A method for determining the content of ethylene amine reactor sample components by gas chromatography internal standard method

Abstract

The application discloses a method for determining the component content of ethylene amine reactor samples by a gas chromatography internal standard method, belongs to the technical field of detection and analysis, and particularly relates to adding accurately weighed to-be-detected samples into a certain amount of internal standard solution, mixing, obtaining a test solution, and then determining the content of each component of the ethylene amine reactor samples by the gas chromatography internal standard method. The method can quickly and accurately determine the component content of the ethylene amine reactor samples by gas chromatography analysis and internal standard method quantification, has high accuracy and precision, and improves production efficiency.

Description

Technical Field

[0001] This invention relates to the field of detection and analysis technology, and to a method for determining the component content of ethyleneamine reactor samples using gas chromatography with internal standard. Background Technology

[0002] Ethylene amines are important organic chemical raw materials. Ethylene amines and their secondary processed derivatives have wide applications in petroleum, pesticides, pharmaceuticals, textiles, papermaking, and metallurgy. In recent years, domestic demand for ethylene amines has steadily increased. In 2021, China's demand for ethylene amines reached 140,000 tons, a year-on-year increase of 11.7%; in 2022, China's demand for ethylene amines reached 160,000 tons, a year-on-year increase of 12.9%. Currently, China still relies on imports for some ethylene amine products. In China, polyethylene polyamines are mainly used in polyamide resins, epoxy curing agents, and lubricants. 60% of polyethylene polyamine products enter epoxy systems, primarily as modified curing agents and polyamide resins.

[0003] According to the "2023 Global and China Ethylene Amine Industry In-Depth Research Report" issued by the New Thinking Industry Research Center, the global ethylene amine market size is expected to grow from US$2.27 billion in 2023 to US$2.85 billion in 2028, with a compound annual growth rate of 4.66%. The increasing demand for ethylene amine from downstream applications such as resins, adhesives, papermaking, automobiles, water treatment, and pharmaceuticals is the main driver of this market growth.

[0004] Therefore, as the demand for ethylene amine continues to expand and various production facilities are established, the detection of ethylene amine samples will inevitably increase.

[0005] Therefore, it is necessary to develop a gas chromatography analysis method for ethylene amine samples to determine the content of various ethylene amines in the ethylene amine reactor, thereby providing a rapid and accurate detection method for the production of ethylene amine units. Summary of the Invention

[0006] The purpose of this invention is to solve the technical problems mentioned in the background art. The method of this invention has the characteristics of short analysis time, high accuracy and repeatability. The technical solution adopted is as follows:

[0007] Step 1: Establishing gas chromatography conditions.

[0008] The chromatographic column is a non-polar quartz capillary column, 100% dimethyl polysiloxane, with column dimensions of 30.0m × 0.53mm × 5μm;

[0009] The column oven uses a gradient heating mode, with temperatures ranging from 55℃ to 230℃.

[0010] Split injection was used with a split ratio of 10:1.

[0011] The injection port temperature is 250℃-350℃;

[0012] The flow rate of the carrier gas nitrogen is 2 mL / min to 7.5 mL / min;

[0013] The air flow rate is 400 mL / min, and the hydrogen flow rate is 30 mL / min;

[0014] A flame ionization detector (FID) was used, with a detector temperature of 260℃-330℃. Samples were injected for analysis after the baseline stabilized for 0.5 hours.

[0015] Step 2: Preparation of internal standard solution. The reagent 3-diethylamino-1-propylamine is prepared into an internal standard solution with a concentration of 0.010-0.015 g / mL using ethanol.

[0016] Step 3: Take one standard sample and one sample to be tested, add internal standard solution to obtain standard sample and sample solution. Take the standard sample and sample solution and inject them into the gas chromatograph. Separate the components of the sample solution through the chromatographic column and calculate the content of each component in the sample using the internal standard method.

[0017] Preferably: Take one part of standard sample and one part of sample to be tested, add internal standard solution to obtain standard sample and sample solution, take 0.2 to 1.5 μL of standard sample and sample solution respectively and inject them into gas chromatograph. Separate each component of the sample solution by chromatographic column and calculate the content of each component in the sample by internal standard method.

[0018] The gas chromatography conditions are set such that the column oven is in gradient temperature mode, with the temperature ranging from 50°C to 250°C.

[0019] The column temperature is preferably started at 55°C, and then increased in two stages at heating rates of 5°C / min and 25°C / min, respectively, before ending at 230°C.

[0020] Split injection was used with a split ratio of 10:1.

[0021] The injection port temperature is 250℃-350℃, preferably 280℃-330℃;

[0022] The injection volume is 0.2 μL to 1.5 μL, preferably 0.5 μL to 1.0 μL.

[0023] The gas chromatography conditions are set as follows: the flow rate of the carrier gas nitrogen is 2 mL / min to 7.5 mL / min, a constant flow rate, preferably 5.5 mL / min to 7.0 mL / min; the air flow rate is 400 mL / min; and the hydrogen flow rate is 30 mL / min.

[0024] The nitrogen gas has a purity greater than 99.999%; the hydrogen gas has a purity greater than 99.999%; and the air is purified air.

[0025] The detection operation uses a flame ionization detector (FID) with a detector temperature of 260℃-330℃, preferably 280℃-300℃. Samples are injected for analysis after the baseline has stabilized for 0.5 hours.

[0026] The aforementioned injection method employs an autosampler.

[0027] The detection method uses a gas chromatograph equipped with a flame ionization detector and a chromatographic data processing machine. The sensitivity and stability should meet the requirements of GB / T 9722.

[0028] Preparation of internal standard solution: Weigh 3-diethylamino-1-propylamine reagent and add ethanol to prepare an internal standard solution with a concentration not exceeding 0.015 g / mL.

[0029] Preparation of standard solutions: Accurately take reagents of each impurity component, dissolve them in a small amount of ethanol, and continue to add ethanol to about 10g to prepare standard solutions with a mass concentration of 0.1% to 35% for each impurity component.

[0030] Preparation of standard sample solution: Weigh 1g of the above standard solution and add 10mL of internal standard solution (concentration of 0.012g / mL) to prepare standard sample solution.

[0031] Preparation of sample solution: Take 1g of the ethyleneamine reactor sample and add 10mL of internal standard solution with a concentration of 0.012g / mL to prepare the sample solution.

[0032] Accurately pipette 0.2 μL to 1.5 μL of standard sample solution and test solution using an autosampler, inject them into the gas chromatograph, separate the components in the test solution through the chromatographic column, and calculate the content using the internal standard method.

[0033] The beneficial effects of this invention are:

[0034] This invention can effectively separate various impurity components in reactor samples. By selecting appropriate internal standards, the content of each impurity component is determined by gas-phase internal standard method. It has high accuracy, high precision, and good repeatability. It has advantages such as convenient and fast operation and is conducive to production control, and has good economic and social benefits. Attached Figure Description

[0035] Figure 1 This is the blank solvent chromatogram provided in Example 1 of the present invention;

[0036] Figure 2 This is the chromatogram of the standard sample solution provided in Example 2 of the present invention;

[0037] Figure 3 This is the chromatogram of the sample solution provided in Example 6 of the present invention. Detailed Implementation

[0038] To deepen understanding and mastery of the present invention, the method of the present invention will be further described in detail below with reference to embodiments. It should be noted that the specific embodiments described herein are only for illustration and explanation of the present invention and do not constitute a limitation on the scope of protection of the present invention. After reading this specification, those skilled in the art can make modifications to these embodiments without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments used are not specified, they are all conventional products that can be purchased commercially.

[0039] The gas chromatograph used in this embodiment of the invention is an Agilent 8890 gas chromatograph.

[0040] The internal standard solutions in the following embodiments are prepared by dissolving 3-diethylamino-1-propylamine in ethanol to a concentration of no more than 0.015 g / mL, with a preferred concentration of 0.012 g / mL.

[0041] Example 1

[0042] This embodiment examines the effectiveness of using Agilent DB-WAX and HP-1 chromatographic columns to determine the ethyleneamine reactor samples, specifically:

[0043] 1. Sample preparation

[0044] Accurately weigh 1g of the above standard solution and add 10mL of internal standard solution, with a concentration of 0.012g / mL.

[0045] 2. Chromatographic conditions

[0046] Gas chromatograph: Agilent 8890. Injector temperature: 300℃; Agilent gas chromatograph column model DB-WAX or HP-1, both with dimensions of 30.0m × 0.53mm × 5μm; column temperature: initial temperature 55℃, hold for 2 min, increase to 200℃ at 5℃ / min, hold for 0 min, then increase to 230℃ at 25℃ / min, hold for 13 min; FID detector, detector temperature 300℃; air: 400mL / min, carrier gas flow rate: 6.5mL / min, H2: 30mL / min, split ratio: 10:1.

[0047] 3. Testing Operation

[0048] Connect all parts of the instrument to the power supply. After the detector temperature reaches the set temperature, ignite it and allow it to stabilize for 0.5 hours. Once the baseline is stable, inject the sample for analysis. Use a pipette to draw the solution from step 1 into the sample vial, place it in the chromatograph's injection tray, and use the autosampler to draw 1.0 μL of the sample solution and inject it into the gas chromatograph.

[0049] The analysis results are as follows:

[0050] When using the DB-WAX column, there was no interference from the solvent peak, but 6 out of 23 components (excluding the internal standard) could not be effectively separated.

[0051] When using the HP-1 column, there is no interference from the solvent peak, and all 23 components can be effectively separated with good separation. Therefore, the internal standard method can be used to calculate the content of each component in this invention.

[0052] Example 2

[0053] This embodiment, based on Example 1, investigated the temperature of the chromatographic column, specifically as follows:

[0054] 1. Sample preparation

[0055] Accurately weigh 1g of the above standard solution and add it to 10mL of internal standard solution (concentration of 0.012g / mL).

[0056] 2. Chromatographic conditions

[0057] Gas chromatograph: Agilent 8890. Injector temperature: 300℃; Agilent HP-1 gas chromatograph column, dimensions: 30.0m × 0.53mm × 5μm, FID detector, detector temperature: 300℃; Air: 400mL / min, carrier gas flow rate: 6.5mL / min, H2: 30mL / min, split ratio: 10:1.

[0058] 3. Testing Operation

[0059] Connect all parts of the instrument to the power supply. After the detector temperature reaches the set temperature, ignite it and allow it to stabilize for 0.5 hours. Once the baseline is stable, inject the sample for analysis. Use a pipette to draw the solution from step 1 into the sample vial, place it in the chromatograph's injection tray, and use the autosampler to draw 1.0 μL of the sample solution and inject it into the gas chromatograph.

[0060] Because the boiling points of the components in the sample vary widely, and many are structurally similar or isomers, and considering that other high-boiling-point impurities will be generated during the process, the termination temperature is set to 230℃, which can remove most of the high-boiling-point impurities in the chromatographic column.

[0061] Apart from the termination temperature, the initial temperature, heating rate, and holding time at each temperature level are the key factors to consider.

[0062] The sample was initially heated to 50℃ and held for 2 min. Then, the temperature was increased to 200℃ at a rate of 6℃ / min and held for 0 min. Next, the temperature was increased to 230℃ at a rate of 25℃ / min and held for 13 min. Of the 23 components in the sample (excluding the internal standard), only 18 target peaks were observed, and 6 components could not be effectively separated.

[0063] The sample was initially heated to 60℃ and held for 10 min. Then, the temperature was increased to 160℃ at a rate of 4℃ / min and held for 1 min. Finally, the temperature was increased to 230℃ at a rate of 25℃ / min and held for 15 min. Of the 23 components in the sample (excluding the internal standard), 20 target peaks were observed, and 4 components could not be effectively separated.

[0064] The sample was initially heated to 55℃ and held for 2 min. Then, the temperature was increased to 200℃ at a rate of 5℃ / min and held for 0 min. Finally, the temperature was increased to 230℃ at a rate of 25℃ / min and held for 13 min. All 23 components (excluding the internal standard) in the sample were effectively separated.

[0065] The preferred column temperature is 55℃ initially, held for 2 min, increased to 200℃ at 5℃ / min, held for 0 min, then increased to 230℃ at 25℃ / min, and held for 13 min.

[0066] Example 3

[0067] Based on Examples 1 and 2, Example 3 investigated the concentrations of the internal standard (3-diethylamino-1-propylamine) used in the method of the present invention at 0.010 g / mL, 0.012 g / mL, and 0.015 g / mL. Specifically:

[0068] 1. Preparation of internal standard

[0069] Internal standard solution with a concentration of 0.010 g / mL: Accurately weigh 1 g of internal standard (3-diethylamino-1-propylamine), dissolve it in 50 mL of ethanol, and then dilute to 100 mL with ethanol.

[0070] Internal standard solution with a concentration of 0.012 g / mL: Accurately weigh 1.2 g of internal standard (3-diethylamino-1-propylamine), dissolve it in 50 mL of ethanol, and then dilute to 100 mL with ethanol.

[0071] Internal standard solution with a concentration of 0.015 g / mL: Accurately weigh 1.5 g of internal standard (3-diethylamino-1-propylamine), dissolve it in 50 mL of ethanol, and then dilute to 100 mL with ethanol.

[0072] 2. Sample preparation

[0073] Sample 1: Accurately weigh 1g of the above standard solution, add 10mL of internal standard solution with a concentration of 0.010g / mL, mix well and set aside.

[0074] Sample 2: Accurately weigh 1g of the above standard solution, add 10mL of internal standard solution with a concentration of 0.012g / mL, mix well and set aside.

[0075] Sample 3: Accurately weigh 1g of the above standard solution, add 10mL of internal standard solution with a concentration of 0.015g / mL, mix well and set aside.

[0076] 3. Chromatographic conditions

[0077] Gas chromatograph: Agilent 8890. Injector temperature: 300℃; Agilent gas chromatograph column model DB-WAX or HP-1, both with dimensions of 30.0m × 0.53mm × 5μm; column temperature: initial temperature 55℃, hold for 2 min, increase to 200℃ at 5℃ / min, hold for 0 min, then increase to 230℃ at 25℃ / min, hold for 13 min; FID detector, detector temperature 300℃; air: 400mL / min, carrier gas flow rate: 6.5mL / min, H2: 30mL / min, split ratio: 10:1.

[0078] 4. Testing Operation

[0079] Connect all parts of the instrument to the power supply. After the detector temperature reaches the set temperature, ignite it and allow it to stabilize for 0.5 hours. Once the baseline is stable, inject the sample for analysis. Use a pipette to aspirate the two solutions into three separate vials, place them in the chromatograph's injection tray, and use the autosampler to aspirate 1.0 μL of the sample solution and inject it into the gas chromatograph.

[0080] The analysis results are as follows:

[0081] When the concentration of the internal standard was 0.010 g / mL and 0.012 g / mL, the internal standard (3-diethylamino-1-propylamine) could be effectively separated from the hydroxyethyldiethylenetriamine in the sample.

[0082] When the concentration of the internal standard is 0.015 g / mL, the peak area of ​​the internal standard (3-diethylamino-1-propylamine) increases, causing it to overlap with the chromatographic peak of hydroxyethyldiethylenetriamine in the sample and making separation impossible.

[0083] Therefore, the concentration of the internal standard used in this invention is less than or equal to 0.015 g / mL.

[0084] Example 4

[0085] Based on Examples 1 and 2, Example 4 examines the reproducibility of the method of the present invention.

[0086] The same sample was selected and tested seven times within a short period of time using the same method under normal and correct operating conditions, by the same operator, in the same laboratory, using the same instrument.

[0087] Specifically as follows:

[0088] 1. Sample preparation

[0089] Accurately weigh 1g of the above standard solution and add it to 10mL of internal standard solution (concentration of 0.012g / mL).

[0090] 2. Chromatographic conditions

[0091] Gas chromatograph: Agilent 8890. Injector temperature: 300℃; Agilent HP-1 gas chromatograph column, dimensions: 30.0m × 0.53mm × 5μm; column temperature: initial temperature 55℃, hold for 2 min, increase to 200℃ at 5℃ / min, hold for 0 min, then increase to 230℃ at 25℃ / min, hold for 13 min; FID detector, detector temperature: 300℃; air: 400mL / min, carrier gas flow rate: 6.5mL / min, H2: 30mL / min, split ratio: 10:1.

[0092] 3. Testing Operation

[0093] Connect all parts of the instrument to the power supply. After the detector temperature reaches the set temperature, ignite it and allow it to stabilize for 0.5 hours. Once the baseline is stable, inject the sample for analysis. Use a pipette to draw the solution from step 1 into the sample vial, place it in the chromatograph's injection tray, and use the autosampler to draw 1.0 μL of the sample solution and inject it into the gas chromatograph.

[0094] The test results are shown in the table below.

[0095] Table 1 Reproducibility Test Results

[0096]

[0097] As shown in Table 1, the standard deviation and relative standard deviation of the internal standard were 0.01 and 0.06%, respectively, and the standard deviation and relative standard deviation of each component of the sample were 0.01-0.04 and 0.03%-0.54%, respectively. The peak times were stable, and the results obtained had good repeatability and high precision.

[0098] Example 5

[0099] This embodiment mainly analyzes the precision and accuracy of the method with internal standard.

[0100] The same sample was selected and tested seven times within a short period of time using the same method under normal and correct operating conditions, by the same operator, in the same laboratory, using the same instrument.

[0101] Specifically as follows:

[0102] 1. Sample preparation

[0103] Accurately weigh 1g of the above standard solution and add it to 10mL of internal standard solution (concentration of 0.012g / mL).

[0104] 2. Chromatographic conditions

[0105] Gas chromatograph: Agilent 8890. Injector temperature: 300℃; Agilent HP-1 gas chromatograph column, dimensions: 30.0m × 0.53mm × 5μm; column temperature: initial temperature 55℃, hold for 2 min, increase to 200℃ at 5℃ / min, hold for 0 min, then increase to 230℃ at 25℃ / min, hold for 13 min; FID detector, detector temperature: 300℃; air: 400mL / min, carrier gas flow rate: 6.5mL / min, H2: 30mL / min, split ratio: 10:1.

[0106] 3. Testing Operation

[0107] Connect all parts of the instrument to the power supply. After the detector temperature reaches the set temperature, ignite it and allow it to stabilize for 0.5 hours. Once the baseline is stable, inject the sample for analysis. Use a pipette to draw the solution from step 1 into the sample vial, place it in the chromatograph's injection tray, and use the autosampler to draw 1.0 μL of the sample solution and inject it into the gas chromatograph.

[0108] The test results are shown in the table below.

[0109] Table 2 Precision Test Results

[0110]

[0111]

[0112] As shown in Table 2, the standard deviation and relative standard deviation of the internal standard are 0.00004 and 0.00027%, respectively, and the standard deviation and relative standard deviation of each component in the sample are 0.00004-0.00785 and 0.00172%-0.12095%, respectively. The results obtained have good repeatability and high precision. The calculated En values ​​of each component in the sample are all less than 1, indicating that the results are highly accurate.

[0113] Example 6

[0114] This example demonstrates the measured content of each component in an ethyleneamine sample.

[0115] 1. Sample preparation

[0116] Accurately weigh 1g of ethyleneamine sample and add 10mL of internal standard solution (concentration of 0.012g / mL).

[0117] 2. Chromatographic conditions

[0118] Gas chromatograph: Agilent 8890. Injector temperature: 300℃; Agilent HP-1 gas chromatograph column, dimensions: 30.0m × 0.53mm × 5μm; column temperature: initial temperature 55℃, hold for 2 min, increase to 200℃ at 5℃ / min, hold for 0 min, then increase to 230℃ at 25℃ / min, hold for 13 min; FID detector, detector temperature: 300℃; air: 400mL / min, carrier gas flow rate: 6.5mL / min, H2: 30mL / min, split ratio: 10:1.

[0119] 3. Testing Operation

[0120] Connect all parts of the instrument to the power supply. After the detector temperature reaches the set temperature, ignite it and allow it to stabilize for 0.5 hours. Once the baseline is stable, inject the sample for analysis. Use a pipette to draw the solution from step 1 into the sample vial, place it in the chromatograph's injection tray, and use the autosampler to draw 1.0 μL of the sample solution and inject it into the gas chromatograph.

[0121] 4. Calculation

[0122] The mass fraction X (%) of each component in the sample is calculated based on the ratio of the peak area of ​​each component in the standard solution to the area of ​​its internal standard and the sample weight.

[0123]

[0124] In the formula:

[0125] m si —The mass of each component in the standard sample, in grams (g);

[0126] m i —The mass of each component in the sample, in grams (g);

[0127] A si —The average value of the ratio of the peak area of ​​each component in the standard solution to that of the internal standard;

[0128] A i —The average value of the ratio of the peak area of ​​each component in the sample solution to that of the internal standard.

[0129] The calculation results are rounded to two decimal places, and then the content of each component in the sample is calculated.

[0130] Table 3 is an explanation of the component codes in Tables 1 and 2 provided in Embodiments 3 and 4 of the present invention.

[0131]

[0132]

[0133] Table 3

[0134] Finally, it should be noted that the embodiments of the present invention are merely illustrative examples for explaining the present invention, and are not intended to limit the implementation of the present invention.

[0135] Unless otherwise specified, the terms used in this invention have the meanings commonly understood by those skilled in the art.

[0136] The embodiments described in this invention are for illustrative purposes only and are not intended to limit the scope of protection of this invention.

[0137] Those skilled in the art can make various other substitutions, changes and improvements within the scope of this invention. Therefore, this invention is not limited to the above-described embodiments, but is only limited by the claims.

Claims

1. A method for determining the component content of a ethyleneamine reactor sample using gas chromatography with internal standard, characterized in that, Includes the following steps: Step 1: Establishing gas chromatography conditions. The chromatographic column is a non-polar quartz capillary column, 100% dimethyl polysiloxane, with column dimensions of 30.0m × 0.53mm × 5μm; The column oven uses a gradient heating mode, with temperatures ranging from 55℃ to 230℃. Split injection was used with a split ratio of 10:

1. The injection port temperature is 250℃-350℃; The flow rate of the carrier gas nitrogen is 2 mL / min to 7.5 mL / min; The air flow rate is 300 mL / min to 500 mL / min, and the hydrogen flow rate is 25 mL / min to 40 mL / min; A flame ionization detector (FID) was used, with a detector temperature of 260℃-330℃. Samples were injected for analysis after the baseline stabilized for 0.5 hours. Step 2: Preparation of internal standard solution: 3-Diethylamino-1-propylamine reagent is added to ethanol to prepare internal standard solution; Step 3: Preparation of standard solutions: Dissolve the reagents of each impurity component in ethanol to prepare standard solutions with a mass concentration of 0.1%-35% for each impurity component; Step 4: Preparation of standard sample solution: Weigh the standard solution from step 3, add the internal standard solution, and prepare the standard sample solution; Step 5: Preparation of sample solution: Take the sample from the ethyleneamine reactor, add the internal standard solution, and prepare the sample solution; Step 6: Take one portion each of the standard solution from Step 3 and the sample solution from Step 5, add the internal standard solution to obtain the standard and sample solutions. Inject the standard and sample solutions into the gas chromatograph separately, separate the components of the sample solution through the chromatographic column, and calculate the content of each component in the sample using the internal standard method.

2. The method for determining the component content of an ethyleneamine reactor sample using gas chromatography with internal standard as described in claim 1, characterized in that, Step 1: The column temperature starts at 55℃ and is increased in two stages, as follows: the initial temperature is 55℃ and held for 2 minutes, then increased to 200℃ at 5℃ / min and held for 0 minutes, and then increased to 230℃ at 25℃ / min and held for 13 minutes.

3. The method for determining the component content of an ethyleneamine reactor sample using gas chromatography with internal standard as described in claim 1, characterized in that, The detector temperature in step one is 280℃-300℃.

4. The method for determining the component content of an ethyleneamine reactor sample using gas chromatography with internal standard as described in claim 1, characterized in that, The injection port temperature is 280℃-330℃.

5. The method for determining the component content of an ethyleneamine reactor sample using gas chromatography with internal standard as described in claim 1, characterized in that, Step 2: Add 3-diethylamino-1-propanamine to ethanol to prepare an internal standard solution with a concentration not exceeding 0.015 g / mL.

6. The method for determining the component content of an ethyleneamine reactor sample using gas chromatography with internal standard as described in claim 1, characterized in that, The injection volume is 0.2 μL to 1.5 μL.

7. The method for determining the component content of an ethyleneamine reactor sample using gas chromatography with internal standard as described in claim 6, characterized in that, The injection volume is 0.5 μL to 1.0 μL.

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