CN110568085B - Method for determining acetonitrile content in sample - Google Patents
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- CN110568085B CN110568085B CN201810567394.7A CN201810567394A CN110568085B CN 110568085 B CN110568085 B CN 110568085B CN 201810567394 A CN201810567394 A CN 201810567394A CN 110568085 B CN110568085 B CN 110568085B
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- WEVYAHXRMPXWCK-UHFFFAOYSA-N Acetonitrile Chemical compound CC#N WEVYAHXRMPXWCK-UHFFFAOYSA-N 0.000 title claims abstract description 213
- 238000000034 method Methods 0.000 title claims abstract description 40
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims abstract description 51
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 45
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims abstract description 45
- 239000012535 impurity Substances 0.000 claims abstract description 35
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 claims abstract description 34
- 229930195733 hydrocarbon Natural products 0.000 claims abstract description 34
- 150000002430 hydrocarbons Chemical class 0.000 claims abstract description 34
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 claims abstract description 30
- 238000000605 extraction Methods 0.000 claims abstract description 15
- 238000004817 gas chromatography Methods 0.000 claims abstract description 11
- 239000002904 solvent Substances 0.000 claims abstract description 9
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 claims description 34
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 24
- 239000004215 Carbon black (E152) Substances 0.000 claims description 19
- 239000012159 carrier gas Substances 0.000 claims description 19
- 230000005526 G1 to G0 transition Effects 0.000 claims description 17
- 229920003020 cross-linked polyethylene Polymers 0.000 claims description 17
- 239000004703 cross-linked polyethylene Substances 0.000 claims description 17
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 claims description 17
- KDKYADYSIPSCCQ-UHFFFAOYSA-N but-1-yne Chemical group CCC#C KDKYADYSIPSCCQ-UHFFFAOYSA-N 0.000 claims description 16
- 239000007789 gas Substances 0.000 claims description 15
- 238000004587 chromatography analysis Methods 0.000 claims description 13
- 238000012937 correction Methods 0.000 claims description 9
- NNPPMTNAJDCUHE-UHFFFAOYSA-N isobutane Chemical compound CC(C)C NNPPMTNAJDCUHE-UHFFFAOYSA-N 0.000 claims description 8
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 8
- 238000010812 external standard method Methods 0.000 claims description 7
- VQTUBCCKSQIDNK-UHFFFAOYSA-N Isobutene Chemical group CC(C)=C VQTUBCCKSQIDNK-UHFFFAOYSA-N 0.000 claims description 6
- WFYPICNXBKQZGB-UHFFFAOYSA-N butenyne Chemical group C=CC#C WFYPICNXBKQZGB-UHFFFAOYSA-N 0.000 claims description 6
- 238000011410 subtraction method Methods 0.000 claims description 6
- VXNZUUAINFGPBY-UHFFFAOYSA-N 1-Butene Chemical compound CCC=C VXNZUUAINFGPBY-UHFFFAOYSA-N 0.000 claims description 5
- 238000004458 analytical method Methods 0.000 claims description 5
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 claims description 5
- LVZWSLJZHVFIQJ-UHFFFAOYSA-N Cyclopropane Chemical compound C1CC1 LVZWSLJZHVFIQJ-UHFFFAOYSA-N 0.000 claims description 4
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 claims description 4
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 claims description 4
- QNRMTGGDHLBXQZ-UHFFFAOYSA-N buta-1,2-diene Chemical compound CC=C=C QNRMTGGDHLBXQZ-UHFFFAOYSA-N 0.000 claims description 4
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 claims description 4
- 239000001282 iso-butane Substances 0.000 claims description 4
- MWWATHDPGQKSAR-UHFFFAOYSA-N propyne Chemical group CC#C MWWATHDPGQKSAR-UHFFFAOYSA-N 0.000 claims description 4
- BBDKZWKEPDTENS-UHFFFAOYSA-N 4-Vinylcyclohexene Chemical compound C=CC1CCC=CC1 BBDKZWKEPDTENS-UHFFFAOYSA-N 0.000 claims description 3
- -1 ethylene, propylene, propane Chemical class 0.000 claims description 3
- 125000000383 tetramethylene group Chemical group [H]C([H])([*:1])C([H])([H])C([H])([H])C([H])([H])[*:2] 0.000 claims description 3
- 239000000539 dimer Substances 0.000 abstract description 15
- 239000000126 substance Substances 0.000 abstract description 8
- 238000001514 detection method Methods 0.000 abstract description 5
- 230000002349 favourable effect Effects 0.000 abstract description 5
- 238000004519 manufacturing process Methods 0.000 abstract description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 9
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 4
- 238000005520 cutting process Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 2
- 239000005977 Ethylene Substances 0.000 description 2
- IAQRGUVFOMOMEM-UHFFFAOYSA-N butene Natural products CC=CC IAQRGUVFOMOMEM-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000001294 propane Substances 0.000 description 2
- FVSKHRXBFJPNKK-UHFFFAOYSA-N propionitrile Chemical compound CCC#N FVSKHRXBFJPNKK-UHFFFAOYSA-N 0.000 description 2
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 2
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- OFOBLEOULBTSOW-UHFFFAOYSA-N Propanedioic acid Natural products OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 239000013043 chemical agent Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910052593 corundum Inorganic materials 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000010813 internal standard method Methods 0.000 description 1
- VZCYOOQTPOCHFL-UPHRSURJSA-N maleic acid Chemical compound OC(=O)\C=C/C(O)=O VZCYOOQTPOCHFL-UPHRSURJSA-N 0.000 description 1
- 239000011976 maleic acid Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000004451 qualitative analysis Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- VZCYOOQTPOCHFL-UHFFFAOYSA-N trans-butenedioic acid Natural products OC(=O)C=CC(O)=O VZCYOOQTPOCHFL-UHFFFAOYSA-N 0.000 description 1
- 229910001845 yogo sapphire Inorganic materials 0.000 description 1
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
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- 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)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention relates to the field of chemical detection, and discloses a method for determining the content of acetonitrile in a sample, wherein the sample contains organic impurities and acetonitrile, and the method comprises the following steps: the samples were analyzed by gas chromatography to determine the content of organic impurities including C1-C4 hydrocarbons, methanol, ethanol, isopropanol, acetone, and dimers, and acetonitrile was then calculated by differential subtraction. The method can accurately determine the acetonitrile content in a sample with low acetonitrile purity (particularly a circulating acetonitrile solvent in the butadiene production process by an acetonitrile extraction process), can monitor the content of each organic impurity in real time, and is favorable for the long-period, high-economical and stable operation of an extraction process device.
Description
Technical Field
The invention relates to the field of chemical detection, in particular to a method for determining the content of acetonitrile in a sample.
Background
Some domestic enterprises adopt acetonitrile extraction process to produce butadiene products, and the quality of the circulating acetonitrile solvent depends on whether the extraction process device can run stably with long period and high economy, and determines the control of the pressure difference of the extraction tower and the temperature of the distillation tower kettle. Therefore, the accurate determination of the purity of the circulating acetonitrile solvent and the content of main organic impurities is very important for improving the quality of the solvent in the process of producing butadiene products by extracting acetonitrile and ensuring the long-period, high-economical and stable operation of the device.
In the devices for producing butadiene from cracking C4 by various acetonitrile extraction processes in China at present, acetonitrile content detection methods are all enterprise self-set standards and are subtraction methods, namely acetonitrile purity is equal to 100% minus the content of moisture and dimers, other organic impurities are not detected, and the acetonitrile purity cannot be accurately detected. However, the industrial standard SHT-1627 "industrial acetonitrile purity and organic impurity measurement" method can measure the acetonitrile purity, but this method is only applicable to acetonitrile with a purity of 98 wt% or more, and the FFAP column used therein is a polar column, and cannot effectively separate C1-C4 hydrocarbons, and SHT-1627 measures only organic components such as acetone, acrylonitrile, propionitrile, and the like, and does not perform qualitative analysis on components such as methanol, ethanol, isopropanol, and the like, and therefore cannot measure acetonitrile with a purity of less than 98 wt%, and further cannot detect the contents of components such as C1-C4 hydrocarbons, methanol, ethanol, isopropanol, and the like dissolved in acetonitrile in detail.
Disclosure of Invention
The invention aims to overcome the defects that the method in the prior art is only suitable for acetonitrile with the purity of more than 98 weight percent, only measures organic components such as acetone, acrylonitrile, propionitrile and the like, and is not suitable for a detection method in the process of producing butadiene by an acetonitrile extraction process, and provides a method for measuring the content of acetonitrile in a sample.
In order to achieve the above object, the present invention provides a method for determining the content of acetonitrile in a sample containing organic impurities and acetonitrile (not limited to acetonitrile having a purity of 98 wt% or more), comprising: the samples were analyzed by gas chromatography to determine the content of organic impurities including C1-C4 hydrocarbons, methanol, ethanol, isopropanol, acetone, and dimers, and acetonitrile was then calculated by differential subtraction.
The method is very convenient and fast, so that the method can accurately determine the acetonitrile content in a sample with low acetonitrile purity (particularly a circulating acetonitrile solvent in the process of producing butadiene by an acetonitrile extraction process), monitor the content of various organic impurities (such as C1-C4 hydrocarbon, methanol, ethanol, isopropanol, acetone, dimer and the like) in real time, is favorable for finding and removing some harmful impurities (such as vinyl acetylene) in time, and is also favorable for stably operating an extraction process device with long period and high economy.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
Detailed Description
The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.
The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.
The invention provides a method for determining the content of acetonitrile in a sample, wherein the sample contains organic impurities and acetonitrile, and the method comprises the following steps: the samples were analyzed by gas chromatography to determine the content of organic impurities including C1-C4 hydrocarbons, methanol, ethanol, isopropanol, acetone, and dimers, and acetonitrile was then calculated by differential subtraction.
According to the invention, the subtraction method is a calculation method in which the contents of the respective organic impurities and water are subtracted from 100% by weight. Wherein, the content means a mass percentage calculated based on the total weight of the sample, i.e., wt%. The water content can be measured by various conventional methods, such as a karl fischer moisture meter.
According to the present invention, the source of the sample is not particularly limited as long as it is satisfied that organic impurities and acetonitrile are contained. The method of the present invention is particularly suitable for detecting samples with low acetonitrile content, preferably samples with acetonitrile content above 70 wt% (such as 70-95 wt%, 70-90 wt% or 70-85 wt% or 70-80 wt% or 70-75 wt%, etc.), more preferably samples with acetonitrile solvent circulating in the process of producing butadiene by acetonitrile extraction process (acetonitrile content is generally 70-95 wt%).
According to the present invention, the kind of C1-C4 hydrocarbon is not particularly limited, and may be various C1-C4 hydrocarbons commonly used in the art. Preferably, the C1-C4 hydrocarbon includes methane, ethane, ethylene, propylene, propane, cyclopropane, acetylene, isobutane, n-butane, butylene, n-butene, isobutylene, maleic, methylacetylene, 1, 2-butadiene, 1, 3-butadiene, vinylacetylene and ethylacetylene. Generally, the C1-C4 hydrocarbons may also include unknown hydrocarbons, i.e., hydrocarbons that have a very small content that have peaks in the measured gas chromatogram, but do not belong to the aforementioned class.
According to the present invention, preferably, the dimer is a dimer of butadiene, i.e., a dimer obtained by polymerization of two molecules of butadiene (i.e., 4-vinyl-1-cyclohexene). The weight average molecular weight is about 108.18.
The inventor of the present invention finds that all the organic impurities are organic impurities which may appear in a sample (especially in the process of producing butadiene by an acetonitrile extraction process), and the content of acetonitrile can be accurately obtained only by effectively performing gas chromatography analysis on the organic impurities, so that the present invention is favorable for timely finding and removing some harmful impurities (such as vinyl acetylene), and is favorable for stable operation of an extraction process device with long period and high economy.
According to the present invention, the method for determining the content of organic impurities is not particularly limited, and may be an external standard method or an internal standard method. Preferably, the method of determining the content of organic impurities is an external standard method. The external standard method is characterized in that a standard sample (namely pure substance) of a component to be detected (such as acetone) with known content is separately measured under the same chromatographic condition with a sample to be detected (such as an acetonitrile sample containing acetone impurities), the chromatographic peak area obtained by the standard sample is divided by the known content to obtain a correction factor, and the chromatographic peak area of the component to be detected in the sample to be detected is divided by the correction factor to obtain the content of the component to be detected in the sample to be detected.
According to the invention, for the part of unknown hydrocarbons with extremely small content, the correction factors of other hydrocarbons can be used to calculate the content of the unknown hydrocarbons. Preferably, the method further comprises: the unknown hydrocarbon content of the sample was calculated using the correction factor for C4 hydrocarbons. More preferably, the method further comprises: the content of unknown hydrocarbons in the sample was calculated using the correction factor for ethyl acetylene.
According to the present invention, in order to efficiently perform gas chromatography analysis of the content of each of the aforementioned organic impurities, the peaks of each of the impurities can be separated using a specific column. Preferably, the gas chromatographic analysis is carried out in the following manner: the samples were analyzed using a bonded cross-linked polyethylene glycol stationary phase (e.g., HP INNOWAX) column and a KCl-deactivated Alumina (e.g., GS-Alumina KCl) column, respectively. Wherein, the bonded cross-linked polyethylene glycol stationary phase chromatographic column is used for the gas chromatographic analysis of methanol, ethanol, isopropanol, acetone and dimer, and the KCl deactivated alumina chromatographic column is used for the gas chromatographic analysis of C1-C4 hydrocarbon.
When the bonded cross-linked polyethylene glycol stationary phase chromatographic column is used for gas chromatographic analysis, the split ratio can be (50-80): 1, preferably (55-65): 1. when a sample is subjected to gas chromatography analysis by using a KCl deactivated alumina chromatographic column, the split ratio can be (2-8): 1, preferably (4-6): 1.
according to the present invention, in order to obtain a better separation effect of methanol, ethanol, isopropanol, acetone and dimer in acetonitrile, the conditions of the chromatographic column (such as column length, column inner diameter, column temperature, carrier gas flow rate, etc.) can also be controlled. Preferably, the chromatographic conditions of the bonded cross-linked polyethylene glycol stationary phase chromatographic column comprise: the column length is 20-40m, the column inner diameter is 0.4-0.7mm, the constant temperature of 40-60 ℃ is 8-12min, then the temperature is increased to 220-240 ℃ at 15-25 ℃/min and is kept for 3-7min, and the flow rate of carrier gas is 2-4 mL/min. More preferably, the chromatographic conditions of the bonded cross-linked polyethylene glycol stationary phase chromatographic column comprise: the column length is 25-35m, the column inner diameter is 0.5-0.6mm, the temperature is kept at 45-55 ℃ for 9-11min, then the temperature is raised to 225-235 ℃ at 18-22 ℃/min and kept at the temperature for 4-6min, and the flow rate of the carrier gas is 2.5-3.5 mL/min.
According to the present invention, in order to obtain a better separation effect of the C1-C4 hydrocarbon in acetonitrile, the conditions of the chromatographic column (such as column length, column inner diameter, column temperature, carrier gas flow rate, etc.) can also be controlled. Preferably, the chromatographic conditions of the KCl-deactivated alumina chromatographic column comprise: the column length is 40-60m, the column inner diameter is 0.4-0.7mm, the temperature is kept constant at 30-45 ℃ for 3-7min, then the temperature is increased to 50-70 ℃ at 1-3 ℃/min, then the temperature is increased to 90-110 ℃ at 2-4 ℃/min, then the temperature is increased to 170-190 ℃ at 8-12 ℃/min, the temperature is kept constant for 5-9min, and the flow rate of carrier gas is 4-6 mL/min. More preferably, the chromatographic conditions of the KCl-deactivated alumina chromatographic column comprise: the column length is 45-55m, the column inner diameter is 0.5-0.6mm, the constant temperature of 35-45 ℃ is 4-6min, then the temperature is increased to 55-65 ℃ at 1.5-2 ℃/min, then the temperature is increased to 95-105 ℃ at 2-3 ℃/min, then the temperature is increased to 185 ℃ at 9-11 ℃/min, the constant temperature is 6-8min, and the flow rate of carrier gas is 4.5-5.5 mL/min.
The carrier gas may be any of various conventional inert gases, such as nitrogen and/or helium, among others.
In addition, when the KCl deactivated alumina chromatographic column is used for carrying out gas chromatographic analysis on C1-C4 hydrocarbon, in order to avoid the damage of acetonitrile to the KCl deactivated alumina chromatographic column, the bonded cross-linked polyethylene glycol stationary phase chromatographic column and the KCl deactivated alumina chromatographic column can be matched for carrying out gas chromatographic analysis on C1-C4 hydrocarbon. Specifically, a sample firstly flows through the bonded cross-linked polyethylene glycol stationary phase chromatographic column and then enters the KCl deactivated alumina chromatographic column, the bonded cross-linked polyethylene glycol stationary phase chromatographic column can be arranged above the KCl deactivated alumina chromatographic column, a valve capable of being opened and closed is arranged at the joint, and when C1-C4 hydrocarbon completely flows out of the bonded cross-linked polyethylene glycol stationary phase chromatographic column and enters the KCl deactivated alumina chromatographic column, valve cutting (valve closing) can be carried out. Preferably, the valve-cut time is 3.5-4.5min, more preferably 3.8-4.2 min. Wherein, the chromatographic conditions (the same as or different from the chromatographic conditions of the KCl deactivated alumina chromatographic column) when the bonded cross-linked polyethylene glycol stationary phase chromatographic column and the KCl deactivated alumina chromatographic column are matched for use can comprise: the column length is 40-60m, the column inner diameter is 0.4-0.7mm, the temperature is kept constant at 30-45 ℃ for 3-7min, then the temperature is increased to 50-70 ℃ at 1-3 ℃/min, then the temperature is increased to 90-110 ℃ at 2-4 ℃/min, then the temperature is increased to 170-190 ℃ at 8-12 ℃/min, the temperature is kept constant for 5-9min, and the flow rate of carrier gas is 4-6 mL/min. Preferably, the chromatographic conditions of the bonded cross-linked polyethylene glycol stationary phase chromatographic column and the KCl deactivated alumina chromatographic column in cooperative use comprise: the column length is 45-55m, the column inner diameter is 0.5-0.6mm, the constant temperature of 35-45 ℃ is 4-6min, then the temperature is increased to 55-65 ℃ at 1.5-2 ℃/min, then the temperature is increased to 95-105 ℃ at 2-3 ℃/min, then the temperature is increased to 185 ℃ at 9-11 ℃/min, the constant temperature is 6-8min, and the flow rate of carrier gas is 4.5-5.5 mL/min.
According to the present invention, the type of the detector is not particularly limited, and various detectors commonly used in the art may be used. Preferably, the detector in gas chromatography is a Flame Ion Detector (FID).
The present invention will be described in detail below by way of examples.
In the following examples, column 1 represents a HP INNOWAX column, and column 2 represents a column consisting of a HP INNOWAX column placed above a GS-Alumina KCl column; the sample 1 to be tested is a circulating acetonitrile solvent in the process of producing butadiene by using an acetonitrile extraction process of China petrochemical and land refining chemical division company; the water content of the sample 1 to be measured was measured to be 17.53 wt% by a Karl Fischer moisture meter.
Wherein, the standard gas prepared by pure substances of methane, ethane, ethylene, propane, cyclopropane, propylene, acetylene, isobutane, normal butane, butylene, normal butene, isobutene, maleic, methylacetylene, 1, 2-butadiene, 1, 3-butadiene, vinylacetylene, ethylacetylene and dimer is purchased from big even super gas company Limited, and the pure substances (chromatographic purity) of methanol, ethanol, isopropanol and acetone are purchased from national pharmaceutical group chemical agent company Limited; HP INNOWAX column (column length of 30m, inner diameter of 0.53mm) from Agilent technologies, GS-Alumina KCl column (column length of 50m, inner diameter of 0.53mm) from Agilent technologies, PLOT Al2O3the/S column (column length 50m, column inner diameter 0.53mm) was purchased from Agilent technologies, Inc., and the gas chromatograph was purchased from Agilent technologies, Inc., model 7890A. The acetonitrile content was calculated by subtracting the contents of organic impurities and water from 100 wt%.
Example 1
Adding 0.5 microliter of sample 1 to be tested into the column 1 for determination,controlling carrier gas N2The flow rate of (2) is 3mL/min, the split ratio is 60: 1, controlling the column temperature to be 50 ℃, keeping the temperature for 10min, and then raising the temperature to 230 ℃ at the speed of 20 ℃/min, and keeping the temperature for 5 min; then adding 1 microliter of sample 1 to be measured into the column 2 for measurement, and controlling the carrier gas N2The flow rate of (2) is 5mL/min, the split ratio is 5: 1, controlling the column temperature to be 40 ℃, keeping the temperature for 5min, then increasing the temperature to 60 ℃ at 2 ℃/min, then increasing the temperature to 100 ℃ at 3 ℃/min, then increasing the temperature to 180 ℃ at 10 ℃/min, keeping the temperature for 7min, and cutting the valve for 4 min.
Then according to an external standard method, methanol, ethanol, isopropanol, acetone and dimer with known contents are respectively added into the column 1 and are measured under the same chromatographic conditions as the previous step, C1-C4 hydrocarbon with known contents is respectively added into the column 2 and is measured under the same chromatographic conditions as the previous step, then the contents of all organic impurities are calculated, the content of unknown hydrocarbon is calculated by using a correction factor of ethyl acetylene, finally the content of acetonitrile is calculated by using a difference subtraction method, and the measured contents of acetonitrile, all organic impurities and water are shown in a table 1.
Example 2
Adding 0.5 μ L of sample 1 to be measured into column 1, and controlling carrier gas N2The flow rate of (2.5 mL/min), the split ratio of 60: 1, controlling the column temperature to be 45 ℃, keeping the temperature for 11min, and then raising the temperature to 225 ℃ at 18 ℃/min, and keeping the temperature for 4 min; then adding 1 microliter of sample 1 to be measured into the column 2 for measurement, and controlling the carrier gas N2The flow rate of (2) is 4.5mL/min, the split ratio is 5: 1, controlling the column temperature to be 35 ℃, keeping the temperature constant for 6min, then increasing the temperature to 65 ℃ at 2 ℃/min, then increasing the temperature to 105 ℃ at 3 ℃/min, then increasing the temperature to 185 ℃ at 11 ℃/min, keeping the temperature constant for 8min, and controlling the valve-cutting time to be 3.8 min.
Then according to an external standard method, respectively adding known contents of methanol, ethanol, isopropanol, acetone and dimer into a column 1, measuring under the same chromatographic conditions as the previous step, respectively adding the contained C1-C4 hydrocarbon into a column 2, measuring under the same chromatographic conditions as the previous step, calculating to obtain the content of each organic impurity, calculating the content of unknown hydrocarbon by using a correction factor of ethyl acetylene, and finally calculating to obtain the content of acetonitrile by using a difference subtraction method, wherein the measured contents of acetonitrile, each organic impurity and water are shown in a table 1.
Example 3
Adding 0.5 μ L of sample 1 to be measured into column 1, and controlling carrier gas N2The flow rate of (2) is 3.5mL/min, the split ratio is 60: 1, controlling the column temperature to be 55 ℃, keeping the temperature for 9min, and then raising the temperature to 235 ℃ at the speed of 22 ℃/min, and keeping the temperature for 6 min; then adding 1 microliter of sample 1 to be measured into the column 2 for measurement, and controlling the carrier gas N2The flow rate of (2) is 5.5mL/min, the split ratio is 5: 1, controlling the column temperature to be 45 ℃, keeping the temperature for 4min, then increasing the temperature to 55 ℃ at 1.5 ℃/min, then increasing the temperature to 95 ℃ at 2 ℃/min, then increasing the temperature to 175 ℃ at 9 ℃/min, keeping the temperature for 6min, and cutting the valve for 4.2 min.
Then according to an external standard method, respectively adding methanol, ethanol, isopropanol, acetone and dimer with known contents into a column 1, measuring under the same chromatographic conditions as the previous step, respectively adding C1-C4 hydrocarbon with known contents into a column 2, measuring under the same chromatographic conditions as the previous step, calculating the contents of all organic impurities, calculating the content of unknown hydrocarbon by using a correction factor of ethyl acetylene, and finally calculating the content of acetonitrile by using a difference subtraction method, wherein the measured contents of acetonitrile, all organic impurities and water are shown in a table 1.
TABLE 1
In table 1, ppm means parts per million, i.e. 1ppm means 1g of this substance per ton of sample.
Test example 1
A sample 2 to be tested with a known concentration is prepared, and the types and the contents of the components in the sample 2 to be tested are shown in the following table 2 (column of theoretical values).
The contents of acetonitrile, organic impurities and water in sample 2 to be tested were measured by the method of example 1, and the results are shown in Table 2.
TABLE 2
| Component/unit | Theoretical value | Example 1 |
| Methane/ppm | 8.67 | 8.5 |
| Ethane/ppm | 7.7 | 7.5 |
| Ethylene/ppm | 4.1 | 4.3 |
| Propane/ppm | 11.8 | 11.5 |
| Cyclopropane/ppm | 5.2 | 4.9 |
| Propylene/ppm | 5.26 | 5.1 |
| Acetylene per ppm | 6.08 | 6.4 |
| Isobutane/ppm | 4.79 | 4.9 |
| N-butane/ppm | 9.76 | 9.8 |
| Butene on ppm | 4.79 | 4.8 |
| N-butene/ppm | 9.95 | 10.3 |
| Isobutene/ppm | 8.12 | 8.4 |
| Maleic acid/ppm | 9.57 | 9.6 |
| Methylacetylene/ppm | 506.62 | 504.3 |
| 1, 2-butadiene/ppm | 6.08 | 5.6 |
| 1, 3-butadiene/ppm | 1562.36 | 1558.6 |
| Vinylacetylene/ppm | 4.93 | 5.1 |
| Ethyl acetylene/ppm | 10.3 | 11.0 |
| Water/weight% | 18.6 | 18.6 |
| Dimer/weight% | 0.297 | 0.292 |
| Acetone/weight% | 1.06 | 1.06 |
| Methanol/weight% | 0.03 | 0.02 |
| Isopropanol/weight% | 0.50 | 0.51 |
| Ethanol/weight% | 2.80 | 2.79 |
| Acetonitrile/weight% | 76.52 | 76.52 |
In table 2, ppm means parts per million, i.e. 1ppm means 1g of this substance per ton of sample.
As can be seen from the results of examples 1-3 and test example 1, the method of the present invention for determining the acetonitrile content in a sample has the advantages of accurate determination result, high repeatability and suitability for samples with low acetonitrile content. In addition, the inventor of the invention also uses the method of the invention to measure the acetonitrile content in the circulating acetonitrile solvent in the butadiene production process of other batches of acetonitrile extraction processes, and finds that the accurate detection can be conveniently and rapidly realized.
The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.
It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.
In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.
Claims (7)
1. A method for determining the amount of acetonitrile in a sample, the sample containing organic impurities and acetonitrile, the method comprising: performing gas chromatography analysis on a sample to determine the content of organic impurities, and calculating the content of acetonitrile by a differential subtraction method, wherein the sample is a circulating acetonitrile solvent in the process of producing butadiene by an acetonitrile extraction process, the organic impurities comprise C1-C4 hydrocarbon, methanol, ethanol, isopropanol, acetone and 4-vinyl-1-cyclohexene, and the content of the acetonitrile is 70-95 wt%; the gas chromatographic analysis mode is as follows: analyzing the sample by using a bonded cross-linked polyethylene glycol stationary phase chromatographic column and a KCl deactivated alumina chromatographic column respectively; the bonded cross-linked polyethylene glycol stationary phase chromatographic column is used for gas chromatographic analysis of methanol, ethanol, isopropanol, acetone and 4-vinyl-1-cyclohexene, and the KCl deactivated alumina chromatographic column is used for gas chromatographic analysis of C1-C4 hydrocarbon; the chromatographic conditions of the bonded cross-linked polyethylene glycol stationary phase chromatographic column comprise: the column length is 20-40m, the column inner diameter is 0.4-0.7mm, the constant temperature is kept for 8-12min at 40-60 ℃, then the temperature is increased to 220-240 ℃ at 15-25 ℃/min and is kept for 3-7min, and the flow rate of carrier gas is 2-4 mL/min; the chromatographic conditions of the KCl deactivated alumina chromatographic column comprise: the column length is 40-60m, the inner diameter of the column is 0.4-0.7mm, the temperature is kept constant at 30-45 ℃ for 3-7min, then the temperature is increased to 50-70 ℃ at 1-3 ℃/min, then the temperature is increased to 90-110 ℃ at 2-4 ℃/min, then the temperature is increased to 170-190 ℃ at 8-12 ℃/min, the temperature is kept constant for 5-9min, and the flow rate of carrier gas is 4-6 mL/min; the flow splitting ratio when the gas chromatographic analysis is carried out by using a bonded cross-linked polyethylene glycol stationary phase chromatographic column is 50-80: 1; the split ratio of a sample subjected to gas chromatography analysis by using a KCl deactivated alumina chromatographic column is 2-8: 1; the detector in the gas chromatographic analysis is a flame ion detector;
wherein the C1-C4 hydrocarbon includes methane, ethane, ethylene, propylene, propane, cyclopropane, acetylene, isobutane, n-butane, butylene, n-butene, isobutylene, maleic, methylacetylene, 1, 2-butadiene, 1, 3-butadiene, vinylacetylene, and ethylacetylene.
2. The method of claim 1, wherein the method of determining the content of organic impurities is external standard method.
3. The method according to claim 1 or 2, wherein the method further comprises: the unknown hydrocarbon content of the sample was calculated using the correction factor for C4 hydrocarbons.
4. The method of claim 1, wherein the chromatographic conditions of the bonded cross-linked polyethylene glycol stationary phase chromatographic column comprise: the column length is 25-35m, the column inner diameter is 0.5-0.6mm, the temperature is kept at 45-55 ℃ for 9-11min, then the temperature is raised to 225-235 ℃ at 18-22 ℃/min and kept at the temperature for 4-6min, and the flow rate of the carrier gas is 2.5-3.5 mL/min.
5. The method of claim 1, wherein the chromatographic conditions of the KCl-deactivated alumina chromatographic column comprise: the column length is 45-55m, the column inner diameter is 0.5-0.6mm, the constant temperature of 35-45 ℃ is 4-6min, then the temperature is increased to 55-65 ℃ at 1.5-2 ℃/min, then the temperature is increased to 95-105 ℃ at 2-3 ℃/min, then the temperature is increased to 185 ℃ at 9-11 ℃/min, the constant temperature is 6-8min, and the flow rate of carrier gas is 4.5-5.5 mL/min.
6. The method of claim 1, wherein the split ratio for gas chromatography using a bonded cross-linked polyethylene glycol stationary phase chromatography column is 55-65: 1.
7. the method of claim 1, wherein the sample is subjected to gas chromatography using a KCl deactivated alumina chromatography column at a split ratio of 4-6: 1.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102253142A (en) * | 2011-06-28 | 2011-11-23 | 太仓意发石化矿材检测有限公司 | Method for determining coexisting impurities and trace arenes in methanol simultaneously |
| CN103792297A (en) * | 2012-10-31 | 2014-05-14 | 上海市计算技术研究所 | Chromatography-mass spectrometry method for determining oxygen-containing compounds in complex olefin matrix |
| CN103965003A (en) * | 2013-01-30 | 2014-08-06 | 中国石油化工股份有限公司 | Production method of butadiene |
| CN105727951A (en) * | 2014-12-11 | 2016-07-06 | 中国石油天然气股份有限公司 | Selective hydrogenation catalyst and preparation method thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102005036039A1 (en) * | 2004-08-28 | 2006-03-02 | Oxeno Olefinchemie Gmbh | Process for the preparation of 2,7-octadienyl derivatives |
-
2018
- 2018-06-05 CN CN201810567394.7A patent/CN110568085B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102253142A (en) * | 2011-06-28 | 2011-11-23 | 太仓意发石化矿材检测有限公司 | Method for determining coexisting impurities and trace arenes in methanol simultaneously |
| CN103792297A (en) * | 2012-10-31 | 2014-05-14 | 上海市计算技术研究所 | Chromatography-mass spectrometry method for determining oxygen-containing compounds in complex olefin matrix |
| CN103965003A (en) * | 2013-01-30 | 2014-08-06 | 中国石油化工股份有限公司 | Production method of butadiene |
| CN105727951A (en) * | 2014-12-11 | 2016-07-06 | 中国石油天然气股份有限公司 | Selective hydrogenation catalyst and preparation method thereof |
Non-Patent Citations (5)
| Title |
|---|
| Gas chromatography of Titan"s atmosphere VII. Analysis of low molecular weight hydrocarbons and nitriles with cyanopropylphenyl dimethyl polysiloxane capillary columns;A.Aflalaye 等;《Journal of Chromatography A》;19961004;第746卷(第1期);第63-69页 * |
| Sampling and analysis of 1,3-butadiene in air by gas chromatography on a porous-layer open-tubular fused-silica column;Kimmo Peltonen 等;《Journal of Chromatography A》;19950825;第710卷(第1期);第237-241页 * |
| 乙腈抽提的丁二烯中微量乙腈的测定;吴克勤 等;《化学世界》;20031125;第11卷;第575-588页 * |
| 毛细管气相色谱法分析1,3-丁二烯中炔烃杂质含量;郑铁柱 等;《石油化工环境保护》;20000330(第1期);第61-64页 * |
| 气相色谱法分析丁烯-1中的微量杂质;韩守廷;《齐鲁石油化工》;19860630(第03期);第10-12页以及第41页 * |
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