Pretreatment method for measuring trace metal impurity elements in high-purity titanium

Abstract

The invention discloses a pretreatment method for measuring trace metal elements in high-purity titanium, which comprises the following steps: reacting titanium with concentrated nitric acid at 70 DEG C or above to generate titanic acid, then adding a barium chloride solution to react with titanic acid to generate barium titanate precipitate, and carrying out constant volume and centrifugation to obtain a pretreatment solution without titanium elements; the specific method comprises the following steps: (1) cutting high-purity titanium; (2) dissolving high-purity titanium; (3) titanic acid precipitation; and (4) centrifuging. According to the method, titanium is oxidized to generate titanic acid, then barium salt reacts with the titanic acid to generate barium titanate precipitate, and the titanium element in the detection solution is removed, so that the interference of the titanium element in ICP-MS (Inductively Coupled Plasma Mass Spectrometry) analysis is eliminated. The method is suitable for measuring trace impurity metal elements in high-purity titanium.

Description

Technical Field

[0001] The present invention relates to high-purity titanium, and more particularly to a method for determining trace metal impurity elements in high-purity titanium, and in particular to a pretreatment method for determining trace metal impurity elements in high-purity titanium. Background Art

[0002] High-purity titanium has the characteristics of low density, high melting point, strong corrosion resistance, low strength and strong plasticity. It is widely used in cutting-edge fields such as electronic information technology, biomedical technology, aerospace technology and ship transportation technology, and has become one of the important national strategic resources.

[0003] High-purity titanium has a silvery-white metallic luster. In addition to the common properties of titanium (corrosion resistance, low density, high melting temperature, and non-magnetic), it also has good plasticity (the cross-sectional shrinkage rate can reach 70% to 80%, and the elongation rate can reach 50% to 60%). In the application of VLSI, titanium is widely used in the production of its electrode materials and wiring materials. The manufacture of these targets can generally be prepared by sputtering, and the sputtering method has very high requirements for the purity of the titanium targets used. The use of magnetron sputtering can make the surface of the titanium-based film smoother, so the magnetron sputtering method is a more commonly used method. In recent years, different sputtering equipment uses titanium with different purities for sputtering titanium targets. For example, for 4-megabit VLSI, 99.995% to 99.999% purity titanium will be used. For 16-megabit VLSI, the requirement for titanium must reach 99.9999 or above.

[0004] The main methods for determining trace impurity metal elements include atomic absorption spectrometry (AAS), inductively coupled plasma emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS) and glow discharge mass spectrometry (GD-MS). Compared with other methods, ICP-OES has a higher detection limit and cannot meet the purity of high-purity titanium above 5N, and there are many characteristic spectral lines of the titanium matrix, which have certain interference; the detection limit of ICP-MS meets the product detection requirements, but there are more complex mass spectrum interference and non-mass spectrum interference, and the sample preparation process is also prone to introduce other impurities and interference sources; AAS can only analyze one element at a time, with low efficiency, and is not suitable for simultaneous analysis of multiple elements in high-purity metals; GD-MS has the advantages of high sensitivity, low detection limit (PPb~PPt) and excellent repeatability, and uses direct solid sampling technology to avoid the risk of element loss or contamination caused by time-consuming sample preparation and wet chemical pretreatment. It is a powerful tool for purity evaluation and characterization analysis of high-purity materials and substances. However, compared with current analytical technologies, GD-MS has the problem of high analysis and maintenance costs, and the mainstream analytical detection technology is still based on ICP-MS and its combined technology. There are many patent applications related to the determination of trace impurity metal elements using ICP-MS in the Chinese patent database, such as CN202311803842.6 "A method for determining the content of ppt-level metal impurities in electronic-grade sulfuric acid" and CN202311718868.0 "A method for determining 18 elements in tetramethylsilane by ICP-MS", etc. However, there are no patent applications for the pretreatment of trace impurity metal elements in high-purity titanium using ICP-MS, and the determination of trace impurity metal elements in high-purity titanium cannot be better achieved. Summary of the invention

[0005] The present invention aims to provide a pretreatment method for determining trace impurity metal elements in high-purity titanium by using ICP-MS, so as to overcome the deficiencies of the prior art and achieve accurate determination of trace impurity metal elements in high-purity titanium.

[0006] The inventor provides a pretreatment method for determining trace metal elements in high-purity titanium, which is to react titanium with concentrated nitric acid at a temperature above 70°C to generate titanic acid, then add a barium chloride solution to react with the titanic acid to generate a barium titanate precipitate, and then obtain a pretreatment solution to remove the titanium element by constant volume and centrifugation. The reaction formula is as follows: (1) (2) The specific method includes the following steps: High purity titanium cutting Cut the high-purity titanium into pieces with a size less than 1 mm, wash them with high-grade pure anhydrous ethanol, and blow dry them for later use; High purity titanium dissolution Weigh a certain mass (0.1 to 0.5 g, accurate to the fourth decimal place) of high-purity titanium chips obtained in the previous step and transfer them into a polytetrafluoroethylene crucible. Heat the polytetrafluoroethylene crucible to 80° C. on a hot plate, then slowly drop high-grade concentrated nitric acid to react completely with titanium, then add 10 mL of ultrapure water and let stand to room temperature to obtain solution 1. Titanate precipitation Transfer solution 1 into a 50 mL centrifuge tube, rinse the polytetrafluoroethylene crucible in step (1) with 15 mL of ultrapure water three times and transfer it into a centrifuge tube; prepare a 100 g / L solution of high-grade pure barium chloride and add it dropwise to the centrifuge tube in an amount of 4.5 mL per 0.1 g of titanium; gently shake the solution to mix it evenly, let it stand for 30 minutes, shake it evenly, and make up to 50 mL; Centrifugation Put the centrifuge tube into the centrifuge after the cap is closed, and centrifuge it at a speed of more than 5000r / min for 20min. Then, take out the supernatant and inject it into ICP-MS to determine the impurity metal elements.

[0007] The above steps start from step (2) and make a blank sample at the same time.

[0008] Compared with the prior art, the method of the present invention oxidizes titanium to generate titanic acid, and then reacts with barium salt to generate barium titanate precipitation, so that the detection solution removes the titanium element, thereby eliminating the interference caused by the titanium element in ICP-MS analysis. It is suitable for the determination of trace impurity metal elements in high-purity titanium. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 The process flow chart of the method of the present invention is shown in FIG. DETAILED DESCRIPTION Example

[0010] Cut high-purity titanium into pieces less than 1 mm in size. Wash with high-grade pure anhydrous ethanol and blow dry for later use. Then weigh 0.1005 g and transfer it into a polytetrafluoroethylene crucible. Place the polytetrafluoroethylene crucible on a hot plate and heat it to 80°C. Then slowly drop high-grade pure concentrated nitric acid to react completely with titanium. Then add 10 mL of ultrapure water and let it stand at room temperature to obtain solution 1. Transfer solution 1 to a 50mL centrifuge tube, rinse the polytetrafluoroethylene crucible in step (1) with 15mL ultrapure water three times and transfer it to a centrifuge tube; prepare a 100.0g / L solution of high-purity barium chloride and add it dropwise to the centrifuge tube in an amount of 4.5mL. Slightly shake the solution to mix it evenly, let it stand for 30 minutes, shake it well, and adjust the volume to 50mL; Then, the centrifuge tube was covered with a lid and placed in a centrifuge, and centrifuged at a speed of more than 5000 r / min for 20 minutes. After that, the supernatant was aspirated and injected into ICP-MS to determine the impurity metal elements.

[0011] Perform the above steps and prepare a blank sample simultaneously starting from step (2).

Claims

1. A pretreatment method for determining trace metal elements in high purity titanium, characterized in that The method is to use titanium to react with concentrated nitric acid at a temperature above 70°C to generate titanic acid, then add a barium chloride solution to react with the titanic acid to generate a barium titanate precipitate, fix the volume, and centrifuge to obtain a pretreatment solution to remove the titanium element. The specific method includes the following steps: (1) High purity titanium cutting Cut the high-purity titanium into pieces with a size less than 1 mm, wash them with high-grade pure anhydrous ethanol, and blow dry them for later use; (2) Dissolution of high purity titanium Weigh 0.1-0.5 g of high-purity titanium chips obtained in step (1) and transfer them into a polytetrafluoroethylene crucible. Heat the polytetrafluoroethylene crucible to 80° C. on a hot plate, then slowly drop high-grade pure concentrated nitric acid to react completely with titanium. Then add 10 mL of ultrapure water and let stand until the mixture reaches room temperature to obtain solution 1. (3) Titanate precipitation Transfer solution 1 into a 50 mL centrifuge tube, rinse the polytetrafluoroethylene crucible in step (1) with 15 mL of ultrapure water three times and transfer it into a centrifuge tube; prepare a 100 g / L solution of high-grade pure barium chloride and add it dropwise to the centrifuge tube in an amount of 4.5 mL per 0.1 g of titanium; gently shake the solution to mix it evenly, let it stand for 30 minutes, shake it evenly, and make up to 50 mL; (4) Centrifugation Put the centrifuge tube into the centrifuge after the cap is closed, and centrifuge it at a speed of more than 5000 rpm for 20 min. Then, take out the supernatant and inject it into ICP-MS to determine the impurity metal elements.

2. The method according to claim 1, characterized in that Start from step (2) of high purity titanium dissolution and prepare a blank sample at the same time.

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