Method for detecting aniline compounds in factory air

Abstract

The invention discloses a method for detecting aniline compounds in factory air, which comprises the following steps: step 1, extracting a sample: adding a hydrochloric acid solution with the volume ratio of 12% into the sample taken from the factory air, then extracting the aniline compounds into an acid liquid phase, adding alkali into the acid liquid phase extraction liquid, adjusting the pH value to be neutral, then adding dichloromethane, and extracting for 2-3 hours; reextracting the aniline compounds in the neutral extract into dichloromethane, and fixing the volume to obtain a sample detection solution; and 2, sample detection: separating the obtained sample detection liquid through a quartz capillary column, and carrying out gas chromatography-mass spectrometry detection according to the following conditions. According to the method, the aniline compounds in the air of the factory are qualitatively and quantitatively analyzed by using a gas chromatography-mass spectrometry method, the detection limit and the accuracy can be properly improved, the separation effect of the aniline compounds can be effectively improved by adopting chromatographic analysis of a capillary chromatographic column, and the aniline compounds can be more accurately, qualitatively and quantitatively analyzed by adopting mass spectrometry.

Description

Technical Field

[0001] The invention belongs to the field of aniline compound detection methods, and particularly relates to a method for detecting aniline compounds in factory air. Background Art

[0002] Amine compounds are representatives of aromatic amines, and refer to a class of compounds formed when the hydrogen atoms in the aniline molecule are replaced by other functional groups. They have a special smell and are very toxic. They can be ingested into the human body through the respiratory tract and digestive tract, and may also be quickly absorbed by the human body through the skin. Aniline has a certain toxic effect on the human body, and some anilines are carcinogenic to the human body. Aniline compounds in the environment mainly come from industries such as dyes, pharmaceuticals, rubber, explosives, coatings, pesticides and plastics. Therefore, it is necessary to analyze aniline compounds in environmental samples.

[0003] In recent years, the use of gas chromatography to detect the content of aniline compounds in the atmosphere has been widely used in my country. Spectrophotometry can only determine the total amount of aniline compounds but cannot perform qualitative and quantitative analysis on each aniline compound; gas chromatography, liquid chromatography and ion chromatography can respectively determine the content of various aniline compounds, but the individual compounds analyzed are also different. The current industry standard "Gas Chromatography Method for Determination of Aniline from Stationary Pollution Sources in the Atmosphere HJ / T68-2001" uses packed column gas chromatography for determination, which has low separation efficiency and severe peak expansion. The six components need to be sampled twice, and qualitative analysis needs to be performed under different instrument conditions. In addition, the experimental process is cumbersome and time-consuming. Summary of the invention

[0004] Purpose of the invention: In order to overcome the deficiencies of the prior art, the present invention provides a method for detecting aniline compounds in factory air.

[0005] Technical solution: A method for detecting aniline compounds in factory air, comprising the following steps:

[0006] Step 1, sample extraction: add 12% by volume hydrochloric acid solution to the sample taken from the factory air, then extract the aniline compounds into the acid liquid phase, add alkali to the acid liquid phase extract, adjust the pH to neutral, then add dichloromethane, back-extract the aniline compounds in the neutral extract into dichloromethane, and fix the volume to obtain the sample test solution;

[0007] Step 2: Sample detection: The obtained sample test solution is separated by DB-WAX capillary column and subjected to gas chromatography-mass spectrometry detection under the following conditions:

[0008] A. Gas chromatography conditions are as follows: injection port temperature 220℃, injection volume 1.5-2.2μL, split injection, split ratio 8-16:1; program temperature, initial temperature 80℃ for 50min, increase to 220℃ at 45℃ / min, maintain for 5min, carrier gas is helium, carrier gas flow rate: 1.4mL / min;

[0009] B. Mass spectrometry conditions are as follows: chromatographic-mass spectrometry interface temperature 270-290°C; electron bombardment ion source, electron energy 70 eV, ion source temperature 220-240°C, quadrupole temperature 140-160°C; solvent delay time: 6-8 min; mass spectrometry scanning mode is ion monitoring mode.

[0010] As an optimization: the column length×inner diameter×membrane thickness of the DB-WAX capillary is 30m×0.25mm×0.25μm.

[0011] As an optimization, the amount of hydrochloric acid solution added is 16%-24% of the sample volume.

[0012] As an optimization: the amount of dichloromethane added is 2.2-2.8 times the volume of the neutral extract.

[0013] Beneficial effects: The present invention uses a gas chromatography-mass spectrometry method to qualitatively and quantitatively analyze aniline compounds in factory air, which can appropriately improve the detection limit and accuracy. The chromatographic analysis using a capillary column can effectively improve the separation effect of aniline compounds. The mass spectrometry analysis can more accurately qualitatively and quantitatively analyze aniline compounds. DETAILED DESCRIPTION

[0014] The technical solutions in the embodiments of the present invention will be described clearly and completely below so that those skilled in the art can better understand the advantages and features of the present invention, thereby making a clearer definition of the protection scope of the present invention. The embodiments described in the present invention are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. Specific embodiment 1

[0016] A method for detecting aniline compounds in factory air comprises the following steps:

[0017] Step 1, sample extraction: add 12% volume ratio hydrochloric acid solution to the sample taken from the factory air, the amount of hydrochloric acid solution added is 16% of the sample volume. Then extract the aniline compounds into the acid liquid phase, add alkali to the acid liquid phase extract, adjust the pH to neutral, add dichloromethane, back-extract the aniline compounds in the neutral extract into dichloromethane, and adjust the volume to obtain the sample test solution; the amount of dichloromethane added is 2.2 times the volume of the neutral extract.

[0018] Step 2, sample detection: the obtained sample test liquid is separated by DB-WAX capillary chromatographic column, and gas chromatography-mass spectrometry detection is performed under the following conditions: the column length × inner diameter × membrane thickness of the DB-WAX capillary is 30m × 0.25mm × 0.25μm.

[0019] A. Gas chromatography conditions are as follows: injection port temperature 220℃, injection volume 1.5μL, split injection, split ratio 8:1; programmed temperature, initial temperature 80℃ for 50min, increased to 220℃ at 45℃ / min, maintained for 5min, carrier gas helium, carrier gas flow rate: 1.4mL / min;

[0020] B. Mass spectrometry conditions are as follows: chromatographic-mass spectrometry interface temperature 270°C; electron bombardment ion source, electron energy 70 eV, ion source temperature 220°C, quadrupole temperature 140°C; solvent delay time: 6 min; mass spectrometry scanning mode is ion monitoring mode. Specific embodiment 2

[0022] A method for detecting aniline compounds in factory air comprises the following steps:

[0023] Step 1, sample extraction: add 12% volume ratio hydrochloric acid solution to the sample taken from the factory air, the amount of hydrochloric acid solution added is 24% of the sample volume. Then extract the aniline compounds into the acid liquid phase, add alkali to the acid liquid phase extract, adjust the pH to neutral, add dichloromethane, extract the aniline compounds in the neutral extract into dichloromethane, and adjust the volume to obtain the sample test solution; the amount of dichloromethane added is 2.8 times the volume of the neutral extract.

[0024] Step 2, sample detection: the obtained sample test liquid is separated by DB-WAX capillary chromatographic column, and gas chromatography-mass spectrometry detection is performed under the following conditions: the column length × inner diameter × membrane thickness of the DB-WAX capillary is 30m × 0.25mm × 0.25μm.

[0025] A. Gas chromatography conditions are as follows: injection port temperature 220℃, injection volume 2.2μL, split injection, split ratio 16:1; program temperature, initial temperature 80℃ for 50min, increase to 220℃ at 45℃ / min, maintain for 5min, carrier gas is helium, carrier gas flow rate: 1.4mL / min;

[0026] B. Mass spectrometry conditions are as follows: chromatographic-mass spectrometry interface temperature 290°C; electron bombardment ion source, electron energy 70 eV, ion source temperature 240°C, quadrupole temperature 160°C; solvent delay time: 8 min; mass spectrometry scanning mode is ion monitoring mode. Specific embodiment 3

[0028] A method for detecting aniline compounds in factory air comprises the following steps:

[0029] Step 1, sample extraction: add 12% volume ratio hydrochloric acid solution to the sample taken from the factory air, the amount of hydrochloric acid solution added is 22% of the sample volume. Then extract the aniline compounds into the acid liquid phase, add alkali to the acid liquid phase extract, adjust the pH to neutral, add dichloromethane, extract the aniline compounds in the neutral extract into dichloromethane, and adjust the volume to obtain the sample test solution; the amount of dichloromethane added is 2.6 times the volume of the neutral extract.

[0030] Step 2, sample detection: the obtained sample test liquid is separated by DB-WAX capillary chromatographic column, and gas chromatography-mass spectrometry detection is performed under the following conditions: the column length × inner diameter × membrane thickness of the DB-WAX capillary is 30m × 0.25mm × 0.25μm.

[0031] A. Gas chromatography conditions are as follows: injection port temperature 220℃, injection volume 1.8μL, split injection, split ratio 14:1; programmed temperature, initial temperature 80℃ for 50min, raised to 220℃ at 45℃ / min, maintained for 5min, carrier gas helium, carrier gas flow rate: 1.4mL / min;

[0032] B. Mass spectrometry conditions are as follows: chromatographic-mass spectrometry interface temperature 286°C; electron bombardment ion source, electron energy 70 eV, ion source temperature 232°C, quadrupole temperature 154°C; solvent delay time: 7 min; mass spectrometry scanning mode is ion monitoring mode.

[0033] The present invention uses a gas chromatography-mass spectrometry method to qualitatively and quantitatively analyze aniline compounds in factory air, which can appropriately improve the detection limit and accuracy. The chromatographic analysis using a capillary chromatographic column can effectively improve the separation effect of aniline compounds. The mass spectrometry analysis can more accurately qualitatively and quantitatively analyze aniline compounds.

Claims

1. A method for detecting aniline compounds in factory air, characterized in that: The steps include: Step 1, sample extraction: add 12% by volume hydrochloric acid solution to the sample taken from the factory air, then extract the aniline compounds into the acid liquid phase, add alkali to the acid liquid phase extract, adjust the pH to neutral, then add dichloromethane, back-extract the aniline compounds in the neutral extract into dichloromethane, and fix the volume to obtain the sample test solution; Step 2: Sample detection: The obtained sample test solution is separated by DB-WAX capillary column and subjected to gas chromatography-mass spectrometry detection under the following conditions: A. Gas chromatography conditions are as follows: injection port temperature 220℃, injection volume 1.5-2.2μL, split injection, split ratio 8-16:1; program temperature, initial temperature 80℃ for 50min, increase to 220℃ at 45℃ / min, maintain for 5min, carrier gas is helium, carrier gas flow rate: 1.4mL / min; B. Mass spectrometry conditions are as follows: chromatographic-mass spectrometry interface temperature 270-290°C; electron bombardment ion source, electron energy 70 eV, ion source temperature 220-240°C, quadrupole temperature 140-160°C; solvent delay time: 6-8 min; mass spectrometry scanning mode is ion monitoring mode.

2. The method for detecting aniline compounds in factory air according to claim 1, characterized in that: The column length×inner diameter×film thickness of the DB-WAX capillary is 30m×0.25mm×0.25μm.

3. The method for detecting aniline compounds in factory air according to claim 1, characterized in that: The amount of the hydrochloric acid solution added is 16%-24% of the sample volume.

4. The method for detecting aniline compounds in factory air according to claim 1, characterized in that: The amount of dichloromethane added is 2.2-2.8 times the volume of the neutral extract.