CN117783103A - High-sensitivity calcium qualitative detection test strip and manufacturing method thereof - Google Patents

Abstract

The invention discloses a high-sensitivity qualitative detection test strip for calcium and a manufacturing method thereof, belonging to the field of analytical chemistry. The high-sensitivity qualitative detection test strip comprises an upper cover card shell, a lower cover card shell and a middle calcium detection test strip, wherein the lower cover card shell is used as a supporting structure of the test strip, and a circular window is arranged in the upper cover card shell and is positioned above the calcium detection test strip for observation of the dripping and result of a sample; the intermediate calcium detection test strip is obtained by dipping in the solution A and the solution B in sequence; composition of solution A: 0.1-1% of color developing agent, 1-2 g/L EGTA, 0.5-1% of dispersing agent, 0.1-0.5% of color fixing agent, 0.05-0.1% of Tween 80 and the balance of water; composition of solution B: 0.5-2% of thickener, 0.1-1% of film forming agent, 20% of ethanol and the balance of water; the test strip has uniform color development, and the color-changing gray area is narrow when a calcium element-containing sample is tested, so that visual observation can be visually realized, and the judgment is convenient.

Description

High-sensitivity calcium qualitative detection test strip and manufacturing method thereof

Technical Field

The invention relates to a high-sensitivity qualitative detection test strip for calcium and a manufacturing method thereof, belonging to the field of analytical chemistry.

Background

Calcium is an important nutrient element of human body, children and adults can indirectly reflect the calcium nutrition condition of human body, and timely measurement and understanding of the calcium urine condition is helpful for timely calcium supplement, and diseases such as convulsion, hypodynamia, osteoporosis and the like caused by calcium deficiency are reduced. In addition, the low milk calcium content can cause calcium deficiency of infants, bone dysplasia, rickets and other diseases can be caused when the infants are severely calcium-deficient, the infants can indirectly know the calcium intake condition by regularly knowing the milk calcium, and the diseases caused by the calcium deficiency of the infants can be timely treated and reduced.

The existing common calcium detection methods in the prior art include spectrophotometry, complexometric titration, atomic absorption methods and the like, and the methods are generally complex in operation, require special instruments and equipment and professional personnel to operate, have high detection cost and are difficult to realize home detection. The existing dry chemical test strips capable of realizing urine calcium detection are mostly based on a monochromatic color development principle, and the color changes from light to dark along with the increase of the calcium ion concentration, so that different testers have large judgment difference, and obvious risk prompt cannot be carried out near the judgment value.

The biochemical detection liquid of calcium in urine disclosed in Chinese patent CN1570635A provides a self-detection method of calcium in urine, but the result of the method has poor discrimination, and whether the concentration of calcium is sufficient or not is judged by milky white precipitation, white micro precipitation, white turbidity, light turbidity, micro turbidity and trace.

Then, as CN106770251B, CN110672598B, CN106770251A, preparing an indicator liquid by combining two calcium ion complexing agents of o-cresyl complexing phenolphthalein and azo arsenic III, a masking agent, a surfactant and the like, soaking the test paper, and airing to prepare a dry chemical test paper for calcium ion detection; however, the indicator of the test paper can only change color in a gradient way after encountering calcium elements with different concentrations, the calcium ions at the medical decision level are not obviously changed, and the test paper standard color card needs to be interpreted, so that the result is not accurately interpreted due to different sensitivity degrees of individuals to the color, and the difference exists in the interpretation of different naked eyes and the accuracy is not high.

The calcium ion detection test paper disclosed in Chinese patent CN105181689B is impregnated with the reagents such as chrome black T, masking agent, surfactant and the like to prepare the red-blue color-changing urine calcium ion detection dry chemical test paper; CN104764738B uses meta-chloroazoantipyrine as a color reagent to prepare a red-blue color-changing chromatographic test paper, and the specific disclosure shows that the meta-chloroazoantipyrine has strong binding force with cellulose and is not easy to redissolve and release after meeting water, but the binding force between the color reagent and the cellulose is still weak in the actual use process, and the color reagent still releases after dipping and drying, so that color development is uneven and the actual application requirement cannot be met. Meanwhile, the color reagent is a chemical synthesis product, has harsh storage conditions, needs to be protected from light and oxygen and stored at low temperature, and is difficult to obtain in a commercial purchasing mode and difficult to apply to actual production due to the characteristics.

The problems of the qualitative detection reagent such as the gray area is enlarged due to the phenomena that the color is scattered after sample addition and the color development process is uneven both in-situ dry chemical color development in CN105181689B and chromatographic color development in CN 104764738B.

Disclosure of Invention

Aiming at the defects and shortcomings in the prior art, the invention provides the high-sensitivity qualitative detection test paper for calcium and the manufacturing method thereof.

The invention aims to provide a high-sensitivity qualitative detection test paper strip for calcium, which comprises an upper cover card shell, a lower cover card shell and a middle calcium detection test paper strip, wherein the lower cover card shell is used as a supporting structure of the test paper strip, and a circular window is arranged in the upper cover card shell and is positioned above the calcium detection test paper strip for observing the dripping and the result of a sample; the intermediate calcium detection test strip is obtained by dipping in the solution A and the solution B in sequence;

wherein the composition of the solution A: 0.1-1% of color developing agent, 1-2 g/L EGTA, 0.5-1% of dispersing agent, 0.1-0.5% of color fixing agent, 0.05-0.1% of Tween 80 and the balance of water;

composition of solution B: 0.5-2% of thickener, 0.1-1% of film forming agent, 20% of ethanol and the balance of water.

In one embodiment, the specific preparation process of the intermediate calcium detection test strip comprises the following steps: the test strip is soaked in the solution A, and then taken out and dried; immersing the dried test strip in the solution B for 5-10 s, immediately taking out, putting into a constant temperature drying oven for drying overnight, and taking out the test strip; cutting and assembling the test paper by using a chopper to obtain a high-sensitivity calcium qualitative detection test paper strip;

in one embodiment, the solution a is immersed for a period of 8 to 10 minutes.

In one embodiment, the drying is: and (3) placing the test paper taken out of the solution A into a constant temperature drying oven to be dried for 2-6 h at 50-60 ℃.

In one embodiment, the temperature in the oven is 30 to 40 ℃.

In one embodiment, the color developer is chrome blue black R or meta-chloroazoantipyrine.

In one embodiment, when the color-developing agent is chrome blue black R, the color-developing agent can display uniform blue when the concentration of calcium in the sample solution is less than or equal to 140mg/L, and when the concentration of calcium in the sample solution is greater than or equal to 180mg/L, the result shows uniform red, namely that the result shows that red is not deficient in calcium, and the blue is observed to indicate that the risk of calcium deficiency exists; when the color-developing agent is meta-chloroazoantipyrine: when the concentration of calcium in the sample solution is not more than 140mg/L, the sample solution shows uniform red, and when the concentration of calcium in the sample solution is not less than 180mg/L, the result shows uniform blue, namely that the red is observed to indicate the risk of calcium deficiency, and the blue indicates no calcium deficiency.

In one embodiment, the dispersant is amine oxide or Gui Er methyl amine oxide.

In one embodiment, the fixing agent is one or more of diallyldimethylammonium chloride, dimethylamine, cetylpyridinium chloride.

In one embodiment, the thickener is one or a combination of two of PEG and sodium alginate.

In one embodiment, the PEG has a molecular weight of 6000 or 8000.

In one embodiment, the film former is one or a combination of two of gelatin and dimethyl phthalate.

In one embodiment, when the developer is chrome blue-black R, the composition of the a solution: 0.1% of color developing agent, 1.8g/L of chelating agent, 0.5-1% of dispersing agent, 0.1-0.5% of color fixing agent, 0.05% of Tween 80 and the balance of water; composition of solution B: 0.5-2% of thickener, 0.1-1% of film forming agent, 20% of ethanol and the balance of water.

In one embodiment, the composition of the a solution: 0.1% of color developing agent, 1.8g/L of chelating agent, 1% of dispersing agent, 0.1% of color fixing agent, 0.05% of Tween 80 and the balance of water; composition of solution B: 0.5% of thickener, 0.1% of film forming agent, 20% of ethanol and the balance of water.

In one embodiment, the composition of the a solution: 0.1% chromium blue black R,1.8g/L EGTA,1% month Gui Er methyl amine oxide, 0.1% diallyl dimethyl ammonium chloride, 0.05% Tween 80 and the balance water; composition of solution B: 0.5% PEG,0.1% dimethyl phthalate, 20% ethanol, the balance being water.

In one embodiment, when the developer is meta-chloroazoantipyrine, the composition of the solution a: 0.1% of color developing agent, 1.8g/L of chelating agent, 0.5% of dispersing agent, 0.5% of color fixing agent, 0.05% of Tween 80 and the balance of water; composition of solution B: 0.5-2% of thickener, 0.1-1% of film forming agent, 20% of ethanol and the balance of water.

In one embodiment, the composition of the a solution: 0.1% of metachloroazoantipyrine, 1.8g/L EGTA,0.5% of amine oxide, 0.5% of dimethylamine, 0.05% of Tween 80 and the balance of water; composition of solution B: 1% PEG,0.5% dimethyl phthalate, 20% ethanol, the balance being water.

In one embodiment, the upper and lower cover shells are made of one or more of high-density polyethylene, polypropylene or polystyrene.

The invention also provides a manufacturing method of the high-sensitivity qualitative detection test paper strip for calcium, which comprises the following steps:

(1) Dividing the plastic clamping shell into an upper layer and a lower layer; one end of the upper layer is provided with a round sample dropping hole, and the corresponding end of the lower layer is provided with a clamping groove for fixing the detection test strip;

(2) And cutting the calcium detection test strip into a proper size, fixing the proper size in a clamping groove of the lower-layer clamping shell, and then assembling the upper-layer plastic clamping shell and the lower-layer clamping shell to form the high-sensitivity qualitative calcium detection test strip.

In one embodiment, the diameter of the circular drop sample well of step (1) is 6 to 10mm.

The invention has the beneficial effects that:

(1) The color developing agent adopted by the high-sensitivity calcium qualitative detection test paper strip is an alkaline calcium ion complexing agent with difference of yin and yang colors, the color developing agent has high sensitivity, can be obviously changed after being combined with calcium under the condition that less than 2mg/L of calcium element exists, has clear color development, and most of raw materials can be purchased easily and can be used for actual production.

(2) The impregnating solution A impregnated by the test strip in the high-sensitivity calcium qualitative detection test strip is provided with the color fixing agent and the dispersing agent, the color developing agent can be fixed on base materials such as filter paper and the like in a fixed proportion, the color developing agent is not impacted by liquid after the sample is wetted, and the color is uniformly developed finally; the combination of the thickening agent and the film forming agent in the impregnating solution B can realize that a layer of loose film structure is covered on the common filter paper again, helps the sample to rapidly disperse and wet the base material, and ensures that the sample is uniformly distributed on the test paper block by matching with the effect of the color fixing agent, simultaneously rapidly permeates the reaction test paper and uniformly develops color. The test paper treated by the two impregnating solutions has uniform color development, and the color-changing gray area is narrow when a calcium element-containing sample is tested, so that visual observation can be visually realized, and the judgment is convenient.

Drawings

FIG. 1 is a physical diagram of a high-sensitivity qualitative detection test strip for calcium prepared by the invention;

FIG. 2 is a graph showing color uniformity of test strips prepared in example 1, examples 3-2 and comparative example 3 of the present invention before they are sheared;

FIG. 3 is a graph showing color development uniformity of the test strips of examples 1-3 according to the present invention under the condition of 180mg/L calcium standard;

FIG. 4 is a color development physical diagram of test strips of comparative examples 1 to 5 under the condition of 180mg/L calcium standard;

FIG. 5 is a graph showing the color development of inventive example 1, examples 3-2, and comparative examples 2, 5, and 6 in the range of 140-180mg/L calcium concentration;

FIG. 6 is a color chart of the chromatographic test paper assembled by the calcium test strips prepared in example 1 and comparative examples 1 to 3 of the present invention under the water-wet condition.

Detailed Description

The following description of the preferred embodiments of the present invention is provided for better illustration of the invention, and should not be construed as limiting the invention.

The base material of the test strip is plant fiber, and the thickness is 0.7mm.

Example 1

A method for manufacturing a high-sensitivity qualitative detection test strip for calcium specifically comprises the following steps:

the test paper strip comprises an upper cover and a lower cover, a clamping shell and a middle calcium detection test paper strip, wherein the lower cover is used as a support structure (made of polystyrene) of the test paper strip, and a circular window is arranged in the upper cover and is positioned above the calcium detection test paper strip for the drip addition of samples and the observation of results;

wherein, the preparation process of the calcium detection test strip comprises the following steps: the test paper is prepared by soaking in solution A (substrate soaking solution) for 8min, and then drying in a constant temperature drying oven at 55deg.C for 4 hr; wherein the composition of the solution A is as follows: 0.1% of chrome blue black R,1.8g/L of EGTA,1% of dispersant Gui Er methyl amine oxide, 0.05% of Tween 80, 0.1% of fixing agent diallyl dimethyl ammonium chloride and the balance of deionized water; immersing the dried test paper into the solution B (substrate film coating liquid) completely for 10s, immediately taking out, and putting into a constant-temperature drying oven for drying at 37 ℃ overnight; wherein the composition of the solution B is as follows: 0.5% by mass of thickener PEG ₆₀₀₀ 0.1% of film forming agent dimethyl phthalate, 20% of ethanol and the balance of deionized water; and taking out the test strip, cutting the test strip into test strips with the thickness of 10mm and the thickness of 10mm by using a chopper, and assembling to obtain the high-sensitivity calcium qualitative detection test strip, as shown in figure 1.

Example 2

The difference from example 1 is only that the contents of each of the substances of the solution A and the solution B were adjusted as shown in the following Table 1, and other parameters and conditions were the same as those of example 1.

TABLE 1 content of substances of solutions A and B

Example 3

The only difference from schemes 2 to 4 in example 2 is that chromium blue black R was replaced with meta-chloroazoantipyrine, as shown in Table 2; the color fixing agent in the solution A is replaced by dimethylamine, the dispersing agent is replaced by amine oxide, and other parameters and conditions are the same as those in the schemes 2-4.

TABLE 2 content of substances of solutions A and B

Comparative example 1

The only difference from example 1 is that diallyldimethyl amine chloride in solution a was omitted; other parameters and conditions were the same as in example 1.

Comparative example 2

The only difference from example 1 is that the diallyldimethylamine chloride in solution a was replaced by cetyltrimethylammonium bromide; other parameters and conditions were the same as in example 1.

Comparative example 3

The only difference from example 1 is that the fixing agent in solution a is replaced with dimethylamine and the dispersant is replaced with amine oxide; other parameters and conditions were the same as in example 1.

Comparative example 4

The only difference from example 1 is that dimethyl phthalate in solution B was omitted; other parameters and conditions were the same as in example 1.

Comparative example 5

The only difference from example 1 is that dimethyl phthalate in solution B is replaced with polyvinyl alcohol; other parameters and conditions were the same as in example 1.

Comparative example 6

A manufacturing method of a qualitative detection test paper strip for calcium specifically comprises the following steps:

a support was produced by cutting an elongated sheet having dimensions of 70mm in length by 5mm in width from a white polyethylene terephthalate (PET) sheet having a thickness of 0.2 mm; immersing 4mL of a mixed buffer of N-cyclohexyl-3-aminopropanesulfonic acid (CAPS), N-methyl-D-glucosamine (MEG), o-cresol peptide complex ketone and 8-hydroxyquinoline; then drying at 40deg.C for 20 min to completely evaporate water to obtain membranous reagent layer; using acrylic adhesive to adhere the film forming reagent layer on a support, thus obtaining the calcium qualitative detection test strip;

wherein, the mixed buffer is prepared as follows: 0.89g CAPS and 3.12g MEG were dissolved in distilled water and 4moL/L NaOH solution was added to bring the pH at 37℃to 10.5, 144mg o-cresolphthalein complex and 144mg 8-hydroxyquinoline were added to fix the volume to 25ml.

Result measurement

1. In the test strips prepared in examples 1 and 3-2 and comparative example 3, the test strips prepared in examples 1 and 3-2 were relatively flat and uniform in color as shown in FIG. 2, and as shown in FIG. 2, the test strips were soaked and dried in the filter paper before being cut; the test paper prepared in comparative example 3 had a rough surface and a non-uniform color.

2. Test strips prepared in examples and comparative examples were used for qualitative detection of 180mg/L calcium standard solution, and the color development uniformity corresponding results are shown in Table 3 and FIG. 3:

TABLE 3 sample color uniformity of test strips prepared in examples 1-3 and comparative example

As can be seen from the results of Table 3 and FIG. 3, the color development of example 1 was relatively uniform with that of examples 2-1 to 2-4, wherein the color development uniformity of example 1 was the highest; the color development of examples 3-1 to 3-3 was relatively uniform, with the color development uniformity of example 3-2 being the highest.

3. Test strips prepared in comparative examples 1 to 5 were used for qualitative detection of 180mg/L calcium standard solution, and the color development uniformity corresponding results are shown in FIG. 4:

as a result, after the samples of comparative examples 1 to 5 were added, 180mg/L of the calcium standard solution was tested, and the color development was uneven, failing to accurately distinguish between negative and positive.

4. The test papers prepared in example 1 and examples 3-2, comparative example 5 and comparative example 6 were qualitatively measured for calcium standards of 140mg/L, 160mg/L, 180mg/L and 200mg/L, and the color development results are shown in FIG. 5:

as can be seen from the results of FIG. 5, examples 1 and 3-2 showed significant discoloration in the calcium concentration range of 140-180mg/L, and samples below 140mg/L and samples above 180mg/L were clearly distinguishable. The existing calcium qualitative test paper has the advantages that the color of the calcium with different concentrations in the comparative example 6 is relatively similar, and samples of 140mg/L and 180mg/L cannot be distinguished. The test strips of comparative example 2 and comparative example 5 were unable to distinguish between 140-180mg/L calcium standard.

5. The calcium test strips prepared in example 1 and comparative examples 1 to 3 were assembled into analytical test strips, and an aqueous solution was added to one end of each test strip, so that the liquid could wet the test strips under the capillary action and be absorbed completely under the action of absorbent paper, and the color fixing effect of the fixing agent was as shown in fig. 6:

as is clear from the results of FIG. 6, in example 1, after the test paper was wetted with the aqueous solution, the developer was not deposited and adsorbed on the absorbent paper at the other end. And the comparative examples 1 to 3 respectively have different degrees of color developing agents precipitated and flow to the end of the absorbent paper along with the liquid, so that the absorbent paper has different degrees of red color.

The above examples are not intended to limit the scope of the invention nor the order of execution of the steps described. The present invention is obviously modified by a person skilled in the art in combination with the prior common general knowledge, and falls within the scope of protection defined by the claims of the present invention.

Claims (10)

1. The high-sensitivity qualitative detection test paper strip is characterized by comprising an upper cover card shell, a lower cover card shell and a middle calcium detection test paper strip, wherein the lower cover card shell is used as a supporting structure of the test paper strip, and a circular window is arranged in the upper cover card shell and is positioned above the calcium detection test paper strip for observing the dripping and result of a sample; the intermediate calcium detection test strip is obtained by dipping in the solution A and the solution B in sequence;

wherein the composition of the solution A: 0.1-1% of color developing agent, 1-2 g/L EGTA, 0.5-1% of dispersing agent, 0.1-0.5% of color fixing agent, 0.05-0.1% of Tween 80 and the balance of water;

composition of solution B: 0.5-2% of thickener, 0.1-1% of film forming agent, 20% of ethanol and the balance of water.

2. The high sensitivity qualitative detection test strip according to claim 1, wherein the dispersant is amine oxide or month Gui Er methyl amine oxide.

3. The high sensitivity qualitative detection test strip according to claim 1, wherein the fixing agent is one or more of diallyldimethylammonium chloride, dimethylamine, cetyl pyridinium chloride.

4. The high-sensitivity qualitative detection test strip according to claim 1, wherein the thickener is one or a combination of PEG and sodium alginate.

5. The high sensitivity qualitative detection test strip according to claim 1, wherein the film forming agent is one or a combination of two of gelatin and dimethyl phthalate.

6. The high sensitivity qualitative detection test strip according to claim 1, wherein the composition of solution a: 0.1% of color developing agent, 1.8g/L of chelating agent, 1% of dispersing agent, 0.1% of color fixing agent, 0.05% of Tween 80 and the balance of water; composition of solution B: 0.5% of thickener, 0.1% of film forming agent, 20% of ethanol and the balance of water.

7. The high sensitivity qualitative detection test strip according to claim 1, wherein the color-developing agent is chrome blue-black R or meta-chloroazoantipyrine.

8. The high-sensitivity qualitative detection test strip for calcium according to claim 7, wherein when the color-developing agent is chrome blue-black R, the color-developing agent shows uniform blue when the concentration of calcium in the sample solution is 140mg/L or less, and shows uniform red when the concentration of calcium in the sample solution is 180mg/L or more, namely, the result is that red is observed to indicate no calcium deficiency, and blue is observed to indicate the risk of calcium deficiency; when the color-developing agent is meta-chloroazoantipyrine: when the concentration of calcium in the sample solution is not more than 140mg/L, the sample solution shows uniform red, and when the concentration of calcium in the sample solution is not less than 180mg/L, the result shows uniform blue, namely, the red is observed to indicate the risk of calcium deficiency, and the blue is observed to indicate no calcium deficiency.

9. The high-sensitivity qualitative detection test strip according to claim 1, wherein the specific preparation process of the intermediate calcium detection test strip comprises the following steps: the test strip is soaked in the solution A, and then taken out and dried; immersing the dried test strip in the solution B for 5-10 s, immediately taking out, putting into a constant temperature drying oven for drying overnight, and taking out the test strip; and cutting and assembling the test paper by using a chopper to obtain the high-sensitivity qualitative detection test paper.

10. The method for manufacturing the high-sensitivity qualitative detection test paper strip for calcium according to any one of claims 1 to 9, which is characterized by comprising the following steps:

(1) Dividing the plastic clamping shell into an upper layer and a lower layer; one end of the upper layer is provided with a round sample dropping hole, and the corresponding end of the lower layer is provided with a clamping groove for fixing the detection test strip;

(2) And cutting the calcium detection test strip into a proper size, fixing the proper size in a clamping groove of the lower-layer clamping shell, and then assembling the upper-layer plastic clamping shell and the lower-layer clamping shell to form the high-sensitivity qualitative calcium detection test strip.