Method for determining molybdenum content in tantalum product

Abstract

The invention discloses a method for determining the molybdenum content in a tantalum product, and relates to the technical field of analysis of impurity elements in tantalum, and the method specifically comprises the following steps: preparing a molybdenum standard sample; a molybdenum standard sample and a spectrum buffering agent are mixed as a spectrum excitation anode; a spectrum excitation anode is excited through a full-spectrum alternating-current and direct-current arc emission spectrometer, a molybdenum standard sample spectral line intensity value is obtained, and a molybdenum standard curve is established with multiple sets of molybdenum standard sample element concentrations and the corresponding molybdenum standard sample spectral line intensity value as coordinate axes; crushing the tantalum product sample, calcining, converting into an oxide, and cooling to room temperature; and mixing the sample powder and the spectrum buffer agent, and determining the molybdenum content in the tantalum product through a full-spectrum alternating-current and direct-current arc emission spectrometer. The sample does not need to be dissolved, and the powder sample can be directly analyzed; a relatively low lower limit can be obtained without diluting a sample, the molybdenum in tantalum is measured by utilizing the full-spectrum alternating-current and direct-current arc emission spectrometer, and the instrument is high in sensitivity, high in analysis speed, simple and convenient to operate and low in maintenance and use cost.

Description

Technical Field

[0001] The present invention relates to the technical field of analysis of impurity elements in tantalum, and in particular to a method for determining the molybdenum content in tantalum products. Background Art

[0002] Tantalum is a refractory metal with a melting point of up to 3017℃. It has the characteristics of corrosion resistance, thermal conductivity, electrical conductivity, good plasticity, and stable chemical properties. It is widely used in various fields such as metallurgy, electronics, aerospace, and medical treatment. High-purity tantalum is an indispensable key material for the production of large-scale integrated circuits. Integrated circuits are an important part of the electronic information industry. In the context of the information age, the demand for high-purity tantalum will continue to grow, which puts forward higher requirements for the determination of impurity elements in tantalum samples. Among them, the impurity molybdenum content is an important component indicator in tantalum products. The product technical conditions require that the mass fraction of molybdenum is not more than 1.0μg / g. The current national standard method (GB / T 15076.5-2017 Inductively coupled plasma atomic emission spectrometry for the determination of molybdenum content) has an analysis lower limit of 5.0μg / g, which cannot meet the requirements of product technology. In addition, ICP-AES and ICP-MS use solution injection, and the sample needs to be dissolved in acid. The reagents used, such as nitric acid and hydrofluoric acid, need to be purified again. In order to determine a lower analysis limit, the sample needs to be diluted repeatedly, and the sample content will be lost or the sample will be contaminated during dilution. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a method for determining the molybdenum content in tantalum products. The specific technical solution is:

[0004] A method for determining the molybdenum content in a tantalum product comprises the following steps:

[0005] Step 1: Add molybdenum oxide to a high-purity tantalum oxide matrix, mix and grind to obtain a main standard molybdenum sample, and dilute the main standard molybdenum sample step by step according to proportion to prepare 4 to 6 groups of molybdenum standard samples;

[0006] Step 2: Mix the molybdenum standard sample and the spectral buffer in a mass ratio of 1:1 and place the mixture in the hole of the lower electrode as a spectral excitation anode;

[0007] Step 3: Excite the spectral excitation anode by a full-spectrum AC / DC arc emission spectrometer to obtain the spectral line intensity value of the molybdenum standard sample, and establish a molybdenum standard curve with multiple groups of molybdenum standard sample element concentrations and corresponding molybdenum standard sample spectral line intensity values ​​as coordinate axes;

[0008] Step 7: crush the tantalum product sample and calcine it at 900-950°C for 1-2h until the sample is completely converted into oxide and then cool it to room temperature;

[0009] Step 8: Mix the cooled sample powder and spectral buffer in a mass ratio of 1:1 and place them in the hole of the lower electrode. Then, the molybdenum content in the tantalum product can be determined by a full spectrum AC / DC arc emission spectrometer.

[0010] Preferably, the spectral buffer in step 2 and step 8 comprises the following components: 90% to 95% pure graphite powder and 5% to 10% pure sodium fluoride, by mass percentage.

[0011] Preferably:

[0012] The main standard molybdenum sample described in step 1 is diluted into a molybdenum standard sample by adding a high-purity tantalum oxide matrix;

[0013] The spectrum buffer is prepared by mixing and grinding 94% by mass of pure graphite powder and 6% by mass of pure sodium fluoride.

[0014] Preferably, in step 3, when exciting the spectral excitation anode by a full spectrum AC / DC arc emission spectrometer, the molybdenum analysis line is selected to be 319.39 nm.

[0015] Preferably, the DC arc working conditions of the full-spectrum AC / DC arc emission spectrometer are set as follows: preheating current 4-5A, preheating time 5 steps, working current 12-14A, exposure time 55 steps, and the spacing between the upper and lower electrodes is 1.5mm.

[0016] Preferably, the upper and lower electrodes of the full spectrum AC / DC arc emission spectrometer are graphite electrodes, wherein:

[0017] The upper electrode has a diameter of 6 mm and a length of 40 mm. Its top is in the shape of a truncated cone with a height of 10 mm and an upper end surface diameter of 2 mm.

[0018] The lower electrode has a diameter of 6mm and a length of 40mm. Its top is cup-shaped. The diameter of the large diameter end of the cup-shaped top is 5.1mm±0.05mm, the length of the large diameter end is 5mm±0.1mm, the diameter of the small diameter end is 3.5mm±0.1mm, the length of the small diameter end is 4mm±0.1mm, the hole diameter is 3.8mm, and the hole depth is 4mm±0.1mm.

[0019] Preferably, step 3 further includes the following steps:

[0020] Step 4: Determination of the lower limit of the analytical method;

[0021] Step 5: Spike recovery test;

[0022] Step 6: Determination of precision.

[0023] Preferably, the mixing and placing in the lower electrode hole in step 2 and step 8 specifically includes:

[0024] Mix and grind the mixture in a mortar and put it into the hole of the lower electrode until it is full and tight;

[0025] Scrape off the residual material around the hole and add 1 to 2 drops of sucrose solution. After drying, it can be used as a spectral excitation anode.

[0026] Preferably, the DC arc of the full-spectrum AC / DC arc emission spectrometer adopts a pulsed arc discharge mode.

[0027] Preferably, step 3 specifically includes the following sub-steps:

[0028] Step 31: collecting original spectrum data of a molybdenum standard sample by a full-spectrum AC / DC arc emission spectrometer, wherein the spectrum data includes characteristic spectrum lines of molybdenum and tantalum elements;

[0029] Step 32: preprocessing the raw spectral data, including smoothing the signal using a Gaussian smoothing or wavelet denoising algorithm to remove high-frequency noise, fitting the baseline drift in the spectral data using at least a quadratic polynomial, and subtracting the fitted baseline component from the raw spectrum;

[0030] Step 33: Perform Gaussian fitting on the spectrum data after removing the baseline drift to extract the characteristic peak of molybdenum. The Gaussian fitting function is expressed as:

[0031]

[0032] Among them, A i is the amplitude of the i-th Gaussian peak, μ i is the peak position, σ i is the peak width;

[0033] Step 34: Use a difference spectrum method or a convolution interference removal method to remove the interference of tantalum on the molybdenum spectrum line to obtain a pure signal of molybdenum;

[0034] Step 35: Based on the molybdenum peak area obtained by Gaussian fitting, the concentration of molybdenum in the sample is calculated by comparing it with a molybdenum standard sample of known concentration through a standard curve method;

[0035] Step 36: Establish a molybdenum standard curve through the relationship between the known concentration of the molybdenum standard sample and the fitted spectral signal.

[0036] The method for determining the molybdenum content in tantalum products provided by the present invention does not require dissolving the sample, and can directly analyze the powder sample; it does not require diluting the sample, and can also obtain a relatively low lower limit, that is, it reaches the lower limit level of the determination result of the molybdenum element in tantalum determined by an inductively coupled plasma emission spectrometer (ICP-AES) or an inductively coupled plasma mass spectrometer (ICP-MS), and the test result can fully meet the requirements for detecting the impurity element molybdenum in high-purity tantalum. The AES-8000 full-spectrum AC / DC arc emission spectrometer is used to determine molybdenum in tantalum. The instrument has high sensitivity, fast analysis speed, simple operation, low maintenance and use cost, and can directly analyze the powder sample; it does not require diluting the sample, and can obtain a lower analysis lower limit. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0038] Figure 1 A flow chart of a method for determining the molybdenum content in a tantalum product provided in an embodiment of the present invention;

[0039] Figure 2 A schematic diagram of the structure of an upper electrode provided in an embodiment of the present invention;

[0040] Figure 3 A schematic diagram of the structure of the lower electrode provided in an embodiment of the present invention;

[0041] Figure 4 This is a molybdenum standard curve diagram established in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings. The description in this part is only exemplary and explanatory and should not have any limiting effect on the protection scope of the present invention.

[0043] See also Figures 1 to 4 , this embodiment provides a method for determining the molybdenum content in a tantalum product, comprising the following steps:

[0044] Step 1: Add molybdenum oxide to a high-purity tantalum oxide matrix, mix and grind to obtain a main standard molybdenum sample, and dilute the main standard molybdenum sample step by step in proportion to prepare 4 to 6 groups of molybdenum standard samples.

[0045] Step 2: Mix the molybdenum standard sample and the spectral buffer in a mass ratio of 1:1 and place it in the hole of the lower electrode as a spectral excitation anode.

[0046] Step 3: Use the full spectrum AC / DC arc emission spectrometer to excite the anode to obtain the molybdenum standard line intensity value. Use multiple sets of molybdenum standard element concentrations and the corresponding molybdenum standard line intensity values ​​as the coordinate axis to establish a molybdenum standard curve. The calibration curve has good linearity (correlation coefficient R 2 =0.9995), see Figure 3 .

[0047] Step 7: Crush the tantalum product sample and calcine it at 900-950°C for 1-2h until the sample is completely converted into oxide and then cool to room temperature.

[0048] Step 8: Mix the cooled sample powder and spectral buffer in a mass ratio of 1:1 and place them in the hole of the lower electrode. Then, the molybdenum content in the tantalum product can be determined by a full spectrum AC / DC arc emission spectrometer.

[0049] Among them, the tantalum product sample and the molybdenum standard sample can be used as the spectral excitation anode in the following steps:

[0050] Weigh about 1.0g of the sample into a porcelain crucible, place it in a muffle furnace, raise the temperature from room temperature to 900℃, keep it warm for about 1h until the sample is completely converted into tantalum pentoxide, and cool it for later use.

[0051] Weigh the cooled sample and buffer in a weight ratio of 1:1 (150 mg sample plus 150 mg buffer), mix and grind in a plexiglass mortar, put into the hole of the lower electrode, fill it up and tighten it, and scrape the residue around the electrode mouth, add 1 to 2 drops of sucrose solution, dry it, and use it as a spectrum excitation anode. Each sample is loaded with 3 parallel samples. The molybdenum series standard samples in tantalum pentoxide are treated in the same way.

[0052] The tantalum pentoxide standard sample was excited under the optimal conditions set by the direct reading spectrometer, and each standard point was measured 4 to 6 times to obtain the intensity value of the molybdenum standard sample. A molybdenum standard curve was established based on the molybdenum analysis element concentration and the corresponding intensity average value.

[0053] Place the lower electrode with the sample on the lower electrode clamp, clamp the upper electrode with the upper electrode clamp, adjust the upper and lower electrodes to the calibration line, and close the operating room protection door. Each sample is excited three times, and the corresponding concentration value is displayed on the computer analysis interface.

[0054] A cup-shaped lower electrode and a sample-to-buffer ratio of 1:1 are used; there is no need to dissolve the sample, the solid sample is directly measured, and there is no need to dilute the sample. The lower limit of the measurement result reaches the lower limit level of the measurement result of molybdenum in tantalum determined by inductively coupled plasma emission spectrometer (ICP-AES) or inductively coupled plasma mass spectrometer (ICP-MS).

[0055] The method for determining the molybdenum content in tantalum products provided in this embodiment does not require dissolving the sample, and can directly analyze the powder sample; it does not require diluting the sample, and can also obtain a relatively low lower limit, that is, it reaches the lower limit level of the determination result of the molybdenum element in tantalum determined by inductively coupled plasma emission spectrometer (ICP-AES) or inductively coupled plasma mass spectrometer (ICP-MS), and the test result can fully meet the requirements for the detection of impurity elements such as molybdenum in high-purity tantalum. The AES-8000 full-spectrum AC and DC arc emission spectrometer is used to determine molybdenum in tantalum. The instrument has high sensitivity, fast analysis speed, simple operation, low maintenance and use costs, and can directly analyze the powder sample; it does not require diluting the sample, and can obtain a lower analysis lower limit.

[0056] Furthermore, the spectral buffer in step 2 and step 8 comprises the following components: by mass percentage, 90% to 95% of pure graphite powder and 5% to 10% of pure sodium fluoride.

[0057] Further:

[0058] In step 1, the main standard molybdenum sample is diluted to a molybdenum standard sample by adding a high-purity tantalum oxide matrix.

[0059] The spectrum buffer is prepared by mixing and grinding 94% by mass of pure graphite powder and 6% by mass of pure sodium fluoride.

[0060] Furthermore, in step 3, when the anode is excited by the full-spectrum AC / DC arc emission spectrometer, the molybdenum analysis line is selected as 319.39 nm, and the conditions of appropriate sensitivity, no background interference, and no interference from impurity elements are selected according to the standard sample spectrum or data.

[0061] Furthermore, the DC arc working conditions of the full-spectrum AC / DC arc emission spectrometer are set as follows: preheating current 4-5A, preheating time 5 steps, working current 12-14A, exposure time 55 steps, and the spacing between the upper and lower electrodes is 1.5mm.

[0062] Furthermore, the upper and lower electrodes of the full spectrum AC / DC arc emission spectrometer are graphite electrodes, wherein:

[0063] The upper electrode has a diameter of 6 mm and a length of 40 mm. Its top is in the shape of a truncated cone with a height of 10 mm and an upper end face diameter of 2 mm.

[0064] The lower electrode has a diameter of 6mm and a length of 40mm. Its top is cup-shaped. The diameter of the large diameter end of the cup-shaped top is 5.1mm±0.05mm, the length of the large diameter end is 5mm±0.1mm, the diameter of the small diameter end is 3.5mm±0.1mm, the length of the small diameter end is 4mm±0.1mm, the hole diameter is 3.8mm, and the hole depth is 4mm±0.1mm.

[0065] Furthermore, after step 3, the following steps are also included:

[0066] Step 4: Determination of the lower limit of the analytical method.

[0067] Step 5: Spike recovery test.

[0068] Step 6: Determination of precision.

[0069] Furthermore, the mixing in step 2 and step 8 and then placing in the lower electrode hole specifically includes:

[0070] Grind the mixture in a mortar and put it into the hole of the lower electrode until it is full and tight.

[0071] Scrape off the residual material around the hole and add 1 to 2 drops of sucrose solution. After drying, it can be used as a spectral excitation anode.

[0072] Furthermore, the DC arc of the full-spectrum AC / DC arc emission spectrometer adopts a pulse arc discharge mode.

[0073] Furthermore, step 3 specifically includes the following sub-steps:

[0074] Step 31: Collect original spectrum data of the molybdenum standard sample by using a full-spectrum AC / DC arc emission spectrometer, where the spectrum data includes characteristic spectrum lines of molybdenum and tantalum elements.

[0075] Step 32: Preprocessing the raw spectral data includes smoothing the signal using a Gaussian smoothing or wavelet denoising algorithm to remove high-frequency noise, fitting the baseline drift in the spectral data using at least a quadratic polynomial, and subtracting the fitted baseline component from the raw spectrum.

[0076] Step 33: Perform Gaussian fitting on the spectrum data after removing the baseline drift to extract the characteristic peak of molybdenum. The Gaussian fitting function is expressed as:

[0077]

[0078] Among them, A i is the amplitude of the i-th Gaussian peak, μ i is the peak position, σ i is the peak width.

[0079] Step 34: Use the difference spectrum method or the convolution interference removal method to remove the interference of tantalum on the molybdenum spectrum line to obtain a pure molybdenum signal.

[0080] Step 35: Based on the molybdenum peak area obtained by Gaussian fitting, the concentration of molybdenum in the sample is calculated by comparing it with a molybdenum standard sample of known concentration using a standard curve method.

[0081] Step 36: Establish a molybdenum standard curve through the relationship between the known concentration of the molybdenum standard sample and the fitted spectral signal.

[0082] Specific examples are provided below. The provided examples may enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way.

[0083] Example 1: Determination of the lower limit of the analytical method

[0084] Establishment of standard curve: Weigh a series of molybdenum standard substances in high-purity tantalum oxide respectively, mix with buffer in a weight ratio of 1:1, mix and grind in a plexiglass mortar, fill and tighten the hole of the cup-shaped lower electrode with the ground standard substances, add 2 drops of sucrose solution, and dry it to serve as the spectral excitation anode. Place the lower electrode loaded with standard substances on the lower electrode clamp, and the upper electrode on the upper electrode clamp. Adjust the upper and lower electrodes to the calibration line, excite a series of standard substances, and use the intensity value of each standard substance as the vertical coordinate and the concentration value of the standard substance as the horizontal coordinate to fit the calibration curve of the molybdenum element. The calibration curve has good linearity (correlation coefficient R 2 =0.9995).

[0085] Under the determined working conditions, the tantalum oxide matrix was continuously measured eleven times, and the detection limit of the method was calculated by 3 times the standard deviation, and the lower limit of the analytical method was calculated by 5 times the standard deviation. The test results are shown in Table 1:

[0086] Table 1

[0087]

[0088] From Table 1, it can be seen that the lower limit of molybdenum analysis determined by this method is less than 0.5 μg / g.

[0089] Example 2: Spike recovery test

[0090] Weigh two portions of high-purity tantalum oxide matrix, add 2.0μg and 5.0μg of molybdenum standard substances respectively, mix and grind in a plexiglass mortar; weigh the evenly ground spiked matrix and buffer in a weight ratio of 1:1, mix and grind in a plexiglass mortar, put them into the hole of the lower electrode, fill it up and tighten it, scrape off the residue around the electrode mouth, add 1-2d sucrose solution, dry it, and use it as a spectral excitation anode.

[0091] Place the lower electrode with the sample on the lower electrode clamp, and the upper electrode on the upper electrode clamp, adjust the upper and lower electrodes to the calibration line, and close the operating room protection door. Excite the sample, and the average value of the measurement results is shown in Table 2:

[0092] Table 2

[0093]

[0094] From Table 2, we can see that the recovery rate of spiked samples is between 95.8% and 99.5%, which indicates that the accuracy of this method is good.

[0095] Example 3: Determination of precision

[0096] Weigh 1.0 g of each of two batches of tantalum powder from different batches into a porcelain crucible, place it in a muffle furnace, raise the temperature from room temperature to 900°C, keep it warm for 1 hour until the sample is completely converted into tantalum pentoxide, and cool it for use.

[0097] Weigh the cooled sample and buffer in a weight ratio of 1:1, mix and grind in a plexiglass mortar, put into the hole of the lower electrode, fill and tighten, scrape the residue around the electrode mouth, add 1-2d sucrose solution, dry, and use it as a spectral excitation anode. Place the lower electrode with the sample on the lower electrode clamp, and the upper electrode on the upper electrode clamp, adjust the upper and lower electrodes to the calibration line, and excite each batch of samples seven times. The measurement results, average results, standard deviation, and relative standard deviation are shown in Table 3.

[0098] Table 3

[0099]

[0100] From Table 3, it can be seen that the relative standard deviations (RSDs) of the determination results of molybdenum in the two batches of tantalum powder are both less than 10%, and the precision of the determination results is good.

[0101] Example 4: Results Comparison Sample S-3

[0102] The comparison of the analysis results of the molybdenum content in tantalum determined by the method of the present invention and the ICP-Ms instrument is shown in Table 4:

[0103] Table 4

[0104] batch number Direct reading spectrometer AES-8000 ICP-Ms deviation Allowable difference S-4 0.50 0.46 0.04 ±0.10

[0105] From Table 4, it can be seen that the results of molybdenum in tantalum determined by direct reading spectrometer are consistent with those determined by ICP-Ms instrument, which are within the allowable difference.

[0106] The above examples illustrate that the method of the present invention is feasible for determining molybdenum in tantalum using an AES-8000 full-spectrum AC / DC arc emission spectrometer, and the lower limit of the molybdenum determination result is less than 0.5 μg / g. The accuracy of the method was verified by a matrix spike recovery test; seven independent determinations were performed on two batches of tantalum powder samples, and the relative standard deviations of the determination results were less than 10%; the results of determining molybdenum in tantalum using the method of the present invention were consistent with the results of the ICP-Ms instrument determination, within the allowable error; indicating that the method has good accuracy and precision and is accurate and feasible.

[0107] The principles and implementation methods of the present invention are described herein using specific examples, and the description of the above embodiments is only used to help understand the method and core ideas of the present invention. The above are only preferred implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention, which should be within the protection scope of the present invention.

Claims

1. A method for determining the molybdenum content in tantalum products, characterized in that: The steps include: S1: adding molybdenum oxide to a high-purity tantalum oxide matrix, mixing and grinding to obtain a main standard molybdenum sample, and then diluting the main standard molybdenum sample step by step according to a certain proportion to prepare 4 to 6 groups of molybdenum standard samples; S2: mixing the molybdenum standard sample and the spectral buffer in a mass ratio of 1:1 and placing the mixture in the hole of the lower electrode as a spectral excitation anode; S3: exciting the spectral excitation anode by a full-spectrum AC / DC arc emission spectrometer to obtain the spectral line intensity value of the molybdenum standard sample, and establishing a molybdenum standard curve with multiple groups of molybdenum standard sample element concentrations and corresponding molybdenum standard sample spectral line intensity values ​​as coordinate axes; S7: crush the tantalum product sample and calcine it at 900-950°C for 1-2h until the sample is completely converted into oxide and then cool it to room temperature; S8: Mix the cooled sample powder and spectral buffer in a mass ratio of 1:1 and place them in the hole of the lower electrode. Then, the molybdenum content in the tantalum product can be determined by a full spectrum AC / DC arc emission spectrometer.

2. The method according to claim 1, characterized in that The spectrum buffer in steps S2 and S8 comprises the following components: by mass percentage, 90% to 95% of pure graphite powder and 5% to 10% of pure sodium fluoride.

3. The method according to claim 2, characterized in that: The main standard molybdenum sample described in step S1 is diluted into a molybdenum standard sample by adding a high-purity tantalum oxide matrix; The spectrum buffer is prepared by mixing and grinding 94% by mass of pure graphite powder and 6% by mass of pure sodium fluoride.

4. The method according to claim 1, characterized in that: In step S3, when the spectral excitation anode is excited by a full spectrum AC / DC arc emission spectrometer, the molybdenum analysis line is selected to be 319.39 nm.

5. The method according to claim 1, characterized in that: The DC arc working conditions of the full-spectrum AC / DC arc emission spectrometer were set as follows: preheating current 4-5A, preheating time 5s, working current 12-14A, exposure time 55s, and the spacing between the upper and lower electrodes was 1.5mm.

6. The method according to claim 1, characterized in that The upper and lower electrodes of the full spectrum AC / DC arc emission spectrometer are made of graphite electrodes, where: The upper electrode has a diameter of 6 mm and a length of 40 mm. Its top is in the shape of a truncated cone with a height of 10 mm and an upper end surface diameter of 2 mm. The lower electrode has a diameter of 6mm and a length of 40mm. Its top is cup-shaped. The diameter of the large diameter end of the cup-shaped top is 5.1mm±0.05mm, the length of the large diameter end is 5mm±0.1mm, the diameter of the small diameter end is 3.5mm±0.1mm, the length of the small diameter end is 4mm±0.1mm, the hole diameter is 3.8mm, and the hole depth is 4mm±0.1mm.

7. The method according to claim 1, characterized in that After step S3, the following steps are also included: S4: Determination of the lower limit of the analytical method; S5: spike recovery test; S6: Determination of precision.

8. The method according to claim 1, characterized in that The steps S2 and S8 of mixing uniformly and placing in the lower electrode hole specifically include: Mix and grind the mixture in a mortar and put it into the hole of the lower electrode until it is full and tight; Scrape off the residual material around the hole and add 1 to 2 drops of sucrose solution. After drying, it can be used as a spectral excitation anode.

9. The method according to claim 5, characterized in that The DC arc of the full-spectrum AC / DC arc emission spectrometer adopts a pulse arc discharge mode.

10. The method according to any one of claims 1 to 9, characterized in that: Step S3 specifically includes the following sub-steps: S31: collecting original spectrum data of a molybdenum standard sample by a full-spectrum AC / DC arc emission spectrometer, wherein the spectrum data includes characteristic spectrum lines of molybdenum and tantalum elements; S32: preprocessing the raw spectral data, including smoothing the signal using a Gaussian smoothing or wavelet denoising algorithm to remove high-frequency noise, fitting the baseline drift in the spectral data using at least a quadratic polynomial, and subtracting the fitted baseline component from the raw spectrum; S33: Performing Gaussian fitting on the spectrum data after removing the baseline drift to extract the characteristic peak of molybdenum. The Gaussian fitting function is expressed as: Among them, A i is the amplitude of the ith Gaussian peak, μ i is the peak position, σ i is the peak width; S34: Use the difference spectrum method or the convolution interference removal method to remove the interference of tantalum on the molybdenum spectrum line to obtain a pure molybdenum signal; S35: According to the molybdenum peak area obtained by Gaussian fitting, the concentration of molybdenum in the sample is calculated by comparing it with a molybdenum standard sample of known concentration through a standard curve method; S36: Establish a molybdenum standard curve based on the relationship between the known concentration of the molybdenum standard and the fitted spectral signal.

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