Method for detecting lanthanum element in limestone
By preparing high-concentration and low-concentration standard solutions and detecting them using inductively coupled plasma emission spectrometer, combined with yttrium internal standard element correction, the problem of low accuracy in lanthanum detection in limestone was solved, and efficient and accurate lanthanum content analysis was achieved.
Patent Information
- Application Number
- CN202511143813.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-15
- Publication Date
- 2025-10-10
AI Technical Summary
Existing detection methods for lanthanum in limestone have low accuracy and efficiency, and are easily interfered by other elements.
High-concentration and low-concentration standard solutions are prepared and tested by inductively coupled plasma emission spectrometry, combined with yttrium internal standard element standard solution for calibration, and a working curve is drawn to ensure the comprehensiveness and accuracy of lanthanum content detection.
The accuracy and efficiency of lanthanum detection in limestone are improved, errors are reduced, and more accurate calculation of lanthanum content is achieved.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of chemical detection, in particular to a method for detecting lanthanum elements in limestone. BACKGROUND
[0002] In steel metallurgical production, limestone as an important auxiliary material, its quality directly affects the performance of steel products. Rare earth elements have key roles in purifying, modifying and micro-alloying in steel, and the content of lanthanum, as one of the rare earth elements, has a significant impact on the performance of steel. The existing detection methods are usually aimed at the phase state analysis of rare earth elements in steel, and the detection method of lanthanum elements in limestone is less studied and the effect is not ideal. For example, chemical analysis method, common such as volumetric method and gravimetric method. Both methods have complicated operation and slow analysis speed, and usually require complex pretreatment of the sample, and may be disturbed by other elements in the reaction process, resulting in reduced accuracy.
[0003] Therefore, there is an urgent need to provide a method for detecting lanthanum elements in limestone with high detection accuracy and high detection efficiency. SUMMARY
[0004] In order to overcome the defects of the prior art, the technical problem solved by the present application is to provide a method for detecting lanthanum elements in limestone. The present application can more comprehensively and accurately cover the possible content range of lanthanum elements in the test material by preparing two standard solutions with high and low concentrations and drawing corresponding working curves, so that the detection result is more representative, thereby more accurately calculating the actual content of lanthanum elements in the test material.
[0005] In order to achieve the above purpose, the present application adopts the following technical scheme:
[0006] A method for detecting lanthanum elements in limestone, comprising the following steps:
[0007] 1) 0.1-2.0g of limestone test material with particle size less than 0.4mm is weighed;
[0008] 2) Prepare a test solution; place the test material in a 200-400mL beaker, add 5-35mL of nitric acid and 5-35mL of hydrochloric acid, heat until the test material is completely dissolved, reduce the volume to 5-10mL, add 20-70mL of water, cool to room temperature, transfer to a 100-500mL volumetric flask, add 5-25mL of yttrium internal standard element standard solution with a concentration of 50μg / mL, dilute to the scale of the volumetric flask with water, and mix well; the density of nitric acid is 1.42g / mL, and the density of hydrochloric acid is 1.19g / mL;
[0009] 3) Prepare standard solutions;
[0010] Prepare high concentration standard solution and low concentration standard solution respectively;
[0011] The high concentration standard solution has a concentration of 500-1000 μg / mL and the low concentration standard solution has a concentration of 1.0-100.0 μg / mL;
[0012] 4) Drawing a working curve;
[0013] A number of matrix calcium carbonate standard solutions with a concentration equivalent to the content in the sample are weighed and placed in 5-10 beakers, 0.50-15.00 mL of the high concentration standard solution is added respectively, 5-35 mL of nitric acid and 5-35 mL of hydrochloric acid are added, heating is performed until the sample is completely dissolved, the volume is reduced to 5-10 mL, 20-70 mL of water is added, cooling is performed to room temperature, the sample is transferred into a 100-500 mL volumetric flask, 5-25 mL of yttrium internal standard element standard solution with a concentration of 50 μg / mL is added, water is used for dilution to the scale of the volumetric flask, mixing is performed, then an inductively coupled plasma emission spectrometer is used for detection to obtain the high concentration working curve;
[0014] A number of matrix calcium carbonate standard solutions with a concentration equivalent to the content in the sample are weighed and placed in 5-10 beakers, 0.50-20.00 mL of the low concentration standard solution is added respectively, 5-35 mL of nitric acid and 5-35 mL of hydrochloric acid are added, heating is performed until the sample is completely dissolved, the volume is reduced to 5-10 mL, 20-70 mL of water is added, cooling is performed to room temperature, the sample is transferred into a 100-500 mL volumetric flask, 5-25 mL of yttrium internal standard element standard solution with a concentration of 50 μg / mL is added, water is used for dilution to the scale of the volumetric flask, mixing is performed, then an inductively coupled plasma emission spectrometer is used for detection to obtain the low concentration working curve;
[0015] 5) Detecting the sample solution
[0016] Under the same conditions, the sample solution is detected, and the content of the lanthanum element in the sample solution is calculated according to the high concentration or low concentration working curve;
[0017] The calculation formula is as follows:
[0018]
[0019] In the formula, w represents the mass fraction of the content of the element to be detected in the sample, %;
[0020] C represents the concentration of the high concentration standard solution or the concentration of the low concentration standard solution in the sample solution, μg / mL;
[0021] V represents the volume of the sample solution, mL;
[0022] m represents the mass of the sample, g.
[0023] The preparation method of the yttrium internal standard solution in the step 2) is as follows: weigh 0.254 g of yttrium oxide with a mass fraction greater than 99.95% and place it in a 100 mL beaker, add 10 mL of hydrochloric acid (1+1), the density of hydrochloric acid is 1.19 g / mL, heat to dissolve, cool to room temperature, transfer to a 200 mL volumetric flask, dilute to the scale with water, mix, transfer 25 mL to a 500 mL volumetric flask, dilute to the scale with water, and mix.
[0024] The preparation method of the high concentration standard solution in step 3) is as follows: weigh 0.5864-1.1728 g of lanthanum oxide with a mass fraction greater than 99.99% and place it in a 200-400 mL beaker, add 10-30 mL of hydrochloric acid with a density of 1.19 g / mL to dissolve it, cool it to room temperature, transfer it to a 1000 mL volumetric flask, dilute it with water to the scale of the volumetric flask, and mix it thoroughly;
[0025] The preparation method of low concentration standard solution is as follows: pipette 1.00-10mL of high concentration standard solution into a 100-500mL volumetric flask, dilute with water to the scale of the volumetric flask, and mix well;
[0026] The inductively coupled plasma emission spectrometer needs to be preheated for at least 0.5 h before detection.
[0027] Compared with the prior art, the present invention has the following beneficial effects:
[0028] The present invention ensures that the sample can fully react and dissolve by strictly controlling the sample particle size and using a suitable acid for dissolution, providing a basic guarantee for the subsequent accurate detection of the lanthanum content. The addition of a standard solution of yttrium as an internal standard element can correct and compensate for various error factors in the detection process, improving the accuracy and reliability of the test results. The preparation of two standard solutions, high and low concentrations, and the drawing of corresponding working curves can more comprehensively and accurately cover the possible content range of lanthanum in the sample, making the test results more representative and thus more accurately calculating the actual content of lanthanum in the sample. DETAILED DESCRIPTION
[0029] The specific embodiments of the present invention are further described below:
[0030] A method for detecting lanthanum in limestone comprises the following steps:
[0031] 1) Weigh 2.0 g of limestone sample with a particle size of less than 0.125 mm.
[0032] 2) Prepare the sample solution: Place the sample in a 200-mL beaker, add 5 mL of nitric acid and 5 mL of hydrochloric acid, and heat until the sample is completely dissolved. Reduce the volume to 5 mL, add 30 mL of water, cool to room temperature, transfer to a 100-mL volumetric flask, add 5 mL of a 50 μg / mL yttrium internal standard solution, dilute to the mark on the volumetric flask with water, and mix thoroughly. The density of nitric acid is 1.42 g / mL, and the density of hydrochloric acid is 1.19 g / mL.
[0033] The preparation method of the yttrium internal standard solution in the step 2) is as follows: weigh 0.254 mass fraction of yttrium oxide greater than 99.95% and place it in a 100 mL beaker, add 10 mL of hydrochloric acid (1+1), the density of hydrochloric acid is 1.19 g / mL, heat to dissolve, cool to room temperature and transfer to a 200 mL volumetric flask, dilute to the scale with water, mix, transfer 25 mL to a 500 mL volumetric flask and dilute to the scale with water, and mix.
[0034] 3) Prepare standard solution;
[0035] Prepare high concentration standard solution and low concentration standard solution respectively;
[0036] The concentration of the high-concentration standard solution is 500-1000 μg / mL and the low-concentration standard solution is 1.0-100.0 μg / mL.
[0037] The preparation method of the high concentration standard solution in step 3) is as follows: weigh 0.5864g of lanthanum oxide with a mass fraction greater than 99.99% and place it in a 250L beaker, add 20mL of hydrochloric acid with a density of 1.19g / mL to dissolve it, cool it to room temperature, transfer it to a 1000mL volumetric flask, dilute it with water to the scale of the volumetric flask, and mix it. 1mL of this solution contains 500μg of lanthanum.
[0038] The preparation method of low concentration standard solution is as follows: pipette 10 mL of high concentration standard solution (500 μg / mL), place it in a 500 mL volumetric flask, dilute to the scale with water, and mix well. 1 mL of this solution contains 10.0 μg of lanthanum.
[0039] 4) Draw the working curve;
[0040] Weigh 5 portions of a standard solution of matrix calcium carbonate equivalent to the content in the sample, place them in 5 200mL beakers, add 0.50mL, 1.00mL, 2.00mL, 4.00mL, and 6.00mL of a high-concentration standard solution (500μg / mL), respectively, add 5mL of nitric acid and 5mL of hydrochloric acid, heat until the sample is completely dissolved, reduce the volume to 5mL, add 30mL of water, cool to room temperature, transfer to a 100mL volumetric flask, add 5mL of a 50μg / mL yttrium internal standard element standard solution, dilute to the scale with water, mix, and then use an inductively coupled plasma optical emission spectrometer to obtain a high-concentration working curve;
[0041] Weigh 5 portions of a matrix calcium carbonate standard solution equivalent to the content in the sample, place them in 5 200mL beakers, add 0.50mL, 1.00mL, 2.00mL, 4.00mL, and 6.00mL of a low-concentration standard solution (10μg / mL), respectively, add 5mL of nitric acid and 5ml of hydrochloric acid, heat until the sample is completely dissolved, reduce the volume to 5mL, add 30mL of water, cool to room temperature, transfer to a 100mL volumetric flask, add 5mL of a 50μg / mL yttrium internal standard element standard solution, dilute to the scale with water, mix, and then use an inductively coupled plasma optical emission spectrometer to obtain a low-concentration working curve;
[0042] 5) Test solution
[0043] Under the same conditions, the test solution is tested and the lanthanum content in the test solution is calculated based on the high concentration or low concentration working curve;
[0044] The calculation formula is as follows:
[0045]
[0046] Where: w—mass fraction of the element to be measured in the sample, %;
[0047] C—Concentration of high-concentration standard solution or low-concentration standard solution in the sample solution, μg / mL;
[0048] V—volume of sample solution, mL;
[0049] m—mass of the sample, g.
[0050] The inductively coupled plasma emission spectrometer needs to be preheated for at least 0.5 h before detection.
[0051] Table 1 shows the results of four tests.
[0052] Table 1
[0053]
[0054] As shown in Table 1, the method of the present invention has high detection accuracy. In addition, the method of the present invention is simple in process, easy to operate, and has high detection efficiency.
[0055] 6) Spike recovery
[0056] According to Table 2, a spike recovery experiment was carried out. Low-concentration standard solutions were added to four limestone samples, and then the samples were tested and the spike recovery rates were calculated.
[0057] Table 2
[0058]
[0059] It can be seen from the data in Table 2 that the spiked recovery value is between 102% and 105%, which proves that the detection method in this patent has good accuracy.
[0060] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all fall within the scope of protection of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner unless there is any contradiction. In order to avoid unnecessary repetition, the present invention will no longer describe various possible combinations separately. In addition, the various different embodiments of the present invention can also be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.
Claims
1. A method for detecting lanthanum in limestone, characterized in that: The steps include: 1) Weigh 0.1-2.0g of limestone sample with a particle size of less than 0.4mm; 2) Prepare the sample solution: Place the sample in a 200-400 mL beaker, add 5-35 mL of nitric acid and 5-35 mL of hydrochloric acid, heat until the sample is completely dissolved and the volume is reduced to 5-10 mL, add 20-70 mL of water, cool to room temperature, transfer to a 100-500 mL volumetric flask, add 5-25 mL of a 50 μg / mL yttrium internal standard element solution, dilute with water to the mark on the volumetric flask, and mix thoroughly; the density of nitric acid is 1.42 g / mL, and the density of hydrochloric acid is 1.19 g / mL; 3) Prepare standard solution; Prepare high concentration standard solution and low concentration standard solution respectively; The concentration of high-concentration standard solution is 500-1000 μg / mL and the low-concentration standard solution is 1.0-100.0 μg / mL; 4) Draw the working curve; Weigh several portions of a standard solution of matrix calcium carbonate equivalent to the content in the sample, place them in 5 to 10 beakers, add 0.50 to 15.00 mL of a high-concentration standard solution, add 5 to 35 mL of nitric acid, and 5 to 35 mL of hydrochloric acid, heat until the sample is completely dissolved and the volume is reduced to 5 to 10 mL, add 20 to 70 mL of water, cool to room temperature, transfer to a 100 to 500 mL volumetric flask, add 5 to 25 mL of a 50 μg / mL yttrium internal standard element standard solution, dilute with water to the scale of the volumetric flask, mix well, and then use an inductively coupled plasma optical emission spectrometer to obtain a high-concentration working curve; Weigh several portions of a standard solution of matrix calcium carbonate equivalent to the content in the sample, place them in 5 to 10 beakers, add 0.50 to 20.00 mL of a low-concentration standard solution, add 5 to 35 mL of nitric acid, and 5 to 35 mL of hydrochloric acid, heat until the sample is completely dissolved and the volume is reduced to 5 to 10 mL, add 20 to 70 mL of water, cool to room temperature, transfer to a 100 to 500 mL volumetric flask, add 5 to 25 mL of a 50 μg / mL yttrium internal standard element standard solution, dilute with water to the scale of the volumetric flask, mix well, and then use an inductively coupled plasma optical emission spectrometer to obtain a low-concentration working curve; 5) Test solution Under the same conditions, the test solution is tested and the lanthanum content in the test solution is calculated based on the high concentration or low concentration working curve; The calculation formula is as follows: Where: w—mass fraction of the element to be measured in the sample, %; C—Concentration of high-concentration standard solution or low-concentration standard solution in the sample solution, μg / mL; V—volume of sample solution, mL; m—mass of the sample, g.
2. A method for detecting lanthanum in limestone according to claim 1, characterized in that, The preparation method of the yttrium internal standard solution in the step 2) is as follows: weigh 0.254 g of yttrium oxide with a mass fraction greater than 99.95% and place it in a 100 mL beaker, add 10 mL of hydrochloric acid (1+1), the density of hydrochloric acid is 1.19 g / mL, heat to dissolve, cool to room temperature, transfer to a 200 mL volumetric flask, dilute to the scale with water, mix, transfer 25 mL to a 500 mL volumetric flask, dilute to the scale with water, and mix.
3. A method for detecting lanthanum in limestone according to claim 1, characterized in that, The preparation method of the high concentration standard solution in step 3) is as follows: weigh 0.5864-1.1728 g of lanthanum oxide with a mass fraction greater than 99.99% and place it in a 200-400 mL beaker, add 10-30 mL of hydrochloric acid with a density of 1.19 g / mL to dissolve it, cool it to room temperature, transfer it to a 1000 mL volumetric flask, dilute it to the scale with water, and mix it thoroughly; The preparation method of low concentration standard solution is as follows: transfer 1.00-10mL of high concentration standard solution into a 100-500mL volumetric flask, dilute with water to the scale of the volumetric flask, and mix well.
4. A method for detecting lanthanum in limestone according to claim 1, characterized in that, The inductively coupled plasma emission spectrometer needs to be preheated for at least 0.5 h before detection.