Method for analyzing impurity components in high-purity methanol reagent

Abstract

The invention relates to the technical field of analysis and testing of high-purity reagent materials, in particular to a method for analyzing impurity components in a high-purity methanol reagent, which can qualitatively detect impurities in the high-purity methanol reagent according to characteristic peaks in a spectrogram on one hand, and can obtain the content of the impurities by utilizing a drawn standard curve on the other hand. The invention provides a method for accurately, qualitatively and quantitatively determining trace impurities in a high-purity methanol reagent, mainly solves the quantitative and qualitative analysis of the contents of various low-concentration impurities in the high-purity methanol reagent, and avoids the work of repeatedly preparing a standard sample to make a standard curve for a single-type standard sample or various-type standard samples. And the detection of low-concentration impurities is very effective.

Description

Technical Field

[0001] The present invention relates to the technical field of analysis and testing of high-purity reagent materials, and particularly to a method for analyzing impurity components in high-purity methanol reagent. Background Art

[0002] Methanol, as an important chemical raw material, plays an important role in the chemical industry. Usually, methanol can be used as a solvent, antifreeze, fuel or denaturant for ethanol, and can also be used to produce biodiesel through transesterification reaction. As one of the basic organic raw materials, it can produce organic products such as chloroethane and methylamine, and is also a raw material for pesticides and pharmaceuticals. In the field of chip manufacturing, high-purity methanol is used as a cleaning agent, which is a cleaning agent for removing certain impurities and metal ions. The purity of methanol and the impurities in methanol will have an obvious impact on the cleaning effect. Among them, organic acids, ketones, alcohols, aldehydes, esters, and some olefins will all affect the quality of high-purity methanol. At the same time, these impurities have the characteristics of low concentration and difficult detection.

[0003] At present, there is no analysis method for various types of low-concentration impurities in high-purity methanol. In the reported methanol inspection and detection, most use chromatography + hydrogen flame detector. This method has the advantages of fast detection speed and high sensitivity. In patent CN102253142A, a method for simultaneously determining coexisting impurities and trace aromatics in methanol is reported. The instrument used is chromatography + hydrogen flame detector, and the detected types are limited, and the detection limit is also limited. The problems existing in the current method are: 1) The detection limit of the hydrogen flame detector is not high, and the detection ability for impurities in the order of several ppm is limited; 2) Multicomponent interference occurs, and the detection effect is less than satisfactory.

[0004] Therefore, developing a test method with simple operation, capable of separating various impurities simultaneously, and having excellent detection ability for low-concentration impurities is of great significance for the technological progress in the field of chip manufacturing. Summary of the Invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a method for analyzing impurity components in high-purity methanol reagent. The method of the present invention can qualitatively and quantitatively analyze low-concentration multi-component impurities in high-purity methanol reagent; it has the advantages of simple operation steps, no need for excessive sample pretreatment, saving pretreatment costs, and being able to reduce human errors during the operation process.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] The present invention provides a method for analyzing impurity components in high-purity methanol reagent, comprising the following steps:

[0008] (S1) Add several impurities to the internal standard substance and dissolve them in methanol to obtain a first standard sample and a second standard sample with different impurity contents;

[0009] (S2) Analyze the first standard sample and the second standard sample prepared in step (S1) by GC-MS. Taking the characteristic peak intensity as the ordinate and the corresponding impurity content as the abscissa, obtain the standard curves for different impurities;

[0010] (S3) Add the sample to be tested to the internal standard substance and mix well to obtain a solution to be tested;

[0011] (S4) Analyze the solution to be tested obtained in step (S3) by GC-MS. After obtaining the characteristic peaks, determine the types of impurities, and then substitute the obtained characteristic peak intensity into the standard curve of the corresponding impurity obtained in step (S2) to obtain the impurity content in the sample to be tested.

[0012] In the present invention, the characteristic peaks corresponding to each impurity are different. For a specific impurity, taking its characteristic peak intensity as the ordinate and its content as the ordinate, establish a standard curve;

[0013] When detecting the solution to be tested, first determine which impurity the characteristic peak corresponds to through the obtained characteristic peak, and then substitute its characteristic peak into the standard curve of the impurity to obtain the content of the corresponding impurity in the solution to be tested (i.e., the sample to be tested).

[0014] In an embodiment of the present invention, the high-purity methanol reagent is a methanol reagent with a purity of more than 99.9%.

[0015] In an embodiment of the present invention, in step (S1), the impurities include pentane, hexane, heptane, octane, nonane, decane, acetone, butanone, methyl propyl ketone, diethyl ketone, methyl formate, methyl acetate, methyl butyrate, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, isobutanol, n-pentanol, 2,3-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-2-butanol, 3-methyl-1-butanol, 2-methyl-1-pentanol, n-hexanol, 2-hexanol, 3-hexanol, 1-heptanol, 2-heptanol, tert-butanol and dimethyl ether.

[0016] In an embodiment of the present invention, in step (S1), the internal standard substance is tert-amyl alcohol (aiming to reduce injection error).

[0017] In the present invention, the characteristic peak of the internal standard substance does not overlap with the characteristic peaks of other substances.

[0018] In an embodiment of the present invention, the first standard sample contains 10 - 500 ppm of tert-amyl alcohol. Preferably, the first standard sample contains 100 ppm of tert-amyl alcohol;

[0019] The second standard sample contains 10 - 500 ppm of tert-amyl alcohol. Preferably, the second standard sample contains 100 ppm of tert-amyl alcohol.

[0020] In one embodiment of the present invention, in step (S1), the contents of tert-amyl alcohol in the first standard sample and the second standard sample are the same.

[0021] For the same impurity, the impurity content in the first standard sample is twice that in the second standard sample.

[0022] In one embodiment of the present invention, in the second standard sample, the content of any impurity is independently selected from one of 25 - 500 ppm.

[0023] In one embodiment of the present invention, in step (S3), the test solution contains 10 - 500 ppm of tert-amyl alcohol; preferably, the test solution contains 100 ppm of tert-amyl alcohol.

[0024] In one embodiment of the present invention, the content of tert-amyl alcohol in the test solution is the same as that in the first sample.

[0025] In one embodiment of the present invention, during the GC-MS analysis, chromatographic column: 5% diphenyl dimethyl polysiloxane - 95% dimethyl silicone stationary phase, programmed temperature rise: 30°C, hold for 2 min, rise to 270°C at 10°C / min, hold for 15 min; carrier gas: helium, purity ≥99.999%, constant pressure mode; inlet temperature: 250 - 260°C, split ratio 50:1; chromatograph-mass spectrometry interface temperature: 250°C; ion source: electron ionization source EI, ion source temperature 250°C; electron energy: 70 eV; mass analyzer: quadrupole mass analyzer; scan mode: selected ion monitoring mode for quantification; mass spectrometry scan range: 0 - 600 m / z; solvent delay: 5 min; gain coefficient: 1.00.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] On the one hand, the method for analyzing impurity components in a high-purity methanol reagent of the present invention can qualitatively detect impurities in the high-purity methanol reagent based on characteristic peaks in the spectrogram, and on the other hand, can obtain the content of impurities by using the drawn standard curve; that is, the present invention provides a method for accurately determining the quantity and quality of trace impurities in a high-purity methanol reagent, mainly solving the quantitative and qualitative analysis of various types and low-concentration impurities in the high-purity methanol reagent, avoiding the work of repeatedly preparing standard samples and formulating standard curves for single-type or multi-type standard samples, and being very effective for detecting low-concentration impurities; it not only has the advantages of simple operation, no need for excessive sample pretreatment, and saving pretreatment costs, but also can reduce human errors during the operation process due to the simple operation steps, with high accuracy. By accurately determining the quantity and quality, the content of various types of low-concentration impurities in the high-purity methanol reagent is obtained, which is crucial for quality control in the chip manufacturing process and has profound strategic significance. Detailed implementation mode

[0028] The present invention provides a method for analyzing impurity components in a high-purity methanol reagent, comprising the following steps:

[0029] (S1) Add several impurities to an internal standard and dissolve them in methanol to obtain a first standard sample and a second standard sample with different impurity contents;

[0030] (S2) Use GC-MS to analyze the first standard sample and the second standard sample prepared in step (S1), with the characteristic peak intensity as the ordinate and the corresponding impurity content as the abscissa, to obtain standard curves for different impurities;

[0031] (S3) Add an internal standard to the sample to be tested and mix well to obtain a test solution;

[0032] (S4) Use GC-MS to analyze the test solution obtained in step (S3), determine the types of impurities after obtaining the characteristic peaks, and then substitute the obtained characteristic peak intensity into the standard curves of the corresponding impurities obtained in step (S2) to obtain the content of impurities in the sample to be tested.

[0033] Further, the high-purity methanol reagent is a methanol reagent with a purity of more than 99.9%.

[0034] Further, in step (S1), the impurities include pentane, hexane, heptane, octane, nonane, decane, acetone, butanone, methyl propyl ketone, diethyl ketone, methyl formate, methyl acetate, methyl butyrate, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, isobutanol, n-pentanol, 2,3-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-2-butanol, 3-methyl-1-butanol, 2-methyl-1-pentanol, n-hexanol, 2-hexanol, 3-hexanol, 1-heptanol, 2-heptanol, tert-butanol, and dimethyl ether.

[0035] Further, in step (S1), the internal standard is tert-amyl alcohol (aiming to reduce injection error).

[0036] In the present invention, the characteristic peak of the internal standard does not overlap with the characteristic peaks of other substances.

[0037] Further, the first standard sample contains 10 - 500 ppm of tert-amyl alcohol. Preferably, the first standard sample contains 100 ppm of tert-amyl alcohol;

[0038] The second standard sample contains 10 - 500 ppm of tert-amyl alcohol. Preferably, the second standard sample contains 100 ppm of tert-amyl alcohol.

[0039] Further, in step (S1), the contents of tert-amyl alcohol in the first standard sample and the second standard sample are the same;

[0040] For the same kind of impurity, the impurity content in the first standard sample is twice that in the second standard sample.

[0041] Further, in the second standard sample, the content of any impurity is independently selected from one of 25 - 500 ppm.

[0042] Further, in step (S3), the test solution contains 10 - 500 ppm of tert-amyl alcohol; preferably, the test solution contains 100 ppm of tert-amyl alcohol.

[0043] Further, the content of tert-amyl alcohol in the test solution is the same as that in the first sample.

[0044] Further, during the GC-MS analysis process, chromatographic column: 5% diphenyl dimethyl polysiloxane - 95% dimethyl siloxane stationary phase, programmed temperature rise: 30°C, hold for 2 min, rise to 270°C at 10°C / min, hold for 15 min; carrier gas: helium, purity ≥99.999%, constant pressure mode; inlet temperature: 250 - 260°C, split ratio 50:1; chromatograph-mass spectrometry interface temperature: 250°C; ion source: electron ionization source EI, ion source temperature 250°C; electron energy: 70 eV; mass analyzer: quadrupole mass analyzer; scan mode: selected ion monitoring mode for quantification; mass spectrometry scan range: 0 - 600 m / z; solvent delay: 5 min; gain coefficient: 1.00.

[0045] The present invention will be described in detail below with reference to specific embodiments.

[0046] In the following examples, unless otherwise specified, the reagents used are commercially available reagents, and the detection means and methods used are conventional detection means and methods in the art.

[0047] In the following examples, the reagents are all commercially available chromatographically pure reagents and are all purchased through Sinopharm Group Co., Ltd.; in the following examples, the GC-MS analyzer used is Agilent 5977 GC / MS.

[0048] Example 1

[0049] This example provides a method for analyzing impurity components in a high-purity methanol reagent, including the following steps:

[0050] (S1) Prepare the first standard sample and the second standard sample in Table 1 by using chromatographically pure methanol for the impurities (both the first standard sample and the second standard sample contain 100 ppm tert-amyl alcohol - internal standard);

[0051] (S2) Perform GC-MS analysis on the first standard sample and the second standard sample obtained in step (S1) and step (S2), identify the corresponding chromatographic peaks, determine the attribution of the peaks, and according to the built-in quantitative software, use the intensity of the characteristic peaks of the impurities as the ordinate and the impurity content as the abscissa to obtain the standard curve of the corresponding substances;

[0052] (S3) Add 100 ppm internal standard to the sample to be tested and mix well to obtain the sample solution to be tested;

[0053] (S4) Perform GC-MS analysis on the sample solution to be tested, compare the obtained characteristic peaks with the characteristic peaks obtained in step (S2), first determine the types of impurities, and then substitute the intensity of the obtained characteristic peaks into the standard curve of the corresponding impurities obtained in step (S2) to obtain the content of the impurities in the sample to be tested.

[0054] Among them, during the GC-MS analysis process:

[0055] Chromatographic column: 5% diphenyl dimethyl polysiloxane - 95% dimethyl siloxane stationary phase (HP-5MS: 60 m × 0.25 um × 0.25 mm); column flow rate: 1.3 mL / min; programmed temperature rise: initial temperature 30°C, hold for 2 min, rise to 270°C at 10°C / min, hold for 15 min; carrier gas: helium, purity ≥ 99.999%, constant pressure mode; inlet temperature: 260°C, split ratio 50:1; chromatograph-mass spectrometry interface temperature: 250°C;

[0056] Ion source: electron ionization source EI, ion source temperature 250°C; electron energy: 70 eV; mass analyzer: quadrupole mass analyzer; scanning mode: selected ion monitoring (SIM) mode for quantification; mass spectrometry scanning range: 0 - 600 (m / z); solvent delay: 5 min; gain coefficient: 1.00.

[0057] The known concentrations and measured concentrations of impurities in the sample to be tested are shown in Table 2; it can be found from Table 2 that the standard curve obtained by using this method can achieve accurate measurement (ppm level) of various impurities in high-purity methanol reagent.

[0058] Table 1 Summary Table of Concentrations of the First Standard Sample and the Second Standard Sample in Each Impurity Reagent

[0059]

[0060]

[0061] Table 2 Comparison Table of Inhibitory Concentrations and Measured Concentrations of Each Impurity Reagent in the Sample to be Tested

[0062]

[0063]

[0064] According to the method of the present invention, in addition to the 33 substances listed in Table 1 above, the impurities in the high-purity methanol may also include any other impurities, and the impurities involved do not affect the analysis results. Semi-quantitative analysis of the impurities not involved can also be performed by comparing other impurities with the internal standard peak.

[0065] The above description of the embodiments is to enable those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the interpretation of the present invention should be within the protection scope of the present invention.

Claims

1. A method for analyzing impurity components in a high-purity methanol reagent, characterized in that, it comprises the following steps: (S1) Add several impurities to an internal standard substance and dissolve them in methanol to obtain a first standard sample and a second standard sample with different impurity contents; (S2) Use GC-MS to analyze the first standard sample and the second standard sample prepared in step (S1). Taking the characteristic peak intensity as the ordinate and the corresponding impurity content as the abscissa, obtain the standard curves for different impurities; (S3) Add the sample to be tested to an internal standard substance and mix well to obtain a test solution; (S4) Use GC-MS to analyze the test solution obtained in step (S3). After obtaining the characteristic peaks, determine the types of impurities, and then substitute the obtained characteristic peak intensities into the standard curves of the corresponding impurities obtained in step (S2) to obtain the impurity contents in the sample to be tested.

2. The method for analyzing impurity components in a high-purity methanol reagent according to claim 1, characterized in that, the high-purity methanol reagent is a methanol reagent with a purity of more than 99.9%.

3. The method for analyzing impurity components in a high-purity methanol reagent according to claim 1, characterized in that, in step (S1), the impurities include pentane, hexane, heptane, octane, nonane, decane, acetone, butanone, methyl propyl ketone, diethyl ketone, methyl formate, methyl acetate, methyl butyrate, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, isobutanol, n-pentanol, 2,3-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-2-butanol, 3-methyl-1-butanol, 2-methyl-1-pentanol, n-hexanol, 2-hexanol, 3-hexanol, 1-heptanol, 2-heptanol, tert-butanol and dimethyl ether.

4. The method for analyzing impurity components in a high-purity methanol reagent according to claim 1, characterized in that, in step (S1), the internal standard substance is tert-amyl alcohol.

5. The method for analyzing impurity components in a high-purity methanol reagent according to claim 4, characterized in that, the first standard sample contains 10 - 500 ppm of tert-amyl alcohol, and the second standard sample contains 10 - 500 ppm of tert-amyl alcohol.

6. The method for analyzing impurity components in a high-purity methanol reagent according to claim 5, characterized in that, in step (S1), the contents of tert-amyl alcohol in the first standard sample and the second standard sample are the same; for the same kind of impurity, the impurity content in the first standard sample is twice that in the second standard sample.

7. The method for analyzing impurity components in a high-purity methanol reagent according to claim 6, characterized in that, in the second standard sample, the content of any one impurity is independently selected from one of 25 - 500 ppm.

8. The method for analyzing impurity components in a high-purity methanol reagent according to claim 1, characterized in that, in step (S3), the test solution contains 10 - 500 ppm of tert-amyl alcohol.

9. The method for analyzing impurity components in a high-purity methanol reagent according to claim 1, characterized in that, the content of tert-amyl alcohol in the test solution is the same as that in the first sample.

10. A method for analyzing impurity components in a high-purity methanol reagent according to claim 1, characterized in that, During the GC-MS analysis, chromatographic column: 5% diphenyl dimethyl polysiloxane - 95% dimethyl silicone stationary phase, programmed temperature rise: 30°C, hold for 2 min, rise to 270°C at 10°C / min, hold for 15 min; Carrier gas: helium, purity ≥ 99.999%, constant pressure mode; inlet temperature: 250 - 260°C, split ratio 50:1; chromatograph-mass spectrometry interface temperature: 250°C; ion source: electron ionization source EI, ion source temperature 250°C; electron energy: 70 eV; mass analyzer: quadrupole mass analyzer; scanning mode: selected ion monitoring mode for quantification; mass spectrometry scanning range: 0 - 600 m / z; solvent delay: 5 min; gain coefficient: 1.00.

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