LC-MS detection method for N, N-diethyl-N ', N'-dimethylethylenediamine in chlorpheniramine maleate

Abstract

The invention discloses an LC-MS (liquid chromatography-mass spectrometry) detection method for N, N-diethyl-N ', N'-dimethylethylenediamine in chlorpheniramine maleate, and belongs to the technical field of analytical chemistry. The method comprises the following steps: firstly, preparing a test solution and a reference solution for later use; then setting liquid chromatography-mass spectrometry detection conditions, and detecting N, N-diethyl-N ', N'-dimethylethylenediamine in chlorpheniramine maleate by adopting a Shim-pack Scept Diol-HILIC-120 chromatographic column, taking a 0.1% difluoroacetic acid aqueous solution-acetonitrile mixed solution as a mobile phase and taking a 1% diethylamine acetonitrile solution as a solvent. According to the method, a liquid chromatography-mass spectrometry technology is adopted, the problem that N, N-diethyl-N ', N'-dimethyl ethylenediamine has no ultraviolet absorption can be effectively solved, and meanwhile, the method is high in specificity, high in sensitivity and high in efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of analytical chemistry, and particularly relates to an LC-MS detection method for N,N-diethyl-N′,N′-dimethylethane-1,2-diamine in chlorphenamine maleate. Background Art

[0002] Chlorphenamine maleate, with the INN name Chlorphenamine maleate, has the chemical name 2-[p-chloro-α-[2-(dimethylamino)ethyl]phenyl]pyridine maleate, molecular formula: C 16 H 19 ClN2·C4H4O4, molecular weight: 390.86, and the structural formula is shown in Formula I. Chlorphenamine maleate is an active pharmaceutical ingredient produced and sold by our company. As a first-generation H1 receptor antagonist, it can selectively block histamine receptors, antagonize the effects of histamine to produce an antihistamine effect; it can counteract the capillary dilation caused by allergic reactions (histamine), reduce the permeability of capillaries, and relieve the wheezing caused by bronchial smooth muscle contraction. The antihistamine effect of this product is relatively persistent, and it also has an obvious central inhibitory effect, which can enhance the effects of anesthetics, analgesics, hypnotics, and local anesthetics. Its main indications are skin allergies such as urticaria, eczema, dermatitis, drug eruption, pruritus, neurodermatitis, insect bites, and solar dermatitis. It can also be used for allergic rhinitis, drug and food allergies. Clinically, it is used for various allergic diseases and can also be combined with other Chinese and Western medicines as one of the main components of compound anti-cold medicines.

[0003]

[0004] The applicant produces chlorphenamine maleate using p-chlorobenzyl cyanide, 2-bromopyridine, dimethylaminoethyl chloride hydrochloride, and maleic acid as starting materials, and obtains chlorphenamine maleate through a total of 5 steps including substitution, condensation, hydrolysis, synthesis of chlorphenamine maleate crude product, and refining of chlorphenamine maleate finished product. During the production process of chlorphenamine maleate, the impurity N,N-diethyl-N′,N′-dimethylethane-1,2-diamine may be introduced by the starting material dimethylaminoethyl chloride hydrochloride, thus affecting the quality of chlorphenamine maleate and its preparations. Therefore, it is necessary to monitor and control N,N-diethyl-N′,N′-dimethylethane-1,2-diamine in chlorphenamine maleate to ensure that N,N-diethyl-N′,N′-dimethylethane-1,2-diamine is not introduced.

[0005] N,N-diethyl-N′,N′-dimethylethane-1,2-diamine, with the English name N,N-diethyl-N′,N′-dimethylethane-1,2-diamine, molecular formula: C8H20N2, molecular weight: 144.26, and the structural formula is shown in Formula II. Its possible generation pathways are:

[0006]

[0007] N,N - Diethyl - N′,N′ - dimethylethylenediamine is commonly used as a bidentate ligand and can form complexes with metal ions (such as Cu 2+ 、Ni 2+ etc.); or it is used in the preparation of drugs, surfactants or ionic liquids, and participates in reactions such as condensation and alkylation; or it is used as a precursor of cationic surfactants for designing polymers with specific functions, etc. It is corrosive and irritating to the skin, eyes and respiratory tract. Prolonged exposure may cause redness, pain, allergies, etc. High doses may cause central nervous system depression (dizziness, nausea), so strict control of N,N - Diethyl - N′,N′ - dimethylethylenediamine is required.

[0008] According to the chemical structural formula of N,N - Diethyl - N′,N′ - dimethylethylenediamine, it has no ultraviolet absorption, so the conventional high - performance liquid chromatography method cannot monitor it, and the content it may contain in chlorpheniramine maleate is very low, so a highly sensitive method is needed to detect and monitor it. The liquid chromatography - mass spectrometry (LC - MS) technique is an analytical technique that combines the high - efficiency separation ability of liquid chromatography with the high - sensitivity and structure - identification ability of mass spectrometry. It can not only identify and detect compounds without ultraviolet absorption by combining the fragment ion information of their mass spectra, but also detect trace - level (ppm to ppb level) compounds due to its high - sensitivity characteristics, and can meet the stringent requirements for quantitative detection of trace impurities without ultraviolet absorption. Currently, there is no reported detection method for N,N - Diethyl - N′,N′ - dimethylethylenediamine. Therefore, this patent provides a detection method with high sensitivity and low product matrix interference by LC - MS method, providing technical support for the quality control of chlorpheniramine maleate and its preparations. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide an LC - MS detection method for N,N - Diethyl - N′,N′ - dimethylethylenediamine in chlorpheniramine maleate, which is fast, simple, effective, highly specific, sensitive and efficient.

[0010] To solve the above - mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0011] An LC - MS detection method for N,N - Diethyl - N′,N′ - dimethylethylenediamine in chlorpheniramine maleate, comprising the following steps:

[0012] 1) Prepare a test solution and a reference solution for later use;

[0013] 2) Set the liquid chromatography-mass spectrometry detection conditions: Use a Shim-pack Scepter Diol-HILIC-120 chromatographic column, with a mixed solution of 0.1% difluoroacetic acid aqueous solution-acetonitrile as the mobile phase, and 1% diethylamine acetonitrile solution as the solvent for isocratic elution;

[0014] 3) Respectively take the test solution and the reference solution, inject them into the liquid chromatography-mass spectrometer, and record and analyze the chromatogram.

[0015] Further, in the step 2), the specification of the Shim-pack Scepter Diol-HILIC-120 chromatographic column is 2.1×100mm, and the packing particle size is 3μm.

[0016] Further, in the step 2), the volume ratio of 0.1% difluoroacetic acid aqueous solution to acetonitrile is 15:85.

[0017] Further, in the step 2), the flow rate of the mobile phase is 0.4 mL / min.

[0018] Further, in the step 2), the column temperature of the chromatographic column is 25°C, and the injection volume is 1 μL.

[0019] Further, in the step 2), the sample disk temperature is 5°C; the mass spectrometer is a quadrupole, and the ion source is AJSESI.

[0020] Further, in the step 2), the drying gas temperature is 300°C, and the drying gas flow rate is 10 L / min.

[0021] Further, in the step 2), the sheath gas temperature is 325°C, and the sheath gas flow rate is 11 L / min.

[0022] Further, in the step 2), the nebulizing gas pressure is 45 psi, and the voltage is 3500 V.

[0023] Further, in the step 2), the scanning mode is SIM(+), and the extracted ion is m / z145.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] The present invention provides a method for detecting N,N-diethyl-N′,N′-dimethyl ethylenediamine in chlorpheniramine maleate. By using liquid chromatography-mass spectrometry (LC-MS) technology, it can not only effectively solve the problem that N,N-diethyl-N′,N′-dimethyl ethylenediamine has no ultraviolet absorption, but also achieve the quantitative detection of N,N-diethyl-N′,N′-dimethyl ethylenediamine. The method has strong specificity, high sensitivity and fast efficiency. The analytical method of the present invention is rapid, simple, effective and reliable, and can effectively determine the content of N,N-diethyl-N′,N′-dimethyl ethylenediamine in chlorpheniramine maleate, thus ensuring the quality of chlorpheniramine maleate raw materials. Description of the Drawings

[0026] Figure 1 It is the chromatogram of the reference solution of this application;

[0027] Figure 2 It is the chromatogram of the test solution of this application;

[0028] Figure 3 It is the chromatogram of the spiked test solution of this application. Detailed Embodiments

[0029] The following will further clarify the present invention in combination with specific embodiments. The embodiments are implemented on the premise of the technical solution of the present invention. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0030] Example 1

[0031] An LC-MS detection method for N,N-diethyl-N′,N′-dimethyl ethylenediamine in chlorpheniramine maleate comprises the following steps:

[0032] 1) Instrument and sample selection: The model of LC-MS is Agilent 6460, and the chlorpheniramine maleate is from Jiangsu Lianhuan Pharmaceutical Co., Ltd., with the batch number NM201912001.

[0033] 2) Instrument parameter settings: the chromatographic column is Shim-pack Scepter Diol-HILIC-120 (2.1×100 mm, 3 μm); the mobile phase A is 0.1% difluoroacetic acid aqueous solution (1.0 mL of difluoroacetic acid is transferred to 1 L of ultrapure water, mixed, and ultrasonicated for 10 min); the mobile phase B is acetonitrile; the isocratic elution is mobile phase A (%): mobile phase B = 15:85; the flow rate is 0.4 mL / min; the column temperature is 25°C; the injection volume is 1 μL; the sample tray temperature is 5°C; the mass spectrometer is a quadrupole, and the ion source is AJS ESI; voltage is 3500V(+); nebulizing gas pressure is 45psi; drying gas temperature is 300℃; sheath gas temperature is 325℃; drying gas flow rate is 10L / min; sheath gas flow rate is 11L / min; scanning mode is SIM(+); extracted ion is m / z145; solvent is 1% diethylamine acetonitrile solution; running time is 8min.

[0034] 3) Preparation of sample solution

[0035] Reference substance stock solution 1: Take about 25 mg of impurity N,N-diethyl-N′,N′-dimethylethylenediamine, accurately weigh it, put it into a 50 mL volumetric flask, add an appropriate amount of solvent to dissolve and dilute to the scale, shake well to obtain;

[0036] Reference substance stock solution 2: Accurately measure 1.25 mL of reference substance stock solution 1 into a 25 mL volumetric flask, dilute to the mark with solvent, and shake well;

[0037] Reference substance solution: Pipette 100 μL of reference substance stock solution 2 into a 25 mL volumetric flask, dilute to the mark with solvent, and shake well;

[0038] Test solution: Take about 25 mg of chlorpheniramine maleate, accurately weigh it, put it into a 25 mL volumetric flask, add an appropriate amount of solvent to dissolve and dilute to the scale, and shake well.

[0039] Blank solution: 1% diethylamine acetonitrile solution;

[0040] 4) Sample testing method

[0041] Take the blank solution, reference solution, and test solution and inject them according to the sequence in Table 1 below, and record the chromatogram. The injection sequence needs to use a running control (reference solution), take the first 5 injections of the first reference solution and 1 injection of the running control, calculate the RSD of the peak area, and require RSD≤15.0%; if multiple running controls are performed, calculate in the same way, and require RSD≤15.0%.

[0042] Table 1 Number of times solution is injected

[0043] Solution Name Number of Injection Needles Blank Solution 2 needles Reference Substance Solution 6 needles Test Solution (2 portions, Batch No. 1) 1 needle each Test Solution (2 portions, Batch No. 2) 1 needle each Reference Substance Solution (every 10 needles of Test Solution) 1 needle Reference Substance Solution 1 needle

[0044] Example 2

[0045] The detection method disclosed in Example 1 was verified in terms of system suitability, specificity, detection limit and quantitation limit, repeatability, linearity and range, stability, intermediate precision and accuracy, as follows:

[0046] 1. System suitability

[0047] Reference stock solution 1: Take about 25 mg of impurity N,N - diethyl - N′,N′ - dimethylethylenediamine, accurately weighed, transfer to a 50 mL volumetric flask, add an appropriate amount of solvent to dissolve and dilute to the mark, shake well to obtain;

[0048] Reference stock solution 2: Accurately pipette 1.25 mL of reference stock solution 1 into a 25 mL volumetric flask, dilute to the mark with solvent, and shake well to obtain;

[0049] Reference solution: Pipette 100 μL of reference stock solution 2 into a 25 mL volumetric flask, dilute to the mark with solvent, and shake well to obtain;

[0050] Operate according to the chromatographic conditions of Example 1 above. After the system is balanced, inject the reference solution 6 times and record the chromatogram. The results are shown in Tables 2 and 3 below.

[0051] Table 2 Results of system suitability test

[0052]

[0053]

[0054] Table 3 Results of intermediate precision

[0055]

[0056] As can be seen from Tables 2 and 3, the maximum RSD of the peak areas of the analyte in the reference solution injected continuously 6 times is 1.10%, RSD ≤ 15.0%, meeting the detection requirements; the maximum RSD of the peak areas of the first 5 injections of the reference solution and the accompanying reference substance is 1.84%, RSD ≤ 15.0%, meeting the detection requirements.

[0057] 2. Specificity

[0058] Blank solution: 1% diethylamine acetonitrile solution;

[0059] Reference stock solution 1: Take about 25 mg of impurity N,N - diethyl - N′,N′ - dimethylethylenediamine, accurately weighed, transfer to a 50 mL volumetric flask, add an appropriate amount of solvent to dissolve and dilute to the mark, shake well to obtain;

[0060] Reference stock solution 2: Accurately pipette 1.25 mL of reference stock solution 1 into a 25-mL volumetric flask, dilute to the mark with the solvent, and mix well to obtain;

[0061] Reference solution: Pipette 100 μL of reference stock solution 2 into a 25-mL volumetric flask, dilute to the mark with the solvent, and mix well to obtain;

[0062] Test solution: Take about 25 mg of chlorpheniramine maleate, accurately weigh it, transfer it to a 25-mL volumetric flask, add an appropriate amount of the solvent to dissolve and dilute to the mark, and mix well to obtain;

[0063] Fortified test solution: Take about 25 mg of chlorpheniramine maleate, accurately weigh it, transfer it to a 25-mL volumetric flask, add 100 μL of reference stock solution 2, add an appropriate amount of the solvent to dissolve and dilute to the mark, and mix well to obtain.

[0064] After the system suitability is qualified, operate according to the chromatographic conditions in Example 1 above. Take the blank solution, reference solution, test solution, and fortified test solution, inject each one needle, and record the chromatogram. The results are shown in Table 4 below, Figure 1 - 3 。

[0065] Table 4 Results of specificity test

[0066]

[0067] As can be seen from Table 4, compared with the chromatogram of the reference solution, the blank solution has no interference at the peak position of the analyte; no detection is found in the test solution, and the retention time of the analyte in the reference solution and the fortified test solution is the same; the peak of the analyte in the fortified test solution is significantly stronger than the corresponding peak in the test solution, and the method has good specificity.

[0068] 3. Detection limit and quantitation limit

[0069] Reference stock solution 1: Take about 25 mg of impurity N,N-diethyl-N′,N′-dimethyl ethylenediamine, accurately weigh it, transfer it to a 50-mL volumetric flask, add an appropriate amount of the solvent to dissolve and dilute to the mark, and mix well to obtain;

[0070] Reference stock solution 2: Accurately pipette 1.25 mL of reference stock solution 1 into a 25-mL volumetric flask, dilute to the mark with the solvent, and mix well to obtain;

[0071] Quantitation limit stock solution: Pipette 3.0 mL of reference stock solution 2 into a 10-mL volumetric flask, dilute to the mark with the solvent, and mix well to obtain;

[0072] Quantitation limit solution: Pipette 100 μL of the quantitation limit stock solution into a 25-mL volumetric flask, dilute to the mark with the solvent, and mix well to obtain;

[0073] Detection limit stock solution: Pipette 1.0 mL of reference stock solution 2 into a 10 mL volumetric flask, dilute to the mark with solvent, and mix well to obtain it;

[0074] Detection limit solution: Pipette 100 μL of detection limit stock solution into a 25 mL volumetric flask, dilute to the mark with solvent, and mix well to obtain it.

[0075] After the system suitability is qualified, operate according to the chromatographic conditions in Example 1 above. Inject 3 injections each of the quantitation limit solution and the detection limit solution, and record the chromatograms. The results are shown in Tables 5 - 6 below.

[0076] Table 5 Results of quantitation limit test

[0077]

[0078] As can be seen from Table 5, the RSD value of the peak areas of the analytes in the quantitation limit solution for 3 consecutive injections is 0.17%, RSD ≤ 15.0%. The minimum signal - to - noise ratio of the analytes in the quantitation limit solution is 131.0, S / N ≥ 10. The quantitation limit of this method is 0.0209 μg / mL, and the quantitation limit meets the detection requirements.

[0079] Table 6 Results of detection limit test

[0080]

[0081] As can be seen from Table 6, the minimum signal - to - noise ratio of the analytes in the detection limit solution is 48.7, S / N ≥ 3. The detection limit of this method is 0.0070 μg / mL, and the detection limit meets the detection requirements.

[0082] 4. Repeatability

[0083] Reference stock solution 1: Take about 25 mg of impurity N,N - diethyl - N′,N′ - dimethylethylenediamine, accurately weigh it, transfer it to a 50 mL volumetric flask, add an appropriate amount of solvent to dissolve and dilute to the mark, and mix well to obtain it;

[0084] Reference stock solution 2: Accurately pipette 1.25 mL of reference stock solution 1 into a 25 mL volumetric flask, dilute to the mark with solvent, and mix well to obtain it;

[0085] Reference solution: Pipette 100 μL of reference stock solution 2 into a 25 mL volumetric flask, dilute to the mark with solvent, and mix well to obtain it;

[0086] Repeatability solution: Take about 25 mg of chlorpheniramine maleate, accurately weigh it, transfer it to a 25 mL volumetric flask, add 100 μL of reference stock solution 2, add an appropriate amount of solvent to dissolve and dilute to the mark, and mix well. Prepare 6 parallel portions.

[0087] After the system suitability is qualified, operate according to the chromatographic conditions of Example 1 above. Take 6 portions of the repeatability solution, inject each one time, and calculate the content of the analyte in the 6 portions of the repeatability solution based on the average value of the peak areas of the reference solution in the system suitability. The results are shown in Table 7 below.

[0088] Table 7 Results of Repeatability Test

[0089]

[0090]

[0091] As can be seen from Table 7, the RSD of the content of the analyte in the 6 portions of the repeatability solution is 1.44%, and RSD ≤ 15.0%, indicating good repeatability.

[0092] 5. Linearity and Range

[0093] Reference stock solution 1: Take about 25 mg of impurity N,N - diethyl - N′,N′ - dimethylethylenediamine, weigh accurately, transfer to a 50 mL volumetric flask, add an appropriate amount of solvent to dissolve and dilute to the mark, and shake well to obtain;

[0094] Reference stock solution 2: Accurately measure 1.25 mL of reference stock solution 1 and transfer it to a 25 mL volumetric flask, dilute to the mark with solvent, and shake well to obtain;

[0095] Reference solution (100% linear solution): Pipette 100 μL of reference stock solution 2 into a 25 mL volumetric flask, dilute to the mark with solvent, and shake well to obtain;

[0096] Quantitation limit solution (30% linear solution): Pipette 100 μL of quantitation limit stock solution into a 25 mL volumetric flask, dilute to the mark with solvent, and shake well to obtain;

[0097] 50% linear stock solution: Pipette 5.0 mL of reference stock solution 2 into a 10 mL volumetric flask, dilute to the mark with solvent, and shake well to obtain;

[0098] 50% linear solution: Pipette 100 μL of 50% linear stock solution into a 25 mL volumetric flask, dilute to the mark with solvent, and shake well to obtain;

[0099] 150% linear stock solution: Pipette 0.75 mL of reference stock solution 1 into a 10 mL volumetric flask, dilute to the mark with solvent, and shake well to obtain;

[0100] 150% linear solution: Pipette 100 μL of 150% linear stock solution into a 25 mL volumetric flask, dilute to the mark with solvent, and shake well to obtain;

[0101] 75% linear stock solution: Pipette 5.0 mL of 150% linear stock solution into a 10 mL volumetric flask, dilute to the mark with solvent, and shake well to obtain;

[0102] 75% linear solution: Pipette 100 μL of 75% linear stock solution into a 25 mL volumetric flask, dilute to the mark with the solvent, and mix well to obtain.

[0103] After the system suitability is qualified, operate according to the chromatographic conditions of Example 1 above. Take 1 injection each of the quantitation limit solution and each linear solution, and record the chromatogram. Calculate the linear correlation coefficient r, the y-axis intercept, and the sum of squared residuals, the 95% confidence interval of the y-axis intercept, and the absolute value of the ratio of the y-axis intercept to the peak area corresponding to 100% concentration. The results are shown in Table 8.

[0104] Table 8 Results of linearity test

[0105]

[0106] As can be seen from Table 8, the concentration of N,N-diethyl-N′,N′-dimethyl ethylenediamine shows a linear relationship in the range of 0.0209 μg / mL to 0.1046 μg / mL (LOQ to 150% concentration level). The linear equation is y = 2016101.0591x - 3202.2546. The ratio of the absolute value of the y-axis intercept to the peak area corresponding to 100% concentration is 2.4%, and the r value is 0.9984, meeting the requirements.

[0107] 6. Stability

[0108] Reference stock solution 1: Weigh accurately about 25 mg of impurity N,N-diethyl-N′,N′-dimethyl ethylenediamine, transfer it to a 50 mL volumetric flask, add an appropriate amount of solvent to dissolve and dilute to the mark, and mix well to obtain;

[0109] Reference stock solution 2: Pipette accurately 1.25 mL of reference stock solution 1 into a 25 mL volumetric flask, dilute to the mark with the solvent, and mix well to obtain;

[0110] Reference solution: Pipette 100 μL of reference stock solution 2 into a 25 mL volumetric flask, dilute to the mark with the solvent, and mix well to obtain;

[0111] Test sample spiked solution: Weigh accurately about 25 mg of chlorpheniramine maleate, transfer it to a 25 mL volumetric flask, add 100 μL of reference stock solution 2, add an appropriate amount of solvent to dissolve and dilute to the mark, and mix well to obtain.

[0112] Place the prepared reference solution and test sample spiked solution on the 5°C sample tray. Without interrupting the system, after the system suitability is qualified, operate according to the chromatographic conditions of Example 1 above. Inject 1 injection of the reference solution at 0 h, 3 h, and 5.5 h respectively, and inject 1 injection of the test sample spiked solution at 0 h, 1.5 h, and 3.5 h respectively. Record the peak area of the analyte, and calculate the ratio of the peak area at each time point to the peak area at 0 h. The results are shown in Table 9.

[0113] Table 9 Results of Stability Test

[0114]

[0115] As can be seen from Table 9, the ratio of the peak area of the analyte in the control and spiked test solutions at each time point to the peak area at 0 h was 1.0 (within the range of 1.0 - 1.2); under the condition of 5 °C, within the investigated time range, the control solution was stable within 5.5 h, and the spiked test solution was stable within 3.5 h, indicating that this method has good stability.

[0116] 7. Intermediate Precision

[0117] Control Stock Solution 1: Take about 25 mg of impurity N,N - diethyl - N′,N′ - dimethylethylenediamine, weigh accurately, transfer to a 50 mL volumetric flask, add an appropriate amount of solvent to dissolve and dilute to the mark, and shake well to obtain;

[0118] Control Stock Solution 2: Accurately measure 1.25 mL of Control Stock Solution 1 and transfer to a 25 mL volumetric flask, dilute to the mark with solvent, and shake well to obtain;

[0119] Control Solution: Pipette 100 μL of Control Stock Solution 2 into a 25 mL volumetric flask, dilute to the mark with solvent, and shake well to obtain;

[0120] Intermediate Precision Solution: Take about 25 mg of chlorpheniramine maleate, weigh accurately, transfer to a 25 mL volumetric flask, add 100 μL of Control Stock Solution 2, add an appropriate amount of solvent to dissolve and dilute to the mark, and shake well to obtain. Prepare 6 parallel portions.

[0121] Operate by different analysts at different times in the same laboratory using the same instrument. After the system suitability is qualified, operate according to the chromatographic conditions in Example 1 above. Take 6 portions of the intermediate precision solution, inject 1 injection each, and record the chromatogram. Record the peak areas of the target peaks in the 6 portions of the intermediate precision solution and calculate the single values of the analyte content, Mean ± SD values, RSD values, and 95% confidence intervals. Calculate the RSD values of the contents of 12 replicates and intermediate precision, and the results are shown in Table 10.

[0122] Table 10 Results of Intermediate Precision Test

[0123]

[0124]

[0125] As can be seen from Table 10, the RSD of the content of the analyte in 6 intermediate precision solutions was 1.68%, RSD ≤ 15.0%, and the RSD of the content of the analyte in 12 solutions of repeatability and intermediate precision was 2.09%, RSD ≤ 15.0%, meeting the requirements, indicating that the method precision was good.

[0126] 8. Accuracy

[0127] Reference stock solution 1: Take about 25 mg of impurity N,N-diethyl-N′,N′-dimethyl ethylenediamine, weigh accurately, transfer to a 50 mL volumetric flask, add an appropriate amount of solvent to dissolve and dilute to the mark, shake well to obtain;

[0128] Reference stock solution 2: Accurately measure 1.25 mL of reference stock solution 1 and transfer it to a 25 mL volumetric flask, dilute to the mark with solvent, and shake well to obtain;

[0129] Reference solution: Pipette 100 μL of reference stock solution 2 into a 25 mL volumetric flask, dilute to the mark with solvent, and shake well to obtain;

[0130] Quantitation limit stock solution: Pipette 3.0 mL of reference stock solution 2 into a 10 mL volumetric flask, dilute to the mark with solvent, and shake well to obtain;

[0131] 150% linear stock solution: Pipette 0.75 mL of reference stock solution 1 into a 10 mL volumetric flask, add an appropriate amount of solvent to dissolve and dilute to the mark, shake well to obtain;

[0132] Accuracy solution: Take about 25 mg of chlorpheniramine maleate, weigh accurately, transfer to a 25 mL volumetric flask, add 100 μL of different concentration solutions (3 replicates for each concentration level) to 9 25 mL volumetric flasks according to the following table, dilute to the mark with solvent, and shake well to obtain. The addition amounts of each solution are shown in Table 11.

[0133] Table 11 Addition amounts of each solution

[0134] Spiking Level 30% (LOQ) Spiked Solution 100% Spiked Solution 150% Spiked Solution Added Solution Stock Solution for Limit of Quantification Stock Solution of Reference Substance 2 150% Linear Stock Solution Added Volume (mL) 0.1 0.1 0.1

[0135] After the system suitability is qualified, operate according to the chromatographic conditions of Example 1 above. Inject 1 injection of the test solution and 9 accuracy solutions respectively, and record the chromatograms. Calculate and report the content of the analyte in the test solution before and after spiking, the measured addition amount, the theoretical addition amount, the single value of recovery, the average value of recovery, the RSD value, and the 95% confidence interval. The results are shown in Table 12 below.

[0136] Table 12 Results of recovery accuracy test

[0137]

[0138] As can be seen from Table 12, the individual recovery rates of the analytes in the 9 accuracy solutions ranged from 98.0% to 108.4%, and the RSD of the overall recovery rate was 4.18%, meeting the requirements, indicating that the method has good accuracy.

[0139] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An LC-MS detection method for N,N-diethyl-N',N'-dimethylethylenediamine in chlorpheniramine maleate, characterized in that: The following steps are involved: 1) Prepare test solution and reference solution for use; 2) Setting the liquid chromatography-mass spectrometry detection conditions: using a Shim-pack Scepter Diol-HILIC-120 chromatographic column, using a mixed solution of 0.1% difluoroacetic acid aqueous solution-acetonitrile as the mobile phase, and a 1% diethylamine acetonitrile solution as the solvent, and performing isocratic elution; 3) Take the test solution and the reference solution respectively, inject them into the liquid chromatography-mass spectrometer, and record and analyze the chromatogram.

2. The LC-MS detection method of N,N-diethyl-N',N'-dimethylethylenediamine in chlorpheniramine maleate according to claim 1, characterized in that: In the step 2), the specification of the Shim-pack Scepter Diol-HILIC-120 chromatographic column is 2.1×100 mm, and the filler particle size is 3 μm.

3. The LC-MS detection method of N,N-diethyl-N',N'-dimethylethylenediamine in chlorpheniramine maleate according to claim 1, characterized in that: In the step 2), the volume ratio of 0.1% difluoroacetic acid aqueous solution to acetonitrile is 15:

85.

4. The LC-MS detection method of N,N-diethyl-N',N'-dimethylethylenediamine in chlorpheniramine maleate according to claim 2, characterized in that: In the step 2), the flow rate of the mobile phase is 0.4 mL / min.

5. The LC-MS detection method of N,N-diethyl-N',N'-dimethylethylenediamine in chlorpheniramine maleate according to claim 1, characterized in that: In the step 2), the column temperature of the chromatographic column is 25° C. and the injection volume is 1 μL.

6. The LC-MS detection method of N,N-diethyl-N',N'-dimethylethylenediamine in chlorpheniramine maleate according to claim 1, characterized in that: In the step 2), the sample tray temperature is 5° C.; the mass spectrometer is a quadrupole, and the ion source is AJS ESI.

7. The LC-MS detection method of N,N-diethyl-N',N'-dimethylethylenediamine in chlorpheniramine maleate according to claim 1, characterized in that: In the step 2), the drying gas temperature is 300° C. and the drying gas flow rate is 10 L / min.

8. The LC-MS detection method of N,N-diethyl-N',N'-dimethylethylenediamine in chlorpheniramine maleate according to claim 1, characterized in that: In the step 2), the sheath gas temperature is 325° C. and the sheath gas flow rate is 11 L / min.

9. The LC-MS detection method of N,N-diethyl-N',N'-dimethylethylenediamine in chlorpheniramine maleate according to claim 1, characterized in that: In the step 2), the atomizing gas pressure is 45 psi and the voltage is 3500V.

10. The LC-MS detection method of N,N-diethyl-N',N'-dimethylethylenediamine in chlorpheniramine maleate according to claim 1, characterized in that: In the step 2), the scanning mode is SIM (+), and the extracted ion is m / z 145.

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