Device for measuring ion exchange capacity of mineral source humic acid

Abstract

The utility model relates to a device for measuring the ion exchange capacity of mineral source humic acid. Comprising a container body used for containing a solution, a dialysis membrane bag of a sealed structure is arranged in the container body, and a conductivity meter probe is arranged in the container body and connected with a conductivity meter. The method is suitable for measuring the ion exchange capacity of the water-soluble mineral source humic acid, the cation adsorption amount and strength of the mineral source humic acid are represented by measuring the change difference of an external solution, the operation is convenient, the flow rate does not need to be controlled, and meanwhile the water-soluble mineral source humic acid ion exchange capacity can be measured by eliminating the permeation speed deviation caused by too high permeation pressure. The stability of the device and the accuracy of a detection result are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of mineral source humic acid detection, in particular to a device for determining the ion exchange capacity of mineral source humic acid. Background Art

[0002] Mineral humic acid can interact with potassium, ammonium and other ions, thereby improving the utilization rate of these ion nutrients in the soil. Therefore, the performance of humic acid with cations affects its compatibility with fertilizers. If it can be tested, it can guide the design of fertilizer formulas and the selection of humic acid raw materials. However, there is no more universal method and equipment for the determination of the ion exchange capacity of mineral humic acid. The available methods include ion exchange resin method and soil cation exchange capacity determination method.

[0003] Taking the ion exchange column method as an example, its structure includes a separatory funnel at the top, which is connected to a glass exchange column with a sand core plate through a valve for measurement; this structural form has the following two defects: 1. Water-soluble humic acid is not applicable, and water-soluble humic acid is easy to flow out of the exchange column with the mobile phase, causing losses; and the mineral potassium humate currently used in agriculture is a water-soluble product; 2. Unstable flow rate can easily lead to fluctuations in elution time, which in turn causes characterization deviations in adsorption intensity; that is, the measurement results are inaccurate; taking the method of measuring soil cation exchange capacity as an example, such as HJ 899-2017, hexaamminecobalt trichloride solution is used as an extractant to extract soil, and cations in the soil are exchanged by hexaamminecobalt trichloride and enter the solution. Hexaamminecobalt trichloride has characteristic absorption at 475nm, and the absorbance is proportional to the concentration. The soil cation exchange capacity is calculated based on the difference in absorbance of the extractant before and after leaching. The above method has the following two problems: first, humic acid has strong absorption at 475nm, which interferes with color development; second, the results of this type of method only measure the amount of adsorbed cations, but cannot characterize the intensity of cation adsorption. Utility Model Content

[0004] The utility model aims to provide a device for measuring the ion exchange capacity of mineral humic acid to overcome the defects in the prior art.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A device for measuring the ion exchange capacity of mineral humic acid comprises a container body for containing solution, a dialysis membrane bag with a sealing structure is arranged inside the container body, and a conductivity meter probe is arranged in the container body, and the conductivity meter probe is connected to the conductivity meter.

[0007] The beneficial effects of the utility model are as follows: the utility model provides a container body for containing deionized water, and a dialysis membrane bag for placing a solution to be tested; cations in the solution to be tested that are not adsorbed by humic acid will first pass through the dialysis membrane bag, and then weakly adsorbed cations will slowly pass through the dialysis membrane bag; at the same time, the conductivity meter probe cooperates with the conductivity meter to monitor the real-time change of the salt ion concentration of the solution in the container body in real time, so as to measure and characterize the amount and intensity of the interaction between mineral-source humic acid and ions; the utility model has the characteristics of being applicable to the determination of the ion exchange capacity of soluble mineral-source humic acid, characterizing the amount and intensity of mineral-source humic acid adsorption by measuring the change difference of the external solution, and being easy to operate without the need to control the flow rate.

[0008] Furthermore, in order to ensure the accuracy of the test results, the difference in EC values ​​between the mineral humic acid treatment and the blank treatment can characterize the amount of cations adsorbed by the humic acid, and the rate of increase in the EC value can characterize the intensity of the adsorption of the cations by the humic acid; thereby achieving the characteristics of measuring the ion exchange capacity of the mineral humic acid and ensuring the accuracy of the test results.

[0009] Preferably, an upper sealing clamp is provided at the upper portion of the dialysis membrane bag, and a lower sealing clamp is provided at the lower portion of the dialysis membrane bag.

[0010] Preferably, support plates are provided on the lower inner walls of the container body corresponding to the two sides of the upper sealing clamp; and counterweights are provided on the two sides of the bottom of the lower sealing clamp.

[0011] Preferably, a protrusion for clamping the end of the upper sealing clip is provided on the inner upper part of the support plate.

[0012] Preferably, a mounting hole for mounting a conductivity meter probe is provided on the support plate between the protrusion and the inner wall of the container body.

[0013] Preferably, a funnel is provided on the upper portion of the container body, and the bottom of the funnel extends to the interior of the dialysis membrane bag; the upper sealing clip is adapted to the lower portion of the funnel.

[0014] Preferably, the dialysis molecular weight of the dialysis membrane in the dialysis membrane bag is 7 kDA or 14 kDa.

[0015] According to the above scheme, a device for determining the ion exchange capacity of mineral humic acid is prepared, wherein a container body is provided for containing deionized water, a dialysis membrane bag is provided for placing a solution to be tested, and NH4 + It will first pass through the dialysis membrane bag, followed by the weakly adsorbed NH4 +It will slowly pass through the dialysis membrane bag; at the same time, the conductivity meter probe cooperates with the conductivity meter to monitor the real-time changes in the salt ion concentration of the solution in the container body in real time, so as to measure the amount and intensity of the interaction between the mineral humic acid and the ions; further, in order to ensure the accuracy of the test results, the mineral humic acid treatment and the blank treatment can be used, and the difference in EC values ​​can characterize the amount of cations adsorbed by the humic acid, and the speed of the EC value increase can characterize the intensity of the adsorption of the cations by the humic acid; thereby achieving the characteristics of measuring the ion exchange capacity of the mineral humic acid and ensuring the accuracy of the test results; the utility model is also provided with an upper sealing clamp and a lower sealing clamp for sealing the dialysis membrane bag to prevent the solution to be tested from entering the container body, and by setting The support plate and the counterweight block can realize the full expansion of the dialysis membrane bag to ensure that the molecules quickly seep out through the dialysis membrane, so as to realize accurate detection by the conductivity meter; further, the funnel can facilitate the rapid entry of the solution to be tested into the dialysis membrane bag, and can eliminate the deviation of the osmotic speed caused by the high osmotic pressure when the osmotic pressure is too high, and prevent accidents such as the dialysis bag being squeezed and broken; it is suitable for the determination of the ion exchange capacity of water-soluble mineral humic acid, and the amount and intensity of the adsorption of cations by the mineral humic acid are characterized by measuring the difference in the change of the external solution. The operation is convenient and there is no need to control the flow rate. At the same time, the deviation of the osmotic speed caused by the high osmotic pressure is eliminated to improve the stability of the device and the accuracy of the detection results. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model.

[0017] Figure 2 It is a schematic diagram of the top view of the container body of the utility model.

[0018] Figure 3 It is a structural schematic diagram of the upper sealing clip of the utility model.

[0019] Figure 4 It is a structural schematic diagram of the lower sealing clip of the utility model.

[0020] In the figure: 1. container body; 2. dialysis membrane bag; 3. conductivity meter probe; 4. conductivity meter; 5. upper sealing clip; 6. lower sealing clip; 7. support plate; 8. counterweight block; 9. protrusion; 10. mounting hole; 11. funnel. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0022] Reference Figure 1-4As shown, a device for measuring the ion exchange capacity of mineral humic acid includes a container body 1 for containing a solution, a dialysis membrane bag 2 with a sealing structure is provided inside the container body 1, and a conductivity meter probe 3 is arranged in the container body 1, and the conductivity meter probe 3 is connected to a conductivity meter 4. The container body 1 described in the utility model is used to hold the solution (deionized water), the dialysis membrane bag 2 is used to hold the solution to be tested (the solution prepared by the reaction of humic acid sample and ammonium chloride, ammonium chloride solution or mineral humic acid solution), the dialysis membrane bag 2 is immersed in the deionized water, and the dialysis membrane bag 2 is in a sealed state to prevent the solution to be tested from directly diffusing into the deionized water, and the cations enter the container body 1 through the dialysis membrane bag 2, and the conductivity meter probe 3 cooperates with the conductivity meter 4 to monitor the real-time change of the salt ion concentration of the solution in the container body in real time, so as to measure the amount and intensity of the interaction between mineral humic acid and ions; the above process is suitable for the determination of the ion exchange capacity of water-soluble mineral humic acid, and the process does not need to limit the flow rate, and can realize the detection of the amount and intensity of the interaction between mineral humic acid and ions.

[0023] Furthermore, an upper sealing clamp 5 is provided at the upper part of the dialysis membrane bag 2, and a lower sealing clamp 6 is provided at the lower part of the dialysis membrane bag 2. The sealing of the dialysis membrane bag 2 described in the utility model can be in various forms. In order to achieve the purpose of convenient use, it is preferred to use the upper sealing clamp 5 and the lower sealing clamp 6 to cooperate with the dialysis membrane for sealing.

[0024] Furthermore, support plates 7 are provided on the lower inner walls of the container body 1 corresponding to the two sides of the upper sealing clamp 5; and weight blocks 8 are provided on the two sides of the bottom of the lower sealing clamp 6. In actual use, the unfolding area of ​​the dialysis membrane bag 2 will affect the speed and amount of ion exchange (the contact area between the solution to be tested and the dialysis membrane). The above arrangement can achieve the characteristic of fully unfolding the dialysis membrane bag 2, thereby reducing the influence on the test results.

[0025] Furthermore, a protrusion 9 for clamping the end of the upper sealing clip 5 is provided on the inner upper part of the support plate 7. The protrusion 9 can be provided to fix the dialysis membrane bag 2 through the upper sealing clip 5, and the above fixation can prevent the dialysis membrane bag 2 from moving, thereby reducing its influence on the detection result.

[0026] Furthermore, a mounting hole 10 for mounting the conductivity meter probe 4 is provided on the support plate 7 between the protrusion 9 and the inner wall of the container body 1 .

[0027] Furthermore, a funnel 11 is provided on the upper part of the container body 1, and the bottom of the funnel 11 extends to the inside of the dialysis membrane bag 2; the upper sealing clip 5 is adapted to the lower part of the funnel 11. The utility model can facilitate the rapid entry of the solution to be tested into the dialysis membrane bag by providing the funnel 11, and when the osmotic pressure is too high, eliminate the osmotic speed deviation caused by the high osmotic pressure, and prevent the dialysis bag from being squeezed and other accidents, so as to achieve the characteristic of improving the stability of the device.

[0028] Furthermore, the dialysis molecular weight of the dialysis membrane in the dialysis membrane bag 2 is 7kDA or 14kDa. As is known to all, mineral humic acid belongs to macromolecular organic matter, and its apparent molecular weight is generally above 100kDa. Choosing dialysis bags of 7kDA and 14kDa can confine most of the mineral humic acid in the dialysis bag, and a small amount of small molecular humic acid that overflows is less than 5% and can be ignored. Then only NH4 that is not adsorbed by humic acid can be absorbed by the dialysis bag. + It will first pass through the dialysis membrane, followed by the weakly adsorbed NH4 + It will slowly pass through the dialysis membrane.

[0029] The detection method of the utility model is as follows: to determine the humic acid to NH4 +Taking the ion exchange capacity of humic acid as an example, three groups of solutions are selected: 1. The humic acid sample is reacted with ammonium chloride to prepare a solution of a specific concentration; 2. An ammonium chloride solution of the same concentration is prepared; 3. A mineral humic acid solution of the same concentration is prepared; three sets of devices in the utility model are selected, and it should be noted that the dialysis areas of the three sets of devices are the same (the distances between the upper sealing clamps 5 and the lower sealing clamps 6 of the three sets of devices are consistent); first, an equal amount of deionized water is added to the container bodies 1 of the three sets of devices, and the dialysis membrane bag 2 is immersed in the deionized water; then Then, the humic acid sample is added to the corresponding dialysis membrane bag 2 through the funnel 11 of the first set of devices to react with ammonium chloride to form a solution of a specific concentration; the ammonium chloride solution of the same concentration is added to the corresponding dialysis membrane bag 2 through the funnel 11 of the second set of devices; the mineral humic acid solution of the same concentration is added to the corresponding dialysis membrane bag 2 through the funnel 11 of the third set of devices; the EC value and time are recorded respectively by the conductivity meter probe 3 and the conductivity meter 4, and the nutrient release curve is drawn with time as the horizontal coordinate and EC value as the vertical coordinate. Through the comparison between the above three, the difference in EC value can ensure the amount of cations adsorbed by humic acid, and the speed of EC value increase can standardize the strength of humic acid adsorption on the cation. The utility model is suitable for water-soluble mineral humic acid / fulvic acid; specifically, the pore size of the dialysis membrane is used for separation, which can limit the diffusion of mineral humic acid, so as to achieve the suitability for water-soluble mineral humic acid / fulvic acid. Furthermore, the conductivity meter probe 3 is matched with the conductivity meter 4 to achieve the purpose of measuring the amount and intensity of ion exchange adsorption; specifically, by measuring the final difference of the external solution, that is, the change trend, the amount and intensity of mineral humic acid adsorption can be characterized. The utility model has the characteristics of simple operation. After the instrument is assembled, the mineral humic acid that has reacted with ions is directly loaded, and then the EC is continuously measured to draw a curve. There is no need to continuously adjust the control flow rate, replace the eluent, and regenerate the washing solution as in the ion exchange column method; the results measured using the utility model have small fluctuations and few unexpected influences, and the measurement results are accurate.

[0030] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for measuring the ion exchange capacity of mineral humic acid, characterized in that: The device comprises a container body (1) for containing a solution, a dialysis membrane bag (2) with a sealing structure is provided inside the container body (1), and a conductivity meter probe (3) is arranged inside the container body (1), and the conductivity meter probe (3) is connected to a conductivity meter (4); An upper sealing clamp (5) is provided on the upper part of the dialysis membrane bag (2), and a lower sealing clamp (6) is provided on the lower part of the dialysis membrane bag (2); A funnel (11) is provided at the upper portion of the container body (1), and the bottom of the funnel (11) extends to the interior of the dialysis membrane bag (2); the upper sealing clip (5) is adapted to fit the lower portion of the funnel (11).

2. The device for measuring the ion exchange capacity of mineral humic acid according to claim 1, characterized in that: Support plates (7) are provided on the lower inner walls of the container body (1) corresponding to the two sides of the upper sealing clamp (5); and counterweight blocks (8) are provided on the two sides of the bottom of the lower sealing clamp (6).

3. The device for measuring the ion exchange capacity of mineral humic acid according to claim 2, characterized in that: A protrusion (9) for clamping the end of the upper sealing clip (5) is provided on the inner upper part of the support plate (7).

4. The device for measuring the ion exchange capacity of mineral-derived humic acid according to claim 3, characterized in that: A mounting hole (10) for mounting a conductivity meter probe (3) is provided on the support plate (7) between the protrusion (9) and the inner wall of the container body (1).

5. The device for measuring the ion exchange capacity of mineral-derived humic acid according to claim 1, characterized in that: The dialysis molecular weight of the dialysis membrane in the dialysis membrane bag (2) is 7 kDa or 14 kDa.

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