阅读说明：本技术 一种离子色谱法测定电子级溴化氢中氯离子的方法 (Method for measuring chloride ions in electronic-grade hydrogen bromide through ion chromatography ) 是由 袁胜芳 张金彪 翟晓颖 铁宁 郭琼 于 2021-08-04 设计创作，主要内容包括：本发明公开了一种离子色谱法测定电子级溴化氢中氯离子的方法,包括以下步骤：(1)配制分析Cl～(-)标准溶液,得到浓度和峰面积的工作曲线；(2)溴化氢样品预处理：溴化氢采样管上串联三个洗气瓶,第一个为缓冲瓶,第二个和第三个分别为装有100mL高纯水的吸收瓶,吸收完毕,合并得到的溴化氢吸收液；(3)加入碱液,调整溴化氢溶液pH值为4～10,容量瓶定容,制得待测溶液；(4)用离子色谱分析仪,对待测溶液进行检测,得到电子级溴化氢中痕量Cl～(-)检测的色谱图,同时根据外标法对待测溶液中Cl～(-)进行定量,得到电子级溴化氢中Cl～(-)的含量。该方法操作简单,重复性好,且灵敏度高。(The invention discloses a method for measuring chloride ions in electronic-grade hydrogen bromide by using ion chromatography, which comprises the following steps: (1) preparation analysis of Cl ‑ Obtaining a working curve of concentration and peak area by using a standard solution; (2) pretreating a hydrogen bromide sample: three gas washing bottles are connected in series on the hydrogen bromide sampling pipe, the first is a buffer bottle, the second and the third are absorption bottles filled with 100mL of high-purity water respectively, and after absorption is finished, the obtained hydrogen bromide absorption liquid is combined; (3) adding alkali liquor, adjusting the pH value of the hydrogen bromide solution to 4-10, and fixing the volume in a volumetric flask to obtain a solution to be detected; (4) detecting the solution to be detected by using an ion chromatographic analyzer to obtain trace Cl in the electronic grade hydrogen bromide ‑ Chromatogram of detection asAccording to the external standard method, the Cl in the solution to be measured is measured ‑ Carrying out quantification to obtain Cl in electronic grade hydrogen bromide ‑ The content of (a). The method is simple to operate, good in repeatability and high in sensitivity.)

1. A method for measuring chloride ions in electronic-grade hydrogen bromide by using ion chromatography is characterized by comprising the following steps:

(1) preparation of Cl^-Standard solution, ion chromatography to obtain Cl at different concentrations^-The peak area of the chlorine ion concentration is used as a horizontal coordinate, and the peak area is used as a vertical coordinate to draw a working curve;

(2) pretreating a hydrogen bromide sample: three gas washing bottles are connected in series on the hydrogen bromide sampling pipe, the first is a buffer bottle, and the second and the third are absorption bottles filled with 100mL of high-purity water respectively; before the sampling pipeline is connected with the buffer bottle and the absorption bottle, purging with high-purity nitrogen; controlling the flow rate of the hydrogen bromide to be 2-4 g/min, so that the weight reduction of the hydrogen bromide source steel cylinder is consistent with the weight increase of the absorption cylinder, and ensuring that a hydrogen bromide sample is completely absorbed; when the weight of the two absorption bottles is increased by 80-110 g, closing the hydrogen bromide gas source, purging the pipeline for 10min by adopting high-purity nitrogen, and recording the final increment of the balance; after absorption, combining the obtained hydrogen bromide absorption liquid;

(3) adding alkali liquor, adjusting the pH value of the hydrogen bromide solution to 4-10, transferring the solution into a volumetric flask, and adding high-purity water to a constant volume to prepare a solution to be detected;

(4) cl in electronic grade hydrogen bromide^-Determination of the content

Detecting the solution to be detected by using an ion chromatographic analyzer to obtain trace Cl in the electronic grade hydrogen bromide^-Detecting chromatogram map, and simultaneously detecting Cl in the solution to be detected according to external standard method^-Carrying out quantification to obtain Cl in electronic grade hydrogen bromide^-The content of (a).

2. The method as set forth in claim 1, wherein the weight gain of the two absorption bottles in the step (2) is 90-100 g.

3. The method as set forth in claim 1, wherein the alkali solution is an aqueous solution of sodium hydroxide, potassium hydroxide or aqueous ammonia.

4. The method according to claim 3, wherein the mass concentration of the ammonia water is 20-22%, and the addition amount of the ammonia water is 90-120 ml.

5. The method according to claim 1, wherein the pH is 6 to 8.

6. The method as set forth in claim 1, wherein the eluent used in the ion chromatograph is a mixed solution of sodium carbonate and sodium bicarbonate, the concentration of sodium carbonate is 1.8mmol/L, and the concentration of sodium bicarbonate solution is 1.7 mmol/L.

7. The method as set forth in claim 1, wherein the column of the ion chromatograph is a high-capacity column, the temperature of the column box is 35 ℃, and the sample volume is 50 μ L.

8. The method as set forth in claim 1, wherein the high purity water has a chlorine ion content of less than 1ppb and the alkali solution has a chlorine ion content of less than 10 ppb.

Technical Field

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 the trace chloride ions in an electronic-grade hydrogen bromide sample by using an ion chromatography method, and belongs to the field of analytical chemistry.

Background

The electronic grade hydrogen bromide is an indispensable raw material in the field of semiconductors, is mainly used for etching polycrystalline silicon in the manufacturing process of 8-inch and 12-inch chips, and is one of core gases in the advanced manufacturing process of the chips. Impurities in electronic grade hydrogen bromide tend to cause damage to the functioning of circuits within the wafer, rendering the integrated circuits ineffective and affecting the formation of geometric features, and therefore the detection of chloride ions in hydrogen bromide is an essential element of the production process. There is no effective analysis method for detecting chloride ions in electronic grade hydrogen bromide. The traditional chloride ion detection method mainly comprises the following steps: the potentiometric titration method comprises the steps of taking a saturated calomel electrode as a reference electrode, taking a silver electrode as an indicating electrode, and titrating with a silver nitrate standard solution to calculate the content of chloride ions, wherein the measuring range of the potentiometric titration method is 5-150 mg/L, and the potentiometric titration method is suitable for detecting higher-content chloride ions, and silver nitrate and hydrogen bromide can generate light yellow precipitates and consume silver nitrate, so that the potentiometric titration method is not suitable for measuring chloride ions in hydrogen bromide; secondly, the Fourier transform infrared spectroscopy needs to establish a standard spectrogram by taking a known low-concentration hydrogen chloride standard gas as a standard, meanwhile, an MCT detector is carried, liquid nitrogen needs to be supplemented at any time, the operation is complex, the ppm-level hydrogen chloride standard gas is not found in the current market, and the reliability of the result cannot be guaranteed in the test.

Disclosure of Invention

The invention aims to provide a method for measuring chloride ions in electronic-grade hydrogen bromide by using an ion chromatography, which is simple to operate, good in repeatability and high in sensitivity.

In order to achieve the purpose, the invention is realized by the following technical scheme: a method for determining chloride ions in electronic-grade hydrogen bromide by ion chromatography comprises the following steps:

(1) preparation analysis of Cl^-Obtaining a working curve of concentration and peak area by using a standard solution;

(2) pretreating a hydrogen bromide sample, absorbing electronic-grade hydrogen bromide with high-purity water, adjusting the pH value of an absorption solution to 4-10 with an alkali liquor, and analyzing by using an ion chromatograph to determine the content of chloride ions in the electronic-grade hydrogen bromide.

Further, the method for measuring the chloride ions in the electronic grade hydrogen bromide by using the ion chromatography comprises the following steps:

(1) preparation of Cl^-Standard solution, ion chromatography to obtain Cl at different concentrations^-The peak area of the chlorine ion concentration is used as a horizontal coordinate, and the peak area is used as a vertical coordinate to draw a working curve;

(2) pretreating a hydrogen bromide sample: three gas washing bottles are connected in series on the hydrogen bromide sampling pipe, the first is a buffer bottle, and the second and the third are absorption bottles filled with 100mL of high-purity water respectively. Before the sampling pipeline is connected with the buffer bottle and the absorption bottle, purging with high-purity nitrogen; and controlling the flow rate of the hydrogen bromide to be 2-4 g/min, so that the weight reduction of the hydrogen bromide source steel cylinder is consistent with the weight increase of the absorption cylinder, and the hydrogen bromide sample is ensured to be completely absorbed. And when the weight of the two absorption bottles is increased by 80-110 g, closing the hydrogen bromide gas source, purging the pipeline for 10min by adopting high-purity nitrogen, and recording the final increment of the balance. After absorption, combining the obtained hydrogen bromide absorption liquid; the absorption amount of the hydrogen bromide is preferably 90 to 100 g.

(3) Adding alkali liquor, adjusting the pH value of the hydrogen bromide solution to be 4-10, transferring the solution into a volumetric flask, adding high-purity water to a constant volume, wherein the volume ratio of the high-purity water to the mixed solution is preferably 100: 1, and preparing the solution to be detected. The alkali liquor is preferably aqueous solution of sodium hydroxide and potassium hydroxide or ammonia water, and more preferably ammonia water; the mass concentration of the ammonia water is preferably 20-22%, and the adding amount of the ammonia water is 90-120 ml, preferably 100-110 ml; the pH value is preferably 5-9, and more preferably 6-8.

(4) Cl in electronic grade hydrogen bromide^-Determination of the content

Detecting the solution to be detected by using an ion chromatographic analyzer to obtain trace Cl in the electronic grade hydrogen bromide^-Detecting chromatogram map, and simultaneously detecting Cl in the solution to be detected according to external standard method^-Carrying out quantification to obtain Cl in electronic grade hydrogen bromide^-The content of (a).

The leacheate used by the ion chromatographic analyzer is a mixed solution of sodium carbonate and sodium bicarbonate, the concentration of the sodium carbonate is preferably 1.8mmol/L, and the concentration of the sodium bicarbonate solution is preferably 1.7 mmol/L.

The chromatographic column of the ion chromatographic analyzer is a high-capacity chromatographic column, the temperature of a column box is 35 ℃, and the sample injection amount is 50 mu L.

The content of chloride ions in the high-purity water is less than 1ppb, and the content of chloride ions in the alkali liquor is less than 10 ppb.

The invention has the beneficial effects that:

the method for measuring the trace chloride ions in the electronic grade hydrogen bromide by using the ion chromatography is simple to operate, high in accuracy and good in repeatability, can effectively measure the content of the chloride ions in the electronic grade hydrogen bromide, is suitable for quality control of the electronic grade hydrogen bromide products, and meets the detection requirements. Compared with the existing Fourier transform infrared spectroscopy analysis, the method does not need hydrogen chloride standard gas, improves the accuracy of chloride ion determination, has good repeatability of test results, and can accurately determine the content of trace chloride ions.

Drawings

FIG. 1 is a standard chromatogram for chloride ion.

Fig. 2 is a plot of chloride ion concentration and peak area work, where H-0.0824 +0.0140Q r-0.9995.

FIG. 3 is a chromatogram of chloride ions in electronic grade hydrogen bromide.

Detailed Description

The invention will be further described with reference to the following examples, and the advantages and features of the invention will become more apparent as the description proceeds. It should be understood that the illustrated embodiments are exemplary only and are not intended to limit the scope of the present invention in any way.

1. Instruments and reagents

883 Basic IC plus ion chromatograph; 0.22 μm disposable needle filter; the temperature of the column box is 35 ℃; 99.999% electronic grade hydrogen bromide; sodium carbonate (reference reagent); sodium bicarbonate (reference reagent); sulfuric acid (guaranteed reagent); chloride ion standard solution (100. mu.g/mL); ammonia (electronic grade); hydrogen bromide flow rate: 1.0 ml/min.

2. Preparation of the solution

Leacheate: accurately weighing 0.3816g of Na₂CO₃And 0.286g NaHCO₃After dissolution, the volume is accurately determined to be 2000mL by ultrapure water, the solution is filtered by a 0.45-micron filter membrane, the filter flask is vibrated to ensure that no bubbles overflow, and ultrasonic degassing is carried out for 1min to obtain 1.8mmol/LNa₂CO₃+1.7mmol/LNaHCO₃；

Preparation of a standard solution: 100. mu.g/mL standard solutions of 5mL, 4mL, 3mL, 2mL, 1mL, 0.5mL and 0.2mL were measured and placed in 50mL volumetric flasks, and the volume was adjusted to a standard level with high purity water to obtain 10. mu.g/mL, 8. mu.g/mL, 6. mu.g/mL, 4. mu.g/mL, 2. mu.g/mL, 1. mu.g/mL and 0.1. mu.g/mL standard solutions.

Preparing a repetitive solution: accurately transferring 0.2mL of standard working solution, and adding 49.8mL of blank solution to obtain 0.1 mu g/mL of standard Cl^-And (3) solution.

3.Cl^-Analysis of the Standard solution

The linear relationship is: sequentially injecting the standard solution obtained in the step (1) from low concentration to high concentration to obtain a linear equation of concentration and peak area to obtain Cl^-The linear equation of (a) is H-0.0824 +0.0140Q, and the linear correlation coefficient is 0.9995, as shown in fig. 2.

Example 1

1.1 determination of the sample introduction speed

In order to ensure that the hydrogen bromide is completely absorbed by the high-purity water and ensure the absorption efficiency, the absorption efficiency and the result accuracy are ensured by changing the sample introduction speed of the hydrogen bromide.

Three gas washing bottles are connected in series on the sampling pipe, the first is a buffer bottle, and the second and the third are absorption bottles filled with 100mL of high-purity water respectively. Before the sampling pipeline is connected with the buffer bottle and the absorption bottle, high-purity nitrogen is used for purging at the flow rate of 10-20L/min. And opening a valve of the hydrogen bromide cylinder, adjusting a pressure reducing valve, and controlling the sample injection speed of the hydrogen bromide to be 2, 3 and 4g/min respectively. And (5) when the balance is increased by 100g, closing the hydrogen bromide steel cylinder valve, purging the pipeline for 10min by adopting high-purity nitrogen, recording the weight increase of the balance and simultaneously recording the weight of the steel cylinder.

Experiments show that when the sampling speed of the hydrogen bromide is 2-4 g/min, the weight gain of the absorption liquid is consistent with the weight reduction amount of the steel cylinder, the hydrogen bromide is completely absorbed by high-purity water, the total absorption time is 25-50 min, the content of chloride ions can be detected within 1 hour, and the analysis accuracy and the analysis efficiency are ensured.

1.2 determination of the absorption of the sample

In order to ensure that the hydrogen bromide is completely absorbed by the high-purity water and ensure the absorption efficiency, the absorption efficiency and the result accuracy are ensured by changing the absorption amount of the hydrogen bromide.

Three gas washing bottles are connected in series on the sampling pipe, the first is a buffer bottle, and the second and the third are absorption bottles filled with 100mL of high-purity water respectively. Before the sampling pipeline is connected with the buffer bottle and the absorption bottle, high-purity nitrogen is used for purging at the flow rate of 10-20L/min. And opening a valve of the hydrogen bromide cylinder, adjusting a pressure reducing valve and controlling the sample introduction speed of the hydrogen bromide to be 3 g/min. And when the balance is weighted by 80, 90 and 110g, closing the hydrogen bromide steel cylinder valve, purging the pipeline for 10min by adopting high-purity nitrogen, recording the weight gain of the balance, and simultaneously recording the total weight and the reduction amount of the steel cylinder.

Experiments show that when the daily average weight gain is 80-110 g, the weight gain of the absorption liquid is consistent with the weight reduction amount of the steel cylinder, and the high-purity water can completely absorb the hydrogen bromide.

1.3 Effect of Ammonia addition on chromatographic analysis

Combining the absorption solutions, adding 7 parts of the same sample solution into 90, 95, 100, 105, 110, 115 and 120mL of 21% (mass fraction) electronic grade ammonia water, measuring the pH values to be 4, 5, 6, 7, 8, 9 and 10, transferring 5mL of the solution into a 250mL volumetric flask, and adding high-purity water to a constant volume to obtain the solution to be measured. The 7 solutions to be detected with different pH values are analyzed, the retention time of chloride ions in the sample solution with the pH value of 4-10 and the retention time of chloride ions in the standard solution are very close to each other, and the difference value between the retention time of the chloride ions and the retention time of the standard solution is shown in table 1. The pH 7 analysis spectrum is shown in figure 3.

TABLE 1 difference between the retention time of chloride ion and the retention time of standard solution

1.4 determination of chloride ions in electronic grade Hydrogen bromide

1.4.1 pretreatment of samples

(1) 2 absorption bottles with the volume of 250mL are used, and the mass of the co-absorption electronic grade hydrogen bromide is 101.20 g;

(2) after the absorption liquid is combined, 105mL of ammonia water is added for reaction;

(3) accurately transferring a sample solution in 5mL (2), placing the sample solution in a 500mL volumetric flask, diluting with high-purity water, and fixing the volume to a scale to obtain a solution to be detected.

1.4.2 electronic grade Cl in hydrogen bromide^-Determination of the content

Taking 1.8mmol/L sodium carbonate solution and 1.7mmol/L sodium bicarbonate solution as leacheate, carrying out high-capacity chromatographic column, carrying out detection on the solution to be detected (to obtain trace Cl in electronic grade hydrogen bromide) under the ion chromatographic conditions that the temperature of a column box is 35 ℃ and the sample injection amount is 50 mu L^-The chromatogram map of the detection is shown in figure 3, and Cl in the solution to be detected is detected according to an external standard method^-Carrying out quantification to obtain Cl in electronic grade hydrogen bromide^-See table 2 for the contents of (a). 0.1. mu.g/mL of Cl was added to the test solution^-Standard solution, standard recovery test, the recovery results are shown in table 2.

TABLE 2 Cl in electronic grade hydrogen bromide^-Content and recovery rate of added standard