CN112067721A - Method for detecting chloromethane in sulfuric acid - Google Patents
Method for detecting chloromethane in sulfuric acid Download PDFInfo
- Publication number
- CN112067721A CN112067721A CN202010971257.7A CN202010971257A CN112067721A CN 112067721 A CN112067721 A CN 112067721A CN 202010971257 A CN202010971257 A CN 202010971257A CN 112067721 A CN112067721 A CN 112067721A
- Authority
- CN
- China
- Prior art keywords
- sulfuric acid
- detection method
- temperature
- solution
- preparing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/04—Preparation or injection of sample to be analysed
- G01N30/06—Preparation
- G01N30/14—Preparation by elimination of some components
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/04—Preparation or injection of sample to be analysed
- G01N2030/042—Standards
- G01N2030/045—Standards internal
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
Abstract
The invention relates to a method for detecting chloromethane in sulfuric acid, which adopts a gas chromatography-mass spectrometer to measure the content of the chloromethane in the sulfuric acid and comprises the following steps: 1) preparing a standard reference substance solution; 2) preparing a test solution; 3) preparation of blank control solution: 4) gas chromatography-mass spectrometry conditions and system adaptability test: 5) and (4) measuring. The method has the advantages of good separation degree, low detection limit, strong operability and small interference of other substances, can be used for controlling the quality of the sulfuric acid used in the production process of the chloromethane, is beneficial to the optimization of the production process of the chloromethane and reduces the pollution to the environment.
Description
Technical Field
The invention belongs to the technical field of chemical detection, and particularly relates to a method for detecting chloromethane in sulfuric acid.
Background
Methyl chloride (methyl chloride, CH3Cl), also known as methyl chloride, is a colorless, easily liquefiable gas that is generally liquefied under pressure and stored in cylinders. Methyl chloride is used in a wide range of modern industries and is an important raw material for organic synthesis. The method is mainly used for producing organosilicon compound-methyl chlorosilane and methyl cellulose. It is also widely used as solvent, extractant, propellant, refrigerant, local anesthetic, and methylating agent, and is used for producing pesticide, medicine, perfume, etc. Of the methyl chloride produced worldwide, about 80% is used to produce methylchlorosilanes and tetramethyllead. In the production process of methyl chloride, concentrated sulfuric acid is needed to be used for drying and purifying methyl chloride, and the used sulfuric acid is processed to remove the methyl chloride and then regenerated for recycling. However, the content of methyl chloride in sulfuric acid is a main factor for regenerating sulfuric acid, improving economy and causing harm to the environment, and how to detect the content of methyl chloride in sulfuric acid becomes a difficult problem.
Aiming at the problems, the inventor provides a detection method which has the advantages of good separation degree, low detection limit, strong operability and small interference of other substances, can be used for controlling the quality of sulfuric acid used in the production process of chloromethane, is beneficial to the optimization of the production process of chloromethane and reduces the pollution to the environment.
Disclosure of Invention
The invention aims to provide a method for detecting chloromethane in sulfuric acid, which comprises the following steps: 1) preparing a standard reference substance solution; 2) preparing a test solution; 3) preparation of blank control solution: 4) gas chromatography-mass spectrometry conditions and system adaptability test: 5) and (4) measuring.
The step 1) of preparing the standard reference substance solution specifically comprises the following steps: accurately measuring 10.0 mu L of methyl chloride in methanol, adding into a headspace bottle filled with 4.0g of sodium chloride and 10.0mL of water, injecting 200ng of fluorobenzene as an internal standard substance, sealing, and uniformly mixing on a vortex mixer to obtain a reference substance solution.
The step 2) of preparing the test solution specifically comprises the following steps: accurately weighing 0.5g of sulfuric acid, adding the sulfuric acid into a headspace bottle filled with 4.0g of sodium chloride and 10.0mL of water, injecting 200ng of fluorobenzene serving as an internal standard substance, sealing, and uniformly mixing on a vortex mixer to obtain a test solution.
The step 3) of preparing the blank reference substance solution specifically comprises the following steps: weighing 4.0g of sodium chloride and 10.0mL of water, adding the sodium chloride and the water into a 20.0mL headspace bottle, injecting 200ng of fluorobenzene as an internal standard substance, sealing, and uniformly mixing on a vortex mixer to obtain a blank reference substance solution.
The step 4) of gas chromatography-mass spectrometry condition and system adaptability test specifically comprises the following steps:
(1) the chromatographic column is a quartz capillary column with the length of 30m, the inner diameter of 0.25mm and the film thickness of 1.4 mu m, and the stationary phase is 6 percent cyanopropylphenyl/94 percent dimethylpolysiloxane, and other equivalent capillary columns can also be used;
(2) chromatographic conditions are as follows:
conditions of the headspace sampler: carrier gas pressure: 120 KPa; the balance time is 40 min; equilibrium temperature: 60 ℃; pressure-displacement time: 150 s; sample introduction time: 6 s; transmission line temperature: 80 ℃; needle temperature: 100 ℃;
temperature programming: keeping the initial temperature at 35 deg.C for 5min, and raising the temperature to 150 deg.C at 5 deg.C/min; sample inlet temperature: 180 ℃; and (3) sample introduction mode: split-flow sample introduction, split-flow ratio: 10: 1; carrier gas: helium gas;
(3) mass spectrum conditions: C. an ionization mode: EI; transmission line temperature: 230 ℃; ion source temperature: 200 ℃; electron acceleration voltage: 70 eV; the detection mode is as follows: scan method, SIM method; and (3) quantifying ions: 50; auxiliary ions: 52.
the step 5) comprises the following steps: under the chromatographic condition, respectively adding 1.0mL of standard reference substance solution, blank reference substance solution and test solution; and (5) performing qualitative determination by using the relative retention time and the characteristic ions, and performing quantitative determination by using the ratio of the area of the target peak to the area of the peak of the internal standard substance, and calculating to obtain the target ion.
The sodium chloride is used after being cooled after being burnt at 500 ℃ for 4 hours.
The concentration of the methane chloride in the methanol is 2000 mg/L.
The chromatography column may also be other equivalent capillary columns.
And (2) the headspace sample injector under the chromatographic condition adopts a constant-pressure sample injection mode.
The defects of the prior art and the advantages of the invention are as follows:
1. the prior art has the following defects:
in the production process of methyl chloride, concentrated sulfuric acid is needed to be used for drying and purifying methyl chloride, and the used sulfuric acid is processed to remove the methyl chloride and then regenerated for recycling. However, how to detect the content of methyl chloride in the sulfuric acid is a main factor for regenerating the sulfuric acid, improving the economy and harming the environment.
2. The invention has the advantages that:
1) in the invention, concentrated sulfuric acid is diluted and then a headspace method is used for detecting a sample to reduce the damage of the concentrated sulfuric acid to an instrument.
2) The added sodium chloride plays a role of salting out, the solubility of the chloromethane in the sulfuric acid aqueous solution is reduced, and the standard addition recovery rate is the highest when the amount of the added sodium chloride is 4.0g through a standard addition experiment.
3) 200ng of fluorobenzene is injected in the detection as an internal standard substance, the fluorobenzene is uniformly mixed on a vortex mixer after being sealed for detection, the measurement error caused by inaccurate sample injection amount can be reduced after the internal standard substance is added, and the precision of the experiment is improved.
4) By adopting a constant-pressure sample introduction mode, the size of the sample introduction amount can be adjusted by adjusting the sample introduction time, and a lower detection limit can be obtained by a longer sample introduction time.
5) In the experiment, the gas chromatography-mass spectrometer is used for detecting the methyl chloride, the mass spectrum belongs to a high-precision detector, even if the content is very low, the mass spectrum has larger response, and the detection limit of the methyl chloride by using the gas chromatography-mass spectrometer is much lower than that by using the gas chromatography.
6) The method adopts a gas chromatography-mass spectrometer to detect the methyl chloride, the mass spectrum adopts characteristic ions to perform qualitative analysis, and the mass spectrum can be searched according to the obtained mass spectrogram to judge what the substance is, so that the interference of other substances to the detection result can be avoided.
7) The method has the advantages of good separation degree, low detection limit, strong operability and small interference of other substances, can be used for controlling the quality of the sulfuric acid used in the production process of the chloromethane, is beneficial to the optimization of the production process of the chloromethane and reduces the pollution to the environment.
Detailed Description
1. Sample and instrument:
sample preparation: sulfuric acid after drying methyl chloride, provided by the unit self.
The instrument comprises the following steps: a Sammer fly TRACE1300 gas chromatograph + ISQ7000 mass spectrometer; an Chengdu Colin AutoHS headspace sample injector; ME204 precision of the Mettler toledo electronic balance is 0.0001 g; HUXI XW-80A vortex mixer.
2. Chromatographic conditions are as follows:
conditions of the headspace device: carrier gas pressure: 120 KPa; the balance time is 40 min; equilibrium temperature: 60 ℃; pressure-displacement time: 150 s; sample introduction time: 6 s; transmission line temperature: 80 ℃; needle temperature: at 100 ℃.
Temperature programming: keeping the initial temperature at 35 deg.C for 5min, and raising the temperature to 150 deg.C at 5 deg.C/min; sample inlet temperature: 180 ℃; and (3) sample introduction mode: split-flow sample introduction, split-flow ratio: 10: 1; carrier gas: helium gas.
Mass spectrometer conditions: an ionization mode: EI; transmission line temperature: 230 ℃; ion source temperature: 200 ℃; electron acceleration voltage: 70 eV; the detection mode is as follows: SIM method; and (3) quantifying ions: 50; auxiliary ions: 52.
example 1
Preparation of standard control solutions: 1.0, 2.0, 5.0, 10.0 and 20.0 mu L of methyl chloride (concentration: 200mg/L) in methanol are respectively measured, and then 100ng of fluorobenzene is injected into a 20.0mL headspace bottle filled with 4.0g of sodium chloride (burned at 500 ℃ for 4 hours and then cooled) and 10.0mL of water as an internal standard substance, and the internal standard substance is sealed and then uniformly mixed on a vortex mixer to obtain a reference substance solution.
Preparation of blank control solution: weighing 4.0g of sodium chloride (burned at 500 ℃ for 4 hours and then cooled) and 10.0mL of water, adding the sodium chloride and the water into a 20.0mL headspace bottle, injecting 100ng of fluorobenzene as an internal standard substance, sealing, mixing in a vortex mode, and mixing uniformly to obtain a blank reference substance solution.
Preparation of a test solution: accurately weighing a sample, taking 0.3g (accurate to 0.0001g), adding the sample into a 20.0mL headspace bottle filled with 4.0g of sodium chloride (cooled after being burned at 500 ℃ for 4 hours) and 10.0mL of water, injecting 100ng of fluorobenzene serving as an internal standard substance, sealing, and uniformly mixing on a vortex mixer to obtain a sample solution.
And (3) determination: under the chromatographic conditions, the standard reference solution, the blank reference solution and the test solution are respectively processed by 1.0 mu m to determine the relative retention time and the characteristic ion, and the ratio of the target peak area to the internal standard substance peak area is used for quantification.
The beneficial effects of the present invention are further illustrated by the following specific experimental examples:
1. examination of sodium chloride addition
0.5g (to the nearest 0.0001g) of sulfuric acid was weighed accurately and added to a 20.0mL headspace bottle containing 4.0g of sodium chloride (cooled after 4 hours at 500 ℃) and 10.0mL of water. It was found that the recovery was highest when the amount of sodium chloride added was 4.0 g. The experimental data are shown in the following table:
| adding sodium chloride (g) | 1.0 | 2.0 | 3.0 | 4.0 | 5.0 | 6.0 |
| Recovery (%) | 72.6 | 79.3 | 85.4 | 90.8 | 88.6 | 87.5 |
2. Methodological validation results
The preparation method of the test solution can be optimized as follows: 200ng of fluorobenzene was injected as an internal standard. The curve is established by an internal standard method, the curve of the method is y which is 0.0651x +4.3940, the correlation coefficient is 0.9999, the linear relation of methyl chloride in the range of 20-400ng is good, the standard adding recovery rate of the method is 91.3% when the standard adding amount is 100ng, 7 standard adding samples with 80ng concentration are made, and the results are as follows:
as a result, the S/N ratio was 81.9 at a sample content of 20ng, and the detection limit of this method calculated from this was 0.73 ng.
Although the invention has been described in detail with respect to the specific embodiments illustrated in the general description, it will be apparent to those skilled in the art that modifications and improvements can be made thereto without departing from the spirit of the invention.
Claims (10)
1. A method for detecting methyl chloride in sulfuric acid is characterized by comprising the following steps: 1) preparing a standard reference substance solution; 2) preparing a test solution; 3) preparation of blank control solution: 4) gas chromatography-mass spectrometry conditions and system adaptability test: 5) and (4) measuring.
2. The detection method according to claim 1, wherein the step 1) of preparing the standard control solution comprises: accurately measuring 10.0 mu L of methyl chloride in methanol, adding into a headspace bottle filled with 4.0g of sodium chloride and 10.0mL of water, injecting 200ng of fluorobenzene as an internal standard substance, sealing, and uniformly mixing on a vortex mixer to obtain a reference substance solution.
3. The detection method according to claim 1, wherein the step 2) of preparing the test solution comprises: accurately weighing 0.5g of sulfuric acid, adding the sulfuric acid into a headspace bottle filled with 4.0g of sodium chloride and 10.0mL of water, injecting 200ng of fluorobenzene serving as an internal standard substance, sealing, and uniformly mixing on a vortex mixer to obtain a test solution.
4. The detection method according to claim 1, wherein the step 3) of preparing the blank control solution comprises: weighing 4.0g of sodium chloride and 10.0mL of water, adding the sodium chloride and the water into a 20.0mL headspace bottle, injecting 200ng of fluorobenzene as an internal standard substance, sealing, and uniformly mixing on a vortex mixer to obtain a blank reference substance solution.
5. The detection method according to claim 1, wherein the step 4) of gas chromatography-mass spectrometry condition and system adaptability test comprises:
(1) the chromatographic column is a quartz capillary column with the length of 30m, the inner diameter of 0.25mm and the film thickness of 1.4 mu m, and the stationary phase is 6 percent cyanopropylphenyl/94 percent dimethylpolysiloxane, and other equivalent capillary columns can also be used;
(2) chromatographic conditions are as follows:
conditions of the headspace sampler: carrier gas pressure: 120 KPa; the balance time is 40 min; equilibrium temperature: 60 ℃; pressure-displacement time: 150 s; sample introduction time: 6 s; transmission line temperature: 80 ℃; needle temperature: 100 ℃;
temperature programming: keeping the initial temperature at 35 deg.C for 5min, and raising the temperature to 150 deg.C at 5 deg.C/min; sample inlet temperature: 180 ℃; and (3) sample introduction mode: split-flow sample introduction, split-flow ratio: 10: 1; carrier gas: helium gas;
(3) mass spectrum conditions: C. an ionization mode: EI; transmission line temperature: 230 ℃; ion source temperature: 200 ℃; electron acceleration voltage: 70 eV; the detection mode is as follows: scan method, SIM method; and (3) quantifying ions: 50; auxiliary ions: 52.
6. the detection method according to claim 1, wherein the step 5) assay is specifically: under the chromatographic condition, respectively adding 1.0mL of standard reference substance solution, blank reference substance solution and test solution; and (5) performing qualitative determination by using the relative retention time and the characteristic ions, and performing quantitative determination by using the ratio of the area of the target peak to the area of the peak of the internal standard substance, and calculating to obtain the target ion.
7. The detection method according to any one of claims 2 to 4, wherein the sodium chloride is used after being cooled after being calcined at 500 ℃ for 4 hours.
8. The detection method according to claim 2, wherein the concentration of methyl chloride in methanol is 2000 mg/L.
9. The detection method according to claim 5, wherein the chromatographic column can also be used as other equivalent capillary columns.
10. The detection method according to claim 5, wherein the (2) chromatographic condition headspace sampler is a constant pressure sample injection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010971257.7A CN112067721A (en) | 2020-09-16 | 2020-09-16 | Method for detecting chloromethane in sulfuric acid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010971257.7A CN112067721A (en) | 2020-09-16 | 2020-09-16 | Method for detecting chloromethane in sulfuric acid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112067721A true CN112067721A (en) | 2020-12-11 |
Family
ID=73695958
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010971257.7A Pending CN112067721A (en) | 2020-09-16 | 2020-09-16 | Method for detecting chloromethane in sulfuric acid |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112067721A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011011627A1 (en) * | 2009-07-22 | 2011-01-27 | The Regents Of The University Of California | Cell-based systems for production of methyl formate |
| CN103487519A (en) * | 2013-09-05 | 2014-01-01 | 上海新亚药业有限公司 | Method for detecting multiple residual solvents in medicament |
| CN105911207A (en) * | 2016-06-25 | 2016-08-31 | 江苏正大清江制药有限公司 | Method for determining chloromethane and chloroethane in chitosamine hydrochloride |
-
2020
- 2020-09-16 CN CN202010971257.7A patent/CN112067721A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011011627A1 (en) * | 2009-07-22 | 2011-01-27 | The Regents Of The University Of California | Cell-based systems for production of methyl formate |
| CN103487519A (en) * | 2013-09-05 | 2014-01-01 | 上海新亚药业有限公司 | Method for detecting multiple residual solvents in medicament |
| CN105911207A (en) * | 2016-06-25 | 2016-08-31 | 江苏正大清江制药有限公司 | Method for determining chloromethane and chloroethane in chitosamine hydrochloride |
Non-Patent Citations (4)
| Title |
|---|
| JI-YOUNG LEE 等: "Rapid determination of volatile organic compounds in human whole blood using static headspace sampling with gas chromatography and mass spectrometry", 《BULL. KOREAN CHEM. SOC.》 * |
| 梁鹏山 等: "气相色谱/质谱法分析挥发性有机物的内标物优化选择", 《中国给水排水》 * |
| 胡恩宇 等: "顶空－气相色谱-质谱法测定地表水和废水中55种挥发性有机物含量", 《理化检验（化学分册）》 * |
| 颜焱 等: "顶空/气相色谱-质谱法测定固废浸出液中的挥发性卤代烃", 《黑龙江环境通报》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111289676B (en) | Method for detecting residual tert-butylamine in terbutaline sulfate bulk drug | |
| CN110031557B (en) | Method for detecting 5-isoquinoline methyl sulfonate and 5-isoquinoline ethyl sulfonate in fasudil hydrochloride | |
| CN113295805B (en) | Method for detecting hydrazine hydrate in medicine | |
| CN106814144B (en) | Method for determining and analyzing content of dimethyl sulfate in dimethyl fumarate | |
| CN114778743B (en) | Detection method of trace chiral isomer D-proline in L-proline | |
| CN109425666B (en) | LC-MS analysis method of acyl chloride derivative | |
| CN112067721A (en) | Method for detecting chloromethane in sulfuric acid | |
| CN113109473B (en) | Formaldehyde derivatization test method | |
| CN112710762B (en) | Method for measuring residual quantity of dimethyl sulfate | |
| CN108982706B (en) | Method for detecting impurity cis-perhydroisoindole in mitiglinide calcium | |
| CN112782301A (en) | Method for accurately and quantitatively determining content of genotoxic impurity nitrite in medicine | |
| CN111024872A (en) | Method for rapidly detecting 3-methylthio propanol in sesame-flavor liquor | |
| CN113252809B (en) | Method for detecting residues of methyl trifluoromethanesulfonate and ethyl trifluoromethanesulfonate | |
| CN114594193B (en) | Liquid phase detection method for detecting p-chlorobenzoyl chloride | |
| CN114755320B (en) | Detection method of 3-amino-6-methoxypyridazine related substances | |
| CN118258925A (en) | Method for detecting 2-chloroethyl sodium sulfonate in medicine | |
| CN117554549A (en) | Method for simultaneously detecting dyclonine hydrochloride residual formic acid and acetic acid | |
| CN116699024A (en) | Method for analyzing lithocholic acid quality | |
| CN115015457A (en) | Method for analyzing bromoacetic acid impurities in serapager by high performance liquid chromatography | |
| CN117825567A (en) | HPLC-MS/MS method, kit and application for detecting Carfilzomib content in blood plasma | |
| CN117825573A (en) | Method for detecting content of hydroxylamine hydrochloride in bulk drug and application | |
| CN116068101A (en) | Method for quantitatively analyzing dimethyl sulfate content by derivatization method | |
| CN116183758A (en) | Analysis method for isomer impurities in diethyl indenamine hydrochloride | |
| CN118483344A (en) | Liquid chromatography detection method for trace acetic anhydride in glacial acetic acid | |
| CN117491548A (en) | Detection method of dyclonine hydrochloride related substances |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20201211 |
|
| RJ01 | Rejection of invention patent application after publication |