A detection reagent, a kit and application of total hardness of dialysis water

Abstract

The present application discloses a detection reagent, a kit and its application for the total hardness of dialysis water, wherein the detection reagent comprises a first reagent, a second reagent and a third reagent; the first reagent is a microemulsion, wherein the microemulsion is a mixture of a surfactant, a cosurfactant, an oil phase and an aqueous phase in a weight ratio of 0.5-2:1-5:0.5-2:50-100; the second reagent is a color developer solution, wherein the color developer in the color developer solution is a bromopyridinium azo compound, the concentration of the color developer is 0.005-0.5 g / L, and the solvent is ethanol, acetone or acetic acid; the third reagent is an alkaline regulator with a pH between 9.5-11.5. The present application is the first to use microemulsion technology and bromopyridinium azo compounds to determine the total hardness of water quality, and the detection method is simple and the accuracy is reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of water quality detection, and in particular to a detection reagent and a kit for total hardness of dialysis water and applications thereof. Background Art

[0002] As hemodialysis technology improves, higher requirements are placed on dialysis machines and dialysis water. Untreated water has high hardness and contains other metal ions. It is acceptable for drinking, but it is not feasible for dialysis. Other metal ions and calcium and magnesium ions related to total hardness can still enter the human body, accumulate in the body and cause complications. Therefore, the purer the dialysis water, the safer it is. Therefore, the dialysis water must be strictly monitored, especially the total hardness, to meet the use standards.

[0003] The dialysis water standard strictly requires that the hardness of soft water after pre-treatment must be less than 17 ppm. If the water hardness cannot meet the requirement, it means that the Ca in the water 2+ Mg 2+ If the content is too high, it is necessary to replace the water softener in the dialysis water treatment system or restore the resin softening function in the water softener. Therefore, testing the total hardness in dialysis water is necessary to ensure the safety of patient treatment on the one hand, and to monitor the dialysis water treatment system on the other hand. Summary of the invention

[0004] The present application provides a detection reagent and a kit for the total hardness of dialysis water and its application, which is the first to use microemulsion technology and bromopyridinium azo compounds to measure the total hardness of water quality. The detection method is simple and the accuracy is reliable.

[0005] A reagent for detecting the total hardness of dialysis water, comprising a first reagent, a second reagent and a third reagent

[0006] The first reagent is a microemulsion, which is a mixture of a surfactant, a co-surfactant, an oil phase and an aqueous phase in a weight ratio of 0.5-2:1-5:0.5-2:50-100;

[0007] The second reagent is a color developer solution, the color developer in the color developer solution is a bromopyridinium azo compound, the concentration of the color developer is 0.005-0.5 g / L, and the solvent is ethanol, acetone or acetic acid;

[0008] The third reagent is an alkaline regulator with a pH between 9.5 and 11.5.

[0009] The detection principle of the present application is as follows: bromopyridinium azo compounds react with calcium and magnesium ions in water to form colored complexes; microemulsions can be dissolved in both oil and water due to their special composition and structure, and have all the properties of organic molecular aggregates, such as changing chemical equilibrium, accelerating the process of chemical reactions, etc., which can significantly improve the sensitivity of color development reactions, reduce the detection limit of determinations, increase the water solubility and stability of color development substances, and have better solubilization, sensitization and stabilization effects; alkaline regulators maintain the pH range required for the reaction.

[0010] Optionally, the brominated pyridyl azo compound is 2-(5-bromo-2-pyridyl azo)-5-diethylaminophenol (5-Br-PADAP) or 2-(3,5-dibromo-2-pyridyl azo)-5-diethylaminophenol (3,5-diBr-PADAP).

[0011] Optionally, the concentration of the developer is 0.1-0.5 g / L.

[0012] Optionally, the surfactant is at least one of cetyltrimethylammonium bromide (CTMAB), octylphenol polyoxyethylene ether (OP), sodium dodecyl sulfate (SDS), cetylpyridinium chloride (CPC), cetylpyridinium chloride-octylphenol polyoxyethylene ether (CPC-OP), tween, span, dodecyltrimethylammonium bromide (DTAB), lauryl alcohol polyoxyethylene ether (LAE), dodecyl polyethylene glycol ether (Brig35), dodecylphenol polyoxyethylene ether (OP-10) and polyoxyethylene octylphenyl ether (OP-15).

[0013] Optionally, the co-surfactant is at least one of n-butanol, n-propanol, butanol, octanol and pentanol.

[0014] Optionally, the oil phase is at least one of n-heptane, n-octane and n-pentane.

[0015] Optionally, the aqueous phase is pure water.

[0016] Optionally, the alkaline regulator is an alkaline buffer system composed of sodium hydroxide or an alkaline buffer system composed of potassium hydroxide. Optionally, the alkaline buffer system composed of sodium hydroxide includes sodium hydroxide, glycine and sodium chloride; the alkaline buffer system composed of potassium hydroxide includes potassium hydroxide, glycine and sodium chloride.

[0017] Further preferred:

[0018] The first reagent is a mixed solution of lauryl alcohol polyoxyethylene ether, n-butanol, n-heptane and pure water in a weight ratio of 1-1.5:2-3:1-2:90-100;

[0019] The second reagent is a 0.15-0.25 g / L 2-(5-bromo-2-pyridyl azo)-5-diethylaminophenol ethanol solution;

[0020] The third reagent is a mixed aqueous solution of glycine, sodium chloride and sodium hydroxide, wherein the concentration of glycine is 3.5-4 g / L, the concentration of sodium chloride is 2.5-3 g / L, and the concentration of sodium hydroxide is 1.5-2.5 g / L. After the mixed aqueous solution is prepared, its pH value is adjusted to 10.5-11.

[0021] Most preferred:

[0022] The first reagent is a mixed solution of lauryl alcohol polyoxyethylene ether (LAE), n-butanol, n-heptane and pure water in a weight ratio of 1.1:2.5:1.5:94.5;

[0023] The second reagent is a 0.2 g / L 5-Br-PADAP ethanol solution;

[0024] The third reagent is a mixed aqueous solution of glycine, sodium chloride and sodium hydroxide, wherein the concentration of glycine is 3.75 g / L, the concentration of sodium chloride is 2.9 g / L, and the concentration of sodium hydroxide is 2 g / L. After the mixed aqueous solution is prepared, its pH value is adjusted to 11 using hydrochloric acid or sodium hydroxide solution.

[0025] The present application also provides a detection kit for the total hardness of dialysis water, comprising a colorimetric card and the detection reagent.

[0026] Optionally, the detection gradient of the colorimetric card is 0, 5 mg / L, 10 mg / L, 15 mg / L, and 20 mg / L.

[0027] The present application also provides a method for detecting the total hardness of dialysis water using the detection kit, comprising:

[0028] Take a dialyzed water sample, add the first reagent, mix well, then add the second reagent, mix well, then add the third reagent, mix well, let stand to develop color, and compare the developed reaction solution with the colorimetric card to determine the total hardness in the test water sample.

[0029] Optionally, add 2-3 drops (100-150 μL) of the first reagent, 1-2 drops (50-100 μL) of the second reagent, and 2-3 drops (100-150 μL) of the third reagent to 2 mL of the dialyzed water sample; let the color develop for 20-40 s.

[0030] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0031] (1) This application is the first to use microemulsion technology and brominated pyridinium azo compounds to determine the total hardness of water. The detection method is simple and accurate.

[0032] (2) The common methods in the general standard for total hardness testing are atomic absorption (flame method), inductively coupled plasma mass spectrometry (flame method) or EDTA titration. However, atomic absorption (flame method) and inductively coupled plasma mass spectrometry (flame method) require expensive instruments and professional technicians, and the relevant detection concentration range cannot fully meet the requirements of the dialysis water detection range. The EDTA concentration used in the standard of EDTA titration is generally 10mmol / L. When the applicant of this application studied this method in 2021, he found that this method has good recovery for spiked water samples with a total hardness higher than 50mg / L, but for water hardness below 50mg / L, the EDTA concentration needs to be appropriately reduced to effectively improve its accuracy. Studies have shown that even when the EDTA concentration is reduced to 2mmol / L, the error of the total hardness of 20mg / L is still >3mg / L, which shows that the EDTA titration method has certain limitations ("EDTA titration method for measuring total water hardness experimental method, laboratory research and exploration, 2021-06-10, 40, 6, 59-63"). The total hardness detection method of this application has a detection concentration range that meets the calcium and magnesium detection range requirements for hemodialysis treatment water, and can be operated by non-professionals. The measurement time is short, and the results can be obtained in 20~40s, which is suitable for real-time monitoring.

[0033] (3) Hemodialysis water is prepared by a high-purity water system. The higher the purity of the water, the better. Due to the reaction characteristics of pyridinium azo compounds, when the dialysis water reacts with this reagent, it indicates that other pollutants may exist in the dialysis water, and it also serves as a warning for other contamination of the dialysis water. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is the total hardness color card.

[0035] Figure 2 This is the color development result of the total hardness standard solution.

[0036] Figure 3 It is the color result when the total hardness of the water sample exceeds 20 mg / L.

[0037] Figure 4 It is the color development result of the total hardness test of actual dialysis water sample.

[0038] Figure 5 It is a wavelength scanning diagram of the total hardness reaction system at 300-800nm.

[0039] Figure 6It is a total hardness standard curve established based on a wavelength of 553 nm. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0042] Example 1

[0043] Detection reagents:

[0044] The first reagent (weight ratio): W (lauryl alcohol polyoxyethylene ether (LAE)) : W (n-butanol) : W (n-heptane) : W (pure water) = 1.1:2.5:1.5:94.5.

[0045] Second reagent: Weigh 0.020 g of 5-Br-PADAP and dissolve it in 100 mL of anhydrous ethanol to prepare a 0.2 g / L 5-Br-PADAP ethanol solution.

[0046] The third reagent: 3.75g glycine, 2.9g sodium chloride, 2g sodium hydroxide are dissolved in 1L water. After the solution is prepared, insert the pH meter and adjust the pH value of the reagent solution to 11.0 with hydrochloric acid solution or sodium hydroxide solution.

[0047] The above reagents are placed in 3 dropper bottles respectively to form a kit for measuring the total hardness of dialysis water.

[0048] The production process of the total hardness color chart:

[0049] (1) Preparation of standard solution:

[0050] Total hardness standard solution (1000 μg / mL) was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., product number H117456.

[0051] Prepare the total hardness standard solution (1000 μg / mL: equivalent to 1000 mg / L) into the "intermediate solution" first, and then use the "total hardness standard solution" and the "intermediate solution" to prepare the required standard gradient solution, see Table 1:

[0052] Table 1

[0053]

[0054] (2) Color reaction:

[0055] Take 2 mL of the standard gradient solution in Table 1, add 2 drops (about 100 μL) of the first reagent and mix well, then add 1 drop (about 50 μL) of the second reagent and mix well, then add 2 drops (about 100 μL) of the third reagent and mix well, let it stand for 30 seconds to obtain the color of each standard solution reaction solution.

[0056] (3) According to the color of each standard solution reaction solution, use CDR software (CorelDraw) on the computer to adjust the color. When the color matches, record and save the color block to obtain the total hardness color card (mg / L), see Figure 1 .

[0057] Semi-quantitative colorimetry:

[0058] Take 2 mL of the standard gradient solution in Table 1, add 2 drops of the first reagent (about 100 μL) and mix well, then add 1 drop of the second reagent (about 50 μL) and mix well, then add 2 drops of the third reagent (about 100 μL) and mix well, let it stand for 30 seconds, and the color development result is the same as Figure 1 Total hardness color chart comparison Figure 2 As shown, it is shown that the detection reagent of the present application can be used for semi-quantitative detection of dialysis water samples. When the total hardness of the standard sample exceeds 20 mg / L (for example, 100 mg / L and 450 mg / L), the color development result is as follows Figure 3 shown.

[0059] Take 5 actual dialysis water samples, and use the atomic absorption spectrophotometry method of GB11905-1989 for the determination of calcium and magnesium in water quality to determine the total hardness content: dialysis water sample A is 0 mg / L, dialysis water sample B is 3 mg / L, dialysis water sample C is 8 mg / L, dialysis water sample D is 13 mg / L, and dialysis water sample E is 17 mg / L. Use the detection reagent of this application to perform the following determination:

[0060] Take 2 mL of each of the above different actual dialysis water samples, add 2 drops of the first reagent (about 100 μL) and mix well, then add 1 drop of the second reagent (about 50 μL) and mix well, then add 2 drops of the third reagent (about 100 μL) and mix well, let it stand for 30 seconds, and the color development results are shown in Figure 4 , visual and Figure 1By comparing the total hardness color card, it can be determined that the concentrations of total hardness from left to right are: dialysis water sample A is around 0 mg / L, dialysis water sample B is between 0-5 mg / L, dialysis water sample C is between 5-10 mg / L, dialysis water sample D is between 10-15 mg / L, and dialysis water sample E is between 15-20 mg / L. This semi-quantitative detection method is consistent with the national standard method.

[0061] The semi-quantitative colorimetric detection reagent uses a colorimeter to measure the correlation between the absorbance value and the standard concentration, and uses the spike recovery rate to judge its detection accuracy as follows:

[0062] The solution after the color reaction of different concentrations of total hardness standard solution was scanned at a wavelength of 300-800nm. The results are as follows Figure 5 As shown by Figure 5 The results show that the optimal absorption wavelength of the reaction is 553nm, and the absorption value of total hardness around 553nm has a large difference from low concentration to high concentration. Therefore, the total hardness concentration in the water sample can be quantitatively detected by measuring the absorbance value of the solution at 553nm after color development.

[0063] Take 2 mL of the standard gradient solution in Table 1, add 2 drops of the first reagent (about 100 μL) and mix well, then add 1 drop of the second reagent (about 50 μL) and mix well, then add 2 drops of the third reagent (about 100 μL) and mix well, let it stand for 30 seconds, then detect the absorbance of the reaction solution at 553 nm, and draw a standard curve with the X-axis as the absorbance value and the Y-axis as the total hardness concentration value ( Figure 6 ).

[0064] For the actual dialysis water sample, according to the total hardness standard curve ( Figure 6 , where the X-axis is the absorbance value and the Y-axis is the total hardness concentration value), a spike recovery test was performed on the dialysate water sample. After calculation, the spike recovery was between 81.41% and 103.24% (Table 2), indicating that the detection reagent of the present application can be used for the semi-quantitative detection of the total hardness of the dialysate water sample, and the accuracy is reliable based on an error of no more than ±20%.

[0065] Table 2

[0066]

[0067] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A reagent for detecting the total hardness of dialyzed water, characterized in that: comprising a first reagent, a second reagent and a third reagent; The first reagent is a microemulsion, which is a mixed solution of lauryl alcohol polyoxyethylene ether, n-butanol, n-heptane and pure water in a weight ratio of 1-1.5:2-3:1-2:90-100; The second reagent is a color developer solution, the color developer in the color developer solution is a bromopyridinium azo compound, the concentration of the color developer is 0.1-0.5 g / L, the bromopyridinium azo compound is 2-(5-bromo-2-pyridyl azo)-5-diethylaminophenol or 2-(3,5-dibromo-2-pyridyl azo)-5-diethylaminophenol, and the solvent is anhydrous ethanol, acetone or acetic acid; The third reagent is a mixed aqueous solution of glycine, sodium chloride and sodium hydroxide, wherein the concentration of glycine is 3.5-4 g / L, the concentration of sodium chloride is 2.5-3 g / L, and the concentration of sodium hydroxide is 1.5-2.5 g / L. After the mixed aqueous solution is prepared, its pH value is adjusted to 10.5-11.

2. The detection reagent according to claim 1, characterized in that The second reagent is a 0.15-0.25 g / L 2-(5-bromo-2-pyridyl azo)-5-diethylaminophenol ethanol solution.

3. The detection reagent according to claim 1, characterized in that The first reagent is a mixed solution of lauryl alcohol polyoxyethylene ether, n-butanol, n-heptane and pure water in a weight ratio of 1.1:2.5:1.5:94.5; The second reagent is a 0.2 g / L 2-(5-bromo-2-pyridyl azo)-5-diethylaminophenol ethanol solution; The third reagent is a mixed aqueous solution of glycine, sodium chloride and sodium hydroxide, wherein the concentration of glycine is 3.75 g / L, the concentration of sodium chloride is 2.9 g / L, and the concentration of sodium hydroxide is 2 g / L. After the mixed aqueous solution is prepared, its pH value is adjusted to 11 using hydrochloric acid or sodium hydroxide solution.

4. A test kit for total hardness of dialysis water, characterized in that: It comprises a colorimetric card and a detection reagent as claimed in any one of claims 1 to 3; the total hardness detection gradient of the colorimetric card is 0, 5 mg / L, 10 mg / L, 15 mg / L, and 20 mg / L.

5. A method for detecting the total hardness of dialysis water using the detection kit according to claim 4, characterized in that: include: Take a dialyzed water sample, add the first reagent, mix well, then add the second reagent, mix well, then add the third reagent, mix well, let stand to develop color, compare the color of the reaction solution after development with the colorimetric card, and determine the total hardness in the dialyzed water sample; Based on 2 mL of dialyzed water sample, add 100-150 μL of the first reagent, 50-100 μL of the second reagent, and 100-150 μL of the third reagent; let stand for 20-40 s for color development.

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