A dry chemical reagent tablet for detecting calcium content and preparation method thereof

Abstract

The present invention provides a dry chemical reagent sheet for detecting calcium content and a preparation method thereof, and relates to the field of dry chemical reagent sheets. The dry chemical reagent sheet includes a light-transmitting layer, a reagent layer and a diffusion layer, wherein the reagent layer is arranged above the light-transmitting layer, the diffusion layer is arranged above the reagent layer, the diffusion layer includes a diffusion layer reagent or is formed by a diffusion layer reagent, the diffusion layer reagent includes a hydrophilic polymer, a surfactant and particulate matter, wherein the particulate matter includes a first particulate matter and a second particulate matter; the number ratio of the first particulate matter to the second particulate matter is 1:(0.25-4), and the difference in particle size between the first particulate matter and the second particulate matter is 1-4 μm. The dry chemical reagent sheet provided by the present invention is easy to operate, can quickly and accurately quantitatively detect the calcium content in a liquid sample, has a simple preparation process, a small sample size, is easy to store and transport, has a low cost, and has a wide range of applications.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] The present invention claims the priority of Chinese patent application CN 202411438172.7 filed on October 15, 2024, entitled “A dry chemical reagent sheet for detecting calcium content and its preparation method”, and the entire contents of the above application are incorporated herein by reference. Technical Field

[0003] The invention relates to the field of dry chemical reagent tablets, and in particular to a dry chemical reagent tablet for detecting calcium content and a preparation method thereof. Background Art

[0004] Calcium is the main component of human bones and teeth. Calcium is the most abundant cation in the human body. It not only participates in the coagulation process and activates a variety of enzymes, but also participates in other physiological activities of the human body, such as participating in nerve and muscle activities, maintaining tissue irritability, adjusting heart rate, reducing the permeability of capillaries and cell membranes, maintaining acid-base balance in the body, controlling metabolism, hormone secretion, cell adhesion and division, and other physiological activities. Serum calcium determination is a diagnostic indicator for calcium metabolism disorders. Increased serum calcium is common in hyperthyroidism, bone disease, etc.; decreased serum calcium is common in hypothyroidism, calcium and vitamin D malabsorption, etc. Therefore, the determination of serum calcium has very important clinical significance in clinical chemistry tests.

[0005] The development of dry chemical analysis technology stems from the progress of enzyme separation, purification, and preservation technology in recent decades, the development of reflectance photometers and microelectrodes, and the application of electronic computers. It is a new detection method that has been applied to clinical laboratory testing in recent years. Compared with wet chemical methods, it has the advantages of high accuracy, rapid detection, and good precision. Dry chemistry is a method of analysis that uses the liquid in the sample to be tested (plasma, serum, urine, etc.) as the reaction medium, and the sample to be tested directly reacts with the dry reagent solidified on the carrier, and uses the water contained in the sample to be tested as a solvent to induce a specific chemical reaction. It has the advantages of being fast, simple, and easy to preserve. These advantages have made dry chemical analysis technology widely used in clinical testing and biomedical fields. With the continuous development of medical technology, the application scope of dry chemical analysis technology is also expanding. In emergency medical scenarios, biochemical tests are gradually replacing traditional wet chemical methods with dry chemical methods. Therefore, the research on dry chemical analysis technology is of great significance. Summary of the invention

[0006] In view of the above analysis, the present invention aims to provide a dry chemical reagent sheet for detecting calcium content and a preparation method thereof, so as to solve the problems in the prior art such as large blood drawing volume, long analysis cycle, complicated process, and inability to measure in real time.

[0007] The purpose of the present invention is mainly achieved through the following technical solutions:

[0008] In the first aspect, the present invention provides a dry chemical reagent sheet for detecting calcium content, comprising a light-transmitting layer, a reagent layer and a diffusion layer, wherein the reagent layer is arranged above the light-transmitting layer, the diffusion layer is arranged above the reagent layer, the diffusion layer comprises a diffusion layer reagent or is formed by a diffusion layer reagent, the diffusion layer reagent comprises a hydrophilic polymer, a surfactant and particulate matter, wherein the particulate matter comprises a first particulate matter and a second particulate matter; the number ratio of the first particulate matter to the second particulate matter is 1:(0.25-4), preferably 1:(0.5-1.5), and the difference in particle size between the first particulate matter and the second particulate matter is 1-4 μm, preferably 1.5-2.5 μm.

[0009] Preferably, the particle size of the first particles is 4 to 8 μm, preferably 4.5 to 5.5 μm.

[0010] Preferably, the particle size of the second particles is 1 to 4 μm, preferably 2.5 to 3.5 μm.

[0011] Preferably, the amount of hydrophilic polymer in the diffusion layer reagent is 1 to 30 g / m 2 , preferably 15-25g / m 2 ; The dosage of surfactant is 5~50g / m 2 , preferably 6 to 15 g / m 2 ; The dosage of particles is 100~500g / m 2 , preferably 120 to 200 g / m 2 .

[0012] Preferably, in the diffusion layer reagent, the hydrophilic high molecular polymer includes at least one of cellulose acetate and cellulose nitrate; preferably, the viscosity of the hydrophilic high molecular polymer is 30 to 45 poise, more preferably 35 to 40 poise.

[0013] Preferably, in the diffusion layer reagent, the surfactant includes at least one of Surfynol, Tween and Triton.

[0014] Preferably, in the diffusion layer reagent, the first particulate matter and the second particulate matter are the same or different, and each independently comprises at least one of titanium dioxide, barium sulfate, barium titanate, polystyrene microspheres, diatomaceous earth, and kaolin.

[0015] Preferably, the reagent layer includes or is formed by a reagent layer reagent, and the reagent layer reagent includes a buffer system, a color developer, a surfactant and a colloid.

[0016] Preferably, it is characterized in that the amount of the buffer system in the reagent layer reagent is 0.01 to 0.02 mol / m 2 , preferably 0.01 to 0.015 mol / m 2 ; The dosage of the developer is 10~40mmol / m 2 , preferably 20 to 30 mmol / m 2 ; The dosage of surfactant is 2~15g / m 2 The dosage is preferably 5 to 10 g / m 2 ; The amount of colloid used is 3 to 30 g / m 2 , preferably 15 to 25 g / m 2 .

[0017] Preferably, in the reagent layer reagent: the buffer system includes at least one of a phosphate buffer system, a Tris buffer system, a boric acid buffer system, and a MES buffer system; preferably, the pH of the buffer system is 4 to 7, preferably 5 to 6, and more preferably 5.5 to 5.6; the color developer includes arsenazo III; the surfactant includes at least one of Tween, Triton, Surfynol, and S24; the colloid includes at least one of gelatin, pullulan, polyvinyl alcohol, polyacrylamide, and a hydrophilic cellulose derivative.

[0018] Preferably, in the reagent layer reagent, the surfactant includes Triton and S24, wherein: the amount of S24 is 2 to 10 g / m 2 , preferably 5 to 7 g / m 2 ; The dosage of Triton is 0.1~5g / m 2 , preferably 0.3 to 3 g / m 2 .

[0019] Preferably, the thickness of the reagent layer is 10-100 μm; the thickness of the diffusion layer is 200-800 μm; and the thickness of the light-transmitting layer is 30-300 μm.

[0020] In a second aspect, the present invention provides a method for preparing the dry chemical reagent sheet, comprising the following steps:

[0021] Step 1: Heat the reagent layer reagent to 35-45°C, stir, apply it on the light-transmitting layer, and dry;

[0022] Step 2: Apply the diffusion layer reagent on the reagent layer and dry.

[0023] Beneficial effects:

[0024] The dry chemical reagent tablet provided by the present invention is easy to operate, can quickly and accurately quantitatively detect the calcium content in a liquid sample, and the detection result has high accuracy and good repeatability. The dry chemical reagent tablet has a simple preparation process, a small sample size, is easy to store and transport, has a low cost, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic structural diagram of the dry chemical reagent tablet provided by the present invention.

[0026] Figure 2 This is a color comparison diagram of the dry chemical reagent sheet of Example 1 provided by the present invention.

[0027] In the figure, 1-upper outer frame, 2-sample loading hole of upper outer frame, 3-diffusion layer, 4-reagent layer, 5-light-transmitting layer, 6-light-transmitting hole of lower outer frame, 7-lower outer frame. DETAILED DESCRIPTION

[0028] Preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used to explain the principles of the present invention together with the embodiments of the present invention.

[0029] The present invention provides a dry chemical reagent sheet for rapidly measuring calcium content. The dry chemical reagent sheet comprises an upper outer frame, a diffusion layer, a reagent layer, a light-transmitting layer and a lower outer frame from top to bottom. The diffusion layer is a porous cellulose membrane, comprising a cellulose solution and particulate matter. The reagent layer comprises a buffer system, a color developer, a surfactant, a colloid and the like. The diffusion layer, the reagent layer and the light-transmitting layer are sequentially bonded together through a coating process. A sample addition hole is provided at the center of the upper outer frame, and a light-transmitting hole is provided at the center of the lower outer frame. A liquid sample is dropped into the sample addition hole, and after being evenly dispersed in the diffusion layer, it reacts with a preset reagent in the reagent layer to produce a color-developing circular spot. The concentration of calcium is quantitatively determined according to the depth of the color of the circular spot. Compared with the wet chemical detection method, the dry chemical reagent sheet has the advantages of fast speed, high accuracy, simple and convenient operation, reliable results and the like, and is an ideal method for calcium detection. It can be widely used in multiple fields such as in vitro diagnosis, drug synthesis and screening, environmental monitoring and protection, health quarantine, and forensic identification.

[0030] Hereinafter, the present invention will be described in detail.

[0031] In a first aspect, the present invention provides a dry chemical reagent sheet for detecting calcium content, comprising a light-transmitting layer and a reagent layer, wherein the reagent layer is arranged above the light-transmitting layer, the reagent layer comprises a reagent layer reagent or is formed by a reagent layer reagent, and the reagent layer reagent comprises a buffer system, a color developer, a surfactant, and a colloid.

[0032] As a specific embodiment of the present invention, in the reagent layer reagent, the buffer system is at least one of a phosphate buffer system, a Tris buffer system, a boric acid buffer system, and a MES buffer system, and the pH of the buffer system is 4 to 7, preferably 5 to 6, and more preferably 5.5 to 5.6. The amount of the buffer system is 0.01 to 0.02 mol / m 2 , preferably 0.01 to 0.015 mol / m 2 , more preferably 0.012 mol / m 2 .

[0033] As a specific embodiment of the present invention, the phosphate buffer system includes disodium hydrogen phosphate and sodium dihydrogen phosphate.

[0034] As a specific embodiment of the present invention, the boric acid buffer system includes boric acid and sodium borate.

[0035] As a specific embodiment of the present invention, the MES buffer system includes MES (4-morpholineethanesulfonic acid) and hydroxide.

[0036] As a specific embodiment of the present invention, the Tris buffer system includes Tris (tris(hydroxymethyl)aminomethane) and hydrochloric acid.

[0037] As a specific embodiment of the present invention, in the reagent layer reagent, the color developer is arsenazo III, and the amount of the color developer is 10 to 40 mmol / m 2 , preferably 20 to 30 mmol / m 2 .

[0038] As a specific embodiment of the present invention, in the reagent layer reagent, the surfactant is at least one of Tween (model may be Teween-80), Triton (model may be TritonX-100), Surfynol (model may be Surfynol 485), S24 (model may be Surfactant 10G). The amount of the surfactant used is 2 to 15 g / m 2 , preferably 5 to 10 g / m 2 .

[0039] As a specific embodiment of the present invention, in the reagent layer reagent, the surfactant includes Triton and S24, wherein:

[0040] The dosage of S24 is 2~10g / m 2 , preferably 5 to 7 g / m 2 , more preferably 6g / m 2 ;

[0041] The dosage of Triton is 0.1~5g / m 2 , preferably 0.3 to 3 g / m2 , more preferably 1.605 g / m 2 .

[0042] It should be noted that the surfactant in the reagent layer makes the reagent dispersed evenly when applied, and the surfactant S24 has a solubilizing effect on the dye.

[0043] As a specific embodiment of the present invention, in the reagent layer reagent, the colloid is at least one of gelatin, pullulan, polyvinyl alcohol, polyacrylamide, and a hydrophilic cellulose derivative, and the amount of the colloid is 3 to 30 g / m 2 , preferably 15 to 25 g / m 2 .

[0044] As a specific embodiment of the present invention, in the reagent layer reagent, the gelatin is selected from at least one of photographic gelatin and edible gelatin.

[0045] As a specific embodiment of the present invention, in the reagent layer reagent, the wet film thickness of the reagent layer is 100-600 μm, the dry film thickness is 10-100 μm, and preferably the dry film thickness is 15-30 μm.

[0046] In the present invention, the pH of the buffer system in the reagent layer reagent cannot be greater than 7, because under alkaline conditions, magnesium ions in the serum sample will react with arsenazo III to develop color, interfering with the experimental results.

[0047] As a specific embodiment of the present invention, the reagent sheet further includes a diffusion layer disposed above the reagent layer, the diffusion layer includes a diffusion layer reagent or is formed by a diffusion layer reagent, and the diffusion layer reagent includes a hydrophilic polymer, a surfactant and particulate matter.

[0048] As a specific embodiment of the present invention, in the diffusion layer reagent, the hydrophilic polymer is selected from at least one of cellulose acetate and cellulose nitrate, and the amount of the hydrophilic polymer is 1 to 30 g / m 2 , preferably 15 to 25 g / m 2 .

[0049] As a specific embodiment of the present invention, in the diffusion layer reagent, the viscosity of the hydrophilic high molecular polymer is 30 to 45 poise, for example, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44 poise, etc., preferably 35 to 40 poise. It should be noted that the viscosity determination method of the hydrophilic high molecular polymer such as cellulose acetate is to determine the intrinsic viscosity of cellulose acetate by the viscosity method, and the intrinsic viscosity of cellulose acetate in tetrahydrofuran solvent is determined by using the viscosity method, that is, the constant in the molecular weight equation.

[0050] As a specific embodiment of the present invention, in the diffusion layer reagent, the surfactant is at least one of Surfynol, Tween, and Triton. The amount of the surfactant is 5 to 50 g / m 2 , preferably 6 to 15 g / m 2 .

[0051] As a specific embodiment of the present invention, in the diffusion layer reagent, the particles include first particles and second particles, the first particles and the second particles are the same or different, and are independently selected from at least one of titanium dioxide, barium sulfate, barium titanate, polystyrene microspheres, diatomaceous earth, and kaolin. The amount of the particles is 100 to 500 g / m 2 , preferably 120 to 200 g / m 2 .

[0052] As a specific embodiment of the present invention, the average particle size of the first particles is 4 to 8 μm, for example, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5 μm, etc., preferably 4.5 to 5.5 μm, and more preferably 5 μm.

[0053] As a specific embodiment of the present invention, the average particle size of the second particulate matter is 1 to 4 μm, for example, 1.5, 2.0, 2.5, 3.0, 3.5 μm, etc., preferably 2.5 to 3.5 μm, and more preferably 3 μm.

[0054] As a specific embodiment of the present invention, the number ratio of the first particles to the second particles is 1:(0.25-4), preferably 1:(0.5-1.5), and more preferably 1:1.

[0055] As a specific embodiment of the present invention, the difference in particle size between the first particle and the second particle is 1-4 μm, such as 1.5, 2.0, 2.5, 3.0, 3.5 μm, etc., preferably 1.5-2.5 μm. It should be noted that the difference in the present invention refers to the absolute value.

[0056] In the present invention, the combination of the first particulate matter and the second particulate matter will change the pore size of the porous cellulose membrane of the diffusion layer, thereby further effectively improving the porosity of the diffusion layer, and further improving the diffusion speed of the droplets on the diffusion layer and the uniformity of the diffusion circular spots. It should be noted that in the present invention, unless otherwise specified, the particle size of the particulate matter is the average particle size.

[0057] As a specific embodiment of the present invention, the diffusion layer has a wet film thickness of 500 to 1500 μm, a dry film thickness of 200 to 800 μm, and preferably a dry film thickness of 400 to 600 μm.

[0058] As a specific embodiment of the present invention, the light-transmitting layer of the dry chemical reagent sheet is a transparent plastic substrate, such as polyethylene PE, polypropylene PP, polyester methyl methacrylate PMMA, polystyrene PS, polycarbonate PC, polyethylene terephthalate PET, etc., with PET being the best.

[0059] As a specific embodiment of the present invention, the thickness of the light-transmitting layer is 30-300 μm, preferably 100-200 μm. The transmittance of visible light with a wavelength of 680 nm is above 80%, preferably above 95%. Both the incident light source and the reflected light can pass through the light-transmitting layer.

[0060] As a specific embodiment of the present invention, the surface of the light-transmitting layer is pre-treated by corona, plasma irradiation, ultraviolet irradiation, etc.

[0061] As a specific embodiment of the present invention, the reagent sheet further comprises an upper outer frame, which is arranged above the diffusion layer. A sample addition hole is arranged at the center of the upper outer frame, and the diameter of the hole is 5 to 10 mm.

[0062] As a specific embodiment of the present invention, the reagent sheet further comprises a lower outer frame, which is arranged below the light-transmitting layer. A light-transmitting hole is arranged at the center of the lower outer frame, and the diameter of the hole is 5 to 10 mm.

[0063] As a specific embodiment of the present invention, a glue layer is attached to the lower outer frame for bonding the upper outer frame. The upper outer frame and the lower outer frame can fix the multi-layer film structure and prevent the oxidation of the pre-set reagent in the reagent layer, thereby extending the storage time of the reagent.

[0064] The dry chemical reagent sheet provided by the present invention has a color development principle as follows: a serum sample is dripped onto a diffusion layer of the reagent sheet, the sample diffuses evenly in the diffusion layer, and then diffuses into the reagent layer, and calcium in the sample reacts with arsenazo III to develop color.

[0065] The dry chemical reagent tablet provided by the present invention is easy to operate and can quickly and accurately quantitatively detect the calcium content in a liquid sample. The test result has high accuracy and good repeatability. The dry chemical reagent tablet has a simple preparation process, a small sample size, is easy to store and transport, has low cost, and has a wide range of applications.

[0066] In a second aspect, the present invention provides a method for preparing a dry chemical reagent tablet for detecting calcium content, comprising the following steps:

[0067] Step 1: Heat the reagent layer reagent to 35-45°C, stir, apply it on the light-transmitting layer, and dry;

[0068] Step 2: Apply the diffusion layer reagent on the reagent layer and dry;

[0069] Step 3: Assemble the upper outer frame and the lower outer frame.

[0070] As a specific embodiment of the present invention, the structure of the dry chemical reagent sheet provided by the present invention can be as follows: Figure 1 shown. Figure 1 In the figure, 1 is an upper outer frame, 2 is a sample loading hole of the upper outer frame, 3 is a diffusion layer, 4 is a reagent layer, 5 is a light-transmitting layer, 6 is a light-transmitting hole of the lower outer frame, and 7 is a lower outer frame.

[0071] The preferred embodiments of the present invention are described in detail below to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0072] It should be noted that, in the present invention, the amount of each component in the reagent layer reagent and the diffusion layer reagent is the amount of the listed substances, and does not include the amount of the solvent for dissolving the component.

[0073] Unless otherwise specified, the reagents used in the embodiments of the present invention are all commercially available products.

[0074] Example 1

[0075] The dry chemical reagent sheet is composed of an upper outer frame 1, a diffusion layer 2, a reagent layer 4, a light-transmitting layer 5 and a lower outer frame 7 from top to bottom (eg Figure 1 A sample adding hole 2 is provided at the center of the upper outer frame, and a light transmission hole 6 is provided at the center of the lower outer frame.

[0076] Use Figure 1 The dry chemical reagent sheet structure shown in the figure has the following specific operation steps:

[0077] The light-transmitting layer 5 is made of PET film with a thickness of 125 μm and a light transmittance of more than 95% at a wavelength of 680 nm. The formula of the reagent layer 4 is shown in Table 1. The prepared reagent layer coating liquid is heated and stirred at 40°C for 20 minutes, and evenly coated on the light-transmitting layer PET film, with a wet film thickness of 300 μm. Place it in a blast drying oven at 37°C, and continue to coat the diffusion layer 3 after it is completely dried, with a wet film thickness of 750 μm. The diffusion layer formula is shown in Table 2. After drying in a fume hood, cut into 1 cm 2 The reagent sheet is assembled by using a plastic sheet as the upper outer frame 1 and the lower outer frame 7 of the reagent sheet. The central opening diameter of the upper and lower outer frames is 10 mm.

[0078] Table 1 Reagent layer reagents

[0079] Serial number Reagent layer reagent Dosage 1 Photographic Gelatin 20g / m2 2 Arsenazo III 26mmol / m2 3 SURFACTANT 10G <![CDATA[6g / m 2 ]]> 4 TritonX-100 <![CDATA[1.605g / m 2 ]]> 5 Buffer (MES buffer system) pH = 5.6, 0.012 mol / m2

[0080] Table 2 Diffusion layer reagents

[0081]

[0082] Example 2

[0083] This embodiment is basically the same as the embodiment 1, except that the type of colloid in the reagent layer is changed to edible gelatin.

[0084] Example 3

[0085] This embodiment is basically the same as the embodiment 1, except that, in the reagent layer, the prepared reagent layer coating liquid is heated at 50° C. and stirred for 20 minutes, and then evenly coated on the light-transmitting layer PET film.

[0086] Example 4

[0087] This embodiment is basically the same as embodiment 1, except that in the reagent layer, the surfactant only includes glycerol, and the amount used is 7.605 g / m 2 .

[0088] Example 5

[0089] This embodiment is basically the same as Embodiment 1, except that the type of buffer in the reagent layer is changed to Tris-HCl buffer.

[0090] Example 6

[0091] This embodiment is substantially the same as the embodiment 1, except that the viscosity of the cellulose acetate in the diffusion layer is 20 poise.

[0092] Example 7

[0093] This embodiment is basically the same as the embodiment 1, except that in the diffusion layer, the type of particles is changed to barium sulfate (the ratio of the number of barium sulfate with particle sizes of 5 μm and 3 μm is 1:1).

[0094] Example 8

[0095] This embodiment is substantially the same as the embodiment 1, except that the viscosity of the cellulose acetate in the diffusion layer is 30 poise.

[0096] Example 9

[0097] This embodiment is substantially the same as the embodiment 1, except that the viscosity of the cellulose acetate in the diffusion layer is 45 poise.

[0098] Example 10

[0099] This embodiment is basically the same as the embodiment 1, except that titanium dioxide particles with particle sizes of 5 μm and 3 μm are added in a quantity ratio of 1:2 into the diffusion layer.

[0100] Embodiment 11

[0101] This embodiment is basically the same as the embodiment 1, except that titanium dioxide particles with particle sizes of 6 μm and 2 μm are added in a quantity ratio of 1:1 into the diffusion layer.

[0102] Example 12

[0103] This embodiment is basically the same as the embodiment 1, except that, during the preparation of the diffusion layer, titanium dioxide particles with particle sizes of 8 μm and 4 μm are added in a quantity ratio of 1:1.

[0104] Embodiment 13

[0105] This embodiment is basically the same as the embodiment 1, except that titanium dioxide particles with particle sizes of 5 μm and 3 μm are added in a quantity ratio of 1:5 in the diffusion layer.

[0106] Comparative Example 1

[0107] This comparative example is substantially the same as Example 1, except that in the diffusion layer, the particles only include titanium dioxide with a particle size of 3 μm.

[0108] Comparative Example 2

[0109] This comparative example is substantially the same as Example 1, except that in the diffusion layer, the particles only include titanium dioxide with a particle size of 5 μm.

[0110] Experimental example

[0111] Prepare five serum samples with calcium ion concentrations of 1.8 mg / dL, 4.8 mg / dL, 9.3 mg / dL, 12.45 mg / dL, and 13.8 mg / dL, respectively (wherein, serum samples with concentrations of 1.8 mg / dL, 9.3 mg / dL, and 13.8 mg / dL are commercially available composite calibrators, and the remaining concentrations are diluted concentrations based on commercially available composite calibrators). 10 μL of the sample to be tested is dripped into the upper outer frame sample well 2, and the sample penetrates uniformly and quickly into the reagent layer through the diffusion layer, reacts at 37° C. for 5 min, and uses an optical density meter to measure the optical density value of the colored circular spot at a wavelength of 680 nm. The test results of the embodiment and the comparative example are shown in Table 3.

[0112] Commercially available composite calibrators with concentrations of 1.8 mg / dL, 9.3 mg / dL, and 13.8 mg / dL were added dropwise to the Example and the Comparative Example for reaction. The coefficient of variation CV was calculated by repeating 10 times. The results are shown in Table 4.

[0113] The color comparison results of Example 1 when three concentrations (1.8 mg / dL, 9.3 mg / dL, 13.8 mg / dL) of commercially available composite calibrants are added are as follows: Figure 2 As shown, the three circular spots with creatinine concentrations from low to high are uniform in size and color, and the colors range from light to dark ( Figure 2 In the figure, from top to bottom, the corresponding concentrations are 1.8 mg / dL, 9.3 mg / dL, and 13.8 mg / dL).

[0114] Table 3 Performance parameters of examples and comparative examples

[0115]

[0116]

[0117] It can be seen from Table 3 that the slope of Example 1 is 0.0464, which is higher than that of Comparative Examples 1-2, indicating that the difference in optical density between high concentration and low concentration is large and the color difference is obvious; the correlation coefficient r of Example 1 is 2 The value is 0.9999, which is higher than that of Comparative Example 1-2, indicating that the correlation coefficient between calcium concentration and optical density is higher.

[0118] Table 4 Coefficient of variation CV of the embodiments and comparative examples

[0119]

[0120]

[0121] It can be seen from Table 4 that the coefficient of variation CV of Example 1 is lower than that of Comparative Examples 1-2, indicating that the precision of Example 1 is better.

[0122] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. A dry chemical reagent tablet for detecting calcium content, characterized in that: The invention comprises a light-transmitting layer, a reagent layer and a diffusion layer, wherein the reagent layer is arranged above the light-transmitting layer, and the diffusion layer is arranged above the reagent layer, and is characterized in that the diffusion layer comprises a diffusion layer reagent or is formed by a diffusion layer reagent, and the diffusion layer reagent comprises a hydrophilic polymer, a surfactant and particulate matter, wherein the particulate matter comprises a first particulate matter and a second particulate matter; The number ratio of the first particles to the second particles is 1:(0.25-4), preferably 1:(0.5-1.5), The difference in particle size between the first particulate matter and the second particulate matter is 1 to 4 μm, preferably 1.5 to 2.5 μm.

2. The dry chemical reagent sheet according to claim 1, characterized in that: The particle size of the first particles is 4 to 8 μm, preferably 4.5 to 5.5 μm; And / or, the particle size of the second particulate matter is 1 to 4 μm, preferably 2.5 to 3.5 μm.

3. The reagent sheet according to any one of claims 1 to 2, characterized in that: In the diffusion layer reagent, The amount of hydrophilic polymer is 1 to 30 g / m 2 , preferably 15-25g / m 2 ; And / or, the amount of surfactant is 5 to 50 g / m 2 , preferably 6 to 15 g / m 2 ; And / or, the amount of particles is 100-500 g / m 2 , preferably 120 to 200 g / m 2 .

4. The reagent sheet according to any one of claims 1 to 3, characterized in that: In the diffusion layer reagent, the hydrophilic polymer includes at least one of cellulose acetate and cellulose nitrate; preferably, the viscosity of the hydrophilic polymer is 30 to 45 poise, preferably 35 to 40 poise; and / or, in the diffusion layer reagent, the surfactant comprises at least one of Surfynol, Tween, and Triton; And / or, in the diffusion layer reagent, the first particulate matter and the second particulate matter are the same or different, and each independently comprises at least one of titanium dioxide, barium sulfate, barium titanate, polystyrene microspheres, diatomaceous earth, and kaolin.

5. The reagent sheet according to any one of claims 1 to 4, characterized in that: The reagent layer includes a reagent layer reagent or is formed by a reagent layer reagent, and the reagent layer reagent includes a buffer system, a color developer, a surfactant and a colloid.

6. The reagent sheet according to any one of claims 1 to 5, characterized in that: In the reagent layer reagent, the amount of the buffer system is 0.01-0.02 mol / m 2 , preferably 0.01 to 0.015 mol / m 2 ; And / or, the amount of the developer is 10 to 40 mmol / m 2 , preferably 20 to 30 mmol / m 2 ; And / or, the amount of surfactant is 2 to 15 g / m 2 , preferably 5 to 10 g / m 2 ; And / or, the amount of colloid is 3 to 30 g / m 2 , preferably 15 to 25 g / m 2 .

7. The reagent sheet according to any one of claims 1 to 6, characterized in that: In the reagent layer reagent: The buffer system includes at least one of a phosphate buffer system, a Tris buffer system, a boric acid buffer system, and a MES buffer system; preferably, the pH of the buffer system is 4 to 7, preferably 5 to 6, and more preferably 5.5 to 5.6; and / or, the developer comprises arsenazo III; and / or, the surfactant comprises at least one of Tween, Triton, Surfynol, and S24; And / or, the colloid includes at least one of gelatin, pullulan, polyvinyl alcohol, polyacrylamide, and a hydrophilic cellulose derivative.

8. The reagent sheet according to any one of claims 1 to 7, characterized in that: In the reagent layer reagent, the surfactant includes Triton and S24, wherein: The dosage of S24 is 2~10g / m 2 , preferably 5 to 7 g / m 2 ; The dosage of Triton is 0.1~5g / m 2 , preferably 0.3 to 3 g / m 2 .

9. The dry chemical reagent sheet according to any one of claims 1 to 8, characterized in that: The thickness of the reagent layer is 10 to 100 μm; and / or, the diffusion layer has a thickness of 200 to 800 μm; And / or, the thickness of the light-transmitting layer is 30 to 300 μm.

10. A method for preparing a dry chemical reagent sheet according to any one of claims 1 to 9, characterized in that: The steps include: Step 1: Heat the reagent layer reagent to 35-45°C, stir, apply it on the light-transmitting layer, and dry; Step 2: coating the diffusion layer reagent on the reagent layer and drying to obtain the dry chemical reagent sheet.

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