Method for detecting substances such as 1-bromo-4-chlorobutane by utilizing gas chromatography

Abstract

The invention discloses a method for detecting substances such as 1-bromo-4-chlorobutane by using a gas chromatography, which comprises the following steps: (1) dissolving reference substances of 1, 4-dichlorobutane, 1, 4-dibromobutane, 1-bromo-4-chlorobutane, 4-chloro-1-butanol and 4-bromo-1-butanol in the same solvent to obtain a system applicable solution; (2) dissolving a test sample containing 1-bromo-4-chlorobutane in a solvent to obtain a test sample solution; (3) performing gas chromatography detection, and calculating the content of each substance by an external standard method; the initial column temperature of the chromatographic column is 45-55 DEG C, the temperature is kept for 2 min, the temperature is increased to 100 DEG C at the rate of 1-5 DEG C / min, then the temperature is increased to 250 DEG C at the rate of 15-25 DEG C / min, and the temperature is kept for 5 The method is simple, convenient and rapid to operate, high in specificity, high in sensitivity and high in accuracy, and effectively fills the blank in the field of methods for detecting haloalkane impurities in synthesis of 1-bromo-4-chlorobutane.

Description

Technical Field

[0001] The invention belongs to the technical field of drug analysis, and in particular relates to a method for detecting substances such as 1-bromo-4-chlorobutane by utilizing gas chromatography. Background Art

[0002] 1-Bromo-4-chlorobutane (1-Bromo-4-chlorobutane), chemical name, is a halogenated alkane compound, its molecular structure contains an alkyl chain and two halogen atoms (bromine and chlorine), and it is easy to undergo nucleophilic substitution reaction in synthesis. 1-Bromo-4-chlorobutane has a wide range of uses, such as breprazol, aripiprazole, and breprazatin compounds synthesized using 1-Bromo-4-chlorobutane as a starting material, which are mainly used as antipsychotic drugs for the treatment of various types of schizophrenia. In the synthesis route, 1-Bromo-4-chlorobutane is generated by the reaction of 1,4-dichlorobutane, 1,4-dichlorobutane and tetrabutylammonium bromide, and 4-chloro-1-butanol and 4-bromo-1-butanol by-products may be derived. These impurities all have the warning structure of genotoxic impurities.

[0003] Chinese patent document with publication number CN114646694A discloses a method for separating and detecting impurities in epiriprazole by gas chromatography, which can realize the analysis and detection of 1-bromo-4-chlorobutane, 1,4-dichlorobutane and 1,4-dibromobutane impurities in epiriprazole. However, it can only detect three impurities, and the types of impurities detected are relatively small, which has limitations.

[0004] Chinese patent document with publication number CN117030868A discloses a method for detecting genotoxic impurities in aripiprazole. Although it can detect 1,4-dichlorobutane, 1,4-dibromobutane, 1-bromo-4-chlorobutane, 4-chloro-1-butanol and 4-bromo-1-butanol, it requires FID and ECD detectors to detect separately, and the operation is relatively complicated. It is impossible to simultaneously separate and quantitatively detect the five impurities of 1,4-dichlorobutane, 4-chloro-1-butanol, 1-bromo-4-chlorobutane, 4-bromo-1-butanol and 1,4-dibromobutane.

[0005] There is no research on the detection of impurities in the synthesis process of 1-bromo-4-chlorobutane in the prior art. However, controlling genotoxic impurities in the synthesis of 1-bromo-4-chlorobutane, the starting material for drug synthesis, can play an important role in the safety performance of the drug. Therefore, it is of great significance to establish a simple, efficient and comprehensive detection method for substances such as 1-bromo-4-chlorobutane. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a method for detecting substances such as 1-bromo-4-chlorobutane by using gas chromatography. The method is simple to operate, has strong specificity, high sensitivity, high accuracy, good linearity and durability, and can accurately and quickly determine the contents of five substances such as 1-bromo-4-chlorobutane, thereby solving the problem that the existing detection method of halogenated alkyl impurities with genetic genotoxicity in the synthesis of 1-bromo-4-chlorobutane is imperfect, the operation is complicated, the accuracy is low, and the drug quality control cannot be effectively guaranteed.

[0007] The content of the present invention includes:

[0008] A method for detecting substances such as 1-bromo-4-chlorobutane by gas chromatography comprises the following steps:

[0009] (1) Dissolve the reference substances of 1,4-dichlorobutane, 1,4-dibromobutane, 1-bromo-4-chlorobutane, 4-chloro-1-butanol and 4-bromo-1-butanol in the same solvent to obtain a system suitability solution;

[0010] (2) dissolving a test sample containing 1-bromo-4-chlorobutane in a solvent to obtain a test sample solution;

[0011] (3) The system suitability solution and the test solution are respectively subjected to gas chromatography to obtain a spectrum of the system suitability solution and a spectrum of the test solution, and the contents of 1,4-dichlorobutane, 1,4-dibromobutane, 4-chloro-1-butanol and 4-bromo-1-butanol in the test solution are calculated using an external standard method;

[0012] The programmed temperature rise of the gas chromatography method is as follows: the initial column temperature of the chromatographic column is 45-55°C, maintained for 2 minutes, then heated to 100°C at a rate of 1-5°C / min, then heated to 250°C at a rate of 15-25°C / min, and maintained for 5 minutes; the preferred programmed temperature rise is as follows: the initial column temperature of the chromatographic column is 50°C, maintained for 2 minutes, then heated to 100°C at a rate of 2°C / min, then heated to 250°C at a rate of 20°C / min, and maintained for 5 minutes.

[0013] The 1-bromo-4-chlorobutane and other substances mainly include the following five kinds:

[0014] 1-Bromo-4-chlorobutane structural formula: English name: 1-Bromo-4-chlorobutane, CAS number: 6940-78-9, molecular weight: 171.46;

[0015] 1,4-Dibromobutane structure: English name: 1,4-Dibromobutane, CAS number: 110-52-1, molecular weight: 215.91;

[0016] 1,4-Dichlorobutane structural formula: English name: 1,4-Dichlorobutane, CAS number: 110-56-5, molecular weight: 127.012;

[0017] 4-Bromo-1-butanol structural formula: English name: 4-Bromo-1-butanol, CAS number: 33036-62-3, molecular weight: 153.02;

[0018] 4-Chloro-1-butanol structural formula: English name: 4-Chloro-1-butanol, CAS number: 928-51-8, molecular weight: 108.57.

[0019] Furthermore, the solvent in step (1) and step (2) includes one or more of acetonitrile, N,N-dimethylformamide, and N,N-dimethylacetamide.

[0020] Furthermore, the concentration of 1-bromo-4-chlorobutane in the test solution is 50 mg / mL.

[0021] Furthermore, the concentrations of 1,4-dichlorobutane, 1,4-dibromobutane, 1-bromo-4-chlorobutane, 4-chloro-1-butanol and 4-bromo-1-butanol in the system suitability solution are all 0.25 mg / mL.

[0022] Furthermore, the injection volumes of the system suitability solution and the test solution in the gas chromatography method are both 1.0 μL.

[0023] Further, the gas chromatography method also includes:

[0024] Capillary column with 5% phenyl-95% methyl polysiloxane as stationary phase;

[0025] Carrier gas: nitrogen;

[0026] Inlet temperature: 255°C to 265°C, preferably 260°C;

[0027] FID detector temperature: 255°C to 265°C, preferably 260°C;

[0028] The flow rate is 1.5-2.5 mL / min, preferably 2.0 mL / min;

[0029] Split ratio: 15-25:1, preferably 20:1.

[0030] Beneficial effects of the present invention:

[0031] (1) The present invention can simultaneously separate and quantitatively detect five substances: 1,4-dichlorobutane, 4-chloro-1-butanol, 1-bromo-4-chlorobutane, 4-bromo-1-butanol, and 1,4-dibromobutane;

[0032] (2) The method of the present invention is easy to operate, has strong specificity, high sensitivity, high accuracy, good linearity and durability;

[0033] (3) The detection method of the present invention fills the technical gap in the field of halogenated hydrocarbon impurity detection methods in drug synthesis, and can effectively detect genotoxic halogenated hydrocarbon impurities such as 1,4-dichlorobutane, 1,4-dibromobutane, 4-chloro-1-butanol, and 4-bromo-1-butanol in the synthesis process of 1-bromo-4-chlorobutane, thereby achieving strict control of drug quality from the source;

[0034] (4) The present invention explored suitable chromatographic conditions and temperature increase program and found that the initial column temperature of the chromatographic column was 50°C, maintained for 2 min, then heated to 100°C at a rate of 2°C / min, then heated to 250°C at a rate of 20°C / min, and maintained for 5 min. The program temperature increase achieved good separation effect of the substances and short time. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The gas chromatography spectrum of Example 1;

[0036] Figure 2 is the spectrum of blank solvent acetonitrile;

[0037] Figure 3 is the spectrum of the system suitability solution;

[0038] Figure 4 is the spectrum of the test solution;

[0039] Figure 5 This is the result graph of 1,4-dichlorobutane linear test;

[0040] Figure 6 This is the result graph of the linear test of 4-chloro-1-butanol;

[0041] Figure 7 This is the result graph of the linear test of 1-bromo-4-chlorobutane;

[0042] Figure 8 This is the result diagram of the linear test of 4-bromo-1-butanol;

[0043] Fig. 9 This is the result diagram of the linear test of 1,4-dibromobutane;

[0044] Fig.10 is the accuracy solution chromatogram;

[0045] Fig.11 The gas chromatography spectrum of Comparative Example 1;

[0046] Fig.12 The gas chromatography spectrum of Comparative Example 2;

[0047] Fig.13 The gas chromatography spectrum of Comparative Example 3;

[0048] Fig.14 This is the gas chromatography measurement spectrum of Comparative Example 4. DETAILED DESCRIPTION

[0049] Example 1

[0050] Preparation of system suitability solution and test sample solution:

[0051] (1) Dissolve the reference substances of 1,4-dichlorobutane, 1,4-dibromobutane, 1-bromo-4-chlorobutane, 4-chloro-1-butanol and 4-bromo-1-butanol in the same acetonitrile solvent to obtain a system suitability solution, wherein the concentrations of 1,4-dichlorobutane, 1,4-dibromobutane, 1-bromo-4-chlorobutane, 4-chloro-1-butanol and 4-bromo-1-butanol in the system suitability solution are all 0.25 mg / mL;

[0052] (2) A test sample containing 1-bromo-4-chlorobutane is dissolved in acetonitrile solvent to obtain a test solution, wherein the concentration of 1-bromo-4-chlorobutane in the test solution is 50 mg / mL.

[0053] Instrument conditions: Gas chromatograph, Shimadzu GC-2030;

[0054] The gas chromatography conditions are:

[0055] Chromatographic column: capillary column with 5% phenyl-95% methyl polysiloxane as stationary liquid;

[0056] Inlet temperature: 260°C;

[0057] FID detector temperature: 260°C;

[0058] Carrier gas: nitrogen;

[0059] Flow rate: 2.0 mL / min;

[0060] Program temperature rise: the initial column temperature is 50°C, maintained for 2 min, then raised to 100°C at a rate of 2°C / min, then raised to 250°C at a rate of 20°C / min, and maintained for 5 min;

[0061] The split ratio is 20:1.

[0062] Accurately measure 1.0 μL of the system suitability solution, inject it into the gas chromatograph, and record the chromatogram.

[0063] Results Figure 1 and Table 1.

[0064] Table 1 System applicability of Example 1 Location time and separation results of each impurity in the solution

[0065] name RT(min) Separation 1,4-Dichlorobutane 6.824 / 4-Chloro-1-butanol 7.700 8.57 1-Bromo-4-chlorobutane 10.202 21.31 4-Bromo-1-butanol 11.382 8.74 1,4-Dibromobutane 14.535 21.02

[0066] The adjacent peaks of impurities in the system suitability solution can be effectively separated, and the resolution is greater than 1.5.

[0067] Example 2 (method verification)

[0068] 1. Exclusive inspection

[0069] Preparation of system suitability solution, test sample solution and impurity location solution:

[0070] (1) Dissolve the reference substances of 1,4-dichlorobutane, 1,4-dibromobutane, 1-bromo-4-chlorobutane, 4-chloro-1-butanol and 4-bromo-1-butanol in the same acetonitrile solvent to obtain a system suitability solution, wherein the concentrations of 1,4-dichlorobutane, 1,4-dibromobutane, 1-bromo-4-chlorobutane, 4-chloro-1-butanol and 4-bromo-1-butanol in the system suitability solution are all 0.25 mg / mL;

[0071] (2) dissolving a test sample containing 1-bromo-4-chlorobutane in an acetonitrile solvent to obtain a test solution, wherein the concentration of 1-bromo-4-chlorobutane in the test solution is 50 mg / mL;

[0072] (3) 1,4-dichlorobutane, 1,4-dibromobutane, 1-bromo-4-chlorobutane, 4-chloro-1-butanol and 4-bromo-1-butanol were dissolved in acetonitrile respectively and diluted to prepare a solution containing 0.25 mg of each of 1,4-dichlorobutane, 1,4-dibromobutane, 1-bromo-4-chlorobutane, 4-chloro-1-butanol and 4-bromo-1-butanol per 1 mL, which was used as an impurity localization solution.

[0073] Accurately measure 1.0 μL of acetonitrile blank solvent, system suitability solution, test sample solution, and each impurity location solution, inject them into the gas chromatograph, and record the chromatogram.

[0074] The results are as follows Figure 2 to Figure 4 As shown: The results of the experimental positioning and separation of each impurity show that the blank has no interference, other related substances have no interference with the sample determination, the separation between each impurity is good, and the specificity of this analysis condition is good. The test results are shown in Table 2 below:

[0075] Table 2 Specificity test results

[0076]

[0077] 2. Sensitivity test results:

[0078] Table 3 Specific test results of limit of quantification (LOQ)

[0079]

[0080] Table 4 Specific test results of detection limit (LOD)

[0081]

[0082] The results of the quantitative limits and detection limits of each known impurity and main component showed that the detection sensitivity of each impurity was high and the method sensitivity met the requirements.

[0083] 3. Linear investigation, such as Figures 5 to 9 As shown:

[0084] When the peak area was plotted against the concentration, the peak area and concentration showed a good linear relationship when the concentration of 1,4-dichlorobutane was in the range of 4.95μg / ml~371.27μg / ml, the concentration of 4-chloro-1-butanol was in the range of 4.50μg / ml~337.64μg / ml, the concentration of 1-bromo-4-chlorobutane was in the range of 6.34μg / ml~380.29μg / ml, the concentration of 4-bromo-1-butanol was in the range of 10.13μg / ml~303.96μg / ml, and the concentration of 1,4-dibromobutane was in the range of 12.70μg / ml~380.88μg / ml.

[0085] Table 5 Linearity test results

[0086] name Regression equation Correlation coefficient r 1,4-Dichlorobutane y=288.1008x-1,631.8607 0.9995 4-Chloro-1-butanol y=285.1451x-1,497.4778 0.9995 1-Bromo-4-chlorobutane y=219.8527x-1,272.8965 0.9994 4-Bromo-1-butanol y=170.7972x-586.1789 0.9999 1,4-Dibromobutane y=186.9107x-1,162.2647 0.9996

[0087] 4. Accuracy test

[0088] Recovery solutions were prepared by adding samples at the limiting concentrations of 50%, 100% and 150% of 1,4-dichlorobutane, 4-chloro-1-butanol, 4-bromo-1-butanol and 1,4-dibromobutane, respectively. Three portions were prepared in parallel for each concentration group. At the same time, two portions of unspecified test solutions and one portion of system suitability solution were prepared. The recovery was calculated according to the chromatographic conditions of Example 1.

[0089] The recovery rates of all related substances were within the range of 90%-110%. The results are shown in Table 6 below and the chromatograms are shown in Fig.10 .

[0090] Table 6 Accuracy test results

[0091]

[0092] 5. Durability inspection

[0093] The initial column temperature (50±5℃), carrier gas flow rate (2.0±1.0ml / min), injection port temperature (260±5℃), and detector temperature (260±2℃) were changed respectively, and the separation results of each peak in the system suitability solution were compared to investigate its durability.

[0094] By changing the chromatographic parameters, the separation of the system suitability solutions was greater than 1.5, indicating that the method had good durability.

[0095] The results are shown in Table 7 below.

[0096] Table 7 Durability test results

[0097]

[0098] Comparative Example 1

[0099] Program temperature rise: the initial column temperature of the chromatographic column is 50°C, maintained for 2 min, then raised to 250°C at a rate of 10°C / min, maintained for 5 min; other conditions are the same as those in Example 1. The results are shown in Tables 8 and Fig.11 .

[0100] Table 8 System applicability of comparative example 1 Solution location time and separation results of each impurity

[0101] name RT(min) Separation 1,4-Dichlorobutane 5.249 / 4-Chloro-1-butanol 5.593 6.18 1-Bromo-4-chlorobutane 6.582 17.57 4-Bromo-1-butanol 6.915 5.76 1,4-Dibromobutane 7.927 17.23

[0102] Adjacent peaks of impurities in the system applicability solution can be effectively separated, and the separation degrees are all greater than 1.5, but the separation effect of Comparative Example 1 is poorer than that of Example 1.

[0103] Comparative Example 2

[0104] Program temperature rise: the initial column temperature is 50°C, maintained for 2 min, then raised to 100°C at a rate of 10°C / min, then raised to 250°C at a rate of 30°C / min, and maintained for 5 min;

[0105] Other results are the same as in Example 1. The results are shown in Tables 9 and Fig.12 .

[0106] Table 9 System applicability of comparative example 2 Solution location time and separation results of each impurity

[0107] name RT(min) Separation 1,4-Dichlorobutane 5.250 / 4-Chloro-1-butanol 5.593 6.11 1-Bromo-4-chlorobutane 6.582 17.45 4-Bromo-1-butanol 6.915 5.77 1,4-Dibromobutane 7.773 16.18

[0108] Adjacent peaks of impurities in the system applicability solution can be effectively separated, and the separation degrees are all greater than 1.5, but the separation effect of Comparative Example 2 is poorer than that of Example 1.

[0109] Comparative Example 3

[0110] Program temperature rise: the initial column temperature is 50°C, maintained for 2 min, then raised to 100°C at a rate of 10°C / min, then raised to 250°C at a rate of 15°C / min, and maintained for 5 min;

[0111] Other results are the same as in Example 1. The results are shown in Tables 10 and 10 below. Fig.13 .

[0112] Table 10 System applicability of comparative example 3 Solution location time and separation results of each impurity

[0113] name RT(min) Separation 1,4-Dichlorobutane 5.248 / 4-Chloro-1-butanol 5.591 6.16 1-Bromo-4-chlorobutane 6.580 17.50 4-Bromo-1-butanol 6.913 5.73 1,4-Dibromobutane 7.876 16.85

[0114] Adjacent peaks of impurities in the system applicability solution can be effectively separated, and the separation degrees are all greater than 1.5, but the separation effect of Comparative Example 3 is poorer than that of Example 1.

[0115] Comparative Example 4

[0116] Program temperature rise: the initial column temperature is 50°C, maintained for 2 min, then raised to 100°C at a rate of 1°C / min, then raised to 250°C at a rate of 10°C / min, and maintained for 5 min;

[0117] Other results are the same as in Example 1. The results are shown in Tables 11 and 11 below. Fig.14 .

[0118] Table 11 System applicability of comparative example 4 Solution location time and separation results of each impurity

[0119]

[0120]

[0121] Adjacent peaks of impurities in the system applicability solution can be effectively separated, and the separation degrees are all greater than 1.5. The separation effect of Comparative Example 4 is equivalent to that of Example 1, but the running time of Comparative Example 4 is longer.

[0122] A person skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of protection of the present application is limited to these examples. In line with the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of different aspects of one or more embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0123] One or more embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the present application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of the present application should be included in the protection scope of the present application.

Claims

1. A method for detecting substances such as 1-bromo-4-chlorobutane by gas chromatography, characterized in that: The following steps are involved: (1) Dissolve the reference substances of 1,4-dichlorobutane, 1,4-dibromobutane, 1-bromo-4-chlorobutane, 4-chloro-1-butanol and 4-bromo-1-butanol in the same solvent to obtain a system suitability solution; (2) dissolving a test sample containing 1-bromo-4-chlorobutane in a solvent to obtain a test sample solution; (3) The system suitability solution and the test solution are respectively subjected to gas chromatography to obtain a spectrum of the system suitability solution and a spectrum of the test solution, and the contents of 1,4-dichlorobutane, 1,4-dibromobutane, 4-chloro-1-butanol and 4-bromo-1-butanol in the test solution are calculated using an external standard method; The temperature program of the gas chromatography method is as follows: the initial column temperature of the chromatographic column is 45-55°C, maintained for 2 minutes, heated to 100°C at a rate of 1-5°C / min, and then heated to 250°C at a rate of 15-25°C / min, and maintained for 5 minutes.

2. The method for detecting 1-bromo-4-chlorobutane and the like by gas chromatography as claimed in claim 1, characterized in that: The solvent in step (1) and step (2) includes one or more of acetonitrile, N,N-dimethylformamide, and N,N-dimethylacetamide.

3. The method for detecting substances such as 1-bromo-4-chlorobutane by gas chromatography as claimed in claim 1, characterized in that: The concentration of 1-bromo-4-chlorobutane in the test solution is 50 mg / mL.

4. The method for detecting substances such as 1-bromo-4-chlorobutane by gas chromatography as claimed in claim 1, characterized in that: The concentrations of 1,4-dichlorobutane, 1,4-dibromobutane, 1-bromo-4-chlorobutane, 4-chloro-1-butanol and 4-bromo-1-butanol in the system suitability solution are all 0.25 mg / mL.

5. The method for detecting 1-bromo-4-chlorobutane and the like by gas chromatography as claimed in claim 1, characterized in that: The injection volume of the system suitability solution and the test solution in the gas chromatography method is 1.0 μL.

6. The method for detecting 1-bromo-4-chlorobutane and the like by gas chromatography as claimed in claim 1, characterized in that: The programmed temperature increase is as follows: the initial column temperature of the chromatographic column is 50°C, maintained for 2 minutes, then increased to 100°C at a rate of 2°C / min, then increased to 250°C at a rate of 20°C / min, and maintained for 5 minutes.

7. The method for detecting 1-bromo-4-chlorobutane and the like by gas chromatography as claimed in any one of claims 1 to 6, characterized in that: The gas chromatography method also includes: a capillary column with 5% phenyl-95% methyl polysiloxane as a stationary liquid; Inlet temperature: 255℃~265℃; FID detector temperature: 255℃~265℃; Flow rate is 1.5-2.5mL / min; Split ratio: 15-25:

1.

8. The method for detecting 1-bromo-4-chlorobutane and the like by gas chromatography as claimed in claim 7, characterized in that: The injection port temperature was 260°C, and the FID detector temperature was 260°C.

9. The method for detecting substances such as 1-bromo-4-chlorobutane by gas chromatography as claimed in claim 7, characterized in that: The flow rate was 2.0 mL / min.

10. The method for detecting 1-bromo-4-chlorobutane and the like by gas chromatography as claimed in claim 8 or 9, characterized in that: The split ratio is 20:1.

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