The invention relates to N, N, Napos; , Napos, Napos; method for detecting content of tetrapropyl-1, 3-allene-1, 4-diamine propionate

Abstract

The invention relates to the technical field of chemical detection, in particular to a method for detecting the content of N, N, N ', N'-tetrapropyl-1, 3-propadiene-1, 4-diamine propionate, which comprises the following steps: (1) respectively dissolving a standard substance and a sample to be detected by using methanol to obtain a standard sample and a sample; (2) adopting a C8 reversed-phase chromatographic column, setting the detection wavelength to be 280-320 nm, selecting a mixed system of acetonitrile and a buffer salt solution as a mobile phase, performing sample injection detection, and calculating an average value of peak areas of N, N, N ', N'-tetrapropyl-1, 3-allene diene-1, 4-diamine propionate in chromatograms of a standard sample and a sample; and (3) calculating the content of N, N, N ', N'-tetrapropyl-1, 3-propadiene-1, 4-diamine propionate in the sample to be detected according to an external standard method formula. According to the method, the blank of detecting the content of the N, N, N ', N'-tetrapropyl-1, 3-propadiene-1, 4-diamine propionate by using a liquid chromatography method is filled.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical detection, and in particular to a method for detecting the content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate. Background Art

[0002] 2-Chloronicotinic acid is one of the important intermediates in the synthesis of nicosulfuron. Its main synthesis route is as follows: ; Wherein, R is -OCH3, -OC2H5, -NH2, -N(CH3)2, etc.

[0003] Among them, the condensation reaction of 3-di-n-propylaminoacrolein with cyanoacetic acid derivatives is the difficulty in the synthesis route of 2-chloronicotinic acid. Propionic acid and diisopropylethylamine are usually used as catalysts in this step. 3-di-n-propylaminoacrolein is easily decomposed to produce di-n-propylamine under the catalysis of propionic acid. Di-n-propylamine and 3-di-n-propylaminoacrolein will generate N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate impurity under the catalysis of organic amines. The structural formula is as follows: .

[0004] New research has found that N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate can be used as a raw material to synthesize 2-chloronicotinic acid and other halogenated pyridine compounds. The reaction route is as follows: ; In the formula, R1 is dimethylaminocarbonyl, ethoxycarbonyl, carboxyl, cyano, anilinocarbonyl, benzylaminocarbonyl or nitro.

[0005] Therefore, the quality of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate affects the quality and yield of nicosulfuron. Common methods for determining the content of quaternary ammonium salts include liquid chromatography-mass spectrometry, gravimetric methods, and spectrophotometry. However, these methods vary depending on the specific substance being tested. Currently, no methods for determining the content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate have been reported. Summary of the Invention

[0006] Aiming at the technical problem of the current lack of a method for detecting the content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate, the present invention provides a method for detecting the content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate.

[0007] The technical solutions of the present invention are as follows: A method for detecting the content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate comprises the following steps: (1) Dissolve N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate standard substance and the sample to be tested in methanol to obtain a standard sample and a test sample; (2) A C8 reverse phase column was used, and the detection wavelength of the high performance liquid chromatography was set to 280-320 nm. A mixture of acetonitrile and buffered saline solution was selected as the mobile phase. After the instrument baseline was stable, the samples were injected in the order of standard, sample, sample, and standard. The average peak area of ​​N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the chromatograms of the standard and sample was calculated respectively. (3) Calculate the content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the sample according to the external standard method formula. The external standard method formula is shown in formula (1): (1), Where, A 1 is the average peak area of ​​N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the standard sample; A 2 is the average peak area of ​​N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the sample; m 1 is the mass of the standard substance; m 2 is the mass of the sample to be tested; P 1 is the content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the standard substance; X 1 is the content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the sample to be tested.

[0008] Furthermore, the C8 reverse phase chromatography column used in step (2) has a column length of 150 mm, an inner diameter of 2.1 to 4.6 mm, and a particle size of 1.8 to 5 μm.

[0009] Furthermore, in step (2), the temperature of the chromatographic column is 30-40° C., preferably 30° C. This range is within the operating temperature range of the chromatographic column and is easy to control. By controlling the constant temperature of the chromatographic column, the stability of the retention time is ensured, and the reproducibility of sample detection is improved.

[0010] Furthermore, the detection wavelength of step (2) is preferably 290 nm. At this wavelength, the UV absorption of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate is suitable and stable, the linear range of the sample is wider, and the peak area is appropriate, which is conducive to improving the detection accuracy and stability.

[0011] Furthermore, in the mobile phase of step (2), the volume ratio of acetonitrile to buffered saline solution is 30-55:70-45, and the pH value of the buffered saline solution is 5.5-6.5. This mobile phase ratio range can ensure that the overall loading time of the standard sample and the sample is appropriately controlled, while also ensuring the separation degree from the solvent and impurities.

[0012] Furthermore, in the mobile phase of step (2), the buffered saline solution is prepared by mixing dihydrogen phosphate and hydrogen phosphate or hydroxide.

[0013] Furthermore, the dihydrogen phosphate is selected from one of potassium dihydrogen phosphate and sodium dihydrogen phosphate; The hydrogen phosphate is selected from one of dipotassium hydrogen phosphate and disodium hydrogen phosphate; The hydroxide is one of sodium hydroxide and potassium hydroxide.

[0014] The buffered salt solution prepared from the above ingredients can not only stabilize the pH value of the mobile phase and be less affected by temperature, but also provide a strong ionic strength environment, thereby better ensuring the chromatographic peak shape.

[0015] Furthermore, in the mobile phase of step (2), the volume ratio of acetonitrile to the buffer saline solution is 35:65, the pH value of the buffer saline solution is 6.0, and the buffer saline solution is prepared by mixing sodium dihydrogen phosphate and disodium hydrogen phosphate.

[0016] Furthermore, the mobile phase flow rate in step (2) is 0.8~1.2 mL / min. If the flow rate is less than 0.8 mL / min, the analysis time will increase, and the chromatographic peaks will be tailed, resulting in peak broadening and poor symmetry. If the flow rate is greater than 1.2 mL / min, although it will not have a significant impact on the separation and the analysis time will be reduced, it will cause the chromatographic system pressure to be too high. If the system is operated for a long time, the pressure will be too high, which will cause significant damage to the instrument. Furthermore, the mobile phase flow rate is preferably 1.0 mL / min.

[0017] Furthermore, in step (2), the sample volume of each injection of the standard sample and the test sample was 5 μL.

[0018] The beneficial effects of the present invention are: The present invention fills the gap in detecting the content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate by liquid chromatography, and the obtained chromatographic peak shape is good, the integral calculation result is accurate and repeatable, the result is highly reliable, and it is more accurate and timely.

[0019] The method provided by the present invention is particularly suitable for quality control of intermediate products, provides strong data support for the production of halogenated pyridine compounds such as 2-chloronicotinic acid, and has an important role and practical significance for ensuring the quality of the final product nicosulfuron. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0021] Figure 1 3 is a mass spectrum of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate prepared and used in a specific embodiment.

[0022] Figure 2 1 is a hydrogen nuclear magnetic spectrum of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate prepared and used in a specific embodiment.

[0023] Figure 3 It is the chromatogram of the standard sample in Example 1.

[0024] Figure 4 This is the chromatogram of the sample in Example 1.

[0025] Figure 5 This is a linear relationship diagram in Experimental Example 2.

[0026] Figure 6 It is the chromatogram of the sample in Comparative Example 1.

[0027] Figure 7 It is the chromatogram of the sample in Comparative Example 2. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0029] The specific implementation method of the present invention uses a 20AT infusion pump and a DAD detector from Shimadzu Corporation as the high performance liquid chromatograph.

[0030] The N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate standard substance and test samples used in the specific embodiments of this invention were prepared according to the synthesis method of compound D in patent US 8652364 B2. N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate was obtained by reacting 1,1,3,3-tetramethoxypropane and dipropylamine in a methanol-propionic acid system. The synthesis route is as follows: .

[0031] The products prepared by this synthetic route were subjected to mass spectrometry and nuclear magnetic resonance detection, and the results were as follows: Figure 1 、 Figure 2 As shown, the content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the product was determined to be 90.2% by nuclear magnetic resonance quantitative analysis. This was used as the standard substance of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in various embodiments, test examples and comparative examples of the present invention.

[0032] MS:M + 239.24; 1 H NMR (400 MHz, DMSO- d 6) δ 12.09 (s, 1H), 7.98 (d, J = 11.6 Hz, 2H),5.65 (t, J = 11.7 Hz, 1H), 3.43 (dt, J = 13.6, 7.3 Hz, 8H), 2.22 (q, J = 7.5 Hz,2H), 1.62 (dh, J = 15.0, 7.4 Hz, 8H), 0.99 (t, J = 7.5 Hz, 3H), 0.91 (t, J = 7.4Hz, 6H), 0.85 (t, J = 7.3 Hz, 6H).

[0033] It should be understood that the detection method of the present invention is applicable to N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate prepared by various routes, including but not limited to the above-mentioned method. The above description does not constitute a limitation on the source of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate.

[0034] N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate can be used to prepare halogenated pyridine compounds. The reaction scheme is as follows: ; Wherein, R1 is dimethylaminocarbonyl, ethoxycarbonyl, carboxyl, cyano, anilinocarbonyl, benzylaminocarbonyl or nitro; X is halogen.

[0035] When R1 is a carboxyl group and X is Cl, the halogenated pyridine compound is 2-chloronicotinic acid. When R1 is a dimethylaminocarbonyl group and X is Cl, the halogenated pyridine compound is 2-chloro-N,N-dimethylnicotinamide, which is also a nicosulfuron intermediate.

[0036] Taking R1 as dimethylaminocarbonyl and X as Cl as an example, the route for preparing 2-chloro-N,N-dimethylnicotinamide using N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate is as follows: .

[0037] (1) Preparation of 5-(N,N-dipropylamino)-2-cyano-N,N-methyl-2,4-pentadienamide Add N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate and N,N-dimethylcyanoacetamide to toluene and heat under reflux. After completion, cool to room temperature and wash with water. Evaporate the organic phase under reduced pressure to remove the solvent, and recrystallize to obtain the intermediate 5-(N,N-dipropylamino)-2-cyano-N,N-methyl-2,4-pentadienamide as a light yellow to off-white solid. MS: [M+H]+ 250.18.

[0038] (2) Preparation of 2-chloro-N,N-dimethylnicotinamide 5-(N,N-dipropylamino)-2-cyano-N,N-methyl-2,4-pentadienamide was added to dichloroethane, and hydrogen chloride gas was introduced with stirring. The reaction was heated to carry out a cyclization reaction. After the reaction, an aqueous sodium hydroxide solution was added to adjust the pH to 3. The solvent was evaporated under reduced pressure, and ethyl acetate was added to the residue. The mixture was heated to dissolve and then cooled to allow crystallization to obtain off-white crystals of 2-chloro-N,N-dimethylnicotinamide.

[0039] MS: [M+H]+ 185.04 / 187.03.

[0040] 1 H NMR (400 MHz, DMSO- d 6) δ 8.47 (dd, J = 4.8, 2.0 Hz, 1H), 7.88 (dd, J =7.5, 2.0 Hz, 1H), 7.52 (dd, J = 7.5, 4.8 Hz, 1H), 3.02 (s, 3H), 2.80 (s, 3H).

[0041] Example 1 The content of 35.6 g of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate obtained in the small test was tested. The specific steps are as follows: (1) Accurately weigh 0.0508 g of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate standard substance and place it in a 100 mL volumetric flask. Add 50 mL of methanol and dissolve it under ultrasonic vibration. After cooling to room temperature, dilute it to the scale with methanol to obtain the standard sample for use.

[0042] Accurately weigh 0.0527 g of the sample to be tested, place it in a 100 mL volumetric flask, add 50 mL of methanol, dissolve it under ultrasonic vibration, cool it to room temperature, and dilute it to the scale with methanol to obtain the sample for use.

[0043] (2) A ZORBAX SB-C8 reversed-phase column (4.6 × 150 mm, 3.5 µm) was used, and the column temperature was 30°C. The mobile phase was an acetonitrile / buffered saline solution mixture with a volume ratio of 35:65. The buffered saline solution was prepared by mixing sodium dihydrogen phosphate and disodium hydrogen phosphate, with a pH of 6.0. The mobile phase flow rate was 1.0 mL / min.

[0044] After the machine self-test passes, under the specified operating conditions, after the instrument baseline is stable, continuously inject several needles of standard sample and calculate the relative response value of each needle. When the relative response value change between two adjacent needles is less than 1.5%, inject the sample in the order of standard sample, sample, sample, and standard sample. The sample volume for each injection is 5 μL. The detection is carried out at a wavelength of 290 nm. The chromatogram is as follows: Figure 3 and 4 As shown, Figure 3 、 Figure 4 The peak at 6.7 min is N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate.

[0045] The peak areas of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the chromatograms of the standard and sample were averaged, and the obtained data are shown in Table 1.

[0046] Table 1 Chromatographic test data of standard sample and sample in Example 1

[0047] (3) Calculate the content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the sample according to the external standard method formula X 1=83.2%.

[0048] Example 2 The content of 32.8 g of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate obtained in the small test was tested. The specific steps are as follows: (1) Accurately weigh N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate standard material ( P 1 = 90.2%), 0.0516 g, was placed in a 100 mL volumetric flask, 50 mL of methanol was added, and ultrasonic vibration was used to dissolve it. After cooling to room temperature, it was diluted to the scale with methanol to obtain a standard sample for use.

[0049] Accurately weigh 0.0572 g of the sample to be tested, place it in a 100 mL volumetric flask, add 50 mL of methanol, dissolve it under ultrasonic vibration, cool it to room temperature, and dilute it to the scale with methanol to obtain the sample for use.

[0050] (2) A ZORBAX SB-C8 reversed-phase column (3×150 mm, 1.8 µm) was used at a column temperature of 40°C. The mobile phase was a mixture of acetonitrile and buffered saline at a volume ratio of 45:55. The buffered saline was prepared by mixing sodium dihydrogen phosphate and sodium hydroxide with a pH of 6.5. The mobile phase flow rate was 0.8 mL / min.

[0051] After the machine self-test passes, under the specified operating conditions, after the instrument baseline is stable, several injections of standard sample are continuously injected, and the relative response value of each injection is calculated. After the relative response value change between two adjacent injections is less than 1.5%, the standard sample, sample, sample, and standard sample are injected in sequence. The sample volume for each injection is 5 μL. The instrument is detected at a wavelength of 300 nm. The chromatograms of the standard sample and sample are obtained. The retention time of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate is approximately 5.3 min. The average peak area of ​​N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the chromatogram is calculated. The obtained data are shown in Table 2.

[0052] Table 2 Chromatographic test data of standard sample and sample in Example 2

[0053] (3) Calculate the content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the sample according to the external standard method formula X 1=82.7%.

[0054] Test Example 1 (1) Accurately weigh N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate standard material ( P 1 = 90.2%), 0.0513 g, was placed in a 100 mL volumetric flask, 50 mL of methanol was added, and ultrasonic vibration was used to dissolve it. After cooling to room temperature, it was diluted to the scale with methanol to obtain a standard sample for use.

[0055] Accurately weigh 6 samples to be tested (from the same batch as the samples to be tested in Example 2). The specific masses are shown in Table 3. The samples to be tested were placed in 100 mL volumetric flasks, 50 mL of methanol was added, and ultrasonic vibration was used to dissolve them. After cooling to room temperature, they were diluted to the scale with methanol to obtain test samples for use.

[0056] (2) A ZORBAX SB-C8 reversed-phase column (4.6 × 150 mm, 3.5 µm) was used, and the column temperature was 30°C. The mobile phase was an acetonitrile / buffered saline solution mixture with a volume ratio of 35:65. The buffered saline solution was prepared by mixing sodium dihydrogen phosphate and disodium hydrogen phosphate, with a pH of 6.0. The mobile phase flow rate was 1.0 mL / min.

[0057] After the machine self-test passes, under the specified operating conditions, after the instrument baseline is stable, several injections of standard sample are continuously injected, and the relative response value of each injection is calculated. After the relative response value change between two adjacent injections is less than 1.5%, the standard sample, sample, sample, and standard sample are injected in sequence. The sample volume for each injection is 5 μL. Six samples are tested at a wavelength of 290 nm, and the chromatograms of the standard sample and sample are obtained. The average peak area of ​​N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the chromatogram is calculated. The content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the test sample is calculated according to the external standard method formula. The obtained data are shown in Table 3.

[0058] Table 3 Chromatographic test data of samples in Experimental Example 1

[0059] As can be seen from the data in Table 3, the results of the method of the present invention have good repeatability.

[0060] Test Example 2 (1) Weigh 7 parts of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate standard material ( P 1=90.2%), placed in a 100 mL volumetric flask, added with 50 mL of methanol, dissolved under ultrasonic vibration, cooled to room temperature, and diluted to the scale with methanol to obtain samples with concentrations of 203 μg / mL, 312 μg / mL, 404 μg / mL, 518 μg / mL, 623 μg / mL, 671 μg / mL, and 716 μg / mL for use.

[0061] A ZORBAX SB-C8 reversed-phase column (4.6 × 150 mm, 3.5 µm) was used, and the column temperature was 30°C. The mobile phase consisted of a 35:65 volume ratio of acetonitrile / buffered saline solution (sodium dihydrogen phosphate and disodium hydrogen phosphate) with a pH of 6.0. The mobile phase flow rate was 1.0 mL / min.

[0062] Seven samples were tested sequentially at a wavelength of 290 nm, and a linear regression was performed using the peak area (A) on the y-axis against the sample concentration (μg / mL) on the x-axis. The results are shown in Figure 2. Figure 5 As shown, the regression equation is as follows: y=4603.6x-8760.2, R 2 =0.9998.

[0063] It can be seen that N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate has a good linear relationship in the range of 200~700 μg / mL.

[0064] Test Example 3 Six experimenters conducted the detection of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate content in different laboratories. The specific steps are as follows: (1) Accurately weigh N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate standard material ( P 1=90.2%), placed in a 100 mL volumetric flask, added 50 mL of methanol, dissolved by ultrasonic vibration, cooled to room temperature, and diluted to the scale with methanol to obtain a standard sample for use.

[0065] Accurately weigh the sample to be tested (from the same batch as the sample to be tested in Example 2). The specific mass is shown in Table 4. The sample to be tested is placed in a 100 mL volumetric flask. 50 mL of methanol is added and dissolved by ultrasonic vibration. After cooling to room temperature, it is diluted to the scale with methanol to obtain a sample for use.

[0066] (2) A ZORBAX SB-C8 reversed-phase column (4.6 × 150 mm, 3.5 µm) was used, and the column temperature was 30°C. The mobile phase was an acetonitrile / buffered saline solution mixture with a volume ratio of 35:65. The buffered saline solution was prepared by mixing sodium dihydrogen phosphate and disodium hydrogen phosphate, with a pH of 6.0. The mobile phase flow rate was 1.0 mL / min.

[0067] After the machine self-test passes, under the specified operating conditions, after the instrument baseline is stable, several injections of standard sample are continuously injected, and the relative response value of each injection is calculated. After the relative response value change between two adjacent injections is less than 1.5%, the standard sample, sample, sample, and standard sample are injected in sequence. The sample volume for each injection is 5 μL. The instrument is detected at a wavelength of 290 nm. The chromatograms of the standard sample and sample are obtained, and the average peak area of ​​N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the chromatogram is calculated. The content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the sample to be tested is calculated according to the external standard method formula. The obtained data are shown in Table 4.

[0068] Table 4 Chromatographic test data of samples in Experimental Example 3

[0069] It can be seen from the data in Table 4 that the intermediate precision of the results of the method of the present invention is good.

[0070] Test Example 4 (1) Accurately weigh 0.0504 g of the sample to be tested, place it in a 100 mL volumetric flask, add 50 mL of methanol, and dissolve it by ultrasonic vibration. After cooling to room temperature, dilute it to the scale with methanol to obtain the sample for use.

[0071] (2) A ZORBAX SB-C8 reversed-phase column (4.6 × 150 mm, 3.5 µm) was used, and the column temperature was 30°C. A mixture of acetonitrile and buffered saline solution with a volume ratio of 45:55 was used as the mobile phase. The buffered saline solution was prepared by mixing sodium dihydrogen phosphate and sodium hydroxide with a pH of 6.0. The mobile phase flow rate was 1.0 mL / min.

[0072] The sample was detected at 0 h, 1 h, 2 h, 4 h, 8 h, and 24 h (detection wavelength was 290 nm). The chromatogram showed a good peak shape. The average peak area of ​​N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the chromatogram was calculated. The obtained data are shown in Table 5.

[0073] Table 5 Peak areas corresponding to the samples in Test Example 4

[0074] It can be seen from the data in Table 5 that the time stability of the results of the method of the present invention is good.

[0075] Test Example 5 (1) Accurately weigh N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate standard material ( P 1 = 90.2%), 0.9972 g, was placed in a 100 mL volumetric flask, 50 mL of methanol was added, and ultrasonic vibration was used to dissolve it. After cooling to room temperature, it was diluted to the scale with methanol to obtain a standard sample for use.

[0076] Accurately weigh 3 portions of the test sample containing N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate from the same batch, 0.02 g, 0.03 g, and 0.04 g, respectively, and place them in 100 mL volumetric flasks. Add 50 mL of methanol and dissolve under ultrasonic vibration. After cooling to room temperature, dilute to the scale with methanol to obtain the sample for use.

[0077] (2) A ZORBAX SB-C8 reversed-phase column (4.6 × 150 mm, 3.5 µm) was used, and the column temperature was 30°C. The mobile phase was an acetonitrile / buffered saline solution mixture with a volume ratio of 35:65. The buffered saline solution was prepared by mixing sodium dihydrogen phosphate and disodium hydrogen phosphate, with a pH of 6.0. The mobile phase flow rate was 1.0 mL / min.

[0078] After the machine self-test passes, under the specified operating conditions, after the instrument baseline is stable, continuously inject several injections of standard sample, calculate the relative response value of each injection, and when the relative response value variation between two adjacent injections is less than 1.5%, inject the standard sample, sample, sample, and standard sample in this order. The sample volume for each injection is 5 μL. Detect 9 samples separately at a wavelength of 290 nm, obtain the chromatograms of the standard sample and sample, calculate the average peak area of ​​N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the chromatogram, and calculate the content of the active ingredient (N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate) in the sample to be tested according to the external standard method formula.

[0079] According to the sample mass, 3.0 mL, 2.0 mL, and 1.0 mL of standard sample were added to the sample, respectively, to obtain 9 mixed samples. The content of the active ingredient in each mixed sample was determined again according to the above method. The specific results are shown in Table 6.

[0080] Table 6 Chromatographic test data of samples in Experimental Example 5

[0081] It can be seen from the data in Table 6 that the method of the present invention has high accuracy and good operability, and can be widely applied to the analysis and detection of the content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate.

[0082] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that different mobile phases are used. In Comparative Example 1, a mixed system of acetonitrile / phosphoric acid aqueous solution with a volume ratio of 35:65 is used as the mobile phase.

[0083] Chromatographic detection was carried out under this mobile phase, and the sample chromatogram obtained was as follows: Figure 6 As shown, it can be seen that the chromatographic peak is in the form of a triangular peak, the peak is widely broadened, and the retention time is unstable during the sample detection process (6.7 min-9.0 min), with poor repeatability, which affects the accuracy of sample detection.

[0084] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that different mobile phases are used. In Comparative Example 2, a mixed system of acetonitrile and buffered saline solution with a volume ratio of 40:60 is used as the mobile phase, and the buffered saline solution is a 10 mol / L ammonium formate solution.

[0085] Chromatographic detection was carried out under this mobile phase, and the sample chromatogram obtained was as follows: Figure 7 As shown, it can be seen that the chromatographic peak is in the form of a triangular peak, the repeatability is poor, and the detection time is long, which affects the timeliness of the detection results in production.

[0086] Although the present invention has been described in detail with reference to the accompanying drawings and in conjunction with preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, persons of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall be within the scope of the present invention. Any changes or substitutions that can be easily conceived by persons skilled in the art within the technical scope disclosed in the present invention shall be within the scope of protection of the present invention.

Claims

1. A method for detecting the content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate, characterized in that: The steps include: (1) Dissolve N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate standard substance and the sample to be tested in methanol to obtain a standard sample and a test sample; (2) A C8 reverse phase column was used, and the detection wavelength of the high performance liquid chromatography was set to 280-320 nm. A mixture of acetonitrile and buffered saline solution was selected as the mobile phase. After the instrument baseline was stable, the samples were injected in the order of standard, sample, sample, and standard. The average peak area of ​​N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the chromatograms of the standard and sample was calculated respectively. (3) Calculate the content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the sample according to the external standard method formula. The external standard method formula is shown in formula (1): （1）， Where, A 1 is the average peak area of ​​N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the standard sample; A 2 is the average peak area of ​​N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the sample; m 1 is the mass of the standard substance; m 2 is the mass of the sample to be tested; P 1 is the content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the standard substance; X 1 is the content of N,N,N',N'-tetrapropyl-1,3-propadiene-1,4-diamine propionate in the sample to be tested.

2. The detection method according to claim 1, wherein The C8 reverse phase chromatography column used in step (2) has a column length of 150 mm, a column inner diameter of 2.1-4.6 mm, and a particle size of 1.8-5 μm.

3. The detection method according to claim 1, wherein In step (2), the column temperature is 30-40°C.

4. The detection method according to claim 1, wherein The detection wavelength of step (2) is 290 nm.

5. The detection method according to claim 1, wherein In the mobile phase of step (2), the volume ratio of acetonitrile to buffered saline solution is 30-55:70-45, and the pH value of the buffered saline solution is 5.5-6.

5.

6. The detection method according to claim 5, wherein In the mobile phase of step (2), the buffered saline solution is prepared by mixing dihydrogen phosphate and hydrogen phosphate or hydroxide.

7. The detection method according to claim 6, wherein The dihydrogen phosphate is selected from potassium dihydrogen phosphate and sodium dihydrogen phosphate; The hydrogen phosphate is selected from one of dipotassium hydrogen phosphate and disodium hydrogen phosphate; The hydroxide is one of sodium hydroxide and potassium hydroxide.

8. The detection method according to claim 1, 5, 6 or 7, wherein: In the mobile phase of step (2), the volume ratio of acetonitrile to buffered saline solution is 35:65, the pH value of the buffered saline solution is 6.0, and the buffered saline solution is prepared by mixing sodium dihydrogen phosphate and disodium hydrogen phosphate.

9. The detection method according to claim 1, wherein The flow rate of the mobile phase in step (2) was 0.8–1.2 mL / min.

10. The detection method according to claim 1, wherein In step (2), the sample volume for each injection of standard and test samples was 5 μL.

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