Detection method of dimethyl ketene and application thereof

Abstract

The invention provides a detection method of dimethyl ketene and application thereof, and the detection method comprises the following steps: mixing a sample to be detected with a compound A for reaction to obtain a reaction solution containing a product B, then performing gas chromatography detection on the reaction solution, and calculating the content of the product B according to a standard curve, and calculating the content of the dimethyl ketene in the sample to be detected. The compound A is a compound containing reactive hydrogen. The method provided by the invention can be used for detecting the dimethyl ketene at normal temperature and normal pressure, the detection speed is high, the accuracy is high, the whole method is simple to operate, and the method is conveniently used for product quality control in the production process.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical analysis, and specifically relates to a detection method of dimethyl ketone and an application thereof, and in particular to a detection method of dimethyl ketone with high accuracy and an application thereof. Background Art

[0002] Dimethyl ketone (DMK) is the most critical intermediate in the preparation of tetramethylcyclobutanediol (CBDO). Thermal cracking with isobutyric anhydride (ANIB) or isobutyric acid (AIB) is the main method for preparing dimethyl ketone (DMK). DMK is a light yellow liquid at room temperature with a boiling point of about 34°C. It is extremely active and has a highly unsaturated molecular structure. It is difficult to store stably at room temperature and pressure, so it is difficult to achieve high-accuracy and high-efficiency quantitative analysis of DMK.

[0003] CN112174797B discloses a highly efficient separation method of dimethyl ketene, comprising: isobutyric anhydride and carrier gas are preheated and then enter a cracking reactor for reaction, and the gas phase cracking product is discharged and mixed with a low temperature inert gas; the mixed gas enters a heat exchanger for condensation, the residence time of the mixed gas in the heat exchanger is 0.01-1.0s, and the temperature of the mixed gas out of the heat exchanger is 20-70°C; the mixed gas enters a gas-liquid cyclone separator; the liquid phase product obtained by separation is collected; the separated gas phase product enters an absorption tower to recover dimethyl ketene. CN117342934A discloses a method and device for preparing dimethyl ketene by a two-stage thermal cracking coupling technology, comprising the following steps: (1) thermally cracking acetic acid to generate ketene; (2) absorbing the obtained ketene with isobutyric acid to generate isobutyric anhydride and acetic acid; (3) thermally cracking the obtained isobutyric anhydride to generate dimethyl ketene. The acetic acid generated in step (2) is returned to step (1), and the isobutyric acid generated in the thermal cracking process of step (3) is returned to step (2). CN112079700B discloses a method for preparing dimethyl ketone with isobutyric anhydride as raw material and quickly separating the product, comprising: isobutyric anhydride and a carrier are preheated and then enter a cracking reactor to react, and the gaseous product directly enters a gas-liquid cyclone separator with a heat exchange jacket from the cracking reactor; the liquid product obtained by separation is collected; and the gaseous product obtained by separation enters an absorption tower to recover dimethyl ketone. However, none of the above methods provide a clear method for detecting dimethyl ketone at normal temperature and pressure.

[0004] Therefore, developing an accurate and reliable quantitative analysis method for dimethyl ketone is of great significance for product quality control in the production process. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a detection method for dimethyl ketone and its application, in particular to provide a detection method for dimethyl ketone with high accuracy and its application. The method provided by the present invention can realize the detection of dimethyl ketone at room temperature and pressure, with fast detection speed and high accuracy. The overall method is simple to operate and is convenient for product quality control in the production process.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In one aspect, the present invention provides a method for detecting dimethyl ketone, the detection method comprising the following steps:

[0008] The sample to be tested is mixed with compound A to react to obtain a reaction solution containing product B, and then the reaction solution is subjected to gas chromatography detection, and the content of product B is calculated according to the standard curve, and then the content of dimethyl ketene in the sample to be tested is calculated;

[0009] The compound A is a compound containing active hydrogen.

[0010] The above method utilizes a compound containing active hydrogen to convert unstable dimethyl ketone into a relatively stable product, and further detects the content of dimethyl ketone in the sample to be tested by detecting the content of the product. It can realize the effective detection of the content of dimethyl ketone under normal temperature and differential pressure, and provides an effective method for product quality control in the production process.

[0011] In the above reaction, compound A can be used only as a reactant, or can be used as both a reactant and a solvent for product B, which can effectively reduce the complexity of the operation and the use of reagents.

[0012] Preferably, the compound A comprises an aliphatic amine or an aromatic amine.

[0013] The compound A can effectively react with dimethyl ketene in the sample to be tested to generate a stable product, and the reaction is rapid with few side reactions, which can effectively improve the accuracy of the detection.

[0014] Preferably, the aliphatic amine is an aliphatic monoamine, an aliphatic diamine or an aliphatic polyamine containing at least one primary amine group.

[0015] Preferably, the aromatic amine is an aromatic monoamine, aromatic diamine or aromatic polyamine containing at least one primary amine group.

[0016] Preferably, the aliphatic amine includes any one of n-propylamine, n-pentylamine, n-hexylamine, isopropylamine, ethylenediamine or 1,3-propylenediamine.

[0017] Preferably, the aromatic amine is any one of aniline, benzylamine, phenethylamine, amphetamine, p-methylaniline or p-phenylenediamine.

[0018] The above-mentioned specific compound A can further improve the accuracy of detection, effectively shorten the reaction time (minimum only 10 minutes), and can obtain a product that can effectively cooperate with subsequent gas phase detection.

[0019] Preferably, the reaction equation is as follows:

[0020]

[0021] Wherein, DMK is dimethyl ethylene ketone, a is the stoichiometric number of dimethyl ethylene ketone, b is the stoichiometric number of compound A, and c is the stoichiometric number of product B;

[0022] Preferably, the calculation formula for the content of dimethyl ketene is as follows:

[0023]

[0024] In the formula, C DMK is the mass concentration of dimethyl ketone, m DMK is the mass of the sample to be tested, m A is the mass of compound A, C B is the mass concentration of product B, Mr B is the relative molecular mass of product B, Mr DMK is the relative molecular mass of dimethyl ketone.

[0025] Preferably, the reaction temperature is 0-40°C and the reaction time is at least 10 min, wherein the temperature can be 0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C or 40°C, etc., but is not limited to the values ​​listed above, and other values ​​not listed within the above numerical range are also applicable.

[0026] Preferably, the chromatographic column model for gas chromatography detection is DB-624.

[0027] Preferably, the temperature rise program for gas chromatography detection is as follows:

[0028] The initial temperature of 45-55°C was maintained for 1.8-2.2 min, then increased to 220-240°C at 8-12°C / min and maintained for 2.5-5 min.

[0029] The above-mentioned specific chromatographic column and temperature program can effectively improve the accuracy of detection.

[0030] On the other hand, the present invention also provides the use of the above-mentioned detection method of dimethyl ketene in the preparation of tetramethylcyclobutanediol.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention provides a method for detecting dimethyl ketone, which utilizes a compound containing active hydrogen to convert unstable dimethyl ketone into a relatively stable product, and further detects the content of dimethyl ketone in a sample to be tested by detecting the content of the product. The method can realize effective detection of the content of dimethyl ketone under normal temperature and differential pressure, and provides an effective method for product quality control in a production process. DETAILED DESCRIPTION

[0033] In order to further explain the technical means and effects adopted by the present invention, the technical solution of the present invention is further described below in conjunction with the preferred embodiments of the present invention, but the present invention is not limited to the scope of the embodiments.

[0034] Example 1

[0035] This embodiment provides a method for detecting dimethyl ketone, and the reaction equation is as follows:

[0036]

[0037] The specific steps are as follows:

[0038] Prepare aniline solutions with N-phenylisobutyramide mass fractions of 0.5%, 1%, 2.5%, and 5%, respectively, perform gas chromatography analysis on the standard solutions, and establish a standard curve for N-phenylisobutyramide. Take 1.0g of the newly prepared ethyl acetate solution with a mass fraction of 5% DMK and add it to 4.0g of aniline. After shaking well, let it stand for 10 minutes, and perform quantitative analysis on the solution using a gas chromatograph. The gas chromatography detection conditions are as follows:

[0039] The gas chromatograph model was Agilent 8890, and the capillary column model was DB-624; the injection port temperature was 250°C, the detector temperature was 250°C, and the column temperature was programmed: 50°C for 2 min, then increased to 230°C at 10°C / min, and maintained at 230°C for 3 min.

[0040] It was determined that the mass concentration of N-phenylisobutyramide (the product was identified by GC-MS) in the obtained solution was 2.34%.

[0041] According to the concentration of N-phenylisobutyramide, the concentration of the newly prepared DMK solution was calculated, and the DMK mass concentration C DMK The calculation formula is as follows:

[0042]

[0043] The calculated concentration of the newly prepared DMK solution was 5.02%, which was consistent with the prepared DMK concentration.

[0044] Example 2

[0045] This embodiment provides a method for detecting dimethyl ketone, and the reaction equation is as follows:

[0046]

[0047] Prepare benzylamine solutions with mass fractions of 0.5%, 1%, 2.5%, and 5% of N-benzylisobutylamide, analyze the standard solutions by gas chromatography, and establish a standard curve of N-benzylisobutylamide. Take 1.0g of the newly prepared ethyl acetate solution with a mass fraction of 5% of DMK and add it to 4.0g of benzylamine. After shaking well, let it stand for 10 minutes. Use gas chromatograph to quantitatively analyze the solution. The gas chromatography detection conditions are as follows:

[0048] The gas chromatograph model was Agilent 8890, and the capillary column model was DB-624; the injection port temperature was 250°C, the detector temperature was 250°C, and the column temperature was programmed: 50°C for 2 min, then increased to 230°C at 10°C / min, and maintained at 230°C for 3 min.

[0049] It was determined that the mass concentration of N-benzylisobutylamide (the product was identified by GC-MS) in the obtained solution was 2.52%.

[0050] According to the concentration of N-benzyl isobutylamide, the concentration of the newly prepared DMK solution was calculated, and the DMK mass concentration C DMK The calculation formula is as follows:

[0051]

[0052] The calculated concentration of the newly prepared DMK solution was 4.98%, which was consistent with the prepared DMK concentration.

[0053] Example 3

[0054] This embodiment provides a method for detecting dimethyl ketone, and the reaction equation is as follows:

[0055]

[0056] Prepare 0.5%, 1%, 2.5%, and 5% phenylethylamine solutions of N-phenylethylisobutyramide mass fraction, respectively, analyze the standard solutions by gas chromatography, and establish a standard curve of N-phenylethylisobutyramide. Take 1.0g of the newly prepared 5% DMK mass fraction ethyl acetate solution and add it to 4.0g phenylethylamine, shake it thoroughly and let it stand for 10 minutes, and use a gas chromatograph to quantitatively analyze the solution. The gas chromatography detection conditions are as follows:

[0057] The gas chromatograph model was Agilent 8890, and the capillary column model was DB-624; the injection port temperature was 250°C, the detector temperature was 250°C, and the column temperature was programmed: 50°C for 2 min, then increased to 230°C at 10°C / min, and maintained at 230°C for 3 min.

[0058] It was determined that the mass concentration of N-phenethyl isobutyramide (the product was identified by GC-MS) in the obtained solution was 2.73%.

[0059] According to the concentration of N-phenylethyl isobutylamide, the concentration of the newly prepared DMK solution was calculated, and the DMK mass concentration C DMK The calculation formula is as follows:

[0060]

[0061] After calculation, the concentration of the newly prepared DMK solution was 5.00%, which was consistent with the prepared DMK concentration.

[0062] Example 4

[0063] This embodiment provides a method for detecting dimethyl ketone, and the reaction equation is as follows:

[0064]

[0065] The specific steps are as follows:

[0066] Prepare isopropylamine solutions with mass fractions of 0.5%, 1%, 2.5%, and 5% of N-isopropyl isobutylamide, analyze the standard solutions by gas chromatography, and establish a standard curve for N-isopropyl isobutylamide. Take 1.0g of the newly prepared ethyl acetate solution with a mass fraction of 5% of DMK and add it to 4.0g of isopropylamine. After shaking well, let it stand for 10 minutes. Use gas chromatograph to quantitatively analyze the solution. The gas chromatography detection conditions are as follows:

[0067] The gas chromatograph model was Agilent 8890, and the capillary column model was DB-624; the injection port temperature was 250°C, the detector temperature was 250°C, and the column temperature was programmed: 50°C for 2 min, then increased to 230°C at 10°C / min, and maintained at 230°C for 3 min.

[0068] It was determined that the mass concentration of N-isopropylisobutyramide (the product was identified by GC-MS) in the obtained solution was 1.84%.

[0069] According to the concentration of N-isopropyl isobutylamide, the concentration of the newly prepared DMK solution was calculated, and the DMK mass concentration C DMK The calculation formula is as follows:

[0070]

[0071] The calculated concentration of the newly prepared DMK solution was 5.02%, which was consistent with the prepared DMK concentration.

[0072] Example 5

[0073] This embodiment provides a method for detecting dimethyl ketone, and the reaction equation is as follows:

[0074]

[0075] Prepare ethylenediamine solutions with mass fractions of 0.5%, 1%, 2.5%, and 5% of N,N'-diisobutyrylethylenediamine, respectively, analyze the standard solutions by gas chromatography, and establish a standard curve for N,N'-diisobutyrylethylenediamine. Take 1.0g of the newly prepared ethyl acetate solution with a mass fraction of 5% DMK and add it to 4.0g of ethylenediamine. After shaking well, let it stand for 10 minutes, and use a gas chromatograph to quantitatively analyze the solution. The gas chromatography detection conditions are as follows:

[0076] The gas chromatograph model was Agilent 8890, and the capillary column model was DB-624; the injection port temperature was 250°C, the detector temperature was 250°C, and the column temperature was programmed: 50°C for 2 min, then increased to 230°C at 10°C / min, and maintained at 230°C for 3 min.

[0077] It was determined that the mass concentration of N,N'-diisobutyrylethylenediamine (the product was identified by GC-MS) in the obtained solution was 1.43%.

[0078] According to the concentration of N,N'-diisobutyrylethylenediamine, the concentration of the newly prepared DMK solution was calculated, and the DMK mass concentration C DMK The calculation formula is as follows:

[0079]

[0080] After calculation, the concentration of the newly prepared DMK solution was 5.00%, which was consistent with the prepared DMK concentration.

[0081] Example 6

[0082] This embodiment provides a method for detecting dimethyl ketone, and the reaction equation is as follows:

[0083]

[0084] The specific steps are as follows:

[0085] Prepare 1,3-propylenediamine solutions with mass fractions of 0.5%, 1%, 2.5%, and 5% of N,N'-diisobutyryl-1,3-propylenediamine, respectively, analyze the standard solutions by gas chromatography, and establish a standard curve for N,N'-diisobutyryl-1,3-propylenediamine. Take 1.0g of the newly prepared ethyl acetate solution with a mass fraction of 5% DMK and add it to 4.0g of 1,3-propylenediamine, shake it thoroughly and let it stand for 10 minutes, and use a gas chromatograph to quantitatively analyze the solution. The gas chromatography detection conditions are as follows:

[0086] The gas chromatograph model was Agilent 8890, and the capillary column model was DB-624; the injection port temperature was 250°C, the detector temperature was 250°C, and the column temperature was programmed: 50°C for 2 min, then increased to 230°C at 10°C / min, and maintained at 230°C for 3 min.

[0087] It was determined that the mass concentration of N,N'-diisobutyryl-1,3-propylenediamine (the product was identified by GC-MS) in the obtained solution was 1.53%.

[0088] According to the concentration of N,N'-diisobutyryl-1,3-propylenediamine, the concentration of the newly prepared DMK solution was calculated, and the DMK mass concentration CDMK The calculation formula is as follows:

[0089]

[0090] After calculation, the concentration of the newly prepared DMK solution was 5.00%, which was consistent with the prepared DMK concentration.

[0091] Example 7

[0092] This embodiment provides a method for detecting dimethyl ketone, and the reaction equation is as follows:

[0093]

[0094] Prepare diisopropylamine solutions with mass fractions of 0.5%, 1%, 2.5%, and 5% of N,N-diisopropylisobutyramide, analyze the standard solutions by gas chromatography, and establish a standard curve for N,N-diisopropylisobutyramide. Take 1.0g of the newly prepared ethyl acetate solution with a mass fraction of 5% DMK and add it to 4.0g of diisopropylamine. After shaking well, let it stand for 10 minutes. Use gas chromatograph to quantitatively analyze the solution. The gas chromatography detection conditions are as follows:

[0095] The gas chromatograph model was Agilent 8890, and the capillary column model was DB-624; the injection port temperature was 250°C, the detector temperature was 250°C, and the column temperature was programmed: 50°C for 2 min, then increased to 230°C at 10°C / min, and maintained at 230°C for 3 min.

[0096] It was determined that the mass concentration of N,N-diisopropylisobutyramide (the product was identified by GC-MS) in the obtained solution was 1.04%.

[0097] According to the concentration of N,N-diisopropylisobutyramide, the concentration of the newly prepared DMK solution was calculated, and the DMK mass concentration C DMK The calculation formula is as follows:

[0098]

[0099] After calculation, the concentration of the newly prepared DMK solution was 2.13%, which was quite different from the prepared DMK concentration.

[0100] Example 8

[0101] This embodiment provides a method for detecting dimethyl ketone, and the operating steps are as follows:

[0102] Take 1.0g of the newly prepared ethyl acetate solution with a mass fraction of 5% DMK and add it to 4.0g of triethylamine. After shaking thoroughly, let it stand for 10 minutes. The solution was analyzed by gas chromatography. The gas chromatography detection conditions are as follows:

[0103] The gas chromatograph model was Agilent 8890, and the capillary column model was DB-624; the injection port temperature was 250°C, the detector temperature was 250°C, and the column temperature was programmed: 50°C for 2 min, then increased to 230°C at 10°C / min, and maintained at 230°C for 3 min.

[0104] It was determined that only ethyl acetate and triethylamine peaks appeared in the gas phase test results, and no other compound peaks appeared.

[0105] Comparative Example 1

[0106] This comparative example provides a method for detecting dimethyl ketone, and the operating steps are as follows:

[0107] Take 1.0g of a newly prepared ethyl acetate solution with a DMK mass fraction of 5%, and analyze the solution using a gas chromatograph. The gas chromatographic detection conditions are as follows:

[0108] The gas chromatograph model was Agilent 8890, and the capillary column model was DB-624; the injection port temperature was 250°C, the detector temperature was 250°C, and the column temperature was programmed: 50°C for 2 min, then increased to 230°C at 10°C / min, and maintained at 230°C for 3 min.

[0109] After determination, only ethyl acetate peak appeared in the gas phase test results, and no other compound peaks appeared. This is because DMK itself is unstable and the chromatographic column used cannot detect DMK.

[0110] According to the above results, it can be found that the present invention can effectively detect the content of dimethyl ketone at room temperature and pressure difference by using a compound containing active hydrogen to convert unstable dimethyl ketone into a relatively stable product, and by detecting the content of the product, thereby avoiding the influence of the unstable characteristics of dimethyl ketone on the detection (Example 1, Comparative Example 1); at the same time, by comparing Examples 1-8, it can be found that the present invention can effectively react with dimethyl ketone in the sample to be tested to generate a stable product by using a specific compound A, the reaction is rapid, and there are few side reactions, which can effectively improve the accuracy of the detection, thereby improving the accuracy of the method.

[0111] Methodological investigation:

[0112] The operation of Example 1 was further repeated twice, and the analysis results of three groups of samples were as follows.

[0113]

[0114] The three groups of experimental results have excellent parallelism, indicating that this scheme can effectively realize the accurate detection of the content of dimethyl vinyl ketone at room temperature and pressure.

[0115] The applicant declares that the present invention illustrates the detection method and application of dimethyl ketene of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0116] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0117] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A method for detecting dimethyl ketone, characterized in that: The detection method comprises the following steps: The sample to be tested is mixed with compound A to react to obtain a reaction solution containing product B, and then the reaction solution is subjected to gas chromatography detection, and the content of product B is calculated according to the standard curve, and then the content of dimethyl ketene in the sample to be tested is calculated; The compound A is a compound containing active hydrogen.

2. The method for detecting dimethyl ketone according to claim 1, characterized in that: The compound A includes aliphatic amine or aromatic amine.

3. The method for detecting dimethyl ketone according to claim 2, characterized in that: The aliphatic amine is an aliphatic monoamine, aliphatic diamine or aliphatic polyamine containing at least one primary amine group; Preferably, the aromatic amine is an aromatic monoamine, aromatic diamine or aromatic polyamine containing at least one primary amine group.

4. The method for detecting dimethyl ketone according to claim 3, characterized in that: The aliphatic amine includes any one of n-propylamine, n-pentylamine, n-hexylamine, isopropylamine, ethylenediamine or 1,3-propylenediamine; Preferably, the aromatic amine is any one of aniline, benzylamine, phenethylamine, amphetamine, p-methylaniline or p-phenylenediamine.

5. The method for detecting dimethyl ketone according to any one of claims 1 to 4, characterized in that: The equation for the reaction is as follows: Wherein, DMK is dimethyl ethylene ketone, a is the stoichiometric number of dimethyl ethylene ketone, b is the stoichiometric number of compound A, and c is the stoichiometric number of product B; Preferably, the calculation formula for the content of dimethyl ketene is as follows: In the formula, C DMK is the mass concentration of dimethyl ketone, m DMK is the mass of the sample to be tested, m A is the mass of compound A, C B is the mass concentration of product B, Mr B is the relative molecular mass of product B, Mr DMK is the relative molecular mass of dimethyl ketone.

6. The method for detecting dimethyl ketone according to any one of claims 1 to 5, characterized in that: The reaction temperature is 0-40°C and the reaction time is at least 10 minutes.

7. The method for detecting dimethyl ketene according to any one of claims 1 to 6, characterized in that: The temperature rise program of the gas chromatography detection is as follows: The initial temperature of 45-55°C was maintained for 1.8-2.2 min, then increased to 220-240°C at 8-12°C / min and maintained for 2.5-5 min.

8. Use of the method for detecting dimethyl ketene according to any one of claims 1 to 7 in the preparation of tetramethylcyclobutanediol.

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