CN108008035B - Method for detecting purity of 3-ethoxy-4-methoxybenzaldehyde - Google Patents

Abstract

The invention discloses a method for detecting the purity of 3-ethoxy-4-methoxybenzaldehyde, which adopts a Philomen chromatographic column and adopts a double mobile phase to carry out gradient elution, wherein the mobile phase A is KH₂PO₄Buffer solution, wherein the mobile phase B is acetonitrile, and the flow rate of the mobile phase is 0.7-1.2 mL/min; the detector is an ultraviolet detector. The detection method is simple, convenient, accurate, rapid, reliable, high in repeatability and stable, can effectively separate 3-ethoxy-4-methoxybenzaldehyde and known impurities thereof, and provides a simple, accurate, rapid and reliable detection method for industrial production of 3-ethoxy-4-methoxybenzaldehyde.

Description

The detection method of 3-ethoxy-4-methoxybenzaldehyde purity

technical field

The invention relates to the technical field of material purity analysis, in particular to the detection of the purity, known impurities and unknown impurities of 3-ethoxy-4-methoxybenzaldehyde, and more particularly to the detection of 3-ethoxyl by liquid chromatography Purity, known impurities, unknown impurities of yl-4-methoxybenzaldehyde.

Background technique

The chemical formula of 3-ethoxy-4-methoxybenzaldehyde is C ₁₀ H ₁₂ O ₃ , and its CAS number is 1131-52-8, and it is an important intermediate for the production of Apremilast. The impurity content of 3-ethoxy-4-methoxybenzaldehyde is an important indicator to measure its quality. If its impurity content is too high, it will affect the efficacy and quality of the prepared Apremilast, because its purity, impurities, etc. It directly affects the purity of Apstar and the size of impurities.

High-performance liquid chromatography has the advantages of high resolution, high sensitivity, fast speed, and reusable columns, so it is widely used in various fields such as biochemistry, food analysis, medical research, environmental analysis, and inorganic analysis. At present, there is no relevant report on the detection of the purity of 3-ethoxy-4-methoxybenzaldehyde by high performance liquid chromatography, in order to be accurate. To quickly analyze the purity of 3-ethoxy-4-methoxybenzaldehyde and strengthen the quality control of 3-ethoxy-4-methoxybenzaldehyde, it is necessary to suggest a simple, accurate, fast, reliable, Highly reproducible and stable liquid chromatography assay for the purity of 3-ethoxy-4-methoxybenzaldehyde.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a simple, accurate, fast, reliable, highly repeatable and stable detection method for the purity of 3-ethoxy-4-methoxybenzaldehyde, which adopts a Philomen chromatographic column, It can effectively separate 3-ethoxy-4-methoxybenzaldehyde and its known impurities, and it can be detected by ultraviolet detector, so as to quickly and accurately determine the content of 3-ethoxy-4-methoxybenzaldehyde. purity.

The technical scheme adopted in the present invention is: a method for detecting the purity of 3-ethoxy-4-methoxybenzaldehyde, comprising the following steps:

1) Preparation of system adaptability solution: Take an appropriate amount of 3-ethoxy-4-methoxybenzaldehyde, isovanillin and ethyl vanillin in the same volumetric flask, dissolve with diluent, and prepare as per milliliter A solution containing 1 mg of 3-ethoxy-4-methoxybenzaldehyde, isovanillin and ethyl vanillin each to obtain a system suitability solution;

2) Preparation of the test solution: take an appropriate amount of the test solution, dissolve it in a diluent, and configure it into a solution with a concentration of 0.5-1 mg/mL to obtain the test solution;

3) blank test: precisely measure 20 μL of diluent, inject it into a liquid chromatograph, and record the chromatogram;

4) System adaptability test: Precisely measure 5-20 μL of the system adaptability solution, inject it into a liquid chromatograph, and record the chromatogram;

5) Test of the test solution: accurately measure 5-20 μL of the test solution, inject it into a liquid chromatograph, record the chromatogram, deduct the blank test chromatographic peak from the chromatogram of the test solution, and use the area normalization method. Calculate the concentration of the test article.

Preferably, the diluent is acetonitrile.

Preferably, the test solution preparation method is as follows: taking an appropriate amount of the test product 3-ethoxy-4-methoxybenzaldehyde, dissolving it with acetonitrile and configuring it into a solution with a concentration of 0.5-1 mg/mL, to obtain the test product solution.

Preferably, in steps 3)-5), the test conditions of the liquid chromatograph are set as follows: the chromatographic column is Phenomenex Luna5u C18(2)100A chromatographic column, and the column temperature is room temperature; dual mobile phases are used for gradient washing The mobile phase A is KH ₂ PO ₄ buffer solution, the mobile phase B is acetonitrile, and the mobile phase flow rate is 0.7-1.2 mL/min; the detector is an ultraviolet detector.

Preferably, when the system adaptability test is carried out in step 4), the number of theoretical plates calculated by 3-ethoxy-4-methoxybenzaldehyde should not be less than 5000, and the degree of separation between the main peak and any impurity peak should not be less than 1.5 .

Preferably, the concentration of the KH ₂ PO ₄ buffer is 0.01-0.05 mol/L, and the pH is adjusted to 2.8-3.2 with phosphoric acid. Adjusting the pH of potassium dihydrogen phosphate buffer to 3.0 is beneficial to improve the peak shape of the main peak and impurity peak.

Preferably, the detection wavelength of the ultraviolet detector is 220-240 nm.

Preferably, the conditions of gradient elution are:

Preferably, the size of the Phenomenex Luna 5u C18(2)100A chromatographic column is 4.6*250mm*5μm.

Using Philomen chromatography column, 3-ethoxy-4-methoxybenzaldehyde and its known impurities can be effectively separated, detected by UV detector, qualitative by retention time and quantitative by peak area.

The beneficial effects of the present invention are: the present invention adopts liquid chromatography to detect the purity, known impurities and unknown impurities of 3-ethoxy-4-methoxybenzaldehyde, and the detection method is simple, accurate, fast, reliable and repeatable. It has high performance and stability, can effectively separate 3-ethoxy-4-methoxybenzaldehyde and its known impurities, and provides a convenient, convenient and efficient way for the industrial production of 3-ethoxy-4-methoxybenzaldehyde. Accurate, fast and reliable detection method; using acetonitrile and potassium dihydrogen phosphate buffer as mobile phases to carry out gradient elution in a certain proportion, which improves the separation effect; adjusting the pH of potassium dihydrogen phosphate buffer to 3.0 improves the main peak and impurities Peak shape.

Description of drawings

Fig. 1 is the high-efficiency liquid phase chromatogram of system adaptability solution among the embodiment 1;

Fig. 2 is the high-efficiency liquid phase chromatogram of need testing solution in embodiment 1;

Fig. 3 is the high-efficiency liquid phase chromatogram of need testing solution in embodiment 2;

Fig. 4 is the high-efficiency liquid phase chromatogram of need testing solution in embodiment 3;

Fig. 5 is the high-efficiency liquid phase chromatogram of need testing solution in embodiment 4;

Wherein, 1 is isovanillin: 3-hydroxy-4-methoxybenzaldehyde, 2 is ethyl vanillin: 3-ethoxy-4-hydroxybenzaldehyde, 3 is BMA: 3-ethoxy- 4-Methoxybenzaldehyde.

Detailed ways

Get four batches of 3-ethoxy-4-methoxybenzaldehyde products produced by the same production specification, and detect according to the detection method of Example 1-3, adopt area normalization method to calculate the purity and impurities thereof, and detect The results are as follows.

Example 1

A method for detecting the purity of 3-ethoxy-4-methoxybenzaldehyde, comprising the following steps:

1) Preparation of system adaptability solution: Take an appropriate amount of 3-ethoxy-4-methoxybenzaldehyde, isovanillin and ethyl vanillin in the same volumetric flask, dissolve with acetonitrile, and prepare each milliliter of A solution containing 1 mg of 3-ethoxy-4-methoxybenzaldehyde, isovanillin and ethyl vanillin to obtain a system suitability solution;

2) Preparation of the test solution: take an appropriate amount of the test product 3-ethoxy-4-methoxybenzaldehyde, dissolve it in acetonitrile, and configure it into a solution with a concentration of 0.5 mg/mL to obtain the test solution;

3) blank test: accurately measure 20 μL of acetonitrile, inject it into a liquid chromatograph, and record the chromatogram;

4) System adaptability test: Precisely measure 5 μL of the system adaptability solution, inject it into a liquid chromatograph, and record the chromatogram, wherein the number of theoretical plates calculated by 3-ethoxy-4-methoxybenzaldehyde is not less than 5000 , the separation between the main peak and any impurity peak should not be less than 1.5;

5) Test of the test solution: accurately measure 5 μL of the test solution, inject it into a liquid chromatograph, record the chromatogram, deduct the blank test chromatographic peak from the chromatogram of the test solution, and calculate the test solution according to the area normalization method. the concentration of the test product;

Among them, the test conditions of the liquid chromatograph are set as follows: the chromatographic column is a Phenomenex Luna 5u C18(2)100A chromatographic column with a specification of 4.6*250mm*5μm, and the column temperature is room temperature; dual mobile phases are used for gradient washing The mobile phase A is a KH ₂ PO ₄ buffer solution with a concentration of 0.01 mol/L (adjust the pH to 2.8 with phosphoric acid), the mobile phase B is acetonitrile, and the flow rate of the mobile phase is 0.7 mL/min; the detector is an ultraviolet detector, The detection wavelength is 220 nm; the conditions of gradient elution are shown in Table 1.

Table 1 Elution conditions of Examples 1-4

The obtained detection results are shown in Table 2-4 and Figure 1-2, wherein, Table 2 is the peak table in the chromatogram of the system adaptability solution, Table 3 is the peak table in the chromatogram of the test solution, Table 4 For the detection result of the test solution, Fig. 1 is the high-performance liquid chromatography of the system adaptability solution, and Fig. 2 is the high-performance liquid chromatography of the test solution.

Table 2 Peak table in the chromatogram of the system suitability solution

Table 3 Peak table in the chromatogram of the test solution

Table 4 is the detection result of the test solution

impurities Peak time (min) Peak area Peak area ratio (%) Main peak resolution The number of theoretical plates of the main peak isovanillin 16.0 36.3 0.01 / / Ethyl vanillin 19.8 44 0.01 / / BMA 22.7 537346 99.98 13.27 175451 maximum single / 0 0 / / total miscellaneous / 80 0.02 / /

Example 2

A method for detecting the purity of 3-ethoxy-4-methoxybenzaldehyde, comprising the following steps:

1) Preparation of system adaptability solution: Take an appropriate amount of 3-ethoxy-4-methoxybenzaldehyde, isovanillin and ethyl vanillin in the same volumetric flask, dissolve with acetonitrile, and prepare each milliliter of A solution containing 1 mg of 3-ethoxy-4-methoxybenzaldehyde, isovanillin and ethyl vanillin to obtain a system suitability solution;

2) Preparation of the test solution: take an appropriate amount of the test product 3-ethoxy-4-methoxybenzaldehyde, dissolve it in acetonitrile, and configure it into a solution with a concentration of 0.6 mg/mL to obtain the test solution;

3) blank test: accurately measure 20 μL of acetonitrile, inject it into a liquid chromatograph, and record the chromatogram;

4) System adaptability test: Precisely measure 10 μL of the system adaptability solution, inject it into a liquid chromatograph, and record the chromatogram, wherein the number of theoretical plates calculated by 3-ethoxy-4-methoxybenzaldehyde is not less than 5000 , the separation between the main peak and any impurity peak should not be less than 1.5;

5) Test of the test solution: accurately measure 10 μL of the test solution, inject it into a liquid chromatograph, record the chromatogram, deduct the blank test chromatographic peak from the chromatogram of the test solution, and calculate the test solution according to the area normalization method. the concentration of the test product;

Among them, the test conditions of the liquid chromatograph are set as follows: the chromatographic column is a Phenomenex Luna 5u C18(2)100A chromatographic column with a specification of 4.6*250mm*5μm, and the column temperature is room temperature; dual mobile phases are used for gradient washing The mobile phase A is a KH ₂ PO ₄ buffer solution with a concentration of 0.02 mol/L (adjust the pH to 3 with phosphoric acid), the mobile phase B is acetonitrile, and the mobile phase flow rate is 0.8 mL/min; the detector is an ultraviolet detector, The detection wavelength is 220 nm; the conditions of gradient elution are shown in Table 1.

The obtained detection result is as shown in table 5-6 and Fig. 3, wherein, table 5 is the peak table in the chromatogram of need testing solution, and table 6 is the detection result of need testing solution, and Fig. 3 is for supplying in embodiment 2. High-performance liquid chromatography of the test solution.

Table 5 is the peak table in the chromatogram of the test solution

Table 6 is the detection result of the test solution

impurities Peak time (min) Peak area Peak area ratio (%) Main peak resolution The number of theoretical plates of the main peak isovanillin 16.0 267 0.07 / / Ethyl vanillin 19.8 162 0.04 / / BMA 22.7 422672 99.83 10.34 142296 maximum single 20.5 222 0.06 / / total miscellaneous / 709 0.17 / /

Example 3

A detection method for the purity of 3-ethoxy-4-methoxybenzaldehyde, comprising the following steps:

1) Preparation of system adaptability solution: Take an appropriate amount of 3-ethoxy-4-methoxybenzaldehyde, isovanillin and ethyl vanillin in the same volumetric flask, dissolve with acetonitrile, and prepare each milliliter of A solution containing 1 mg of 3-ethoxy-4-methoxybenzaldehyde, isovanillin and ethyl vanillin to obtain a system suitability solution;

2) Preparation of the test solution: take an appropriate amount of the test product 3-ethoxy-4-methoxybenzaldehyde, dissolve it in acetonitrile, and configure it into a solution with a concentration of 0.5-1 mg/mL to obtain a test solution;

3) blank test: accurately measure 20 μL of acetonitrile, inject it into a liquid chromatograph, and record the chromatogram;

4) System adaptability test: Precisely measure 15 μL of the system adaptability solution, inject it into a liquid chromatograph, and record the chromatogram, wherein the number of theoretical plates calculated by 3-ethoxy-4-methoxybenzaldehyde is not less than 5000 , the separation between the main peak and any impurity peak should not be less than 1.5;

5) Test of the test solution: accurately measure 15 μL of the test solution, inject it into a liquid chromatograph, record the chromatogram, deduct the blank test chromatographic peak from the chromatogram of the test solution, and calculate the test solution according to the area normalization method. the concentration of the test product;

Among them, the test conditions of the liquid chromatograph are set as follows: the chromatographic column is a Phenomenex Luna 5u C18(2)100A chromatographic column with a specification of 4.6*250mm*5μm, and the column temperature is room temperature; dual mobile phases are used for gradient washing The mobile phase A is a KH ₂ PO ₄ buffer with a concentration of 0.03 mol/L (adjust the pH to 3 with phosphoric acid), the mobile phase B is acetonitrile, and the mobile phase flow rate is 1 mL/min; the detector is an ultraviolet detector, which detects The wavelength is 230 nm; the conditions of gradient elution are shown in Table 1.

The obtained detection result is as shown in table 7-8 and Fig. 4, wherein, table 7 is the peak table in the chromatogram of need testing solution, and table 8 is the detection result of need testing solution, and Fig. 4 is the test result of need testing solution. High performance liquid chromatography.

Table 7 Peak table in the chromatogram of the test solution

The detection result of table 8 need testing solution

impurities Peak time (min) Peak area Peak area ratio (%) Main peak resolution The number of theoretical plates of the main peak isovanillin 16.0 406 0.06 / / Ethyl vanillin 19.8 243 0.03 / / BMA 22.7 732519 99.88 10.32 184403 maximum single 20.5 185 0.03 / / total miscellaneous / 835 0.12 / /

Example 4

A method for detecting the purity of 3-ethoxy-4-methoxybenzaldehyde, comprising the following steps:

1) Preparation of system adaptability solution: Take an appropriate amount of 3-ethoxy-4-methoxybenzaldehyde, isovanillin and ethyl vanillin in the same volumetric flask, dissolve with acetonitrile, and prepare each milliliter of A solution containing 1 mg of 3-ethoxy-4-methoxybenzaldehyde, isovanillin and ethyl vanillin to obtain a system suitability solution;

2) Preparation of the test solution: take an appropriate amount of the test product 3-ethoxy-4-methoxybenzaldehyde, dissolve it in acetonitrile, and configure it into a solution with a concentration of 0.5-1 mg/mL to obtain a test solution;

3) blank test: accurately measure 20 μL of acetonitrile, inject it into a liquid chromatograph, and record the chromatogram;

4) System adaptability test: Precisely measure 20 μL of the system adaptability solution, inject it into a liquid chromatograph, and record the chromatogram, wherein the number of theoretical plates calculated by 3-ethoxy-4-methoxybenzaldehyde is not less than 5000 , the separation between the main peak and any impurity peak should not be less than 1.5;

5) Test of the test solution: accurately measure 20 μL of the test solution, inject it into a liquid chromatograph, record the chromatogram, deduct the blank test chromatographic peak from the chromatogram of the test solution, and calculate the test solution according to the area normalization method. the concentration of the test product;

Among them, the test conditions of the liquid chromatograph are set as follows: the chromatographic column is a Phenomenex Luna 5u C18(2)100A chromatographic column with a specification of 4.6*250mm*5μm, and the column temperature is room temperature; dual mobile phases are used for gradient washing The mobile phase A is a KH ₂ PO ₄ buffer solution with a concentration of 0.05mol/L (adjust the pH to 3.2 with phosphoric acid), the mobile phase B is acetonitrile, and the mobile phase flow rate is 1.2 mL/min; the detector is an ultraviolet detector, The detection wavelength is 240 nm; the conditions of gradient elution are shown in Table 1.

The gained detection result is as shown in table 9-10 and Fig. 5, wherein, table 9 is the peak table in the chromatogram of need testing solution, table 10 is the detection result of need testing solution, and Fig. 5 is the test result of need testing solution. High performance liquid chromatography.

Table 9 Peak table in the chromatogram of the test solution

The detection result of table 10 need testing solution

Claims (7)

1. a detection method for the purity of 3-ethoxy-4-methoxybenzaldehyde, is characterized in that, comprises the following steps: 1) Preparation of system adaptability solution: Take an appropriate amount of 3-ethoxy-4-methoxybenzaldehyde, isovanillin and ethyl vanillin in the same volumetric flask, dissolve with diluent, and prepare as per milliliter A solution containing 1 mg of 3-ethoxy-4-methoxybenzaldehyde, isovanillin and ethyl vanillin each to obtain a system suitability solution; 2) Preparation of the test solution: take an appropriate amount of the test solution, dissolve it in a diluent, and configure it into a solution with a concentration of 0.5-1 mg/mL to obtain the test solution; 3) blank test: precisely measure 20 μL of diluent, inject it into a liquid chromatograph, and record the chromatogram; 4) System adaptability test: Precisely measure 5-20 μL of the system adaptability solution, inject it into a liquid chromatograph, and record the chromatogram; 5) Test of the test solution: accurately measure 5-20 μL of the test solution, inject it into a liquid chromatograph, record the chromatogram, deduct the blank test chromatographic peak from the chromatogram of the test solution, and use the area normalization method. Calculate the concentration of the test article; Wherein, the test conditions of the liquid chromatograph are set as follows: the chromatographic column is Phenomenex Luna 5u C18(2) 100A chromatographic column; dual mobile phases are used for gradient elution, and mobile phase A is KH ₂ PO ₄ buffer solution. Phase B is acetonitrile; The gradient elution conditions are: time (min) Mobile phase A (%) Mobile phase B (%) 0.00 90 10 10 90 10 30 30 70 40 30 70 40.01 90 10 45 90 10 . 2. detection method according to claim 1 is characterized in that, described diluent is acetonitrile. 3. detection method according to claim 1, is characterized in that, in step 3)-5), the column temperature of chromatographic column is room temperature; Mobile phase flow rate is 0.7-1.2mL/min; Detector is ultraviolet detector. 4. detection method according to claim 1 is characterized in that, when carrying out system suitability test in step 4), the theoretical plate number is calculated by 3-ethoxy-4-methoxybenzaldehyde and is not less than 5000, The resolution between the main peak and any impurity peak should not be less than 1.5. 5 . The detection method according to claim 3 , wherein the concentration of the KH ₂ PO ₄ buffer is 0.01-0.05 mol/L, and the pH is adjusted to 2.8-3.2 with phosphoric acid. 6 . 6 . The detection method according to claim 3 , wherein the detection wavelength of the ultraviolet detector is 220-240 nm. 7 . 7. detection method according to claim 3 is characterized in that, the specification of Phenomenex Luna 5u C18 (2) 100A chromatographic column is 4.6*250mm*5μm.

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