Method for detecting content of lanthanum element in low alloy steel based on inductively coupled plasma mass spectrometry

Abstract

The invention discloses a method for detecting the content of lanthanum in low alloy steel based on inductively coupled plasma mass spectrometry. The method comprises the following steps: preparing an iron matrix solution; preparing a standard solution: after selecting a lanthanum element standard mother solution, preparing the lanthanum element standard solution with gradient concentration by adopting an iron matrix solution; preparing an yttrium internal standard solution; preparing a test sample solution: mixing a low alloy steel sample with nitric acid, and digesting to obtain the test sample solution; iCAP-Q detection: carrying out ICAP-Q detection on the standard solution to obtain a standard curve, detecting the test solution under the same condition, introducing an yttrium internal standard solution on line during measurement to inhibit the matrix effect, and calculating the content of the lanthanum element in the test solution according to the standard curve. By optimizing a digestion method and detection parameters, rapid and accurate quantitative analysis of the lanthanum element is realized, and the method has the advantages of high sensitivity, low detection lower limit, good stability, accurate quantification, short detection time, low cost and the like.

Description

Technical Field

[0001] The invention relates to the technical field of materials and metallurgy, and more specifically, to a method for detecting the content of lanthanum in low alloy steel based on inductively coupled plasma mass spectrometry. Background Art

[0002] Lanthanum (La) is the main element of rare earth elements in low alloy steel. The change in the content of La has a certain influence on the corrosion resistance of low alloy steel. Therefore, it is very important to accurately determine the La content in low alloy steel.

[0003] Because the lanthanum content is too high, it is not suitable for the detection of trace elements. The Chinese patent application number 202210859217.2 discloses a method for determining the lanthanum and cerium content in steel using spark source atomic emission spectrometry, comprising the following steps: (1) According to the estimated content of lanthanum and cerium in the spectral sample to be tested, find at least 5 spectral standard samples with suitable lanthanum and cerium content; (2) Use sample preparation equipment to prepare the standard sample and the sample to be tested into a surface qualified analysis sample; (3) Excite the prepared 5-point standard sample in a spark source atomic emission spectrometer to obtain the corresponding 5 intensities, and establish a corresponding relationship based on the intensity and the content of lanthanum and cerium in the standard sample to obtain a calibration working curve of lanthanum and cerium elements; (4) Use the established calibration working curve to detect the lanthanum and cerium elements of the steel sample to be tested, and obtain the lanthanum and cerium content of the steel sample to be tested. However, this patent is for block samples, and there are problems such as poor detection flexibility, and only for surface detection, and poor representativeness. At the same time, the existing analysis methods also have defects such as many types of reagents used and high detection limits. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned defects of the prior art and provide a method for detecting the lanthanum content in low alloy steel based on inductively coupled plasma mass spectrometry with high sensitivity, good stability, accurate quantification, short detection time and low cost, and to achieve rapid and accurate quantitative analysis of lanthanum by optimizing detection parameters.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] A method for detecting the content of lanthanum in low alloy steel based on inductively coupled plasma mass spectrometry, the method comprising the following steps:

[0007] S1. preparing an iron matrix solution: the concentration of the iron matrix solution is 95% to 99%;

[0008] S2. Prepare standard solution:

[0009] After selecting a lanthanum element standard mother solution, the iron matrix solution is used to prepare a lanthanum element standard solution with a gradient concentration of 0 g / L to 0.005 g / L;

[0010] S3, preparing yttrium internal standard solution;

[0011] S4. Prepare the test solution:

[0012] The low alloy steel sample is mixed with nitric acid and digested to obtain the test solution;

[0013] S5, ICAP-Q test:

[0014] The standard solution is detected by ICAP-Q to obtain a standard curve, and the test solution is detected under the same conditions. During measurement, the yttrium internal standard solution is introduced online to suppress the matrix effect, and the content of lanthanum in the test solution is calculated according to the standard curve.

[0015] Optionally, S5 is specifically calculated according to the following formula:

[0016]

[0017] Among them, ω m : The content of the element to be tested in the sample, %; ρ m : Concentration of the element to be tested, μg / ml; ω m0 : The content of the element to be measured in pure iron, %; m: sample weight, g; V: solution volume, ml.

[0018] Optionally, the detection conditions of ICAP-Q in S5 are as follows: RF power is 1200W~1400W; nebulizer gas flow rate is 0.85L / min~0.88L / min; collision gas flow rate is 4.0L / min~4.2L / min; cooling gas flow rate is 13.8L / min~14.2L / min; auxiliary gas flow rate is 0.7L / min~0.9L / min; scanning mode: peak jumping; number of scans: 10 times; sampling depth: 5.0mm; sample lifting amount: 1.2L / min~1.3L / min.

[0019] Optionally, in S2, the preparation of the lanthanum standard solution specifically includes the following steps: 10 mL of a lanthanum standard solution with a concentration of 1000 μg / mL is taken and the volume is adjusted to prepare lanthanum standard solutions with concentrations of 50 μg / mL, 2.5 μg / mL and 0.1 μg / mL respectively; 0 mL and 2 mL of a lanthanum standard solution with a concentration of 0.1 μg / mL, 2 mL, 4 mL and 8 mL of a lanthanum standard mother solution with a concentration of 0.25 μg / mL, and 4 mL and 8 mL of a lanthanum standard mother solution with a concentration of 2.5 μg / mL are taken respectively, and then mixed with 100 ml of the iron matrix solution respectively, and after adjusting the volume, lanthanum standard solutions with lanthanum concentrations of 0 g / L, 0.0001 g / L, 0.00025 g / L, 0.0005 g / L, 0.001 g / L, 0.003 g / L and 0.005 g / L are prepared respectively.

[0020] Optionally, the S1 specifically includes the following steps: dissolving high-purity iron in nitric acid and diluting it with deionized water to obtain the iron matrix solution; the mass volume ratio of the high-purity iron to the nitric acid is 1g:(40ml~100ml).

[0021] Optionally, in S3, the preparation of the yttrium internal standard solution specifically includes the following steps: 10 ml of yttrium standard solution with a concentration of 1000 μg / mL is taken and fixed to volume, and a yttrium internal standard solution with a concentration of 10 μg / mL is prepared.

[0022] Optionally, in S4, the digestion temperature is 280°C to 340°C.

[0023] The present invention also discloses a method for detecting the lanthanum content in low alloy steel based on inductively coupled plasma mass spectrometry, the method comprising the following steps:

[0024] S1. Prepare standard solution:

[0025] After selecting the lanthanum element standard mother solution, a lanthanum element standard solution with a gradient concentration of 0 g / L to 0.005 g / L is prepared;

[0026] S2, preparing yttrium internal standard solution;

[0027] S3. Prepare the test solution:

[0028] The low alloy steel sample is mixed with nitric acid and digested, and ammonia water is added to the digested solution to form a precipitate, and the test solution is obtained after filtering;

[0029] S4, ICAP-Q test:

[0030] The standard solution is detected by ICAP-Q to obtain a standard curve, and the test solution is detected under the same conditions. During measurement, the yttrium internal standard solution is introduced online to suppress the matrix effect, and the content of lanthanum in the test solution is calculated according to the standard curve.

[0031] Optionally, S4 is calculated according to the following formula:

[0032]

[0033] Among them, ω m : The content of the element to be tested in the sample, %; ρ m : concentration of the element to be measured, μg / ml; m: sample weight, g; V: solution volume, ml.

[0034] Optionally, the detection conditions of ICAP-Q in S4 are as follows: RF power is 1200W~1400W; nebulizer gas flow rate is 0.85L / min~0.88L / min; collision gas flow rate is 4.0L / min~4.2L / min; cooling gas flow rate is 13.8L / min~14.2L / min; auxiliary gas flow rate is 0.7L / min~0.9L / min; scanning mode: peak jumping; number of scans: 10 times; sampling depth: 5.0mm; sample lifting amount: 1.2L / min~1.3L / min.

[0035] Optionally, in S1, the preparation of the lanthanum standard solution specifically includes the following steps: aspirate 10 mL of a lanthanum standard solution with a concentration of 1000 μg / mL and then dilute to prepare lanthanum standard solutions with concentrations of 50 μg / mL, 2.5 μg / mL and 0.1 μg / mL respectively; aspirate 0 mL and 2 mL of a lanthanum standard solution with a concentration of 0.1 μg / mL, 2 mL, 4 mL and 8 mL of a lanthanum standard mother solution with a concentration of 0.25 μg / mL, and 4 mL and 8 mL of a lanthanum standard mother solution with a concentration of 2.5 μg / mL respectively, and then dilute to prepare lanthanum standard solutions with lanthanum concentrations of 0 g / L, 0.0001 g / L, 0.00025 g / L, 0.0005 g / L, 0.001 g / L, 0.003 g / L and 0.005 g / L respectively.

[0036] Optionally, the preparation of the yttrium internal standard solution in S2 specifically includes the following steps: 10 ml of yttrium standard solution with a concentration of 1000 μg / mL is taken and fixed to volume to prepare a yttrium internal standard solution with a concentration of 10 μg / mL.

[0037] Optionally, in S3, the digestion temperature is 280°C to 340°C.

[0038] Implementing the embodiments of the present invention will have the following beneficial effects:

[0039] (1) The present invention establishes for the first time a method for determining lanthanum in low alloy steel by ICAP-Q, and achieves rapid and accurate quantitative analysis of lanthanum by optimizing detection parameters.

[0040] (2) The present invention optimizes the digestion method and adopts the nitric acid (1+2) digestion and dissolution method, which can quickly dissolve the sample completely, and at the same time effectively reduce the interference of the sample matrix and impurity components on the ICAP-Q determination process, so that the extracted sample can meet the subsequent analysis requirements; and the present application only uses nitric acid to dissolve the sample, increases the sample weight, uses internal standard elements, and reduces interference, so as to realize the detection of trace lanthanum in low alloy steel, and provides an accurate data basis for on-site personnel to understand the trace lanthanum.

[0041] (3) The detection method of the present invention is simple to operate and easy for other experimenters to learn; the detection of drugs is routine and easy for other laboratories to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a relationship diagram between the sample weight of the lanthanum element and the relative standard deviation in Example 1 of the present invention. DETAILED DESCRIPTION

[0043] The present invention is further described below in conjunction with specific embodiments, but the present invention is not limited in any way.

[0044] The present invention discloses a method for detecting the content of lanthanum in low alloy steel based on inductively coupled plasma mass spectrometry, the method comprising the following steps:

[0045] S1. Prepare an iron matrix solution: the concentration of the iron matrix solution is 95% to 99%.

[0046] In a specific embodiment, step S1 specifically includes: dissolving high-purity iron in nitric acid (1+2), and diluting it with deionized water to obtain an iron matrix solution.

[0047] In a specific embodiment, the mass volume ratio of high purity iron to nitric acid is 1g:(40ml-100ml).

[0048] S2. Prepare standard solution:

[0049] S21. After selecting the lanthanum element standard mother solution, use the iron matrix solution to prepare a lanthanum element standard solution with a gradient concentration of 0 g / L to 0.005 g / L.

[0050] In a specific embodiment, step S21 specifically includes: absorbing 10 mL of a lanthanum standard solution with a concentration of 1000 μg / mL and then diluting the volume to prepare a lanthanum standard solution with a concentration of 50 μg / mL, a lanthanum standard solution with a concentration of 2.5 μg / mL, and a lanthanum standard solution with a concentration of 0.1 μg / mL; respectively absorbing 0 mL and 2 mL of a lanthanum standard solution with a concentration of 0.1 μg / mL, 2 mL, 4 mL and 8 mL of a lanthanum standard mother solution with a concentration of 0.25 μg / mL, and 4 mL and 8 mL of a lanthanum standard mother solution with a concentration of 2.5 μg / mL, respectively, and mixing them with 100 ml of an iron matrix solution, and preparing lanthanum standard solutions with lanthanum concentrations of 0 g / L, 0.0001 g / L, 0.00025 g / L, 0.0005 g / L, 0.001 g / L, 0.003 g / L, and 0.005 g / L, respectively, after diluting the volume.

[0051] S3, preparing yttrium internal standard solution;

[0052] In a specific embodiment, step S3 specifically includes: aspirating 10 ml of a yttrium standard solution with a concentration of 1000 μg / mL and then diluting the volume to prepare a yttrium internal standard solution with a concentration of 10 μg / mL.

[0053] S4. Prepare the test solution:

[0054] Sample pretreatment is a key step in the detection process and directly affects the subsequent ICAP-Q analysis results. Specifically, it includes: mixing the low-alloy steel sample with nitric acid (1+2) and digesting it to obtain the test solution.

[0055] In a specific embodiment, the digestion temperature is 280°C to 340°C.

[0056] Specifically, the present invention optimizes the digestion method and adopts the nitric acid (1+2) digestion and sample dissolution method, which can quickly dissolve the sample completely, and at the same time can effectively reduce the interference of the sample matrix and impurity components on the ICAP-Q determination process, so that the extracted sample can meet the subsequent analysis requirements.

[0057] S5. ICAP-Q detection: The standard solution is detected by ICAP-Q to obtain a standard curve. The test solution is detected under the same conditions. During the measurement, yttrium internal standard solution is introduced online to suppress the matrix effect. The content of lanthanum in the test solution is calculated based on the standard curve.

[0058] In a specific embodiment, S5 specifically includes: sampling the standard solution, drawing a standard curve with the peak area as the ordinate and the concentration as the abscissa, sampling the test solution, testing the test solution under the same conditions, substituting the test results into the above standard curve to obtain the lanthanum content in the test solution.

[0059] In a specific embodiment, S5 is calculated according to the following formula:

[0060]

[0061] Among them, ω m : The content of the element to be tested in the sample, %; ρ m : Concentration of the element to be tested, μg / ml; ω m0 : The content of the element to be measured in pure iron, %; m: sample weight, g; V: solution volume, ml.

[0062] In a specific embodiment, the detection conditions of ICAP-Q in step S5 are as follows: RF power is 1200W~1400W, preferably 1300W; nebulizer gas flow rate is 0.85L / min~0.88L / min, preferably 0.86L / min; collision gas flow rate is 4.0L / min~4.2L / min, preferably 4.10L / min; cooling gas flow rate is 13.8L / min~14.2L / min, preferably 14.0L / min; auxiliary gas flow rate is 0.7L / min~0.9L / min, preferably 0.80L / min; scanning mode: peak jumping; number of scans: 10 times; sampling depth: 5.0mm; sample lifting amount: 1.2L / min~1.3L / min, preferably 1.2L / min.

[0063] Specifically, the present invention selects once as the number of operations to prevent drift of individual points caused by multiple excitations; and each sample is tested at least 4 times, and the appropriate test results are selected to take the average value.

[0064] The present invention also discloses a method for detecting the content of lanthanum in low alloy steel based on inductively coupled plasma mass spectrometry, the method comprising the following steps:

[0065] S1. Prepare standard solution: After selecting the standard mother solution of lanthanum element, prepare a standard solution of lanthanum element with a gradient concentration of 0 g / L to 0.005 g / L.

[0066] In a specific embodiment, step S1 specifically includes: taking 10 mL of a lanthanum standard solution with a concentration of 1000 μg / mL and then diluting the volume to prepare a lanthanum standard solution with a concentration of 50 μg / mL, a lanthanum standard solution with a concentration of 2.5 μg / mL, and a lanthanum standard solution with a concentration of 0.1 μg / mL; respectively taking 0 mL and 2 mL of a lanthanum standard solution with a concentration of 0.1 μg / mL, 2 mL, 4 mL and 8 mL of a lanthanum standard mother solution with a concentration of 0.25 μg / mL, and 4 mL and 8 mL of a lanthanum standard mother solution with a concentration of 2.5 μg / mL, and then diluting the volume to prepare lanthanum element standard solutions with lanthanum concentrations of 0 g / L, 0.0001 g / L, 0.00025 g / L, 0.0005 g / L, 0.001 g / L, 0.003 g / L, and 0.005 g / L, respectively.

[0067] S2. Prepare yttrium internal standard solution:

[0068] In a specific embodiment, step S2 specifically includes the following steps: 10 ml of yttrium standard solution with a concentration of 1000 μg / mL is drawn and fixed to volume, and yttrium internal standard solution with a concentration of 10 μg / mL is prepared.

[0069] S3. Prepare the test solution:

[0070] The low alloy steel sample is mixed with nitric acid and digested, and ammonia water is added to the digested solution to form a precipitate, which is then filtered to obtain a test solution.

[0071] In a specific embodiment, the digestion temperature is 280°C to 340°C.

[0072] S4, ICAP-Q test:

[0073] The standard solution was detected by ICAP-Q to obtain a standard curve. The test solution was detected under the same conditions. During the measurement, yttrium internal standard solution was introduced online to suppress the matrix effect. The content of lanthanum in the test solution was calculated according to the standard curve.

[0074] In a specific embodiment, S4 is calculated according to the following formula:

[0075]

[0076] Among them, ω m : The content of the element to be tested in the sample, %; ρ m : concentration of the element to be measured, μg / ml; m: sample weight, g; V: solution volume, ml.

[0077] In a specific embodiment, the detection conditions of ICAP-Q in step S4 are as follows: RF power is 1200W~1400W, preferably 1300W; nebulizer gas flow rate is 0.85L / min~0.88L / min, preferably 0.86L / min; collision gas flow rate is 4.0L / min~4.2L / min, preferably 4.10L / min; cooling gas flow rate is 13.8L / min~14.2L / min, preferably 14.0L / min; auxiliary gas flow rate is 0.7L / min~0.9L / min, preferably 0.80L / min; scanning mode: peak jumping; number of scans: 10 times; sampling depth: 5.0mm; sample lifting amount: 1.2L / min~1.3L / min, preferably 1.2L / min.

[0078] Specifically, the present invention establishes for the first time a method for determining lanthanum in low alloy steel by ICAP-Q, and realizes rapid and accurate quantitative analysis of lanthanum by optimizing detection parameters. The detection method of the present invention has the advantages of high sensitivity, good stability, accurate quantification, short detection time, and low cost.

[0079] The following are specific embodiments

[0080] Example 1

[0081] 1. Experimental instruments and reagents

[0082] Lanthanum standard solution: 1000μg / mL, national standard solution.

[0083] Yttrium standard solution: 1000μg / mL, national standard solution.

[0084] 2. Experimental steps

[0085] 2.1 Solution preparation

[0086] 2.1.1 Preparation of iron matrix solution:

[0087] 0.2 g of high-purity iron (99.98%) was dissolved in 20 ml of nitric acid (1+2), and diluted with deionized water to obtain an iron matrix solution.

[0088] 2.1.2 Preparation of standard solution:

[0089] 10 mL of 1000 μg / mL lanthanum standard solution was taken and diluted to volume to prepare 50 μg / mL, 2.5 μg / mL and 0.1 μg / mL lanthanum standard solutions respectively; 0 mL and 2 mL of 0.1 μg / mL lanthanum standard solution, 2 mL, 4 mL and 8 mL of 0.25 μg / mL lanthanum standard mother solution, and 4 mL and 8 mL of 2.5 μg / mL lanthanum standard mother solution were taken respectively, and then mixed with 100 mL of iron matrix solution respectively, and diluted to volume to prepare lanthanum element standard solutions with lanthanum concentrations of 0 g / L, 0.0001 g / L, 0.00025 g / L, 0.0005 g / L, 0.001 g / L, 0.003 g / L and 0.005 g / L respectively.

[0090] 2.1.3 Preparation of yttrium internal standard solution:

[0091] Pipette 10 ml of yttrium standard solution with a concentration of 1000 μg / mL, dilute to a 1000 ml volumetric flask, and then transfer to the detection bottle for use.

[0092] 2.1.4 Preparation of test solution:

[0093] Accurately weigh 0.2g of low alloy steel sample, place the sample in a 100ml two-purpose bottle, add 20ml nitric acid (1+2), slowly heat to 280℃~340℃ on a hot plate until completely dissolved, and adjust the volume to obtain the test solution.

[0094] 2.2 Testing conditions:

[0095] Turn on ICAP-Q and run it for at least 1 hour before measurement. Draw the vacuum after 24 hours of operation. Adjust the parameters according to the working conditions in Table 1, and set the number of cleaning runs to once and the number of measurements to four. Take the average value of multiple measurements to reduce the system error.

[0096] Example 2

[0097] 1. Experimental instruments and reagents

[0098] Lanthanum standard solution: 1000μg / mL, national standard solution.

[0099] Yttrium standard solution: 1000μg / mL, national standard solution.

[0100] 2. Experimental steps

[0101] 2.1 Solution preparation

[0102] 2.1.1 Preparation of standard solution:

[0103] Pipette 10 mL of 1000 μg / mL lanthanum standard solution and dilute to volume to prepare 50 μg / mL lanthanum standard solution, 2.5 μg / mL lanthanum standard solution and 0.1 μg / mL lanthanum standard solution respectively; plute 0 mL and 2 mL of 0.1 μg / mL lanthanum standard solution, 2 mL, 4 mL and 8 mL of 0.25 μg / mL lanthanum standard mother solution, and 4 mL and 8 mL of 2.5 μg / mL lanthanum standard mother solution respectively, and dilute to volume to prepare lanthanum element standard solutions with lanthanum concentrations of 0 g / L, 0.0001 g / L, 0.00025 g / L, 0.0005 g / L, 0.001 g / L, 0.003 g / L and 0.005 g / L respectively.

[0104] 2.1.2 Preparation of yttrium internal standard solution:

[0105] Pipette 10 ml of yttrium standard solution with a concentration of 1000 μg / mL, dilute to a 1000 ml volumetric flask, and then transfer to the detection bottle for use.

[0106] 2.1.3 Preparation of test solution:

[0107] Accurately weigh 0.2g of low alloy steel sample, place the sample in a 100ml two-purpose bottle, add 20ml nitric acid (1+2) and slowly heat to 280℃~340℃ on a hot plate until it is completely dissolved, and add 0.91g / ml ammonia water to the digested solution to form a precipitate, and obtain the test solution after filtering.

[0108] 2.2 Testing conditions:

[0109] Turn on ICAP-Q and run it for at least 1 hour before measurement. Draw the vacuum after 24 hours of operation. Adjust the parameters according to the working conditions in Table 1, and set the number of cleaning runs to once and the number of measurements to four. Take the average value of multiple measurements to reduce the system error.

[0110] Table 1 ICAP-Q working conditions

[0111]

[0112] 2.3 Methodological investigation

[0113] 2.3.1 Investigation of linear relationship

[0114] A series of standard solutions with concentration gradients were measured under the above conditions, and the peak area-concentration standard curve was plotted and linear regression was performed to obtain the regression equation of the lanthanum standard curve, as shown in Table 2. It has a good linear relationship and the correlation coefficient R 2 Greater than 0.99, with a wide linear range, which can meet the detection requirements.

[0115] Table 2 Results of investigation on the linear relationship of lanthanum element

[0116]

[0117] 2.3.2 Stability study

[0118] Weigh 0.1g, 0.2g, 0.3g, and 0.4g of low alloy steel samples for comparison. Repeat the test 8 times under the above conditions. The test results are as follows: Figure 1 As shown in Table 3, as the sample weight increases, the stability of the test results increases. Considering the dissolution of the sample, a sample weight of 0.2 g can meet the stability requirements of the test.

[0119] Table 3 Results of stability study of lanthanum

[0120]

[0121]

[0122] 2.3.2 Investigation of spike recovery

[0123] Take two identical test solution, one of which is tested for lanthanum according to the above analysis steps, and the other is tested after adding a certain amount of standard substance of the component to be tested. The ratio of the difference between the result of the spiked one and the theoretical value of the added standard substance is the sample spike recovery rate. The results are shown in Table 4.

[0124] Table 4 Results of the recovery rate of spiked lanthanum

[0125]

[0126]

[0127] According to the above results, the recovery rate of spiked samples ranged from 96% to 102%, which met the needs of analytical determination.

[0128] 2.3.2 Inspection of testing equipment

[0129] Inductively coupled plasma emission mass spectrometer and direct reading spectrometer were selected to detect 5 groups of samples 8 times respectively. The results are shown in Table 5.

[0130] Table 5 Results of the inspection of lanthanum detection equipment

[0131]

[0132] According to the test results in Table 5, the test results of direct reading spectrometer have a large fluctuation range and poor precision, while the test results of inductively coupled plasma emission mass spectrometer have better precision and are more suitable for the detection of low-content elements.

[0133] In summary, the present invention establishes for the first time a method for determining lanthanum in low alloy steel by ICAP-Q, and realizes rapid and accurate quantitative analysis of lanthanum by optimizing the digestion method and detection parameters. The detection method of the present invention has the advantages of high sensitivity, good stability, accurate quantification, short detection time, low cost, etc., and provides a reliable detection method for rapid, efficient and accurate determination of the lanthanum content in low alloy steel.

[0134] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent application. 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 invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for detecting the lanthanum content in low alloy steel based on inductively coupled plasma mass spectrometry, characterized in that: The method comprises the following steps: S1. preparing an iron matrix solution: the concentration of the iron matrix solution is 95% to 99%; S2. Prepare standard solution: After selecting a lanthanum element standard mother solution, the iron matrix solution is used to prepare a lanthanum element standard solution with a gradient concentration of 0 g / L to 0.005 g / L; S3, preparing yttrium internal standard solution; S4. Prepare the test solution: The low alloy steel sample is mixed with nitric acid and digested to obtain the test solution; S5, ICAP-Q test: The standard solution is detected by ICAP-Q to obtain a standard curve, and the test solution is detected under the same conditions. During measurement, the yttrium internal standard solution is introduced online to suppress the matrix effect, and the content of lanthanum in the test solution is calculated according to the standard curve.

2. The method for detecting the lanthanum content in low alloy steel based on inductively coupled plasma mass spectrometry according to claim 1, characterized in that: S5 is specifically calculated according to the following formula: Among them, ω m : The content of the element to be tested in the sample, %; ρ m : Concentration of the element to be tested, μg / ml; ω m0 : The content of the element to be measured in pure iron, %; m: sample weight, g; V: solution volume, ml.

3. The method for detecting the lanthanum content in low alloy steel based on inductively coupled plasma mass spectrometry according to claim 1, characterized in that: The detection conditions of ICAP-Q in the S5 are as follows: RF power is 1200W~1400W; nebulizer gas flow rate is 0.85L / min~0.88L / min; collision gas flow rate is 4.0L / min~4.2L / min; cooling gas flow rate is 13.8L / min~14.2L / min; auxiliary gas flow rate is 0.7L / min~0.9L / min; scanning mode: peak jumping; number of scans: 10 times; sampling depth: 5.0mm; sample lifting amount: 1.2L / min~1.3L / min.

4. The method for detecting the lanthanum content in low alloy steel based on inductively coupled plasma mass spectrometry according to claim 1, characterized in that: In S2, the preparation of the lanthanum element standard solution specifically includes the following steps: absorbing 10 mL of a lanthanum standard solution with a concentration of 1000 μg / mL and then diluting the volume to prepare a lanthanum standard solution with a concentration of 50 μg / mL, a lanthanum standard solution with a concentration of 2.5 μg / mL, and a lanthanum standard solution with a concentration of 0.1 μg / mL; 0 mL and 2 mL of lanthanum standard solution with a concentration of 0.1 μg / mL, 2 mL, 4 mL and 8 mL of lanthanum standard mother solution with a concentration of 0.25 μg / mL, and 4 mL and 8 mL of lanthanum standard mother solution with a concentration of 2.5 μg / mL were respectively absorbed, and then mixed with 100 ml of the iron matrix solution, and after constant volume, lanthanum standard solutions with lanthanum concentrations of 0 g / L, 0.0001 g / L, 0.00025 g / L, 0.0005 g / L, 0.001 g / L, 0.003 g / L, and 0.005 g / L were prepared.

5. The method for detecting the lanthanum content in low alloy steel based on inductively coupled plasma mass spectrometry according to claim 1, characterized in that: The S1 specifically comprises the following steps: dissolving high-purity iron in nitric acid and diluting with deionized water to obtain the iron matrix solution; the mass volume ratio of the high-purity iron to the nitric acid is 1g:(40ml-100ml); In S3, the preparation of the yttrium internal standard solution specifically includes the following steps: 10 ml of a yttrium standard solution with a concentration of 1000 μg / mL is taken and fixed to a volume, and a yttrium internal standard solution with a concentration of 10 μg / mL is prepared; In S4, the digestion temperature is 280°C to 340°C.

6. A method for detecting the lanthanum content in low alloy steel based on inductively coupled plasma mass spectrometry, characterized in that: The method comprises the following steps: S1. Prepare standard solution: After selecting the lanthanum element standard mother solution, a lanthanum element standard solution with a gradient concentration of 0 g / L to 0.005 g / L is prepared; S2, preparing yttrium internal standard solution; S3. Prepare the test solution: The low alloy steel sample is mixed with nitric acid and digested, and ammonia water is added to the digested solution to form a precipitate, and the test solution is obtained after filtering; S4, ICAP-Q test: The standard solution is detected by ICAP-Q to obtain a standard curve, and the test solution is detected under the same conditions. During measurement, the yttrium internal standard solution is introduced online to suppress the matrix effect, and the content of lanthanum in the test solution is calculated according to the standard curve.

7. The method for detecting the lanthanum content in low alloy steel based on inductively coupled plasma mass spectrometry according to claim 1, characterized in that: S4 is calculated according to the following formula: Among them, ω m : The content of the element to be tested in the sample, %; ρ m : concentration of the element to be measured, μg / ml; m: sample weight, g; V: solution volume, ml.

8. The method for detecting the lanthanum content in low alloy steel based on inductively coupled plasma mass spectrometry according to claim 1, characterized in that: The detection conditions of ICAP-Q in the S4 are as follows: RF power is 1200W~1400W; nebulizer gas flow rate is 0.85L / min~0.88L / min; collision gas flow rate is 4.0L / min~4.2L / min; cooling gas flow rate is 13.8L / min~14.2L / min; auxiliary gas flow rate is 0.7L / min~0.9L / min; scanning mode: peak jumping; number of scans: 10 times; sampling depth: 5.0mm; sample lifting amount: 1.2L / min~1.3L / min.

9. The method for detecting the lanthanum content in low alloy steel based on inductively coupled plasma mass spectrometry according to claim 1, characterized in that: In S1, the preparation of the lanthanum element standard solution specifically includes the following steps: absorbing 10 mL of a lanthanum standard solution with a concentration of 1000 μg / mL and then diluting the volume to prepare a lanthanum standard solution with a concentration of 50 μg / mL, a lanthanum standard solution with a concentration of 2.5 μg / mL, and a lanthanum standard solution with a concentration of 0.1 μg / mL; After taking 0mL and 2mL of lanthanum standard solution with a concentration of 0.1μg / mL, 2mL, 4mL and 8mL of lanthanum standard mother solution with a concentration of 0.25μg / mL, and 4mL and 8mL of lanthanum standard mother solution with a concentration of 2.5μg / mL, respectively, lanthanum standard solutions with lanthanum concentrations of 0g / L, 0.0001g / L, 0.00025g / L, 0.0005g / L, 0.001g / L, 0.003g / L, and 0.005g / L were prepared after diluting the volume.

10. The method for detecting the lanthanum content in low alloy steel based on inductively coupled plasma mass spectrometry according to claim 1, characterized in that: The preparation of the yttrium internal standard solution in S2 specifically includes the following steps: 10 ml of a yttrium standard solution with a concentration of 1000 μg / mL is taken and fixed to a volume, and a yttrium internal standard solution with a concentration of 10 μg / mL is prepared; In S3, the digestion temperature is 280°C to 340°C.

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