A method for preparing AuNi alloy sample for ICP-OES analysis

Abstract

The application belongs to the technical field of element detection, and relates to an AuNi alloy sample preparation method for ICP-OES analysis, comprising the following steps: dissolving an AuNi alloy sample in a mixed acid solution, then sequentially performing first heat treatment and second heat treatment to obtain an AuNi alloy sample solution; the mixed acid solution is nitric acid and hydrochloric acid with a volume ratio of (2.5-3.5):1. The AuNi alloy sample preparation method provided in the application can completely dissolve the AuNi alloy, so that the AuNi alloy is suitable for ICP-OES detection, and accurate analysis of the contents of Au and Ni is realized.

Description

Technical Field

[0001] This application belongs to the field of elemental detection technology and relates to a method for preparing AuNi alloy samples for ICP-OES analysis. Background Technology

[0002] Currently, the commonly used testing equipment for AuNi alloys is inductively coupled plasma optical emission spectrometry (ICP-OES). This technology has the advantages of low interference, stable signal, and simple operation, and can be used to detect most metallic elements and some non-metallic elements.

[0003] Before using ICP-OES testing, the solid alloy sample needs to be completely dissolved in a suitable acid solution to obtain a clear solution suitable for instrumental analysis. However, gold in AuNi alloys is chemically extremely stable. Gold does not react with oxygen at room temperature or under heating conditions, and gold oxide can only be obtained through special processes. Gold is usually only soluble in highly oxidizing media such as aqua regia, selenic acid, perchloric acid, and fluorinated aqua regia, and it can burn in fluorine gas to form gold trifluoride when heated. Nickel is chemically relatively reactive, but more stable than iron. It is difficult to oxidize in air at room temperature, does not readily react with concentrated nitric acid, and fine nickel wire is flammable. It can react with halogens when heated, dissolves relatively quickly in dilute acid and releases hydrogen gas, and can absorb a considerable amount of hydrogen gas.

[0004] Due to the significant differences in chemical properties between gold and nickel, existing studies have only addressed the dissolution methods for single metals. However, there is currently no clear and reliable dissolution method for the AuNi alloy, a two-component system. This makes it impossible to directly obtain a sample solution suitable for the simultaneous determination of the two main elements, Au and Ni, by ICP-OES.

[0005] In summary, there is an urgent need to develop a method that can effectively, rapidly, and completely dissolve AuNi alloys, making the dissolved samples suitable for ICP-OES detection, thereby achieving accurate and simultaneous analysis of the Au and Ni content in the alloy. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this application is to provide a method for preparing AuNi alloy samples for ICP-OES analysis, which can completely dissolve the AuNi alloy, making it suitable for ICP-OES detection and enabling accurate analysis of Au and Ni content.

[0007] To achieve the purpose of this application, the following technical solution is adopted: This application provides a method for preparing AuNi alloy samples for ICP-OES analysis, comprising the following steps: The AuNi alloy sample was dissolved in a mixed acid solution, and then subjected to a first heat treatment and a second heat treatment in sequence to obtain an AuNi alloy sample solution; the mixed acid solution was nitric acid and hydrochloric acid with a volume ratio of (2.5-3.5):1.

[0008] The AuNi alloy sample preparation method provided in this application for ICP-OES analysis, combined with the solubility of Au and Ni elements in the AuNi alloy in acid, determines that a mixed acid solution of nitric acid and hydrochloric acid is used as the dissolving solution, controls a reasonable ratio, and designs a two-step heating process to ensure that the AuNi alloy can be completely dissolved, meeting the requirements for ICP-OES sample solution, thereby achieving accurate analysis of Au and Ni content.

[0009] The mixed acid solution is a volume ratio of nitric acid and hydrochloric acid of (2.5-3.5):1, for example, it can be 2.5:1, 2.8:1, 3:1, 3.2:1 or 3.5:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0010] The ratio of nitric acid to hydrochloric acid used in this application can effectively combine and dissolve AuNi alloy. If the volume ratio exceeds the limit, the AuNi alloy will not be completely dissolved, and thus will not meet the requirements for being used as a sample solution.

[0011] In some embodiments, the ratio between the mass of the AuNi alloy sample and the volume of the mixed acid solution is 1g:(75-85)mL, for example, it can be 1g:75mL, 1g:78mL, 1g:80mL, 1g:82mL or 1g:85mL, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0012] The ratio between the mass of the AuNi alloy sample and the volume of the mixed acid solution needs to be controlled within a reasonable range. If too much AuNi alloy sample is used, the mixed acid solution will not be able to completely dissolve the AuNi alloy sample. If too much mixed acid solution is used, acid consumption will increase and production costs will increase, without increasing the dissolution effect of the AuNi alloy sample.

[0013] In some embodiments, the concentration of the nitric acid is 65-68 wt%, for example, it may be 65 wt%, 66 wt%, 67 wt% or 68 wt%, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0014] In some embodiments, the concentration of the hydrochloric acid is 35-38 wt%, for example, it can be 35 wt%, 36 wt%, 37 wt% or 38 wt%, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0015] In some embodiments, the AuNi alloy sample contains 25-28 wt% Au by mass, with the balance being Ni.

[0016] The mass percentage of Au in the AuNi alloy sample is 25-28 wt%, for example, it can be 25 wt%, 26 wt%, 27 wt% or 28 wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0017] In some embodiments, the dissolution is carried out in a polytetrafluoroethylene tube.

[0018] It should be noted that this application does not specifically limit the dissolution temperature. For example, it can be room temperature of 15-30°C, as long as the AuNi alloy sample can be completely dissolved in the mixed acid solution. Those skilled in the art can make adaptive adjustments according to the actual application scenario.

[0019] In some embodiments, the temperature of the first heat treatment is 60-70°C, for example, it can be 60°C, 62°C, 65°C, 68°C or 70°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0020] In some embodiments, the temperature of the second heat treatment is 70-75°C, for example, 70°C, 71°C, 72°C, 73°C or 75°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0021] This application designs a two-step heat treatment process consisting of a first heat treatment and a second heat treatment, which can improve the dissolution effect of AuNi alloy compared to a single heat treatment.

[0022] In some embodiments, the endpoint of the second heat treatment is to make the solution clear and transparent.

[0023] In some embodiments, the second heat treatment is followed by a volume adjustment step.

[0024] It should be noted that this application does not specifically limit the volume determination steps. Volume determination is a conventional technical means in the field, and those skilled in the art can make adaptive settings according to actual application scenarios.

[0025] In some embodiments, both the first heat treatment and the second heat treatment are performed on a hot plate.

[0026] The numerical range described in this application includes not only the point values ​​listed above, but also any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific point values ​​included in the range.

[0027] Compared with the prior art, this application has the following advantages: The AuNi alloy sample preparation method provided in this application for ICP-OES analysis, combined with the solubility of Au and Ni elements in the AuNi alloy in acid, determines that a mixed acid solution of nitric acid and hydrochloric acid is used as the dissolving solution, controls a reasonable ratio, and designs a two-step heating process to ensure that the AuNi alloy can be completely dissolved, meeting the requirements for ICP-OES sample solution, thereby achieving accurate analysis of Au and Ni content. Detailed Implementation

[0028] The technical solution of this application will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely to help understand this application and should not be regarded as specific limitations on this application.

[0029] Example 1 This embodiment provides a method for preparing AuNi alloy samples for ICP-OES analysis, including the following steps: In a polytetrafluoroethylene tube, an AuNi alloy sample is dissolved in a mixed acid solution. The mass percentage of Au in the AuNi alloy sample is 26 wt%, and the balance is Ni. The ratio between the mass of the AuNi alloy sample and the volume of the mixed acid solution is 1 g: 80 mL.

[0030] Then, the solution was subjected to a first heat treatment at 65°C and a second heat treatment at 72°C on a hot plate until it became clear and transparent. After adjusting the volume, an AuNi alloy sample solution was obtained. The mixed acid solution was nitric acid and hydrochloric acid in a volume ratio of 3:1, with the concentration of nitric acid being 66 wt% and the concentration of hydrochloric acid being 36 wt%.

[0031] In this embodiment, the AuNi alloy sample can be completely dissolved in the mixed acid solution. The resulting AuNi alloy sample solution can be used for ICP-OES detection and analysis, and the Au content is determined to be 25.9 wt% and the Ni content is 73.8 wt%.

[0032] Example 2 This embodiment provides a method for preparing AuNi alloy samples for ICP-OES analysis, including the following steps: In a polytetrafluoroethylene tube, an AuNi alloy sample is dissolved in a mixed acid solution. The mass percentage of Au in the AuNi alloy sample is 25 wt%, and the balance is Ni. The ratio between the mass of the AuNi alloy sample and the volume of the mixed acid solution is 1 g: 75 mL.

[0033] Then, the solution was subjected to a first heat treatment at 60°C and a second heat treatment at 70°C on a hot plate until it became clear and transparent. After adjusting the volume, an AuNi alloy sample solution was obtained. The mixed acid solution was nitric acid and hydrochloric acid in a volume ratio of 2.5:1, with the concentration of nitric acid being 65wt% and the concentration of hydrochloric acid being 38wt%.

[0034] In this embodiment, the AuNi alloy sample can be completely dissolved in the mixed acid solution. The resulting AuNi alloy sample solution can be used for ICP-OES detection and analysis, and the Au content is determined to be 24.7 wt% and the Ni content is 75.1 wt%.

[0035] Example 3 This embodiment provides a method for preparing AuNi alloy samples for ICP-OES analysis, including the following steps: In a polytetrafluoroethylene tube, an AuNi alloy sample is dissolved in a mixed acid solution. The mass percentage of Au in the AuNi alloy sample is 28 wt%, and the balance is Ni. The ratio between the mass of the AuNi alloy sample and the volume of the mixed acid solution is 1 g: 85 mL.

[0036] Then, the solution was subjected to a first heat treatment at 70°C and a second heat treatment at 75°C on a hot plate until it became clear and transparent. After adjusting the volume, an AuNi alloy sample solution was obtained. The mixed acid solution was nitric acid and hydrochloric acid in a volume ratio of 3.5:1, with the concentration of nitric acid being 68 wt% and the concentration of hydrochloric acid being 35 wt%.

[0037] In this embodiment, the AuNi alloy sample can be completely dissolved in the mixed acid solution. The resulting AuNi alloy sample solution can be used for ICP-OES detection and analysis, and the Au content is determined to be 27.5 wt% and the Ni content to be 72.6 wt%.

[0038] Example 4 This embodiment provides a method for preparing AuNi alloy samples for ICP-OES analysis. The difference from Embodiment 1 is that the ratio between the mass of the AuNi alloy sample and the volume of the mixed acid solution is adjusted to 1g:70mL, while the rest is the same as in Embodiment 1.

[0039] In this embodiment, the ratio of AuNi alloy sample to mixed acid solution is too high, that is, too much AuNi alloy sample is used, which will cause the AuNi alloy sample to not be completely dissolved in the mixed acid solution. As a result, the AuNi alloy sample solution cannot be detected and analyzed by ICP-OES.

[0040] Example 5 This embodiment provides a method for preparing AuNi alloy samples for ICP-OES analysis. The difference from Embodiment 1 is that the ratio between the mass of the AuNi alloy sample and the volume of the mixed acid solution is adjusted to 1g:90mL, while the rest is the same as in Embodiment 1.

[0041] In this embodiment, because the ratio of AuNi alloy sample to mixed acid solution is too small, i.e., the amount of AuNi alloy sample used is too small, the AuNi alloy sample can be completely dissolved in the mixed acid solution, but the consumption of mixed acid increases without increasing the dissolution effect of the alloy. The resulting AuNi alloy sample solution can be used for ICP-OES detection and analysis, and the Au and Ni contents are not significantly different compared to Example 1.

[0042] Example 6 This embodiment provides a method for preparing AuNi alloy samples for ICP-OES analysis. The difference from Embodiment 1 is that the temperature of the second heat treatment is adjusted to 67°C, while the rest is the same as in Embodiment 1.

[0043] In this embodiment, the temperature of the second heat treatment is too low, which causes the AuNi alloy sample to not completely dissolve in the mixed acid solution, and the resulting AuNi alloy sample solution cannot be detected and analyzed by ICP-OES.

[0044] Example 7 This embodiment provides a method for preparing AuNi alloy samples for ICP-OES analysis. The difference from Embodiment 1 is that the temperature of the second heat treatment is adjusted to 80°C, while the rest is the same as in Embodiment 1.

[0045] In this embodiment, due to the excessively high temperature of the second heat treatment, the AuNi alloy sample could be completely dissolved in the mixed acid solution, but energy consumption increased. The resulting AuNi alloy sample solution could be used for ICP-OES detection and analysis, and the Au and Ni contents showed no significant change compared to Example 1.

[0046] Comparative Example 1 This comparative example provides a method for preparing AuNi alloy samples for ICP-OES analysis. The difference from Example 1 is that the mixed acid solution is adjusted to a volume ratio of nitric acid and hydrochloric acid of 2:1, while the rest is the same as in Example 1.

[0047] In this comparative example, the proportion of nitric acid in the mixed acid solution was too low, which resulted in the AuNi alloy sample not being able to completely dissolve in the mixed acid solution. Consequently, the resulting AuNi alloy sample solution could not be analyzed by ICP-OES.

[0048] Comparative Example 2 This comparative example provides a method for preparing AuNi alloy samples for ICP-OES analysis. The difference from Example 1 is that the mixed acid solution is adjusted to a volume ratio of 4:1 of nitric acid and hydrochloric acid, while the rest is the same as in Example 1.

[0049] In this comparative example, due to the low proportion of hydrochloric acid in the mixed acid solution, the AuNi alloy sample took too long to completely dissolve in the mixed acid solution. The resulting AuNi alloy sample solution could be analyzed by ICP-OES, and the Au and Ni contents were not significantly different compared to Example 1.

[0050] Comparative Example 3 This comparative example provides a method for preparing AuNi alloy samples for ICP-OES analysis. The difference from Example 1 is that the mixed acid solution is adjusted to a volume ratio of 3:1 of nitric acid and hydrofluoric acid, while the rest is the same as in Example 1.

[0051] In this comparative example, a mixed acid solution of nitric acid and hydrofluoric acid was used. Although hydrofluoric acid can also dissolve the AuNi alloy sample by replacing hydrochloric acid, hydrofluoric acid is highly toxic and poses a safety hazard during the process. Furthermore, it is necessary to adjust the appropriate ratio of hydrofluoric acid to nitric acid. Otherwise, the AuNi alloy sample will not be completely dissolved in the mixed acid solution, and the resulting AuNi alloy sample solution will not be able to be detected and analyzed by ICP-OES.

[0052] Comparative Example 4 This comparative example provides a method for preparing AuNi alloy samples for ICP-OES analysis. The difference between this example and Example 1 is that the first heat treatment step is omitted, while the rest are the same as in Example 1.

[0053] In this comparative example, the absence of a first heat treatment step resulted in an excessively long time for the AuNi alloy sample to completely dissolve in the mixed acid solution. The resulting AuNi alloy sample solution could be analyzed by ICP-OES, and the Au and Ni contents showed no significant change compared to Example 1.

[0054] In summary, the AuNi alloy sample preparation method for ICP-OES analysis provided in this application, based on the solubility of Au and Ni elements in the AuNi alloy in acid, determines a mixed acid solution of nitric acid and hydrochloric acid as the dissolving solution, controls a reasonable ratio, and designs a two-step heating process to ensure that the AuNi alloy can be completely dissolved, meeting the requirements for ICP-OES sample solution, thereby achieving accurate analysis of Au and Ni content.

[0055] The above description is only a specific embodiment of this application, but the protection scope of this application is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application fall within the protection and disclosure scope of this application.

Claims

1. A method for preparing AuNi alloy samples for ICP-OES analysis, characterized in that, Includes the following steps: The AuNi alloy sample was dissolved in a mixed acid solution, and then subjected to a first heat treatment and a second heat treatment in sequence to obtain an AuNi alloy sample solution; the mixed acid solution was nitric acid and hydrochloric acid with a volume ratio of (2.5-3.5):

1.

2. The method for preparing AuNi alloy samples according to claim 1, characterized in that, The ratio between the mass of the AuNi alloy sample and the volume of the mixed acid solution is 1 g:(75-85) mL.

3. The method for preparing AuNi alloy samples according to claim 1 or 2, characterized in that, The concentration of the nitric acid is 65-68 wt%.

4. The method for preparing AuNi alloy samples according to any one of claims 1-3, characterized in that, The concentration of the hydrochloric acid is 35-38 wt%.

5. The method for preparing AuNi alloy samples according to any one of claims 1-4, characterized in that, The AuNi alloy sample contains 25-28 wt% Au by mass, with the balance being Ni.

6. The method for preparing AuNi alloy samples according to any one of claims 1-5, characterized in that, The dissolution is carried out in a polytetrafluoroethylene tube.

7. The method for preparing AuNi alloy samples according to any one of claims 1-6, characterized in that, The temperature of the first heat treatment is 60-70℃.

8. The method for preparing AuNi alloy samples according to any one of claims 1-7, characterized in that, The temperature of the second heat treatment is 70-75℃.

9. The method for preparing AuNi alloy samples according to any one of claims 1-8, characterized in that, The endpoint of the second heat treatment is to make the solution clear and transparent; And / or, the second heat treatment may be followed by a volume adjustment step.

10. The method for preparing AuNi alloy samples according to any one of claims 1-9, characterized in that, Both the first and second heat treatments are performed on a hot plate.