrate buffer solution, and acetate-sodium acetate buffer solution;

[0020] The buffer solution concentration is 0.01–3.0 M, and the buffer solution pH is 7.0–12.0;

[0021] Furthermore, the oxidant comprises one or more of the sodium salt, potassium salt, sodium salt hydrate, or potassium salt hydrate of benzenesulfonyl haloamine derivatives;

[0022] The benzenesulfonyl halide derivatives include one or more of the following: benzenesulfonyl chloride, benzenesulfonyl bromide, p-toluenesulfonyl chloride, p-toluenesulfonyl bromide, o-toluenesulfonyl chloride, o-toluenesulfonyl bromide, p-nitrobenzenesulfonyl chloride, p-nitrobenzenesulfonyl bromide, N,N-dichlorobenzenesulfonamide, N,N-dibromobenzenesulfonamide, N,N-dichloro-p-toluenesulfonamide, N,N-dibromo-p-toluenesulfonamide, p-(N,N-dichloroaminesulfonyl)benzoic acid, and p-(N,N-dibromoaminesulfonyl)benzoic acid.

[0023] Furthermore, the stabilizer comprises one or more of gelatin, sodium dodecyl sulfonate, polyvinylpyrrolidone K30, ethylene glycol 4000, polyethylene glycol 2000, dextran T70, CMC-Na, sodium alginate, maltodextrin, quinoline, sodium chloride, and decanol.

[0024] The volume-to-mass ratio of the buffer solution, oxidant, and stabilizer is 1000 mL: 0.1–20.0 g: 0.5–50.0 g;

[0025] Furthermore, the B solution contains a colorimetric agent and an organic solvent;

[0026] The colorimetric reagent comprises one or more of the benzidine class colorimetric reagents, wherein the benzidine class colorimetric reagent comprises one or more of 3,3'-dichlorobenzidine, 3,3'-diaminobenzidine, 3,3'-dihydroxybenzidine, 2,2'-disulfonic acid benzidine (BDSA), 3,3'-dihydroxybenzidine (HAB), 3,3'-diaminobenzidine (DAB), and 3,3',5,5'-tetramethylbenzidine (TMB);

[0027] The organic solvent comprises one or more of methanol, ethanol, acetone, tetrahydrofuran, ethyl acetate, dichloromethane, and acetonitrile;

[0028] The mass-to-volume ratio of the colorimetric reagent to the organic solvent is 0.1–20.0 g: 1000 mL.

[0029] Furthermore, in the impregnation step, the filter paper is impregnated in solution A and solution B for 5 to 90 seconds independently.

[0030] In the drying step, the filter paper is immersed in solution A and then dried at a temperature of 30–80°C and a drying rate of 70–160 m / h. The filter paper is then immersed in solution B and dried at a temperature of 30–70°C and a drying rate of 60–150 m / h.

[0031] In the step of cutting the test paper into strips, the width of the strips is 3 to 10 millimeters.

[0032] In the process of cutting the magnetic white sheet into strips, the width of the magnetic white sheet is 3-10 mm and the length of the magnetic white sheet is 40-100 mm.

[0033] The filter paper includes 3MM type filter paper, 31ET type filter paper, MN818 type filter paper, MN827 type filter paper or 7218 type filter paper.

[0034] Furthermore, in the urine treatment matrix preparation step:

[0035] The treatment reagent contains one or more of sodium indophenolate compounds;

[0036] The indophenol compounds include one or more of o-chlorophenol indophenol, 3'-chloroindophenol, 5-isopropyl-2-methylindophenol, 2,6-dichloroindophenol, 2,6-dichloroindophenol acetate, 2,3',6-trichloroindophenol, 2,2',6-trichloro-indophenol, 2,6-dichloro-3'-methylindophenol, 2,6-dibromoindophenol, 2,6-dibromoindophenol acetate, 2,3',6-tribromoindophenol, 2,2',6-tribromo-indophenol, and 2,6-dibromo-3'-methylindophenol.

[0037] The activated carbon is one of coal-based activated carbon, synthetic material activated carbon, and wood-based activated carbon, and the activated carbon has a mesh size of 150-400 and a porosity of 50%-80%.

[0038] The mass ratio of the treatment reagent to activated carbon is 0.5-20%;

[0039] The baking temperature is 100-150℃, and the baking time is 1-12 hours.

[0040] Furthermore, in the standard colorimetric kit preparation step:

[0041] The iodide ion standard substance is potassium iodide or sodium iodide; the iodide ion standard solution is prepared with artificial urine, which is a sodium acetate-acetic acid buffer solution with a molar concentration of 0.01-2.0 M and a pH of 5-7.

[0042] The iodide ion standard solution is available in five concentrations, corresponding to five color levels: 0 μg / l, 50 μg / l, 150 μg / l, 300 μg / l, and 550 μg / l.

[0043] The mass-to-volume ratio of the urine treatment matrix to the iodide ion standard solution is 0.05–0.3 g: 1 mL; the treatment time of the urine treatment matrix is ​​1–30 s.

[0044] In this invention, the time for the urine iodine test strip to be immersed in the iodine ion test solution is 1 to 6 seconds; the reaction temperature of the urine iodine test strip is room temperature, which is 20 to 25°C; and the timing reaction time is 0.5 to 1 minute.

[0045] This invention provides an application of a dry chemical test strip for detecting iodide ions in urine, comprising the following steps:

[0046] 1) Take a natural urine sample, add urine treatment matrix, shake well, filter, and obtain the natural urine test solution;

[0047] 2) Immerse the urine iodine test strip into the test solution of natural urine, remove it, and time the reaction;

[0048] 3) Compare the results of the urine iodine test strip reaction with the standard color chart and read the values.

[0049] The urine sample is a 24-hour urine sample or a midstream morning urine sample, and the urine sample is stored at 4–8°C for later use.

[0050] The mass-to-volume ratio of the urine treatment matrix to natural urine is 0.05–0.3 g: 1 mL; the treatment time of the urine treatment matrix is ​​1–30 s;

[0051] Furthermore, the time for the urinary iodine test strip to be immersed in urine is 1–6 seconds; the reaction temperature is room temperature, specifically 20–25°C; and the timing reaction time is 0.5–1 minute.

[0052] The beneficial effects of this invention are:

[0053] 1. The urine iodine test strip of the present invention uses a TMB-type compound as the colorimetric reagent, which has high stability and sensitivity, especially significant dichroism, good colorimetric reaction, obvious color gradation, easy to distinguish with the naked eye, stable color development, not easily interfered with, fast color development, high detection sensitivity, high accuracy, and good repeatability.

[0054] 2. The oxidant used in the urine iodine test strip of this invention is a benzenesulfonyl haloamine salt derivative, which is a water-soluble oxidant. It does not contain heavy metals or aldehyde condensates and can be directly dissolved in buffer solution without the need for organic solvents. It is safe, environmentally friendly, and environmentally friendly. This type of compound not only has high stability and requires a small amount, but also produces test strips with long validity, high sensitivity, high accuracy, and good repeatability.

[0055] 3. The urinary iodine test strip of the present invention contains a urine treatment matrix package, wherein the urine treatment matrix is ​​formed by fully dispersing and adsorbing sodium indophenolate and activated carbon in an aqueous phase and bonding them by high-temperature baking; the urine treatment matrix can adsorb pigment substances such as bilirubin in urine and can completely eliminate the interference of reducing substances such as vitamin C in urine on the color reaction, thereby improving the sensitivity, accuracy and repeatability of urinary iodine detection; in the past, after urine pretreatment, interfering substances in urine were not completely eliminated, resulting in poor effect and low sensitivity, low accuracy and poor repeatability of urinary iodine detection;

[0056] 4. The urine iodine test strip of this invention has a reaction time of only 1 minute, which is fast and has a short reaction time. It is effective in testing a large number of samples and can save a lot of time and has high detection efficiency. Previous technologies required a reaction time of at least 1.5 minutes, which was time-consuming and had low detection efficiency.

[0057] 5. The urine iodine test strip of the present invention, through the selection of preferred colorimetric reagents, preferred oxidants, preferred stabilizers, preferred surfactants and preferred buffers, has good system compatibility, high sensitivity, high accuracy, good stability and long shelf life (20 months); previous detection technologies have poor system compatibility, low sensitivity, low accuracy, poor stability and short shelf life (8 months).

[0058] 6. The urine iodine test strip of the present invention is easy to store and transport, and has high detection sensitivity, high accuracy and good repeatability; previous detection technologies, such as reagent kits, are not easy to store and transport, and have low detection sensitivity, low accuracy and poor repeatability.

[0059] 7. The present invention provides a urine iodine dry chemical test strip, comprising urine iodine test strips, a urine treatment matrix, a standard colorimetric card pack, and an iodine ion standard solution. The urine iodine test strips are used to detect iodine ions in urine, the urine treatment matrix is ​​used to pre-treat the urine, the iodine ion standard solution is used to calibrate the readings, and the standard colorimetric card is used for comparison. The urine iodine dry chemical test strip of the present invention allows for visual comparison with the standard colorimetric card readings, or measurement using a small urine analyzer. Compared with previous detection technologies, the present invention is simple to operate and convenient to use.

[0060] Furthermore, this invention is greener and non-toxic than the iodine-catalyzed arsenic-cerium redox method, and more sensitive, accurate, and operable than the iodine-catalyzed hydrazine-[oxidant-Ferroin reagent] method.

[0061] Therefore, it can be seen that the present invention is simple to operate, convenient to use, accurate in detection, and can be used on a wide range of applications. It can not only meet the needs of clinical use, but also meet the needs of home testing and other different needs. Attached Figure Description

[0062] Figure 1The color scale diagram of the iodine ion standard colorimetric card prepared in Example 14 of this invention;

[0063] Among them, 1 shows the color when the iodine ion concentration is 0 μg / L, 2 shows the color when the iodine ion concentration is 50 μg / L, 3 shows the color when the iodine ion concentration is 150 μg / L, 4 shows the color when the iodine ion concentration is 300 μg / L, and 5 shows the color when the iodine ion concentration is 550 μg / L.

[0064] Figure 2 The urine iodine test strip prepared in Example 8 of this invention was used to test five standard solutions of concentrations of 0, 50, 150, 300, and 550 μg / L in sequence. The reaction time was 1 minute, and the color development results of the urine iodine test strip were obtained. Detailed Implementation

[0065] This invention provides a dry chemical test strip for detecting iodide ions in urine, comprising urine iodide test strip, urine treatment matrix pack and standard colorimetric pack;

[0066] The urine iodine test strip comprises a magnetic white sheet and a reagent module, with the reagent module attached to one end of the magnetic white sheet; the reagent module is made by impregnating filter paper soaked in solution A and solution B, then drying and cutting it.

[0067] The urine treatment matrix package consists of a package containing a urine treatment matrix, which is composed of activated carbon and treatment reagents.

[0068] The standard colorimetric kit contains an iodine ion standard solution and a standard colorimetric card.

[0069] This invention provides a method for preparing dry chemical test strips for detecting iodide ions in urine, comprising the following steps:

[0070] 1) Preparation of urinary iodine test paper: Filter paper is soaked in solution A and dried, then soaked in solution B and dried, and cut into strips to obtain reagent modules; one side of the reagent module is pasted onto a magnetic white sheet, and then the magnetic white sheet is cut into strips to obtain urinary iodine test paper;

[0071] 2) Preparation of urine treatment matrix package: Activated carbon and treatment reagents are mixed in pure water, the filtrate is filtered off after precipitation, the filter cake is collected, and the filter cake is baked until dry to obtain urine treatment matrix; the urine treatment matrix is ​​added to packaging, vacuumed and sealed to obtain urine treatment matrix package;

[0072] 3) Preparation of standard colorimetric kits: Preparation of iodide ion standard solution: Take iodide ion standard substance, add artificial urine, and prepare iodide ion standard solutions of various concentrations for later use; Preparation of standard colorimetric cards: Take iodide ion standard solution, add urine treatment matrix, shake well, filter, and prepare iodide ion test solutions of various concentrations; Immerse urine iodine test strips into iodide ion test solutions of various concentrations respectively, take them out, time the reaction, read the values, and use the concentration of iodide ion test solution and the corresponding endpoint color of urine iodine test strip as color standard to obtain standard colorimetric cards.

[0073] In this invention, the preparation steps of the urinary iodine test strip include:

[0074] Solution A contains a buffer solution, an oxidizing agent, and a stabilizer;

[0075] In this invention, the buffer solution comprises one or more of the following: potassium dihydrogen phosphate-disodium hydrogen phosphate buffer, disodium hydrogen phosphate-sodium hydroxide buffer solution, citrate-sodium citrate buffer solution, and acetate-sodium acetate buffer solution, preferably potassium dihydrogen phosphate-disodium hydrogen phosphate buffer solution and / or disodium hydrogen phosphate-sodium hydroxide buffer solution. The concentration of the buffer solution is 0.01–3.0 M, the pH is 7.0–12.0, preferably the concentration is 0.1–2.0 M, and preferably the pH is 8.0–11.0.

[0076] The oxidant used in this invention is selected from one or more of sodium dichloroisocyanate, urea peroxide, diisopropyl dihydroperoxide, diisopropylbenzene hydrogen peroxide, peracetic acid, hydrogen peroxide, urea peroxide, sodium nitrite, and sodium hypochlorite. Experimental results show that the reagent kit has poor stability and short shelf life when using the above oxidants.

[0077] The research results show that the oxidant selected by the present invention is a benzenesulfonyl haloamine derivative, which has good compound stability and a long shelf life of the kit; the oxidant selected by the present invention is a sodium or potassium salt of a benzenesulfonyl haloamine derivative, which has good water solubility, does not require organic solvents for dissolution, and has high compound stability, resulting in a longer shelf life of the kit; the oxidant selected by the present invention is a benzenesulfonyl monohaloamine salt, which is more stable than the corresponding benzenesulfonyl dihaloamine salt derivative, resulting in a longer shelf life of the kit.

[0078] In this invention, the oxidant comprises one or more of the sodium salt, potassium salt, sodium salt hydrate, or potassium salt hydrate of a benzenesulfonyl haloamine derivative; further, the oxidant is one or more of the sodium salt, potassium salt, sodium salt hydrate, or potassium salt hydrate of a benzenesulfonyl monohaloamine derivative.

[0079] The benzenesulfonyl halide derivatives include benzenesulfonyl chloride, benzenesulfonyl bromide, p-toluenesulfonyl chloride, p-toluenesulfonyl bromide, o-toluenesulfonyl chloride, o-toluenesulfonyl bromide, p-nitrobenzenesulfonyl chloride, p-nitrobenzenesulfonyl bromide, N,N-dichlorobenzenesulfonamide, N,N-dibromobenzenesulfonamide, N,N-dichloro-p-toluenesulfonamide, N,N-dibromo-p-toluenesulfonamide, p-(N,N-dichloroaminesulfonyl)benzoic acid, and p-(N,N-dibromoaminesulfonyl)benzoic acid; the phenyl and phenyl derivative sulfonyl monohalogen amines include benzenesulfonyl chloride, benzenesulfonyl bromide, p-toluenesulfonyl chloride, p-toluenesulfonyl bromide, o-toluenesulfonyl chloride, o-toluenesulfonyl bromide, p-nitrobenzenesulfonyl chloride, and p-nitrobenzenesulfonyl bromide.

[0080] In this invention, the stabilizer comprises one or more of gelatin, sodium dodecyl sulfonate, polyvinylpyrrolidone K30, ethylene glycol 4000, polyethylene glycol 2000, dextran T70, CMC-Na, maltodextrin, quinoline, sodium chloride, and decanol, preferably glucosamine T70 and / or maltodextrin and / or sodium alginate and / or gelatin, and more preferably glucosamine T70 and / or maltodextrin.

[0081] In this invention, the volume-to-mass ratio of the buffer solution, oxidant, and stabilizer is 1000mL:0.1-20.0g:0.5-50.0g, preferably 1000mL:0.5-15.0g:1.0-40.0g, and more preferably 1000mL:1.0-10.0g:2.0-30.0g.

[0082] Solution B contains a colorimetric reagent and an organic solvent.

[0083] The colorimetric reagent described in this invention is a benzidine-based colorimetric reagent. Studies have shown that this type of colorimetric reagent provides stable and rapid color development with high detection sensitivity.

[0084] In this invention, the colorimetric agent includes one or more of the benzidine-based colorimetric agents, wherein the benzidine-based colorimetric agent comprises 3,3'-dichlorobenzidine, 2,2'-disulfonic benzidine, 3,3'-dihydroxybenzidine, 3,3'-diaminobenzidine, and 3,3',5,5'-tetramethylbenzidine; preferably 3,3'-dichlorobenzidine, 3,3'-dihydroxybenzidine, and 3,3',5,5'-tetramethylbenzidine, and more preferably 3,3',5,5'-tetramethylbenzidine.

[0085] In this invention, the organic solvent comprises one or more of methanol, ethanol, acetone, tetrahydrofuran, ethyl acetate, dichloromethane, and acetonitrile, preferably one of acetone, dichloromethane, or acetonitrile.

[0086] In this invention, the mass-to-volume ratio of the color developer to the organic solvent is 0.1–20.0 g: 1000 mL, preferably 0.5–15.0 g: 1000 mL, and more preferably 1.0–10.0 g: 1000 mL.

[0087] In this invention, the filter paper is immersed in solution A and solution B for 5 to 90 seconds, preferably 10 to 60 seconds, and more preferably 15 to 40 seconds.

[0088] In this invention, the filter paper is immersed in solution A and then dried at a temperature of 30–80°C and a drying rate of 70–160 m / h. Preferably, the drying temperature is 40–70°C and the drying rate is 80–130 m / h. The filter paper is immersed in solution B and then dried at a temperature of 30–70°C and a drying rate of 60–150 m / h. Preferably, the drying temperature is 35–65°C and the drying rate is 70–120 m / h.

[0089] In the step of cutting the test paper into strips, the width of the strips is 3 to 10 mm, preferably 5 to 8 mm.

[0090] In the process of cutting the magnetic white sheet into strips, the length of the magnetic white sheet is 3-10 mm, preferably 5-8 mm; the length of the magnetic white sheet is 40-100 mm, preferably 50-90 mm.

[0091] In this invention, the filter paper is one of 3MM type filter paper, 31ET type filter paper, MN818 type filter paper, MN827 type filter paper or 7218 type filter paper, preferably 3MM type filter paper or 31ET type filter paper.

[0092] In this invention, for ease of use, after the filter paper is dried, it can be cut to the required size. One side of the filter paper is attached to the magnetic white sheet with double-sided tape and then cut to the required size to obtain urine iodine test paper.

[0093] In this invention, the urine treatment matrix preparation step includes:

[0094] The treatment reagents used in this invention are potassium permanganate or sodium nitrite. Research results show that the substances generated after potassium permanganate or sodium nitrite reacts with reduced substances in urine cannot be adsorbed by activated carbon and remain in the urine, affecting the measurement results of urinary iodine.

[0095] The treatment reagent described in this invention uses indophenol compounds. Research results show that the substances generated after the reaction of indophenol compounds with reduced substances in urine can be adsorbed by activated carbon, thus eliminating the influence of reduced substances in urine. However, indophenol compounds have low water solubility and require solvents for dissolution, which affects the detection and makes them unsuitable for use.

[0096] This invention uses sodium indophenolate compounds. Research results show that sodium indophenolate compounds have good water solubility, can be completely adsorbed by activated carbon, and can be completely bonded at high temperatures to form a urine treatment matrix with good application effect. Compared with sodium chloroindophenolate, sodium bromoindophenolate has a stronger bonding ability with activated carbon, a stronger adsorption capacity, and a better urine treatment effect.

[0097] In this invention, the treatment reagent comprises one or more sodium indophenolate compounds, and further, the treatment reagent comprises one or more sodium bromoindophenolate compounds.

[0098] The indophenols mentioned herein include o-chlorophenol indophenol, 3'-chloroindophenol, 5-isopropyl-2-methylindophenol, 2,6-dichloroindophenol, 2,6-dichloroindophenol acetate, 2,3',6-trichloroindophenol, 2,2',6-trichloro-indophenol, 2,6-dichloro-3'-methylindophenol, 2,6-dibromoindophenol, 2,6-dibromoindophenol acetate, 2,3',6-tribromoindophenol, 2,2',6-tribromo-indophenol, and 2,6-dibromo-3'-methylindophenol; further, the bromoindophenols are 2,6-dibromoindophenol, 2,6-dibromoindophenol acetate, 2,3',6-tribromoindophenol, 2,2',6-tribromo-indophenol, and 2,6-dibromo-3'-methylindophenol;

[0099] The activated carbon is one of coal-based activated carbon, synthetic material activated carbon, and wood-based activated carbon, preferably wood-based activated carbon;

[0100] The activated carbon has a mesh size of 150-400 and a porosity of 50%-80%, preferably a mesh size of 200-350 and a porosity of 55%-75%.

[0101] The mass ratio of the treatment reagent to activated carbon is 0.5-20%, preferably 1-10%;

[0102] The baking temperature is 100-150℃, preferably 105-140℃, and more preferably 110-130℃; the baking time is 1-12h, preferably 2-8h.

[0103] In this invention, the standard colorimetric kit preparation step includes:

[0104] The iodide ion standard substance is potassium iodide or sodium iodide; the iodide ion standard solution is prepared with artificial urine, which is a sodium acetate-acetic acid buffer solution with a molar concentration of 0.01-2.0 M and a pH of 5-7; preferably, the molar concentration is 0.1-1.0 M and the pH is 5.1-6.5.

[0105] The iodide ion standard solution is available in five concentrations, corresponding to five color levels: 0 μg / l, 50 μg / l, 150 μg / l, 300 μg / l, and 550 μg / l.

[0106] The mass-to-volume ratio of the urine treatment matrix to the iodide ion standard solution is 0.05–0.3 g: 1 mL, preferably 0.1–0.2 g: 1 mL;

[0107] The urine treatment matrix treatment time is 1 to 30 seconds, preferably 3 to 15 seconds.

[0108] In this invention, the time for the urine iodine test paper to be immersed in the iodine ion test solution is 1 to 6 seconds, preferably 1 to 3 seconds; the reaction temperature of the urine iodine test paper is room temperature, which is 20 to 25°C; and the timing reaction time is 0.5 to 1 minute, preferably 1 minute.

[0109] This invention provides an application of a dry chemical test strip for detecting iodide ions in urine, comprising the following steps:

[0110] 1) Take a natural urine sample, add urine treatment matrix, shake well, process, filter, and obtain the natural urine test solution;

[0111] 2) Immerse the urine iodine test strips in the natural urine test solution at room temperature, remove them, and time the reaction.

[0112] 3) Compare the results of the urine iodine test strip reaction with the standard color chart and read the values.

[0113] In this invention, the urine sample is a 24-hour urine sample or a midstream morning urine sample, and the urine sample is stored at 4-8°C for later use.

[0114] The mass-to-volume ratio of the urine treatment matrix to natural urine is 0.05–0.3 g:1 mL, preferably 0.1–0.2 g:1 mL;

[0115] The urine treatment matrix treatment time is 1–30 s, preferably 3–15 s;

[0116] In this invention, the time for the urinary iodine test strip to be immersed in urine is 1 to 6 seconds, preferably 1 to 3 seconds;

[0117] The reaction temperature is room temperature, specifically 20–25°C; the reaction time is 0.5–1 minute, preferably 1 minute.

[0118] The detection principle of this invention is as follows: Iodide ions in urine catalyze the oxidation of benzidine-based colorimetric reagents, causing the urine iodine test strip to change from yellow-green to blue-green. Within the same time period, the degree of color change is positively correlated with the concentration of iodide ions, thereby determining the content of iodide ions in the urine sample.

[0119] The method for reading the urine iodine test strip is as follows: When visually inspecting, compare it with a standard colorimetric card. The iodine ion concentration corresponding to the color level of the standard colorimetric card that is closest to the color of the test strip is the iodine ion concentration of the urine to be tested. If it is between two color levels, estimate the iodine ion concentration in the test solution. When using a urine analyzer, obtain the test result through the reflectance value.

[0120] Therefore, it is evident that the dry chemical test strip for detecting iodide ions in urine, its preparation method, and its application are essential.

[0121] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0122] Example 1

[0123] Preparation of urinary iodine test strips:

[0124] 1) Prepare homogeneous solution A and homogeneous solution B;

[0125] Liquid A:

[0126] 1000 mL of 0.2 M potassium dihydrogen phosphate-disodium hydrogen phosphate buffer solution (pH 8.0)

[0127] 25g of gelatin

[0128] Sodium benzenesulfonyl chloride 5.0g

[0129] Liquid B:

[0130] 3,3',5,5'-Tetramethylbenzidine 1.0g

[0131] 1000mL of acetone

[0132] 2) Impregnation, drying, and cutting into strips: Take 31ET type filter paper, immerse it in solution A at a uniform speed for 10 seconds, and dry it in a drying chamber at a temperature of 45℃ with a drying speed of 100m / h; take the filter paper that has been impregnated and dried in solution A, immerse it in solution B at a uniform speed for 15 seconds, and dry it in a drying chamber at a temperature of 25℃ with a drying speed of 100m / h; cut the dried filter paper into strips with a width of 5mm, stick one side of the strip to a magnetic white sheet with double-sided tape, cut it into strips with a length of 70mm and a width of 5mm, pack it in a bucket, seal it, dry it, and store it for later use to obtain urine iodine test strips.

[0133] Example 2

[0134] Preparation of urinary iodine test strips:

[0135] 1) Prepare homogeneous solution A and homogeneous solution B;

[0136] Liquid A:

[0137]

[0138] Liquid B:

[0139] 3,3',5,5'-Tetramethylbenzidine 7.5g

[0140] 1000mL of acetone

[0141] 2) Impregnation, drying, and cutting into strips: Take 3mm filter paper, immerse it in solution A at a uniform speed for 15 seconds, and dry it in a drying chamber at 50℃ with a drying speed of 100m / h; take the filter paper that has been impregnated and dried in solution A, immerse it in solution B at a uniform speed for 10 seconds, and dry it in a drying chamber at 35℃ with a drying speed of 100m / h; cut the dried filter paper into strips with a width of 6mm, stick one side of the strip to a magnetic white sheet with double-sided tape, cut it into strips with a length of 80mm and a width of 6mm, pack it in a bucket, seal it, dry it, and store it for later use to obtain urine iodine test strips.

[0142] Example 3

[0143] Preparation of urinary iodine test strips:

[0144] 1) Prepare homogeneous solution A and homogeneous solution B;

[0145] Liquid A:

[0146]

[0147] Liquid B:

[0148] 3,3',5,5'-Tetramethylbenzidine 2.0g

[0149] 1000mL of acetone

[0150] 2) Impregnation, drying, and cutting into strips: Take 3mm filter paper, immerse it in solution A at a uniform speed for 15 seconds, and dry it in a drying chamber at a temperature of 48℃ with a drying speed of 100m / h; take the filter paper that has been impregnated and dried in solution A, immerse it in solution B at a uniform speed for 15 seconds, and dry it in a drying chamber at a temperature of 40℃ with a drying speed of 100m / h; cut the dried filter paper into strips with a width of 6mm, stick one side of the strip to a magnetic white sheet with double-sided tape, cut it into strips with a length of 70mm and a width of 6mm, pack them in a bucket, seal and dry them for later use, and obtain urine iodine test strips.

[0151] Example 4

[0152] Preparation of urinary iodine test strips:

[0153] 1) Prepare homogeneous solution A and homogeneous solution B;

[0154] Liquid A:

[0155]

[0156] Liquid B:

[0157] 3,3',5,5'-Tetramethylbenzidine 5.0g

[0158] 1000 mL of dichloromethane

[0159] 2) Impregnation, drying, and cutting into strips: Take 31ET type filter paper, immerse it in solution A at a uniform speed for 10 seconds, and dry it in a drying chamber at a temperature of 50℃ with a drying speed of 100 m / h; take the filter paper that has been impregnated and dried in solution A, immerse it in solution B at a uniform speed for 15 seconds, and dry it in a drying chamber at a temperature of 35℃ with a drying speed of 100 m / h; cut the dried filter paper into strips with a width of 8 mm, stick one side of the strip to a magnetic white sheet with double-sided tape, cut it into strips with a length of 90 mm and a width of 8 mm, pack it in a bucket, seal it, dry it, and store it for later use to obtain urine iodine test strips.

[0160] Example 5

[0161] Preparation of urinary iodine test strips:

[0162] 1) Prepare homogeneous solution A and homogeneous solution B;

[0163] Liquid A:

[0164] 1000 mL of 0.5 M disodium hydrogen phosphate-sodium hydroxide buffer solution (pH 9.0)

[0165] Polyethylene glycol 2000 7.0g

[0166] Sodium p-toluenesulfonyl chloride 1.0g

[0167] Liquid B:

[0168] 3,3',5,5'-Tetramethylbenzidine 6.0g

[0169] 1000 mL of dichloromethane

[0170] 2) Impregnation, drying, and cutting into strips: Take 3mm filter paper, immerse it in solution A at a uniform speed for 10 seconds, and dry it in a drying chamber at a temperature of 45℃ with a drying speed of 100m / h; take the filter paper that has been impregnated and dried in solution A, immerse it in solution B at a uniform speed for 15 seconds, and dry it in a drying chamber at a temperature of 30℃ with a drying speed of 100m / h; cut the dried filter paper into strips with a width of 6mm, stick one side of the strip to a magnetic white sheet with double-sided tape, cut it into strips with a length of 80mm and a width of 6mm, pack them in a bucket, seal and dry them for later use, and obtain urine iodine test strips.

[0171] Example 6

[0172] Preparation of urinary iodine test strips:

[0173] 1) Prepare homogeneous solution A and homogeneous solution B;

[0174] Liquid A:

[0175] 1000 mL of 0.4 M disodium hydrogen phosphate-sodium hydroxide buffer solution (pH 10.0)

[0176] Glucan T70 5.0g

[0177] Sodium p-toluenesulfonyl bromide 1.0g

[0178] Liquid B:

[0179] 3,3',5,5'-Tetramethylbenzidine 4.0g

[0180] 1000mL of acetone

[0181] 2) Impregnation, drying, and cutting into strips: Take 31ET type filter paper, immerse it in solution A at a uniform speed for 10 seconds, and dry it in a drying chamber at a temperature of 40℃ with a drying speed of 100m / h; take the filter paper that has been impregnated and dried in solution A, immerse it in solution B at a uniform speed for 10 seconds, and dry it in a drying chamber at a temperature of 35℃ with a drying speed of 100m / h; cut the dried filter paper into strips with a width of 7mm, stick one side of the strip to a magnetic white sheet with double-sided tape, cut it into strips with a length of 70mm and a width of 7mm, pack it in a bucket, seal it, dry it, and store it for later use to obtain urine iodine test strips.

[0182] Example 7

[0183] Preparation of urinary iodine test strips:

[0184] 1) Prepare homogeneous solution A and homogeneous solution B;

[0185] Liquid A:

[0186] 1000 mL of 0.25 M disodium hydrogen phosphate-sodium hydroxide buffer solution (pH 8.5)

[0187] Sodium alginate 7.5g

[0188] 1.0g of p-toluenesulfonyl chloride potassium

[0189] Liquid B:

[0190] 3,3',5,5'-Tetramethylbenzidine 3.5g

[0191] 1000mL of acetone

[0192] 2) Impregnation, drying, and cutting into strips: Take 3mm filter paper, immerse it in solution A at a uniform speed for 12 seconds, and dry it in a drying chamber at 50℃ with a drying speed of 100m / h; take the filter paper that has been impregnated and dried in solution A, immerse it in solution B at a uniform speed for 10 seconds, and dry it in a drying chamber at 25℃ with a drying speed of 100m / h; cut the dried filter paper into strips with a width of 6mm, stick one side of the strip to a magnetic white sheet with double-sided tape, cut it into strips with a length of 80mm and a width of 6mm, pack them in a bucket, seal and dry them for later use, and obtain urine iodine test strips.

[0193] Example 8

[0194] Preparation of urinary iodine test strips:

[0195] 1) Prepare homogeneous solution A and homogeneous solution B;

[0196] Liquid A:

[0197] 0.35M disodium hydrogen phosphate-sodium hydroxide buffer solution (pH 9.0) 1000mL

[0198] Maltodextrin 5.0g

[0199] Sodium o-toluenesulfonyl chloride 2.5g

[0200] Liquid B:

[0201] 3,3',5,5'-Tetramethylbenzidine 4.0g

[0202] 1000mL of acetonitrile

[0203] 2) Impregnation, drying, and cutting into strips: Take 31ET type filter paper, immerse it in solution A at a uniform speed for 12 seconds, and dry it in a drying chamber at a temperature of 48℃ with a drying speed of 100 m / h; take the filter paper that has been impregnated and dried in solution A, immerse it in solution B at a uniform speed for 10 seconds, and dry it in a drying chamber at a temperature of 32℃ with a drying speed of 100 m / h; cut the dried filter paper into strips with a width of 5 mm, stick one side of the strip to a magnetic white sheet with double-sided tape, cut it into strips with a length of 70 mm and a width of 5 mm, pack it in a bucket, seal it, dry it, and store it for later use to obtain urine iodine test strips.

[0204] Example 9

[0205] Preparation of urinary iodine test strips:

[0206] 1) Prepare homogeneous solution A and homogeneous solution B;

[0207] Liquid A:

[0208] 1000 mL of 0.5 M disodium hydrogen phosphate-sodium hydroxide buffer solution (pH 10.0)

[0209] Glucan T70 10.0g

[0210] Sodium o-toluenesulfonyl bromide 5.0g

[0211] Liquid B:

[0212] 3,3'-Dihydroxybenzidine 3.0g

[0213] 1000mL of acetone

[0214] 2) Impregnation, drying, and cutting into strips: Take 31ET type filter paper, immerse it in solution A at a uniform speed for 15 seconds, and dry it in a drying chamber at a temperature of 42℃ with a drying speed of 100 m / h; take the filter paper that has been impregnated and dried in solution A, immerse it in solution B at a uniform speed for 12 seconds, and dry it in a drying chamber at a temperature of 23℃ with a drying speed of 100 m / h; cut the dried filter paper into strips with a width of 8 mm, stick one side of the strip to a magnetic white sheet with double-sided tape, cut it into strips with a length of 90 mm and a width of 8 mm, pack it in a bucket, seal it, dry it, and store it for later use to obtain urine iodine test strips.

[0215] Example 10

[0216] Preparation of urinary iodine test strips:

[0217] 1) Prepare homogeneous solution A and homogeneous solution B;

[0218] Liquid A:

[0219]

[0220] Liquid B:

[0221] 4.5g of 3,3'-dichlorobenzidine

[0222] 1000mL of acetonitrile

[0223] 1) Impregnation, drying, and cutting into strips: Take 3mm filter paper, immerse it in solution A at a uniform speed for 10 seconds, and dry it in a drying chamber at a temperature of 45℃ with a drying speed of 100m / h; take the filter paper that has been impregnated and dried in solution A, immerse it in solution B at a uniform speed for 10 seconds, and dry it in a drying chamber at a temperature of 33℃ with a drying speed of 100m / h; cut the dried filter paper into strips with a width of 6mm, stick one side of the strip to a magnetic white sheet with double-sided tape, cut it into strips with a length of 70mm and a width of 6mm, pack them in a bucket, seal and dry them for later use, and obtain urine iodine test strips.

[0224] Example 11

[0225] Preparation of urinary iodine test strips:

[0226] 1) Prepare homogeneous solution A and homogeneous solution B;

[0227] Liquid A:

[0228] 1000 mL of 0.1 M potassium dihydrogen phosphate-disodium hydrogen phosphate buffer solution (pH 8.5)

[0229] Sodium alginate 20g

[0230] 15g of sodium p-nitrobenzenesulfonyl bromide

[0231] Liquid B:

[0232] 0.5g of 3,3'-dichlorobenzidine

[0233] 1000mL of acetone

[0234] 2) Impregnation, drying, and cutting into strips: Take 31ET type filter paper, immerse it in solution A at a uniform speed for 13 seconds, and dry it in a drying chamber at a temperature of 55℃ with a drying speed of 100 m / h; take the filter paper that has been impregnated and dried in solution A, immerse it in solution B at a uniform speed for 12 seconds, and dry it in a drying chamber at a temperature of 35℃ with a drying speed of 100 m / h; cut the dried filter paper into strips with a width of 8 mm, stick one side of the strip to a magnetic white sheet with double-sided tape, cut it into strips with a length of 90 mm and a width of 8 mm, pack it in a bucket, seal it, dry it, and store it for later use to obtain urine iodine test strips.

[0235] Example 12

[0236] Preparation of urinary iodine test strips:

[0237] 1) Prepare homogeneous solution A and homogeneous solution B;

[0238] Liquid A:

[0239] 1000 mL of 2.0 M disodium hydrogen phosphate-sodium hydroxide buffer solution (pH 8.0)

[0240] Glucan T70 5.0g

[0241] 0.5g of potassium p-nitrobenzenesulfonyl bromide

[0242] Liquid B:

[0243] 3,3'-Dihydroxybenzidine 15.0g

[0244] 1000 mL of dichloromethane

[0245] 2) Impregnation, drying, and cutting into strips: Take 31ET type filter paper, immerse it in solution A at a uniform speed for 10 seconds, and dry it in a drying chamber at a temperature of 60℃ with a drying speed of 100m / h; take the filter paper that has been impregnated and dried in solution A, immerse it in solution B at a uniform speed for 10 seconds, and dry it in a drying chamber at a temperature of 40℃ with a drying speed of 100m / h; cut the dried filter paper into strips with a width of 5mm, stick one side of the strip to a magnetic white sheet with double-sided tape, cut it into strips with a length of 60mm and a width of 5mm, pack it in a bucket, seal it, dry it, and store it for later use to obtain urine iodine test strips.

[0246] Example 13

[0247] Preparation of urine treatment matrix package

[0248] 1) Preparation of urine treatment matrix: Take 100g of wood-based activated carbon (300 mesh, porosity 66%), place it in a suitable beaker, add 5g of sodium 2,6-dibromoindophenol, pour 500mL of pure water into the beaker, stir at room temperature for 5h, filter, collect the filter cake, bake the filter cake at 120℃ for 5h to obtain urine treatment matrix.

[0249] 2) Preparation of urine treatment matrix package: Weigh the urine treatment matrix, each package contains 150mg, and vacuum seal to prepare the urine treatment matrix package.

[0250] Example 14

[0251] Preparation of standard colorimetric card packs:

[0252] Preparation of dry chemical test strips for detecting iodide ions in urine: 1) Preparation of urine iodide test strips: Prepare urine iodide test strips according to Example 8 for later use; 2) Preparation of urine treatment matrix package: Prepare urine treatment matrix package according to Example 13; 3) Preparation of iodide ion standard solutions: Take potassium iodide standard substance and use 0.1M sodium acetate buffer solution (pH 5.5) to prepare five iodide ion standard solutions with final concentrations of 0.0 μg / L, 50.0 μg / L, 150.0 μg / L, 300.0 μg / L, and 550.0 μg / L, respectively, to obtain iodide ion standard solutions;

[0253] Preparation of iodide ion test solutions: At room temperature, take 1 ml of each of the five concentrations of iodide ion standard solutions, add 150 mg of urine treatment matrix package, shake well for 5 seconds, filter, and obtain the five concentrations of iodide ion test solutions.

[0254] Preparation of standard colorimetric cards: The urinary iodine test paper prepared in Example 8 was immersed in the five standard solutions mentioned above for 3 seconds at room temperature, then removed and allowed to react for 1 minute. Each concentration was tested three times, and the values ​​were read. Based on the color development results of the five concentrations of iodine ion test solutions and the urinary iodine test paper, standard colorimetric cards were prepared.

[0255] Experimental results: The standard colorimetric scale obtained by the urine iodine test strips is five levels: 0.0 μg / L, 50.0 μg / L, 150.0 μg / L, 300.0 μg / L, and 550.0 μg / L. The color of the colorimetric scale ranges from yellow-green to blue-green, with the color increasing from light to dark.

[0256] Following the same steps as described above, the urinary iodine test strips prepared in Examples 1-7 and Examples 9-12 were used to detect five concentrations of iodine ion standard solutions. The reaction time was 1 minute, and the results were consistent with those obtained from the urinary iodine test strip in Example 8.

[0257] Example 15

[0258] Urine analyzer test:

[0259] Preparation of dry chemical test strips for detecting iodide ions in urine: 1) Preparation of urine iodide test strips: Urine iodide test strips were prepared according to Example 8 for later use; 2) Preparation of urine treatment matrix package: Urine treatment matrix package was prepared according to Example 13; 3) Preparation of iodide ion standard colorimetric card package: Iodide ion standard colorimetric card package was prepared according to Example 14, and iodide ion standard colorimetric cards and iodide ion standard solutions with five concentrations of 0.0 μg / L, 50.0 μg / L, 150.0 μg / L, 300.0 μg / L, and 550.0 μg / L were obtained;

[0260] Preparation of iodide ion test solutions: At room temperature, take 1 ml of each of the five concentrations of iodide ion standard solutions, add 150 mg of urine treatment matrix package, shake well for 5 seconds, filter, and obtain the five concentrations of iodide ion test solutions.

[0261] Detection reaction: Immerse the urine iodine test strip into the five iodine ion test solutions mentioned above for 3 seconds, remove it, and time the reaction for 1 minute. Test each concentration 3 times. Determine the concentration value of iodine ions based on the reflectance value of the color development results of the urine iodine test strip in the five iodine ion test solutions.

[0262] Experimental results: The urine iodine test strips prepared in Example 8, when measured with a urine analyzer, showed consistent values ​​for five concentrations of iodine ion test solutions with the corresponding concentrations of five standard solutions: 0.0 μg / L, 50.0 μg / L, 150.0 μg / L, 300.0 μg / L, and 550.0 μg / L.

[0263] Following the same steps as described above, the urine iodine test strips prepared in Examples 1-7 and Examples 8-12 were tested using a urine analyzer, and the results were consistent with those obtained from the urine iodine test strip prepared in Example 8.

[0264] Example 16

[0265] Performance verification of dry chemical test strips for detecting iodide ions in urine

[0266] Preparation of dry chemical test strips for detecting iodide ions in urine: 1) Preparation of urine iodide test strips: Urine iodide test strips were prepared according to Example 8 for later use; 2) Preparation of urine treatment matrix package: Urine treatment matrix package was prepared according to Example 13; 3) Preparation of iodide ion standard colorimetric card package: Iodide ion standard colorimetric card package was prepared according to Example 14, and iodide ion standard colorimetric cards and iodide ion standard solutions with five concentrations of 0.0 μg / L, 50.0 μg / L, 150.0 μg / L, 300.0 μg / L, and 550.0 μg / L were obtained;

[0267] Preparation of iodide ion test solutions: At room temperature, take 1 ml of each of the five concentrations of iodide ion standard solutions, add 150 mg of urine treatment matrix package, shake well for 5 seconds, filter, and obtain the five concentrations of iodide ion test solutions.

[0268] Detection reaction: Immerse the urine iodine test strip into the five iodine ion test solutions mentioned above for 3 seconds, remove it, and time the reaction for 1 minute. Test each concentration 3 times. Determine the concentration value of iodine ions based on the color development results of the urine iodine test strip in the five iodine ion test solutions and the reflectance value measured by the urine analyzer.

[0269] 1) Visual inspection results: Compared with the standard colorimetric card (0.0 μg / L, 50.0 μg / L, 150.0 μg / L, 300.0 μg / L, 550.0 μg / L), the color development results of the urine iodine test strip at each concentration are consistent with the corresponding color levels on the standard colorimetric card prepared in Example 14. The accuracy is good, the results of the three tests are consistent, and the repeatability is good.

[0270] 2) Results of urine analyzer test: The test results of each concentration of urine iodine test strip are consistent with the corresponding standard solution concentrations (0.0μg / L, 50.0μg / L, 150.0μg / L, 300.0μg / L, 550.0μg / L), with good accuracy. The results of three tests are consistent and have good repeatability.

[0271] Following the same steps as described above, the urine iodine test strips prepared in Examples 1-7 and Examples 9-12 were treated with the urine treatment matrix package prepared in Example 13 to treat five iodine ion standard solutions. The results were compared with the standard colorimetric card prepared in Example 14, and the results were consistent with those of the urine iodine test strips prepared in Example 8.

[0272] Example 17

[0273] Applications of dry chemical test paper for detecting iodide ions

[0274] One hundred clinical natural urine samples were collected. At room temperature, 150 mg of urine treatment matrix was added to each sample, and the mixture was shaken for 3 seconds. The samples were then filtered to obtain the natural urine test solution.

[0275] Test: Immerse the urinary iodine test strip prepared in Example 8 into the standard solution for 2 seconds, remove it, and time the color development for 1 minute. Test 3 times for each concentration and read the value. The application effect of the urinary iodine test strip obtained in Example 8 can be evaluated by comparing it with the standard solution of iodine ions of known concentrations.

[0276] Visual inspection results: Compared with the standard colorimetric card (0, 50, 150, 300, 550 μg / l), the color development results of the urine iodine test strip prepared in Example 8 for detecting natural urine all fall within the corresponding color levels on the standard colorimetric card. The urine iodine test strip has a wide linear range, and the color development results of each urine sample are consistent after 3 tests, indicating good repeatability.

[0277] Urine analyzer test results: The urine iodine test strip prepared in Example 8 can detect natural urine and the results of urine analyzer tests can all fall within the set concentrations of iodine ion standard solution. The linear range is wide. The results of three tests on each urine sample are consistent, indicating good repeatability.

[0278] Following the same steps as described above, the urinary iodine test strips prepared in Examples 1-7 and Examples 9-12 were used to treat 100 natural urine samples with the urine treatment matrix package prepared in Example 13. The results were compared with the standard colorimetric card prepared in Example 14, and the results were consistent with those of the urinary iodine test strips prepared in Example 8.

[0279] Example 18

[0280] Performance verification of urine treatment matrix applied to urine iodine test strips

[0281] The performance of the urine treatment matrix in pretreatment of test samples was verified by visual inspection with urine iodine test strips and testing with a urine analyzer.

[0282] Verification content: ① Adsorption of iodide ions on urine treatment matrix; ② The ability of urine treatment matrix to treat interfering factors such as vitamin C, bilirubin, and pigments; ③ The treatment effect of urine treatment matrix on natural urine.

[0283] Four urinary iodine solutions—an aqueous solution of iodine ions, a standard solution of iodine ions, a standard solution of iodine ions interfering substances, and natural urine from the subjects—were treated with a urine treatment matrix to obtain four pre-treated iodine ion test solutions. The untreated and post-treated solutions were then simultaneously tested using urinary iodine test strips to verify the performance of the urine treatment matrix. The specific operating steps are as follows:

[0284] 1) Solution preparation:

[0285] Preparation of iodide ion aqueous solutions: Potassium iodide standard substance was prepared with water to prepare five iodide ion standard aqueous solutions of 0 μg / L, 50 μg / L, 150 μg / L, 300 μg / L, and 550 μg / L.

[0286] Preparation of iodide ion standard solutions: Take potassium iodide standard substance and prepare five iodide ion standard solutions of 0 μg / L, 50 μg / L, 150 μg / L, 300 μg / L and 550 μg / L with 0.1M sodium acetate buffer solution (pH 5.5);

[0287] Preparation of iodide ion interference standard solutions: Take potassium iodide standard substance and prepare five iodide ion standard solutions of 0 μg / L, 50 μg / L, 150 μg / L, 300 μg / L and 550 μg / L with 0.1 M sodium acetate buffer solution (pH 5.5). Add vitamin C and bilirubin interference substance respectively to prepare iodide ion interference standard solutions containing 20 mM vitamin C and 100 mM bilirubin.

[0288] Preparation of natural urine samples from subjects: 24-hour urine samples were collected from 50 healthy individuals and stored at 2–8°C.

[0289] 2) Detection reaction:

[0290] The above four solutions were divided into two parts. At room temperature, 1 ml of each part was taken and 150 mg of urine treatment matrix was added. The mixture was shaken for 5 seconds and filtered. The resulting four treated test solutions were tested using the urine iodine test paper prepared in Example 8, and compared with the above four iodine ion solutions and four iodine ion test solutions.

[0291] 3) Experimental results:

[0292] ① Comparing the test results of the treated iodide ion aqueous solution and the untreated iodide ion standard solution, the color development of each gradient test strip was consistent, indicating that the urine treatment matrix did not adsorb iodide ions;

[0293] ② Comparison of the test results of the treated iodide ion aqueous solution and the untreated iodide ion standard solution showed that the color development of each gradient test strip was consistent, indicating that the urine treatment matrix has no adsorption effect on iodide ions. At the same time, the urine treatment matrix can adsorb the dye pigments in artificial urine, and the pH of artificial urine has no effect on the test results.

[0294] ③ The results of the test of the treated solution containing 20mM vitamin C and 100mM bilirubin with the untreated standard aqueous solution of iodide ions were compared. The color of each gradient test strip was consistent, indicating that the urine treatment matrix can remove the interference of 20mM vitamin C and 100mM bilirubin at the same time, and does not adsorb iodide ions.

[0295] ④ The test results of the treated subject's natural urine and the treated iodine ion standard solution were compared. The iodine ion concentration in the urine fell within the range of 0 μg / L to 550 μg / L. The gradient range of the iodine ion standard solution is suitable for the detection of urinary iodine in the natural urine of clinical subjects.

[0296] 4) Experimental conclusions:

[0297] The urine treatment matrix package prepared according to Example 13 of the present invention was verified by using the urine iodine test paper of Example 8 to test the above sodium ion standard solution and natural urine, and it was determined that it can meet the requirements and effects of urine pretreatment.

[0298] Following the same steps as described above, the urine iodine test strips prepared according to Examples 1-7 and Examples 9-12 were used to test four iodine ion solutions: aqueous iodine ion solution, standard iodine ion solution, standard iodine ion interfering substance solution, and natural urine of the subject. The results were consistent with those of the urine iodine test strips prepared in Example 8.

[0299] Example 19

[0300] Comparison of the dry chemical test strip for detecting iodide ions in urine and commercially available urine iodine reagent kits according to this invention

[0301] Preparation of dry chemical test strips for detecting iodide ions in urine: Preparation of urine sodium test strips: Urine iodine test strips were prepared according to Example 8; Preparation of standard colorimetric card packs: Standard colorimetric card packs were prepared according to Example 14;

[0302] Urine iodine test strip test: Use urine iodine test strips to test five concentrations of iodine ion standard solution (0, 50, 150, 300, 550 μg / L) and compare the results with a urine analyzer. The reaction time is 1 minute, and the values ​​are read. Test once a month.

[0303] Urinary iodine reagent kit detection: Take potassium iodide standard material and prepare iodine ion standard solutions with concentrations of 100, 200, 300, and 500 μg / L using 0.1 M sodium acetate buffer solution (pH 5.5). Use a commercially available urinary iodine reagent kit to detect the iodine ion standard solutions of 100, 200, 300, and 500 μg / L concentrations sequentially according to the usage instructions. Detect each concentration standard solution 3 times and read the values ​​every 1.5 minutes.

[0304] The urinary iodine test strip of this invention was verified by visual inspection or urine analyzer testing, and compared with commercially available urinary iodine test kits. The results showed that:

[0305] Performance Comparison: Compared with the urinary iodine reagent kit, the urinary iodine test strip of this invention exhibits better sensitivity, accuracy, and repeatability at low concentration levels (0–50 μg / L); at medium concentration levels (150–300 μg / L), the sensitivity is comparable, with good accuracy and repeatability; and at high concentration levels (300–550 μg / L), the sensitivity, accuracy, and repeatability are all better.

[0306] Detection range: The detection range of the urine iodine reagent kit is 100 μg / l to 500 μg / l; the detection range of the urine iodine test strip of this invention is 0 μg / l to 550 μg / l, and the detection range of this invention is wider.

[0307] Sensitivity: The urine iodine reagent kit can detect iodine ions at a concentration of 50 μg / L; the urine iodine test strip of this invention can detect iodine ions at a concentration of 5.0 μg / L, and the detection sensitivity of this invention is higher.

[0308] Repeatability: The consistency of the urinary iodine reagent kit is higher than 90%; the consistency of the urinary iodine test strip of this invention is higher than 95%, and the repeatability of this invention is higher.

[0309] Detection speed: The reaction time of the urine iodine reagent kit is at least 1.5 minutes; the detection time of the urine iodine dry chemical test strip of this invention is 1 minute, making the detection of this invention faster and more time-saving;

[0310] Testing Procedure: Urine iodine test kits require large instruments, making the operation complex and inconvenient. The urine iodine test strips of this invention can be used directly by visual inspection or with the aid of a small urine analyzer, eliminating the need for large instruments. Compared to other methods, this invention is simpler to operate and more convenient to use.

[0311] Shelf life: The urinary iodine test kit has a shelf life of 8 months; the urinary iodine test strip of this invention has a shelf life of more than 20 months, and the shelf life of this invention is longer.

[0312] Storage conditions: The urinary iodine reagent kit should be refrigerated at 2-8°C, while the urinary iodine test strip of this invention should be stored at room temperature. The storage conditions of this invention are more flexible.

[0313] Carrying and transporting: Urine iodine test kits are inconvenient to carry and transport. This invention provides urine iodine test strips, which are easy to carry and transport.

[0314] Following the same steps as described above, the urine iodine test strips prepared according to Examples 1-7 and Examples 9-12 were compared with commercially available kits to detect five iodine ion standard solutions. At the same time, a urine analyzer was used for testing, and the results obtained were consistent with those of the urine iodine test strips prepared in Example 8.

[0315] As can be seen from the above embodiments, the present invention provides a dry chemical test strip for detecting iodide ions in urine, its preparation method, and its application. This invention, being a dry chemical test strip, is easier to carry and transport compared to reagent kits. Furthermore, the principle of this invention is the catalytic oxidation of benzidine-based colorimetric reagents by iodide ions, which is more environmentally friendly and non-toxic than the iodine-catalyzed arsenic-cerium redox method, and more sensitive, accurate, and operable than the iodine-catalyzed hydrazine-[oxidant-Ferroin reagent] method. The dry chemical test strip for detecting iodide ions in urine prepared by this invention can be read visually or the results can be obtained using a urine analyzer. Therefore, the urine iodine dry chemical test strip of this invention is simple to operate, convenient to use, highly accurate, fast, low-cost, and suitable for widespread use.

[0316] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A dry chemical test strip for detecting iodide ions in urine, characterized in that, Includes urine iodine test strips, urine treatment matrix pack, and standard colorimetric pack; The urine iodine test strip comprises a magnetic white sheet and a reagent module, with the reagent module attached to one end of the magnetic white sheet; the reagent module is made by drying and cutting filter paper impregnated with solution A and solution B. The urine treatment matrix package consists of a package containing a urine treatment matrix, which is composed of activated carbon and treatment reagents. The standard colorimetric kit includes an iodine ion standard solution and a standard colorimetric card; Solution A contains a buffer solution, an oxidizing agent, and a stabilizer; Solution B contains a colorimetric reagent and an organic solvent.

2. The method for preparing a dry chemical test strip for detecting iodide ions in urine as described in claim 1, characterized in that, Includes the following steps: 1) Preparation of urine iodine test strips: Filter paper is soaked in solution A and dried, then soaked in solution B and dried, and cut into strips to obtain reagent modules; one side of the reagent modules is pasted onto a magnetic white sheet, and then the magnetic white sheet is cut into strips to obtain urine iodine test strip packs; 2) Preparation of urine treatment matrix package: Activated carbon and treatment reagents are mixed in pure water, the filtrate is filtered off after precipitation, the filter cake is collected, and the filter cake is baked until dry to obtain urine treatment matrix; the urine treatment matrix is ​​added to packaging and vacuum sealed to obtain urine treatment matrix package; 3) Preparation of standard colorimetric card pack: Preparation of iodide ion standard solution: Take iodide ion standard substance, add artificial urine, and prepare iodide ion standard solutions of various concentrations for later use; Preparation of standard colorimetric card: Take iodide ion standard solution, add urine treatment matrix, shake well, filter, and prepare iodide ion test solutions of various concentrations; Immerse urine iodine test paper into iodide ion test solutions of various concentrations respectively, take it out, time the reaction, read the value, and use the concentration of iodide ion test solution and the corresponding endpoint color of urine iodine test paper as color standard to obtain standard colorimetric card.

3. The preparation method according to claim 2, characterized in that, In the preparation steps of the urinary iodine test strip: Solution A contains a buffer solution, an oxidizing agent, and a stabilizer; The buffer solution comprises one or more of the following: tris(hydroxymethyl)aminomethane hydrochloride buffer solution, potassium dihydrogen phosphate-disodium hydrogen phosphate buffer solution, disodium hydrogen phosphate-sodium hydroxide buffer solution, citrate-sodium citrate buffer solution, and acetate-sodium acetate buffer solution; the concentration of the buffer solution is 0.1–2.0 M; the pH of the buffer solution is 8.0–11.

0. The oxidant comprises one or more of the sodium salt, potassium salt, sodium salt hydrate, or potassium salt hydrate of benzenesulfonyl haloamine derivatives; The benzenesulfonyl halide derivatives include one or more of the following: benzenesulfonyl chloride, benzenesulfonyl bromide, p-toluenesulfonyl chloride, p-toluenesulfonyl bromide, o-toluenesulfonyl chloride, o-toluenesulfonyl bromide, p-nitrobenzenesulfonyl chloride, p-nitrobenzenesulfonyl bromide, N,N-dichlorobenzenesulfonamide, N,N-dibromobenzenesulfonamide, N,N-dichloro-p-toluenesulfonamide, N,N-dibromo-p-toluenesulfonamide, p-(N,N-dichloroaminesulfonyl)benzoic acid, and p-(N,N-dibromoaminesulfonyl)benzoic acid; The stabilizer comprises one or more of gelatin, sodium dodecyl sulfonate, polyvinylpyrrolidone K30, ethylene glycol 4000, polyethylene glycol 2000, dextran T70, CMC-Na, sodium alginate, maltodextrin, quinoline, sodium chloride, and decanol. The volume-to-mass ratio of the buffer solution, oxidant, and stabilizer is 1000 mL: 0.5–15.0 g: 1.0–40.0 g.

4. The preparation method according to claim 2, characterized in that, The B solution contains a colorimetric reagent and an organic solvent; the colorimetric reagent includes one or more of the benzidine class of colorimetric reagents, wherein the benzidine class of colorimetric reagents includes one or more of 3,3'-dichlorobenzidine, 2,2'-disulfonic benzidine, 3,3'-dihydroxybenzidine, 3,3'-diaminobenzidine, and 3,3',5,5'-tetramethylbenzidine; The organic solvent comprises one or more of methanol, ethanol, acetone, tetrahydrofuran, ethyl acetate, dichloromethane, and acetonitrile; The mass-to-volume ratio of the colorimetric reagent to the organic solvent is 0.5–15.0 g: 1000 mL.

5. The preparation method according to claim 2, characterized in that, The filter paper is immersed in solution A and solution B for 10–60 s independently; The filter paper is immersed in solution A and then dried. The drying temperature is 40-70°C and the drying speed is 80-130 m / h. The temperature at which the sample is removed from solution B and dried is 35–65°C, and the drying rate is 70–120 m / h. In the step of cutting the test paper into strips, the width of the strips is 5 to 8 millimeters; In the process of cutting the magnetic white sheet into strips, the width of the magnetic white sheet is 5-8 mm and the length of the magnetic white sheet is 50-90 mm; The filter paper includes 3MM type filter paper, 31ET type filter paper, MN818 type filter paper, MN827 type filter paper or 7218 type filter paper.

6. The preparation method according to claim 2, characterized in that, In the preparation steps of the urine treatment matrix package: The treatment reagent contains one or more sodium indophenolate salt compounds; The indophenol comprises one or more of o-chlorophenol indophenol, 3'-chloroindophenol, 5-isopropyl-2-methylindophenol, 2,6-dichloroindophenol, 2,6-dichloroindophenol acetate, 2,3',6-trichloroindophenol, 2,2',6-trichloro-indophenol, 2,6-dichloro-3'-methylindophenol, 2,6-dibromoindophenol, 2,6-dibromoindophenol acetate, 2,3',6-tribromoindophenol, 2,2',6-tribromo-indophenol, and 2,6-dibromo-3'-methylindophenol. The activated carbon is wood-based activated carbon with a mesh size of 200-350 and a porosity of 55%-75%. The mass ratio of the treatment reagent to activated carbon is 1-10%. The baking temperature is 105–140°C; the baking time is 2–8 hours. The activated carbon is one or more of coal-based activated carbon, synthetic material activated carbon, and wood-based activated carbon; The activated carbon has a mesh size of 150-400 and a porosity of 50%-80%, preferably a mesh size of 200-350 and a porosity of 60%-70%.

7. The preparation method according to claim 2, characterized in that, In the preparation steps of the standard colorimetric kit: The iodide ion standard substance is potassium iodide or sodium iodide; the iodide ion standard solution is prepared with artificial urine, which is a sodium acetate-acetic acid buffer solution with a molar concentration of 0.1-1.0 M and a pH of 5.1-6.

5. The iodide ion standard solution is available in five concentrations, corresponding to five color levels: 0 μg / l, 50 μg / l, 150 μg / l, 300 μg / l, and 550 μg / l. The mass-to-volume ratio of the urine treatment matrix to the iodide ion standard solution is 0.1–0.2 g: 1 mL; The urine treatment matrix treatment time is 3–15 seconds; In this invention, the time for the urine iodine test strip to be immersed in the iodine ion test solution is 1 to 3 seconds; the reaction temperature of the urine iodine test strip is room temperature, which is 20 to 25°C; and the timing reaction time is 0.5 to 1 minute.

8. The application of the dry chemical test strip for detecting iodide ions in urine as described in claim 1, characterized in that, Includes the following steps: 1) Take a natural urine sample, add urine treatment matrix, shake well, filter, and obtain the natural urine test solution; 2) Immerse the urine iodine test strip into the test solution of natural urine, remove it, and time the reaction; 3) Compare the results of the urine iodine test strip reaction with the standard color chart and read the values.

9. The application according to claim 8, characterized in that, The urine sample is a 24-hour urine sample or a midstream morning urine sample, and the urine sample is stored at 4–8°C for later use. The mass-to-volume ratio of the urine treatment matrix to the urine to be tested is 0.1–0.2 g: 1 ml; the treatment time is 3–15 s.

10. The application according to claim 8, characterized in that, The time for the urinary iodine test strip to be immersed in urine is 1 to 3 seconds; the reaction temperature is room temperature, specifically 20 to 25°C; and the timing reaction time is 0.5 to 1 minute.

Images