Method for simultaneously determining bismuth content and selenium content in electric nickel

Abstract

The invention discloses a method for simultaneously determining the content of bismuth and selenium in electric nickel, and particularly relates to the technical field of metal trace element determination.The method comprises the steps of preparing a sample solution, preparing a calibration solution, measuring the concentration of bismuth and selenium in the sample solution and the like, and calculating the measurement result to obtain the content of bismuth and selenium. According to the method, the hydride generation-atomic fluorescence spectrometry is adopted for simultaneously and directly determining the bismuth and the selenium in the electric nickel, when the sample solution is prepared, the ferric chloride solution and the citric acid mixed solution better inhibit nickel interference, separation and enrichment of a nickel matrix are not needed, the bismuth and the selenium in the electric nickel can be directly and simultaneously determined, operation is easy, sensitivity is high, accuracy is high, and the method is suitable for large-scale popularization and application. The relative standard deviation of sample determination is low, and the sample adding standard recovery rate is high.

Description

Technical Field

[0001] This invention relates to the field of trace element determination technology, and in particular to a method for simultaneously determining the bismuth and selenium content in electrolytic nickel. Background Technology

[0002] Nickel possesses excellent properties such as corrosion resistance, high temperature resistance, oxidation resistance, and good ductility, and is widely used in metallurgy, chemical industry, aerospace and other fields. It is an important raw material for the preparation of stainless steel, high-temperature alloys, power batteries and other materials. With the increasing application of metallic nickel in high-end fields such as electroplating, battery materials and high-temperature alloys, the requirements for impurity elements in metallic nickel products are becoming increasingly stringent. Among them, although bismuth and selenium are present in very low amounts in metallic nickel, bismuth reduces the durability and plasticity of alloys, while the content of selenium also has an important impact on the mechanical properties of nickel-based high-temperature alloys. The international standard controls the selenium content at 0.0001%-0.001%, so it is necessary to accurately detect the content of bismuth and selenium.

[0003] When using the existing atomic fluorescence spectrometry (AFS) method to determine the bismuth and selenium content in electrolytic nickel, the nickel content in the electrolytic nickel is extremely high, while bismuth and selenium are trace impurities. The AFS detection process has technical problems such as high relative standard deviation, low spiked recovery rate, and the addition of anti-interference agents may affect the hydrogenation reaction efficiency. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for simultaneously determining the bismuth and selenium content in electrolytic nickel, which solves the technical problems of high relative standard deviation, low spiked recovery rate, and potential impact on hydrogenation reaction efficiency when using existing atomic fluorescence spectrometry (AFS) to determine the bismuth and selenium content in electrolytic nickel.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: A method for simultaneously determining the bismuth and selenium content in electrolytic nickel comprises the following steps: S1. Preparation of reagents used in the measurement process Prepare standard solutions of bismuth and selenium with a mass concentration of 0.5 µg / mL; S2. Preparation of sample solution S2.1. Weigh 1.00g of nickel electrolytic sample and place it in a beaker. Add 10-20mL of nitric acid and heat until the sample is completely dissolved. Then add 5-10mL of hydrochloric acid and boil to remove nitrogen oxides. Add another 5-10mL of hydrochloric acid and simmer for 3-5 minutes. After cooling, transfer the solution to a 100mL volumetric flask and dilute with water to the 100mL mark. Mix well. S2.2. Take 10.00 mL of the test solution prepared in S2.1 and add it to a 100 mL volumetric flask. Add 50-70 mL of water, 5-20 mL of hydrochloric acid, 1-3 mL of ferric chloride solution, and 5-10 mL of citric acid mixed solution. Dilute with water to the 100 mL mark on the volumetric flask, mix well, and let stand. S3. Prepare calibration curve solution Transfer the bismuth and selenium mixed standard solution prepared in S1 to prepare the calibration curve solution for bismuth and selenium elements; S4. Measurement The working conditions of the atomic fluorescence spectrometer were set. Potassium borohydride solution and hydrochloric acid were added to the sample solution prepared in S2.2, and argon gas was used as both the shielding gas and the carrier gas. The sample solution was placed on the atomic fluorescence spectrometer, and the fluorescence intensity of the sample solution was measured synchronously with a series of standard solutions. The working curve was plotted, and the corresponding mass concentrations of bismuth and selenium were obtained from the working curve.

[0006] Further, the step in S1 to prepare bismuth and selenium standard solutions with a mass concentration of 0.5 µg / mL is as follows: S1.1. Prepare standard solutions of bismuth and selenium with a mass concentration of 1000 µg / mL; S1.2. Take the solution from S1.1 and prepare bismuth and selenium standard solutions with a mass concentration of 100 µg / mL; S1.3. Take the solution prepared in S1.2 to prepare bismuth and selenium standard solutions with a mass concentration of 0.5 µg / mL.

[0007] Further, the preparation step of the calibration curve solution in S3 is as follows: take the bismuth and selenium mixed standard solution obtained in S1 and prepare calibration curve solutions with bismuth and selenium concentrations of 0 μg / L, 1.0 μg / L, 5.0 μg / L, 10.0 μg / L, 20.0 μg / L and 30.0 μg / L respectively.

[0008] Further, the process of preparing bismuth and selenium calibration curve solutions with concentrations of 0 μg / L, 1.0 μg / L, 5.0 μg / L, 10.0 μg / L, 20.0 μg / L, and 30.0 μg / L in S3 is as follows: 0 mL, 0.20 mL, 1.00 mL, 2.00 mL, 4.00 mL, and 6.00 mL of the bismuth and selenium mixed standard solution prepared in S1 are transferred into six 100 mL volumetric flasks, respectively. 5-20 mL of hydrochloric acid, 1-3 mL of ferric chloride solution, and 5-10 mL of citric acid mixed solution are added. The solution is diluted with water to the 100 mL mark on the volumetric flask, mixed well, and allowed to stand.

[0009] Furthermore, the operating conditions of the atomic fluorescence spectrometer in step S4 are as follows: photomultiplier tube negative high voltage 280-300V, observation height 8-12mm, lamp current 80mA, carrier gas flow rate 400mL / min, shielding gas flow rate 800mL / min, and auxiliary cathode current 40mA.

[0010] Furthermore, the concentration of the potassium borohydride solution in step S4 is 5-10 g / L.

[0011] Compared with the prior art, the beneficial effects of the present invention are: This invention employs hydride generation-atomic fluorescence spectrometry to simultaneously and directly determine bismuth and selenium in electrolytic nickel. The relative standard deviation of the sample determination is low, and the sample spike recovery rate is high. When preparing the sample solution, a mixture of ferric chloride solution and citric acid solution is used to better suppress the interference of nickel. Furthermore, it does not require separation and enrichment of the nickel matrix. It can directly and simultaneously determine bismuth and selenium in electrolytic nickel. The operation is simple, sensitive, and accurate. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the selenium and bismuth working curves of the present invention.

[0013] Figure 2 This is a schematic diagram showing the fluorescence intensity of the 10 μg / L standard solution of the present invention under different concentrations of hydrochloric acid.

[0014] Figure 3 The graph shows the fluorescence intensity changes of the bismuth and selenium standard solutions of this invention in potassium borohydride solutions of different concentrations. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0016] Example 1 A method for simultaneously determining the bismuth and selenium content in electrolytic nickel comprises the following steps: S1. Preparation of reagents used in the measurement process S1.1. Prepare standard solutions of bismuth and selenium with a mass concentration of 1000 µg / mL; S1.2. From the standard bismuth and selenium solutions prepared in S1.1, transfer 10.00 mL of the bismuth and selenium standard solutions into a 100 mL volumetric flask, add 20 mL of hydrochloric acid, dilute with water to the 100 mL mark on the volumetric flask, and mix well. S1.3. Transfer the bismuth and selenium mixed standard solution prepared in S1.2 into a 200mL volumetric flask, add 20mL of hydrochloric acid, dilute with water to the 200mL mark on the volumetric flask, and mix well.

[0017] S2. Preparation of sample solution S2.1 Weigh 1.00g of nickel electrolytic sample and place it in a beaker. Add 10mL of nitric acid and heat until the sample is completely dissolved. Then add 5mL of hydrochloric acid and boil to remove nitrogen oxides. Add 5mL of hydrochloric acid and gently boil for 3 minutes. After cooling, transfer it to a 100mL volumetric flask and dilute with water to the 100mL mark on the volumetric flask. Mix well. S2.2 Take 10.00 mL of the test solution prepared in S2.1 and add it to a 100 mL volumetric flask. Add 50 mL of water, 5 mL of hydrochloric acid, 1 mL of 20 mg / mL ferric chloride solution, and 5 mL of 400 g / L citric acid mixed solution. Dilute with water to the 100 mL mark on the volumetric flask, mix well, and let stand.

[0018] S3. Prepare calibration curve solution The bismuth and selenium mixed standard solution prepared in S1 was transferred to six 100mL volumetric flasks at concentrations of 0mL, 0.20mL, 1.00mL, 2.00mL, 4.00mL, and 6.00mL, respectively. 5mL of hydrochloric acid, 1mL of 20mg / mL ferric chloride solution, and 5mL of 400g / L citric acid mixed solution were added. The solutions were then diluted with water to the 100mL mark on each flask. After mixing and allowing to stand, calibration curve solutions with bismuth and selenium concentrations of 0μg / L, 1.0μg / L, 5.0μg / L, 10.0μg / L, 20.0μg / L, and 30.0μg / L were prepared. A schematic diagram of the standard curve is shown below. Figure 1 .

[0019] S4. Measurement and Method Validation The operating conditions of the atomic fluorescence spectrometer are set as shown in Table 1. Then, a 5 g / L potassium borohydride solution and a 15% hydrochloric acid solution are added to the sample solution prepared in S2.2 as the carrier gas, and argon gas with a flow rate of 400 ml / min is used as the shielding gas and carrier gas. The sample solution is placed on the atomic fluorescence spectrometer, and the fluorescence intensity of the sample solution is measured synchronously with a series of standard solutions. The working curve is plotted, and the corresponding mass concentrations of bismuth and selenium are obtained from the working curve.

[0020] Example 2 A method for simultaneously determining the bismuth and selenium content in electrolytic nickel comprises the following steps: S1. Preparation of reagents used in the measurement process S1.1. Prepare standard solutions of bismuth and selenium with a mass concentration of 1000 µg / mL; S1.2. From the standard bismuth and selenium solutions prepared in S1.1, transfer 10.00 mL of the bismuth and selenium standard solutions into a 100 mL volumetric flask, add 20 mL of hydrochloric acid, dilute with water to the 100 mL mark on the volumetric flask, and mix well. S1.3. Transfer the bismuth and selenium mixed standard solution prepared in S1.2 into a 200mL volumetric flask, add 20mL of hydrochloric acid, dilute with water to the 200mL mark on the volumetric flask, and mix well.

[0021] S2. Preparation of sample solution S2.1 Weigh 1.00g of nickel electrolytic sample and place it in a beaker. Add 15mL of nitric acid and heat until the sample is completely dissolved. Then add 8mL of hydrochloric acid and boil to remove nitrogen oxides. Add 8mL of hydrochloric acid and gently boil for 4min. After cooling, transfer it to a 100mL volumetric flask and dilute with water to the 100mL mark on the volumetric flask. Mix well. S2.2 Take 10.00 mL of the test solution prepared in S2.1 and add it to a 100 mL volumetric flask. Add 60 mL of water, 10 mL of hydrochloric acid, 2 mL of 20 mg / mL ferric chloride solution, and 7 mL of 400 g / L citric acid mixed solution. Dilute with water to the 100 mL mark on the volumetric flask, mix well, and let stand.

[0022] S3. Prepare calibration curve solution The bismuth and selenium mixed standard solution prepared in S1 was transferred to six 100mL volumetric flasks at concentrations of 0mL, 0.20mL, 1.00mL, 2.00mL, 4.00mL, and 6.00mL, respectively. 10mL of hydrochloric acid, 2mL of 20mg / mL ferric chloride solution, and 7mL of 400g / L citric acid mixed solution were added. The solutions were then diluted with water to the 100mL mark on each flask. After mixing and allowing to stand, calibration curve solutions with bismuth and selenium concentrations of 0μg / L, 1.0μg / L, 5.0μg / L, 10.0μg / L, 20.0μg / L, and 30.0μg / L were prepared. A schematic diagram of the standard curve is shown below. Figure 1 .

[0023] S4. Measurement and Method Validation The operating conditions of the atomic fluorescence spectrometer are set as shown in Table 1. Then, a 7 g / L potassium borohydride solution and 18% hydrochloric acid are added to the sample solution prepared in S2.2 as the carrier gas, and argon gas with a flow rate of 500 ml / min is used as the shielding gas and carrier gas. The sample solution is placed on the atomic fluorescence spectrometer, and the fluorescence intensity of the sample solution is measured synchronously with a series of standard solutions. The working curve is plotted, and the corresponding mass concentrations of bismuth and selenium are obtained from the working curve.

[0024] Example 3 A method for simultaneously determining the bismuth and selenium content in electrolytic nickel comprises the following steps: S1. Preparation of reagents used in the measurement process: S1.1. Prepare standard solutions of bismuth and selenium with a mass concentration of 1000 µg / mL; S1.2. From the standard bismuth and selenium solutions prepared in S1.1, transfer 10.00 mL of the bismuth and selenium standard solutions into a 100 mL volumetric flask, add 20 mL of hydrochloric acid, dilute with water to the 100 mL mark on the volumetric flask, and mix well. S1.3. Transfer the bismuth and selenium mixed standard solution prepared in S1.2 into a 200mL volumetric flask, add 20mL of hydrochloric acid, dilute with water to the 200mL mark on the volumetric flask, and mix well.

[0025] S2. Preparation of sample solution S2.1 Weigh 1.00g of nickel electrolytic sample and place it in a beaker. Add 20mL of nitric acid and heat until the sample is completely dissolved. Then add 10mL of hydrochloric acid and boil to remove nitrogen oxides. Add 10mL of hydrochloric acid and gently boil for 5 minutes. After cooling, transfer it to a 100mL volumetric flask and dilute with water to the 100mL mark on the volumetric flask. Mix well. S2.2 Take 10.00 mL of the test solution prepared in S2.1 and add it to a 100 mL volumetric flask. Add 70 mL of water, 20 mL of hydrochloric acid, 3 mL of 20 mg / mL ferric chloride solution, and 10 mL of 400 g / L citric acid mixed solution. Dilute with water to the 100 mL mark on the volumetric flask, mix well, and let stand.

[0026] S3. Prepare calibration curve solution The bismuth and selenium mixed standard solution prepared in S1 was transferred to six 100mL volumetric flasks at concentrations of 0mL, 0.20mL, 1.00mL, 2.00mL, 4.00mL, and 6.00mL, respectively. 20mL of hydrochloric acid, 3mL of 20mg / mL ferric chloride solution, and 10mL of 400g / L citric acid mixed solution were added. The solutions were then diluted with water to the 100mL mark on each flask. After mixing and standing, calibration curve solutions with bismuth and selenium concentrations of 0μg / L, 1.0μg / L, 5.0μg / L, 10.0μg / L, 20.0μg / L, and 30.0μg / L were prepared. A schematic diagram of the standard curve is shown below. Figure 1 .

[0027] S4. Measurement and Method Validation The operating conditions of the atomic fluorescence spectrometer are set as shown in Table 1. Then, a 10 g / L potassium borohydride solution and 20% hydrochloric acid are added to the sample solution prepared in S2.2 as the carrier gas, and argon gas with a flow rate of 600 ml / min is used as the shielding gas and carrier gas. The sample solution is placed on the atomic fluorescence spectrometer, and the fluorescence intensity of the sample solution is measured synchronously with a series of standard solutions. The working curve is plotted, and the corresponding mass concentrations of bismuth and selenium are obtained from the working curve.

[0028] (1) Selection of instrument working conditions Recommended operating conditions for the KYlin-S12 atomic fluorescence spectrometer are shown in Table 1.

[0029] Table 1 Instrument conditions for atomic fluorescence spectrometer (2) Effect of acidity Because bismuth and selenium in different valence states have different hydrogenation reaction rates, and selenium has multiple valence states, such as hexavalent and tetravalent, hexavalent selenium cannot form hydride gas with potassium borohydride; only tetravalent selenium can produce hydrides. Therefore, before measurement, hexavalent selenium must be pre-reduced to tetravalent selenium. For the determination of selenium and bismuth, 5 mL of hydrochloric acid is added during sample dissolution, and the solution is gently boiled for 2-3 minutes to reduce hexavalent selenium to tetravalent selenium. Since only tetravalent selenium can react with potassium borohydride to form hydrides, pre-reduction treatment is required to reduce the higher valence selenium to tetravalent selenium. This experiment investigated the change in hydrochloric acid concentration fraction of the sample solution from 5% to 20%, and the fluorescence intensity showed an increasing trend. Figure 2 Therefore, this experiment selected hydrochloric acid with a concentration of 15%-25% as the optimal acidity for sample determination.

[0030] Table 2 Effects of different concentrations of hydrochloric acid on bismuth and selenium. (3) Effect of potassium borohydride concentration Potassium borohydride, as a reducing agent, directly affects the formation process of hydrides and the state of the subhydrogen flame. If the concentration of potassium borohydride is too low, the reaction is slow, the reduction is incomplete, the flame is small, the fluorescence signal is weak, the sensitivity is low, and the precision is poor. If the concentration is too high, the reaction is too violent, and the large amount of hydrogen produced will dilute the concentration of hydrides, resulting in a decrease in fluorescence intensity and a decrease in precision. Moreover, the higher the concentration of potassium borohydride, the more likely it is to cause liquid phase interference. To maintain the relative stability of the potassium borohydride solution, the solution needs to be slightly alkaline. In this experiment, potassium borohydride concentrations of 5 g / L, 10 g / L, 15 g / L, and 20 g / L were added to a series of 5 g / L potassium hydroxide solutions, respectively. The fluorescence intensity of 10 μg / L bismuth and selenium standard solutions in potassium borohydride solutions of different concentrations was investigated. The intensity changes are shown in the figure. Figure 3 ; The results showed that the fluorescence intensity of bismuth and selenium was highest when the concentration of potassium borohydride solution was selected in the range of 5-10 g / L.

[0031] (4) Dosage of citric acid mixed solution and ferric chloride solution In this experiment, the nickel matrix caused significant interference from selenium and bismuth. The mixed solution of ferric chloride and citric acid was used to suppress the interference of nickel, which was effective. The recovery rates of the mixed solution of ferric chloride and citric acid with different concentrations are shown in Tables 3 and 4.

[0032] Table 3. Effects of different amounts of ferric chloride solution on the determination of bismuth and selenium. Table 4. Effects of different citric acid dosages on the determination of bismuth and selenium. The experimental results show that adding 1-3 mL of ferric chloride solution and 5-10 mL of citric acid solution can suppress the interference of the nickel matrix on selenium and bismuth elements, and the spiked recovery rate is better.

[0033] (5) Interference test of nickel In electrolytic nickel plating, the main nickel content is generally greater than 99.95%. Therefore, it is necessary to consider whether the presence of the nickel matrix interferes with the determination of bismuth and selenium. When determining selenium and bismuth, adding a mixture of ferric chloride solution and citric acid solution can also act as a masking agent. To investigate whether the influence of the nickel matrix can be eliminated, after adding ferric chloride solution and citric acid solution, different mass concentrations of nickel matrix were taken according to the relationship between the matrix and impurity element content in the sample: 0.00 mg / mL, 0.50 mg / mL, 1.00 mg / mL, 2.00 mg / mL, and 3.00 mg / mL. The mass concentrations of bismuth and selenium were added respectively at 5 μg / L and 10 μg / mL. Under the listed instrument operating conditions, the concentration values ​​of each analyte in the above series of solutions were determined. The results are shown in Table 5. Table 5. Influence of nickel matrix on the determination results of analytes As shown in Table 5, when the nickel matrix concentration is ≤1.00 mg / mL, the concentrations of bismuth and selenium do not change significantly compared with the values ​​measured without a nickel matrix. This indicates that the interference from the nickel matrix is ​​effectively suppressed, and the working curve can be plotted using the standard curve method to determine bismuth and selenium in electrolytic nickel.

[0034] (6) Detection limit of the method Under optimal instrument operating conditions, the blank solution of the accompanying sample was measured 11 times consecutively according to the experimental method to conduct detection limit experiments for each element. The detection limit was set at 3 times the standard deviation of the concentration of the element being measured, and the lower limit of determination of the method was set at 10 times the standard deviation. The results are shown in Table 6.

[0035] Table 6. Limits of detection and limits of quantification for the methods The data in Table 6 show that the limits of determination for Bi and Se in electrolytic nickel by atomic fluorescence spectrometry are 0.311 μg / L and 0.282 μg / L, respectively, which meet the analytical requirements.

[0036] (7) Precision test To examine the consistency between data from multiple measurements, a batch of electrolytic nickel was subjected to seven independent measurements. The results are shown in Table 7.

[0037] Table 7 Method precision experiment As can be seen from Table 7, the precision of bismuth in electrolytic nickel is 3.86% and the precision of selenium is 4.89%, which can meet the requirements for the determination of bismuth and selenium in electrolytic nickel.

[0038] (8) Sample spike recovery experiment To verify the accuracy of this method, the spiked recoveries of Bi and Se elements in a batch of electrolytic nickel were determined according to experiments S2.1 and S2.2, and the results are shown in Table 8.

[0039] Table 8 Sample Spike Recovery Experiment As can be seen from Table 8, the spiked recoveries of bismuth and selenium in electrolytic nickel are both between 97.20% and 109.33%.

[0040] (9) Results of standard sample analysis The bismuth and selenium in the nickel spectral standard sample were determined according to the planned analytical procedure, and the results are shown in Table 9.

[0041] Table 9. Results of Standard Sample Analysis The data in the table show that the values ​​obtained using this experimental method are close to the recommended values, which meets the accuracy requirements, indicating that the method is accurate and reliable.

[0042] The experimental results above show that the relative standard deviation of bismuth and selenium in electrolytic nickel is between 3.86% and 4.89% when hydride generation-atomic fluorescence spectrometry is used for the simultaneous and direct determination of bismuth and selenium in electrolytic nickel. The sample spike recovery rate is between 97.2% and 109.33%. This method does not require separation and enrichment of the nickel matrix and can directly and simultaneously determine bismuth and selenium in electrolytic nickel. It is simple to operate, highly sensitive, and highly accurate, and is suitable for the simultaneous analysis of bismuth and selenium in electrolytic nickel.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for simultaneously determining the bismuth and selenium content in electrolytic nickel, characterized in that: Includes the following steps: S1. Preparation of reagents used in the measurement process Prepare standard solutions of bismuth and selenium with a mass concentration of 0.5 µg / mL; S2. Preparation of sample solution S2.

1. Weigh 1.00g of nickel electrolytic sample and place it in a beaker. Add 10-20mL of nitric acid and heat until the sample is completely dissolved. Then add 5-10mL of hydrochloric acid and boil to remove nitrogen oxides. Add another 5-10mL of hydrochloric acid and simmer for 3-5 minutes. After cooling, transfer the solution to a 100mL volumetric flask and dilute with water to the 100mL mark. Mix well. S2.

2. Take 10.00 mL of the test solution prepared in S2.1 and add it to a 100 mL volumetric flask. Add 50-70 mL of water, 5-20 mL of hydrochloric acid, 1-3 mL of ferric chloride solution, and 5-10 mL of citric acid mixed solution. Dilute with water to the 100 mL mark on the volumetric flask, mix well, and let stand. S3. Prepare calibration curve solution Transfer the bismuth and selenium mixed standard solution prepared in S1 to prepare the calibration curve solution for bismuth and selenium elements; S4. Measurement The working conditions of the atomic fluorescence spectrometer were set. Potassium borohydride solution and hydrochloric acid were added to the sample solution prepared in S2.2, and argon gas was used as both the shielding gas and the carrier gas. The sample solution was placed on the atomic fluorescence spectrometer, and the fluorescence intensity of the sample solution was measured synchronously with a series of standard solutions. The working curve was plotted, and the corresponding mass concentrations of bismuth and selenium were obtained from the working curve.

2. The method for simultaneously determining the bismuth and selenium content in electrolytic nickel according to claim 1, characterized in that: The steps in S1 for preparing bismuth and selenium standard solutions with a mass concentration of 0.5 µg / mL are as follows: S1.

1. Prepare bismuth and selenium standard solutions with a mass concentration of 1000 µg / mL; S1.

2. Take the solution from S1.1 and prepare bismuth and selenium standard solutions with a mass concentration of 100 µg / mL; S1.

3. Take the solution prepared in S1.2 to prepare bismuth and selenium standard solutions with a mass concentration of 0.5 µg / mL.

3. The method for simultaneously determining the bismuth and selenium content in electrolytic nickel according to claim 1, characterized in that: The preparation steps of the calibration curve solution in S3 are as follows: take the bismuth and selenium mixed standard solution obtained in S1 and prepare calibration curve solutions with bismuth and selenium concentrations of 0 μg / L, 1.0 μg / L, 5.0 μg / L, 10.0 μg / L, 20.0 μg / L and 30.0 μg / L respectively.

4. The method for simultaneously determining the bismuth and selenium content in electrolytic nickel according to claim 3, characterized in that: The process of preparing bismuth and selenium calibration curve solutions with concentrations of 0 μg / L, 1.0 μg / L, 5.0 μg / L, 10.0 μg / L, 20.0 μg / L, and 30.0 μg / L in S3 is as follows: 0 mL, 0.20 mL, 1.00 mL, 2.00 mL, 4.00 mL, and 6.00 mL of the bismuth and selenium mixed standard solution prepared in S1 are transferred into six 100 mL volumetric flasks, respectively. 5-20 mL of hydrochloric acid, 1-3 mL of ferric chloride solution, and 5-10 mL of citric acid mixed solution are added. The solution is diluted with water to the 100 mL mark on the volumetric flask, mixed well, and allowed to stand.

5. The method for simultaneously determining the bismuth and selenium content in electrolytic nickel according to claim 1, characterized in that: The operating conditions of the atomic fluorescence spectrometer in step S4 are as follows: photomultiplier tube negative high voltage 280-300V, observation height 8-12mm, lamp current 80mA, carrier gas flow rate 400mL / min, shielding gas flow rate 800mL / min, and auxiliary cathode current 40mA.

6. The method for simultaneously determining the bismuth and selenium content in electrolytic nickel according to claim 1, characterized in that: In step S4, the concentration of the potassium borohydride solution is 5-10 g / L.

Images