A method for determining chloride ions in electronic grade hydrogen bromide by ion chromatography
Detection of chloride ions in electronic grade hydrogen bromide by ion chromatography solves the problems of complex operation and unreliable results in the prior art, and realizes simple and accurate chloride ion detection, which is suitable for quality control of electronic grade hydrogen bromide products.
Patent Information
- Application Number
- CN202110935110.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-08-04
- Publication Date
- 2025-08-19
- Estimated Expiration
- 2041-08-04
AI Technical Summary
The prior art is difficult to effectively detect trace chloride ions in electronic grade hydrogen bromide. Traditional methods such as potential titration and Fourier transform infrared spectroscopy have problems such as complex operation, high cost or unreliable results.
The method of determining chloride ions in electronic grade hydrogen bromide was used by ion chromatography, including preparing and analyzing Cl-standard solution, pretreatment of hydrogen bromide sample and pH adjustment, and detection using an ion chromatography instrument. The leachate was a mixed solution of sodium carbonate and sodium bicarbonate. The column temperature was 35℃ and the injection volume was 50μL.
It realizes simple, accurate and repeatable chloride ion detection, which is suitable for quality control of electronic grade hydrogen bromide products, and improves the accuracy and reliability of trace chloride ion determination.
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Figure CN113655168B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for quantitatively determining trace chloride ions in electronic-grade hydrogen bromide, in particular to a method for determining the content of trace chloride ions in an electronic-grade hydrogen bromide sample by ion chromatography, and belongs to the field of analytical chemistry. Background Art
[0002] Electronic-grade hydrogen bromide is an indispensable raw material in the semiconductor industry. It is primarily used for polysilicon etching in the manufacturing of 8-inch and 12-inch chips and is a core gas in advanced chip manufacturing processes. Impurities in electronic-grade hydrogen bromide can easily damage circuit functions within the chip, causing integrated circuit failure and affecting the formation of geometric features. Therefore, the detection of chloride ions in hydrogen bromide is a necessary step in the production process. However, there is no effective analytical method for the detection of chloride ions in electronic-grade hydrogen bromide. Traditional methods for chloride ion detection mainly include: 1. Potentiometric titration, using a saturated calomel electrode as the reference electrode and a silver electrode as the indicator electrode, titrating with a silver nitrate standard solution to calculate the chloride ion content. This method has a detection range of 5 to 150 mg / L and is suitable for detecting higher levels of chloride ions. Silver nitrate and hydrogen bromide also produce light yellow precipitates, consuming silver nitrate. Therefore, this method is not suitable for the determination of chloride ions in hydrogen bromide; 2. Fourier transform infrared spectroscopy, which requires a known low-concentration hydrogen chloride standard gas to establish a standard spectrum. At the same time, it is equipped with an MCT detector and requires frequent replenishment of liquid nitrogen. The operation is relatively complicated. In addition, there is currently no ppm-level hydrogen chloride standard gas on the market, and the test cannot guarantee the reliability of the results. Summary of the Invention
[0003] The invention aims to provide a method for determining chloride ions in electronic-grade hydrogen bromide by ion chromatography, which has the advantages of simple operation, good repeatability and high sensitivity.
[0004] To achieve the above object, the present invention is achieved through the following technical solution: A method for determining chloride ions in electronic-grade hydrogen bromide by ion chromatography, comprising the following steps:
[0005] (1) Preparation and analysis of Cl - Standard solution, obtain working curve of concentration and peak area;
[0006] (2) Pre-treating the hydrogen bromide sample, absorbing the electronic grade hydrogen bromide with high-purity water, adjusting the pH value of the absorption liquid to 4-10 with alkaline solution, and analyzing it with an ion chromatograph to determine the chloride ion content in the electronic grade hydrogen bromide.
[0007] Furthermore, a method for determining chloride ions in electronic grade hydrogen bromide by ion chromatography comprises the following steps:
[0008] (1) Preparation of Cl -Standard solution, ion chromatography analysis was performed to obtain Cl at different concentrations - The peak area of the chloride ion was used as the horizontal axis and the peak area as the vertical axis to draw the working curve;
[0009] (2) Pretreatment of hydrogen bromide samples: Three washing bottles are connected in series to the hydrogen bromide sampling tube. The first is a buffer bottle, and the second and third are absorption bottles filled with 100 mL of high-purity water. Before connecting the sampling line to the buffer bottle and the absorption bottle, it is first purged with high-purity nitrogen; the hydrogen bromide flow rate is controlled to 2-4 g / min, so that the weight loss of the hydrogen bromide gas source cylinder is consistent with the weight gain of the absorption bottle, ensuring that the hydrogen bromide sample is completely absorbed. When the two absorption bottles have gained a total weight of 80-110 g, the hydrogen bromide gas source is turned off, and the pipeline is purged with high-purity nitrogen for 10 minutes. The final increase on the balance is recorded. After the absorption is completed, the hydrogen bromide absorption liquid obtained is combined; the amount of hydrogen bromide absorbed is preferably 90-100 g.
[0010] (3) Adding alkali solution to adjust the pH value of the hydrogen bromide solution to 4-10, pipetting the solution into a volumetric flask, and adding high-purity water to make up the volume. The volume ratio of high-purity water to the mixed solution is preferably 100:1, to prepare the test solution. The alkali solution is preferably an aqueous solution of sodium hydroxide, potassium hydroxide, or ammonia water, more preferably ammonia water; the mass concentration of the ammonia water is preferably 20% to 22%, and the amount of ammonia water added is 90-120 ml, preferably 100-110 ml; the pH value is preferably 5-9, more preferably 6-8.
[0011] (4) Cl in electronic grade hydrogen bromide - Determination of content
[0012] The solution to be tested was tested using an ion chromatograph to obtain trace amounts of Cl in electronic grade hydrogen bromide. - The chromatogram of the test was obtained, and the Cl in the test solution was detected according to the external standard method. - Quantitatively obtain Cl in electronic grade hydrogen bromide - content.
[0013] The eluent used in the ion chromatograph is a mixed solution of sodium carbonate and sodium bicarbonate. The concentration of the sodium carbonate is preferably 1.8 mmol / L, and the concentration of the sodium bicarbonate solution is preferably 1.7 mmol / L.
[0014] The chromatographic column of the ion chromatographic analyzer was a high-capacity column, the column box temperature was 35°C, and the injection volume was 50 μL.
[0015] The chloride ion content in the high-purity water is less than 1 ppb, and the chloride ion content in the alkali solution is less than 10 ppb.
[0016] Beneficial effects of the present invention:
[0017] The ion chromatography method disclosed herein is simple to operate, highly accurate, and reproducible, effectively measuring the chloride ion content in electronic-grade hydrogen bromide. It is suitable for quality control of electronic-grade hydrogen bromide products and meets testing requirements. Compared with existing Fourier transform infrared spectroscopy analysis, it does not require hydrogen chloride standard gas, improving the accuracy of chloride ion determination. Furthermore, the test results are reproducible, enabling accurate determination of trace chloride ion content. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is the standard chromatogram of chloride ion.
[0019] Figure 2 This is the working curve of chloride ion concentration and peak area, where H = -0.0824 + 0.0140Q r = 0.9995.
[0020] Figure 3 This is the chromatogram of chloride ions in electronic grade hydrogen bromide. DETAILED DESCRIPTION
[0021] The present invention will be further described below with reference to the following examples, and the advantages and features of the present invention will become clearer as the description proceeds. However, it should be understood that the examples are merely illustrative and do not constitute any limitation on the scope of the present invention.
[0022] 1. Instruments and Reagents
[0023] 883 Basic IC plus ion chromatograph; 0.22 μm disposable syringe filter; column oven temperature, 35°C; 99.999% electronic-grade hydrogen bromide; sodium carbonate (reference reagent); sodium bicarbonate (reference reagent); sulfuric acid (superior purity); chloride ion standard solution (100 μg / mL); ammonia (electronic-grade); hydrogen bromide flow rate: 1.0 ml / min.
[0024] 2. Solution Preparation
[0025] Eluent: Accurately weigh 0.3816 g Na2CO3 and 0.286 g NaHCO3, dissolve them, and use ultrapure water to determine the volume to 2000 mL. Filter through a 0.45 μm filter membrane. Shake the filter flask until no bubbles escape, then ultrasonically degas for 1 min to obtain 1.8 mmol / L Na2CO3 + 1.7 mmol / L NaHCO3.
[0026] Preparation of standard solution: Measure 5 mL, 4 mL, 3 mL, 2 mL, 1 mL, 0.5 mL, and 0.2 mL of 100 μg / mL standard solution into 50 mL volumetric flasks respectively, and dilute to the scale with high-purity water to obtain a series of standard solutions of 10 μg / mL, 8 μg / mL, 6 μg / mL, 4 μg / mL, 2 μg / mL, 1 μg / mL, and 0.1 μg / mL.
[0027] Preparation of reproducible solution: Accurately pipette 0.2 mL of standard working solution and add 49.8 mL of blank solution to obtain Cl spiked with 0.1 μg / mL. - solution.
[0028] 3.Cl - Analysis of standard solutions
[0029] Linear relationship: The standard solution obtained in step (1) was injected sequentially from low concentration to high concentration to obtain a linear equation of concentration and peak area, and Cl - The linear equation is H = -0.0824 + 0.0140Q, and the linear correlation coefficient is 0.9995. Figure 2 shown.
[0030] Example 1
[0031] 1.1 Determination of injection speed
[0032] In order to ensure that hydrogen bromide is completely absorbed by high-purity water and at the same time ensure the absorption efficiency, the injection speed of hydrogen bromide is changed to ensure the absorption efficiency and result accuracy.
[0033] Connect three scrubbers in series to the sampling line: the first is a buffer bottle, and the second and third are absorption bottles filled with 100 mL of high-purity water. Before connecting the sampling line to the buffer and absorption bottles, purge it with high-purity nitrogen at a flow rate of 10 to 20 L / min. Open the valve of the hydrogen bromide cylinder and adjust the pressure reducing valve to control the hydrogen bromide injection rate to 2, 3, and 4 g / min, respectively. After the balance increases by 100 g, close the hydrogen bromide cylinder valve and purge the line with high-purity nitrogen for 10 minutes. Record the weight increase on the balance and the weight of the cylinder.
[0034] Through experiments, it was found that when the hydrogen bromide injection rate was 2 to 4 g / min, the weight increase of the absorption liquid was consistent with the weight decrease of the cylinder. The hydrogen bromide was completely absorbed by the high-purity water. The total absorption time was 25 to 50 minutes. The chloride ion content could be detected within 1 hour, ensuring the accuracy and efficiency of the analysis.
[0035] 1.2 Determination of sample absorption
[0036] In order to ensure that hydrogen bromide is completely absorbed by high-purity water and at the same time ensure the absorption efficiency, the absorption efficiency and result accuracy are guaranteed by changing the absorption amount of hydrogen bromide.
[0037] Connect three scrubbers in series to the sampling line: the first is a buffer bottle, and the second and third are absorption bottles filled with 100 mL of high-purity water, respectively. Before connecting the sampling line to the buffer and absorption bottles, purge them with high-purity nitrogen at a flow rate of 10 to 20 L / min. Open the valve of the hydrogen bromide cylinder and adjust the pressure reducing valve to control the hydrogen bromide injection rate to 3 g / min. When the balance increases by 80, 90, and 110 g, close the valve of the hydrogen bromide cylinder and purge the line with high-purity nitrogen for 10 minutes. Record the weight gain on the balance, as well as the total weight and weight loss of the cylinder.
[0038] Through experiments, it was found that when the weight gain of the balance was 80 to 110 g, the weight gain of the absorption liquid was consistent with the weight loss of the cylinder, and the high-purity water could completely absorb this weight of hydrogen bromide.
[0039] 1.3 Effect of ammonia addition on chromatographic analysis
[0040] Combine the absorption liquids, take 7 portions of the same sample solution and add 90, 95, 100, 105, 110, 115 and 120 mL of 21% (mass fraction) electronic grade ammonia water respectively, and measure the pH values to be 4, 5, 6, 7, 8, 9 and 10 respectively. Pipette 5 mL of the solution into a 250 mL volumetric flask and add high-purity water to make up the volume to prepare the test solution. The 7 test solutions with different pH values were analyzed and it was found that the retention time of chloride ions in the sample solutions with pH values of 4 to 10 was very close to that in the standard solution. The difference between the retention time of chloride ions and the retention time of the standard solution is shown in Table 1. The analysis spectrum of pH value = 7 is shown in the figure below. Figure 3 shown.
[0041] Table 1 Difference between chloride ion retention time and standard solution retention time
[0042]
[0043] 1.4 Determination of chloride ions in electronic grade hydrogen bromide
[0044] 1.4.1 Sample pretreatment
[0045] (1) Using two 250 mL absorption bottles, a total of 101.20 g of electronic grade hydrogen bromide was absorbed;
[0046] (2) After combining the absorption liquid, add 105 mL of ammonia water for reaction;
[0047] (3) Accurately pipette 5 mL of the sample solution in (2) into a 500 mL volumetric flask, dilute with high-purity water and adjust the volume to the mark to obtain the solution to be tested.
[0048] 1.4.2 Cl in electronic grade hydrogen bromide - Determination of content
[0049] The solution to be tested (was tested under ion chromatography conditions with 1.8mmol / L sodium carbonate solution and 1.7mmol / L sodium bicarbonate solution as eluent, high capacity chromatographic column, column box temperature 35℃, injection volume 50μL, and trace Cl in electronic grade hydrogen bromide was obtained. - See attached for the chromatogram of the test. Figure 3 At the same time, according to the external standard method, the Cl in the test solution - Quantitatively obtain Cl in electronic grade hydrogen bromide - The content of Cl is shown in Table 2. 0.1 μg / mL of Cl was added to the test solution. - The standard solution was used to perform the spike recovery experiment. The recovery results are shown in Table 2.
[0050] Table 2 Cl in electronic grade hydrogen bromide - Content and spike recovery
[0051]
Claims
1. A method for determining chloride ions in electronic grade hydrogen bromide by ion chromatography, characterized in that The following steps are involved: (1) Preparation of Cl - Standard solution, ion chromatography analysis was performed to obtain Cl at different concentrations - The peak area of the chloride ion was used as the horizontal axis and the peak area as the vertical axis to draw the working curve; (2) Pretreatment of hydrogen bromide samples: connect three washing bottles in series on the hydrogen bromide sampling tube, the first one is a buffer bottle, and the second and third ones are absorption bottles filled with 100 mL of high-purity water respectively; purge the sampling line with high-purity nitrogen before connecting it to the buffer bottle and the absorption bottle; control the hydrogen bromide flow rate to 2-4 g / min, so that the weight loss of the hydrogen bromide source cylinder is consistent with the weight gain of the absorption bottle, to ensure that the hydrogen bromide sample is completely absorbed; when the two absorption bottles have gained a total of 80-110 g, turn off the hydrogen bromide source, purge the pipeline with high-purity nitrogen for 10 minutes, and record the final increase on the balance; after absorption is completed, combine the obtained hydrogen bromide absorption liquid; (3) Add alkali solution to adjust the pH value of the hydrogen bromide solution to 4-10, transfer the solution to a volumetric flask, and add high-purity water to make up to volume to prepare the test solution; (4) Cl in electronic grade hydrogen bromide - Determination of content The solution to be tested was tested using an ion chromatograph to obtain trace amounts of Cl in electronic grade hydrogen bromide. - The chromatogram of the test was obtained, and the Cl in the test solution was detected according to the external standard method. - Quantitatively obtain Cl in electronic grade hydrogen bromide - content; Preparation of standard solutions: Measure 5 mL, 4 mL, 3 mL, 2 mL, 1 mL, 0.5 mL, and 0.2 mL of the 100 μg / mL standard solution into 50 mL volumetric flasks, and dilute to the mark with high-purity water to obtain a series of standard solutions of 10 μg / mL, 8 μg / mL, 6 μg / mL, 4 μg / mL, 2 μg / mL, 1 μg / mL, and 0.1 μg / mL. Preparation of reproducible solution: Accurately pipette 0.2 mL of standard working solution and add 49.8 mL of blank solution to obtain Cl spiked with 0.1 μg / mL. - solution; The Cl in the electronic grade hydrogen bromide - The content is 0.11μg / ml or 0.12μg / ml.
2. The method according to claim 1, wherein In step (2), the total weight increase of the two absorption bottles is 90 to 100 g.
3. The method according to claim 1, wherein The alkali solution is an aqueous solution of sodium hydroxide, potassium hydroxide or ammonia water.
4. The method according to claim 3, wherein The mass concentration of the ammonia water is 20% to 22%, and the amount of ammonia water added is 90 to 120 ml.
5. The method according to claim 1, wherein The pH value is 6-8.
6. The method according to claim 1, wherein The eluent used in the ion chromatograph is a mixed solution of sodium carbonate and sodium bicarbonate, with the concentration of sodium carbonate being 1.8 mmol / L and the concentration of sodium bicarbonate solution being 1.7 mmol / L.
7. The method according to claim 1, wherein The chromatographic column of the ion chromatographic analyzer was a high-capacity column, the column box temperature was 35°C, and the injection volume was 50 μL.
8. The method according to claim 1, wherein The chloride ion content in high-purity water is less than 1ppb, and the chloride ion content in alkali solution is less than 10ppb.