Application of rhodamine B saturated acid solution in detection of calcium ion content and measurement of ash amount of earthwork roadbed
By using rhodamine B saturated acid solution to detect calcium ions, the existing ash dose detection methods are solved, and the rapid and accurate detection of ash dose at the construction site is achieved, reducing the environmental and personnel requirements for the detection.
Patent Information
- Application Number
- CN202510132833.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-06
- Publication Date
- 2025-05-06
AI Technical Summary
Existing ash dose detection methods such as EDTA titration require sampling and taking back to the laboratory for testing, resulting in a long detection cycle of building materials such as earthwork roadbeds, large damage and requirements for testers, and lack of simple and convenient detection methods.
Calcium ions were detected by using the saturated acid solution of rhodamine B. The calcium ions were detected by spraying the saturated acid solution of rhodamine B to the area to be tested, and the ratio of the reflective area to the total area to be tested was recorded using ultraviolet light irradiation. The calcium ion content was calculated in combination with the standard curve, so as to estimate the ash dose.
This method simplifies the inspection process, reduces the requirements for the testing environment and personnel, and can quickly obtain test results at the construction site, with errors controlled within 4%, with high accuracy.
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Figure CN119936004A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of calcium ion detection, in particular to application of a rhodamine B saturated acid solution in detecting calcium ion content and measuring ash dosage of an earthwork roadbed. Background Art
[0002] The current mainstream method for detecting ash dosage is EDTA titration, which is a coordination titration method. It uses the complexing agent ethylenediaminetetraacetate to react with the calcium ions in the lime soil. The amount of disodium EDTA consumed by the sample is determined using the color change of disodium EDTA titration as the endpoint. The corresponding lime dosage is then found using the standard curve of lime and disodium EDTA consumption.
[0003] However, the above test method requires sampling and taking it back to the laboratory for testing. For construction materials such as earthwork and roadbed, sampling will cause certain damage, and the test cycle is long. Titration experiments are required, which has certain requirements for testers. In view of this, a simple and convenient method for testing ash dosage is particularly necessary. Summary of the invention
[0004] The invention aims to provide an application of a saturated acid solution of rhodamine B in detecting calcium ion content and measuring ash dosage of an earthwork roadbed, so as to improve the detection efficiency of calcium ions.
[0005] The present invention is achieved in that:
[0006] In a first aspect, the present invention provides an application of a saturated acid solution of rhodamine B in the detection of calcium ion content.
[0007] In an optional embodiment, the Rhodamine B saturated acid solution also includes acetic acid and sodium acetate.
[0008] In an optional embodiment, the pH of the Rhodamine B saturated acid solution is 5.5-7.
[0009] In a second aspect, the present invention provides a method for detecting calcium ion content, comprising:
[0010] Spraying the rhodamine B saturated acid solution onto the sample to be tested area;
[0011] The unit area to be tested is irradiated with ultraviolet light and the ratio of the reflective area to the total area of the unit area to be tested is recorded, and the ratio of the reflective area to the total area of the unit area to be tested is recorded as W, in %;
[0012] Substitute W into the standard curve of W and calcium ion content, and calculate the calcium ion content in the sample based on the standard curve and W.
[0013] In an optional embodiment, the Rhodamine B saturated acid solution is sprayed onto the sample test area until the ratio W of the reflective area to the total area of the test area no longer increases after continuing to spray the Rhodamine B saturated acid solution, and then the spraying of the Rhodamine B saturated acid solution is stopped.
[0014] In an optional embodiment, the method for preparing the standard curve comprises:
[0015] Divide the area to be tested of the reference sample into area 1 and area 2;
[0016] Take samples from area 1 and test the calcium ion content in the samples using EDTA titration method;
[0017] Spray the Rhodamine B saturated acid solution in area 2, and record the ratio W of the reflective area to the total area of the area to be measured;
[0018] Draw a standard curve of W and calcium ion content.
[0019] In an optional embodiment, the Rhodamine B saturated acid solution is sprayed onto area 2 until the ratio W of the reflective area to the total area of the measured area no longer increases after continuing to spray the Rhodamine B saturated acid solution, and then the spraying of the Rhodamine B saturated acid solution is stopped.
[0020] In an optional implementation, the reflective area is calculated by a pixel method.
[0021] In an optional embodiment, the area to be tested is photographed while being irradiated with ultraviolet light, and the reflective area is determined using Photoshop graphic analysis software.
[0022] In a third aspect, the present invention provides an application of the method for detecting calcium ion content described in the aforementioned embodiment in measuring the ash dosage of an earthwork roadbed.
[0023] The present invention has the following beneficial effects:
[0024] In this application, the Ca(OH) generated after the reaction of lime (CaO) and water is completed. 2 Rhodamine B is easily soluble in water and Ca ions easily react with acid to form precipitation. Rhodamine B is dissolved in an acidic solution in advance to make a saturated solution. 2 After the reaction is completed, a precipitate is generated and the acidity decreases. As the acidity decreases, Rhodamine B gradually precipitates. Since the amount of Rhodamine B precipitated is correlated with both the reflective area and the calcium ion content, the calcium ion content can be calculated based on the reflective area.
[0025] This method has a simple process, is not restricted by the environment, can obtain test results at the construction site, has low requirements for testers, and has high accuracy. Compared with the EDTA titration method, the error can be controlled within 4%. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.
[0027] Figure 1 The graph is a graph showing the change of Ca ions measured by EDTA over time in Example 1;
[0028] Figure 2 1 is a graph showing the corresponding relationship between the ratio W of the reflective area measured by EDTA to the total area of the region to be measured and the gray dose in Example 1;
[0029] Figure 3 This is a schematic diagram of step 4 in Example 1. DETAILED DESCRIPTION
[0030] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.
[0031] In the process of lime stabilization of expansive soil, after lime (CaO) is added to the expansive soil, it first reacts with the water in the soil to produce slaked lime. The reaction formula is as follows:
[0032] CaO+H 2 O=Ca(OH) 2
[0033] MgO+H 2 O=Mg(OH) 2
[0034] Ca(OH) produced after the reaction 2 and Ca(OH) 2 , dissociating a large amount of Ca in the soil solution 2+ Mg 2+ , Ca 2+ and Mg 2+ It is easy to absorb Na adsorbed on the surface of soil particles + and K +The water is replaced, which results in a thinner thickness of the bound water film, thereby improving the early strength of the soil.
[0035] During the carbonation reaction, the Ca(OH) produced by the decomposition of lime 2 and Mg(OH) 2 Can react with CO in the air 2 The CaCO generated by the reaction 3 and MgCO 3 , the reaction formula is as follows:
[0036] Ca(OH) 2 +CO 2 =CaCO 3 +H 2 O
[0037] Mg(OH) 2 +CO 2 =Mg(OH) 2 +H 2 O
[0038] CaCO 3 and MgCO 3 It is a solid particle that is difficult to dissolve in water and has high strength and stability in water environment. 3 and MgCO 3 It crystallizes in the soil to form calcium cementation and a crystal grid, which increases soil strength and reduces soil expansion and contraction.
[0039] Ash dosage refers to the amount of lime (CaO or Ca(OH)) or other alkaline materials added to stabilize the soil in the stabilized soil base, usually expressed as a percentage. By testing the ash dosage, the performance and quality of the base material can be ensured, thereby ensuring the stability and durability of the road.
[0040] The ash dosage test measures the content of Ca ions in the soil, not the actual content of lime added. In actual projects, there is a "decay" phenomenon in ash dosage, that is, the EDTA consumption of a sample with a fixed ash addition rate decays with the extension of the placement time, but it is not the lime dosage added to the soil that decays.
[0041] The commonly used ash dosage determination method in the prior art is to determine the lime content in the sample by chemical titration, which requires: 1. Taking representative samples from the construction site; 2. Sample preparation: crushing the sample and mixing it evenly; 3. Dissolving: dissolving the sample in an acidic solution; 4. Titration: titrating with a standard solution and recording the volume of the consumed standard solution; 5. Calculation: calculating the ash dosage based on the titration results. The test process is complicated and the test results cannot be obtained at the construction site.
[0042] The embodiment of the present invention provides an application of a rhodamine B saturated acid solution in the detection of calcium ion content.
[0043] In the implementation mode of the present application, the principle of fluorescent staining is utilized to track and mark calcium ions using the fluorescent agent Rhodamine B. The calcium ion content obtained from previous experiments and the reflection area of light by Rhodamine B are then combined to infer the calcium ion content in the sample, and the ash dose of the sample can be calculated through the calcium ions.
[0044] In the embodiment of the present application, after the reaction of lime (CaO) and water is completed, the generated Ca(OH) 2 Rhodamine B is easily soluble in water and Ca ions easily react with acid to form precipitation. Rhodamine B is dissolved in an acidic solution in advance to make a saturated solution. 2 After the reaction is completed, a precipitate is generated and the acidity decreases. As the acidity decreases, Rhodamine B gradually precipitates. Since the amount of Rhodamine B precipitated is correlated with the reflective area and the calcium ion content, the calcium ion content can be calculated based on the reflective area, and then the ash dosage can be calculated.
[0045] In an optional embodiment, the Rhodamine B saturated acid solution also includes acetic acid and sodium acetate.
[0046] In an optional embodiment, the pH of the Rhodamine B saturated acid solution is 5.5-7.
[0047] An acidic environment is conducive to improving the solubility of Rhodamine B, but too low acidity will increase the consumption of Rhodamine B, which is not conducive to cost control.
[0048] The present invention also provides a method for detecting calcium ion content, comprising:
[0049] Spraying the rhodamine B saturated acid solution onto the sample to be tested area;
[0050] The area to be tested is irradiated with ultraviolet light and the ratio of the reflective area to the total area of the area to be tested is recorded, where the ratio of the reflective area to the total area of the area to be tested is recorded as W, in %;
[0051] Substitute W into the standard curve of W and calcium ion content, and calculate the calcium ion content in the sample based on the standard curve and W.
[0052] In an optional embodiment, the Rhodamine B saturated acid solution is sprayed onto the sample test area until the ratio W of the reflective area to the total area of the test area no longer increases after continuing to spray the Rhodamine B saturated acid solution, and then the spraying of the Rhodamine B saturated acid solution is stopped.
[0053] The saturated acid solution of Rhodamine B needs to be sprayed in sufficient amount so that the calcium ions contained in the sample in the test area can fully react with the saturated acid solution of Rhodamine B. If the amount of the saturated acid solution of Rhodamine B sprayed is too small, the calcium ions cannot react completely and too little Rhodamine B is precipitated, which may cause the actual measured value to be low.
[0054] In an optional embodiment, the method for preparing the standard curve comprises:
[0055] Divide the area to be tested of the reference sample into area 1 and area 2;
[0056] Take samples from area 1 and test the calcium ion content in the samples using EDTA titration method;
[0057] Spray the Rhodamine B saturated acid solution in area 2, and record the ratio W of the reflective area to the total area of the area to be measured;
[0058] Draw a standard curve of W and calcium ion content.
[0059] In an optional embodiment, the Rhodamine B saturated acid solution is sprayed onto area 2 until the ratio W of the reflective area to the total area of the measured area no longer increases after continuing to spray the Rhodamine B saturated acid solution, and then the spraying of the Rhodamine B saturated acid solution is stopped.
[0060] In an optional embodiment, the reflective area is calculated manually using a grid method.
[0061] In an optional embodiment, the area to be tested is photographed while being irradiated with ultraviolet light, and the reflective area is determined using Photoshop graphic analysis software.
[0062] In the implementation manner of the present application, the area is determined by the pixel method using Photoshop graphic analysis software, the reflective pixels of rhodamine b are screened out in the Photoshop analysis software, and the total number of pixels in the unit area to be tested is compared to obtain the ratio W.
[0063] The embodiment of the present invention also provides an application of the method for detecting calcium ion content described in the aforementioned embodiment in measuring the ash dosage of earthwork roadbed.
[0064] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.
[0065] Example 1
[0066] This embodiment provides a method for detecting ash dose, which specifically includes the following steps.
[0067] Step 1, preparation of standard solution: At a temperature of 18 ± 1 ° C, in order to improve the solubility and fluorescence performance of Rhodamine B, sodium acetate (pH 5.5) solution is used as a buffer to prepare a Rhodamine B standard solution.
[0068] Weigh 0.2500g of Rhodamine B, add a small amount of water to dissolve, transfer to a 250mL volumetric flask, dilute to scale with distilled water, and shake well. The concentration of this Rhodamine B solution is 1.000g·L -1 , draw 1.0 ml of this solution into a 100 mL volumetric flask, dilute to the mark with distilled water, and shake well. This Rhodamine B solution is 10 mg·L -1 .
[0069] 10mg·L per 100ml -1 Add 10 ml of acetic acid-sodium acetate (pH 5.5) solution and 0.1000 g of rhodamine B to the rhodamine B solution to ensure that the rhodamine B in the solution is saturated, stir evenly, and prepare a reagent standard solution.
[0070] Step 2, preparation of standard curve:
[0071] During the construction of the "roadbed test section", the EDTA titration method was used to test the Ca ion content in the mixed lime soil (raw material of the roadbed test section) at the optimal moisture content after different reaction times with air (0 days, 2 days, 3 days, 5 days, 7 days, 9 days, 11 days, 13 days and 15 days), and the curve of the change of Ca ion with time was determined, as shown in Figure 2. Figure 1 As shown in the figure, it is a curve diagram of the change of Ca ions with time corresponding to the two mixed lime-soil samples (three groups of parallel experiments were performed at each point); at the same time, the "roadbed test section" with different reaction times with air (0 days, 2 days, 3 days, 5 days, 7 days, 9 days, 11 days, 13 days and 15 days) was sprayed with the prepared reagent standard solution, and the ratio W of the reflective area to the total area of the test area was recorded. Figure 1 As well as the relationship between EDTA consumption and ash dosage (y = 0.2667x-0.7104) (y is ash dosage, unit is %; x is EDTA consumption, unit is ml), it can be calculated that W is in a corresponding relationship with ash dosage at this time, such as Figure 2 (Note: Since the gray dose attenuation rate varies in different regions, a corresponding standard curve needs to be developed for each project).
[0072] When testing the "roadbed test section" to calculate the ratio of the reflective area to the total area of the area to be tested, three areas are selected in the area to be tested, three groups of parallel tests are conducted and the average value is taken to reduce the error.
[0073] Step 3: After the construction of the "roadbed test section" is completed, use the reagent standard solution to spray the test area on the compacted earth roadbed. After the Rhodamine B fluorescent agent no longer precipitates, use "ultraviolet light" to irradiate the area sprayed with the fluorescent agent and take photos. 在 The pixel method is used in Photoshop graphic analysis software to determine the area. The reflective pixels of rhodamine b are screened out in the analysis software, and the total number of pixels in the unit test area is compared to obtain the ratio W. The ratio W of the reflective area at this time to the total area of the test area is recorded. Figure 2 The standard curve shown is used to calculate the gray dose.
[0074] Step 4: After the construction is completed, if the ash dose needs to be detected, repeat step 3 to determine the ash dose by the ratio W of the reflective area to the total area of the area to be tested.
[0075] Specifically, on the fourth day after the construction is completed, step 3 is repeated, as shown in the schematic diagram. Figure 3 As shown, the ratio W of the measured reflective area to the total area of the measured area is 16%. Figure 2 The calculated ash dosage content is 4.0%; at the same time, the ash dosage content tested by EDTA titration method is 4.1%, which means that the error of the present application method is only 2.4% compared with the EDTA titration method.
[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. Application of a rhodamine B saturated acid solution in the detection of calcium ion content.
2. The use of the rhodamine B saturated acid solution in calcium ion content detection according to claim 1, characterized in that: The rhodamine B saturated acid solution also includes acetic acid and sodium acetate.
3. The use of the rhodamine B saturated acid solution in calcium ion content detection according to claim 1, characterized in that: The pH of the rhodamine B saturated acid solution is 5.5-7.
4. A method for detecting calcium ion content, characterized in that: include: Spraying the rhodamine B saturated acid solution onto the sample to be tested area; The area to be tested is irradiated with ultraviolet light and the ratio of the reflective area to the total area of the area to be tested is recorded, where the ratio of the reflective area to the total area of the area to be tested is recorded as W, in %; Substitute W into the standard curve of W and calcium ion content, and calculate the calcium ion content in the sample based on the standard curve and W.
5. The method for detecting calcium ion content according to claim 4, characterized in that: The rhodamine B saturated acid solution is sprayed onto the sample test area until the ratio W of the reflective area to the total area of the test area no longer increases after continuing to spray the rhodamine B saturated acid solution, and then the spraying of the rhodamine B saturated acid solution is stopped.
6. The method for detecting calcium ion content according to claim 4, characterized in that: The method for preparing the standard curve comprises: Divide the area to be tested of the reference sample into area 1 and area 2; Take samples from area 1 and test the calcium ion content in the samples using EDTA titration method; Spray the Rhodamine B saturated acid solution in area 2, and record the ratio W of the reflective area to the total area of the area to be measured; Draw a standard curve of W and calcium ion content.
7. The method for detecting calcium ion content according to claim 4, characterized in that: The Rhodamine B saturated acid solution is sprayed onto the area 2 until the ratio W of the reflective area to the total area of the area to be measured no longer increases after continuing to spray the Rhodamine B saturated acid solution, and then the spraying of the Rhodamine B saturated acid solution is stopped.
8. The method for detecting calcium ion content according to claim 4, characterized in that: The reflective area is calculated by a pixel method.
9. The method for detecting calcium ion content according to claim 4, characterized in that: The area to be tested is photographed while being irradiated with ultraviolet light, and the reflective area is determined using Photoshop graphic analysis software.
10. Use of the method for detecting calcium ion content according to any one of claims 4 to 9 in measuring ash dosage of earthwork roadbed.