CN114965749A

CN114965749A - Detection method of related substances in sulpiride bulk drug

Info

Publication number: CN114965749A
Application number: CN202210463401.5A
Authority: CN
Inventors: 王明慧; 朱峰妍; 孙莉莉; 王华娟
Original assignee: Nanjing Healthnice Pharmaceutical Co ltd; Nanjing Yinuo Medicine Technology Co ltd; Nanjing Healthnice Pharmaceutical Technology Co ltd
Current assignee: Nanjing Healthnice Pharmaceutical Co ltd; Nanjing Yinuo Medicine Technology Co ltd; Nanjing Healthnice Pharmaceutical Technology Co ltd
Priority date: 2022-04-28
Filing date: 2022-04-28
Publication date: 2022-08-30

Abstract

The invention relates to a detection method of related substances in sulpiride bulk drug, belonging to the technical field of drug analysis, wherein the detection method respectively adopts a high performance liquid chromatography to ensure that the content of 11 related impurities in the sulpiride bulk drug can be presented in one-time chromatographic behavior, and through selecting a specific chromatographic column and optimizing an elution gradient proportion, the types and the number of the monitored impurities are more, the separation degrees among the impurities and between the impurities and main components are good, the retention capacities of the main components and the impurities are higher, the response of each component is higher, and the related substances in the sulpiride bulk drug can be rapidly and accurately monitored; the impurity A is accurately measured by adopting a gas chromatography, and the method is simple and easy to implement and has higher accuracy and precision.

Description

Detection method of related substances in sulpiride bulk drug

Technical Field

The invention belongs to the technical field of pharmaceutical analysis, and particularly relates to a detection method of related substances in sulpiride bulk drug.

Background

Sulpiride is an atypical antipsychotic, is a benzamide medicine mainly used for treating psychosis, schizophrenia and depression related diseases, has the action characteristics of selectively blocking dopamine (DA2) receptors of the midbrain limbic system, having little influence on other transmitter receptors, having light anticholinergic effect and no obvious sedative and antimanic effects, and also has the effects of strongly stopping vomiting and inhibiting gastric secretion.

The related substances are initial materials, intermediates, side reaction products, degradation impurities and the like brought in the process of synthesizing the medicament, and the quality and the safety of the medicament can be controlled by detecting the related substances. At present, detection methods for related substances of sulpiride bulk drugs are recorded in Chp, EP, BP and JP pharmacopoeias, wherein chromatographic conditions in the Chp, EP and BP pharmacopoeias are basically the same, an isocratic elution mode is adopted, impurities with small polarity are difficult to elute, the number of the studied impurities is small, 7 common impurities are listed in the EP pharmacopoeias, a thin layer chromatography with poor sensitivity and accuracy is adopted for detecting the impurity a, the JP pharmacopoeias directly select the thin layer chromatography to detect all related substance impurities, and the quality detection requirements in the production process of the sulpiride bulk drugs cannot be met by all the existing methods.

Chinese patent CN10851530A discloses a method for detecting sulpiride tablets, in which a potassium dihydrogen phosphate buffer solution and a methanol acetonitrile mixed organic phase are used as mobile phases to perform isocratic elution to determine the content of the sulpiride tablets, the mobile phases are selected by referring to the mobile phases of related substances of sulpiride bulk drugs in Chp, EP and BP pharmacopoeia, the types of analyzed impurities are few, the sensitivity and the accuracy are low, and the requirements of quality monitoring in the production process of the sulpiride bulk drugs cannot be met.

According to different synthesis routes, production processes and storage conditions of the medicines, in order to ensure the safety and effectiveness of the medicines, a proper analysis method needs to be established to research, detect and monitor related substances in the medicines.

Disclosure of Invention

The invention aims to provide a method for detecting related substances in sulpiride bulk drug on the basis of the prior art, which adopts high performance liquid chromatography to ensure that the content of 11 related impurities in the sulpiride bulk drug can be presented in one-time chromatography behavior, the separation degree among the impurities and between the impurities and main components is good, the retention capacity of the main components and the impurities is high, the response of each component is high, and the related substances in the sulpiride bulk drug can be rapidly and accurately monitored; meanwhile, the gas chromatography is adopted to detect the impurity 2- (aminomethyl) -1-ethylpyrrolidine, so that the product quality control in the production process is facilitated, and the method is simple and feasible, high in accuracy and precision and good in repeatability.

The technical scheme of the invention is as follows:

a detection method for related substances in sulpiride bulk drug adopts high performance liquid chromatography and/or gas chromatography to carry out quantitative detection on sulpiride and related substances:

wherein, the high performance liquid chromatography conditions comprise: the chromatographic column is a Feilomen Titank C18 column; gradient elution is carried out by adopting a mobile phase A and a mobile phase B as a mixed mobile phase; the mobile phase A is potassium dihydrogen phosphate water solution, and the pH value is adjusted to 3.1-3.5; the mobile phase B is methanol; the initial ratio of the mobile phase A to the mobile phase B in the gradient elution process is 89-91: 11-9; the specific gradient elution procedure is as follows: the volume ratio of the mobile phase A and the mobile phase B is kept unchanged at the initial ratio within 0-14 minutes; the volume ratio of the mobile phase A to the mobile phase B is gradually changed from the initial ratio to 75:25 at a constant speed within 14-34 minutes; the volume ratio of the mobile phase A to the mobile phase B is kept constant at 75:25 within 34-75 minutes; the volume ratio of the mobile phase A to the mobile phase B is gradually changed from 75:25 to the initial ratio at a constant speed within 75-80 minutes; the volume ratio of mobile phase a and mobile phase B was kept constant for the initial ratio during 80-90 minutes.

The gas chromatography conditions included: the chromatographic column is a CP-Volamine column.

For the purposes of the present invention, the initial ratio of mobile phase A to mobile phase B in the gradient elution process in the HPLC analysis is 89-91: 11-9, and may be, but is not limited to, 89:11, 90:10 or 91:9, and in a preferred embodiment, the initial ratio of mobile phase A to mobile phase B is 90: 10.

During gradient elution, the initial ratio of mobile phase a to mobile phase B is 90: 10; the specific gradient elution procedure is as follows: the volume ratio of the mobile phase A to the mobile phase B is kept constant at 90:10 within 0-14 minutes; the volume ratio of the mobile phase A to the mobile phase B is uniformly graded from 90:10 to 75:25 within 14-34 minutes; the volume ratio of the mobile phase A to the mobile phase B is kept constant at 75:25 within 34-75 minutes; the volume ratio of the mobile phase A to the mobile phase B is gradually changed from 75:25 to 90:10 at a constant speed within 75-80 minutes; the volume ratio of mobile phase a to mobile phase B was kept constant at 90:10 for 80-90 minutes. The specific gradient elution procedure is shown in table 1 below:

TABLE 1 gradient elution procedure

When the high performance liquid chromatography is adopted for detection, the mobile phase A is 48 mmol/L-52 mmol/L potassium dihydrogen phosphate buffer solution, and the pH value is adjusted to 3.1-3.5; the mobile phase B is methanol. In a preferred scheme, the mobile phase A is 50mmol/L potassium dihydrogen phosphate buffer solution, and the preparation method comprises the following steps: taking 6.8g of monopotassium phosphate and 1g of octane sodium sulfonate, adding 1000ml of water to dissolve, and adjusting the pH value to 3.1-3.5, preferably to 3.3.

In chromatography, the choice of the chromatographic column is important and the requirements for the chromatographic column: high column efficiency, good selectivity, high analysis speed and the like. When the invention adopts the high performance liquid chromatography to carry out quantitative detection on the sulpiride and related substances, the chromatographic column is a Feilomen Titank C18 column, the types and the number of the monitored impurities are more in the chromatographic analysis process, the separation degree among the impurities and between the impurities and the main component is good, and the related substances in the sulpiride can be quickly and accurately monitored. In the case of not affecting the detection effect, the length of the column is preferably 150mm, the diameter is preferably 4.6mm, and the particle size of the packing is preferably 3 μm, i.e., the column used in the present invention is a Firmonet Titan C18 column (150X4.6mm,3 μm). During the course of the experiment, it was found that with other similar columns, for example, an Agilent ZORBAX SB-C18 column (150 mm. times.4.6 mm, 3.5 μm), the separation between some of the impurities was poor or even no baseline separation could be achieved during the course of the chromatographic analysis.

Further, the high performance liquid chromatography conditions include: the detection wavelength is 200-400 nm, preferably 240 nm.

Further, the flow rate is 0.6-1.0 ml/min; preferably 0.8 ml/min.

Further, the column temperature is 25 ℃ to 35 ℃, preferably 30 ℃.

Furthermore, the sample amount is 5-20 μ l, but is not limited to 5 μ l, 10 μ l, 15 μ l or 20 μ l; preferably, the sample size is 10. mu.l.

A detection method for impurity A in sulpiride bulk drug is characterized in that gas chromatography is adopted to carry out quantitative detection on sulpiride and impurity A (2- (aminomethyl) -1-ethylpyrrolidine) thereof, and the gas chromatography conditions comprise: the chromatographic column is a CP-Volamine column, preferably, the length of the chromatographic column is 60m, and the diameter is 0.32 mm; namely, the column was a CP-Volamine column (60 m. times.0.32 mm). The temperature-raising program is as follows: the initial column temperature is 158-162 ℃, the initial column temperature is maintained for 10-15 minutes, the initial column temperature is increased to 190-205 ℃ at the speed of 35-45 ℃/min, and the initial column temperature is maintained for 8-12 minutes.

In a preferred embodiment, the temperature-raising procedure is as follows: the initial column temperature was 160 ℃ for 13 minutes, increased to 200 ℃ at 40 ℃/min for 10 minutes.

Further, the temperature of a sample inlet is 190-205 ℃; preferably 200 deg.c.

Furthermore, the flow dividing ratio is 5-10: 1, and preferably 7: 1.

Furthermore, the temperature of the detector is 240-260 ℃, and preferably 250 ℃.

Further, the flow rate is 1.3-1.8 ml/min; preferably 1.5 ml/min.

The related substances in the sulpiride bulk drug provided by the invention comprise the following substances: impurity 2: 2-methoxy-5-aminosulfonylbenzoic acid methyl ester; impurity 3: 2-methoxy-5-sulfamoylbenzoic acid ethyl ester; impurity 4: 2-methoxy-5-sulfamoylbenzoic acid, impurity 5: 2-methoxy-5-aminosulfonylbenzamide; impurity 6: sulpiride-N-oxide; impurity 7: o-desmethylsulpiride; impurity 12: 2-hydroxy-5-sulfamoylbenzoic acid; impurity 13: n- [ (1-ethyl-2-pyrrolidinyl) methyl ] -2-methoxy-5-sulfonyl-benzamide; impurity 14: 2-hydroxy-5-sulfonylbenzoic acid; impurity 15: 2-methoxy-5-sulfonylbenzoic acid; impurity 16: 3-oxo-2, 3-dihydrobenzo [ d ] isoxazole-5-sulfonamide and impurity a: 2- (aminomethyl) -1-ethylpyrrolidine.

The structural formula of the related substances mentioned above is as follows:

the invention adopts high performance liquid chromatography and gas chromatography, and respectively screens and optimizes chromatographic conditions and the like, draws up a method for related substances, and performs methodology verification.

In a preferred scheme, the high performance liquid chromatography detection method for related substances in sulpiride bulk drug provided by the invention comprises the following operation steps:

(1) solution preparation:

taking a proper amount of sulpiride sample, precisely weighing, dissolving with a solvent [ potassium dihydrogen phosphate buffer solution (the pH is adjusted to 3.3) -methanol (the volume ratio is 90:10) ] and quantitatively diluting to prepare a solution containing 1mg of sulpiride per 1ml, wherein the solution is used as a test solution; precisely weighing a proper amount of each of the sulpiride reference substance, the impurity 2-7 reference substance and the impurity 12-16 reference substance, adding a solvent to dissolve and quantitatively diluting to prepare a mixed solution containing 1 mu g of sulpiride and each impurity reference substance in each lml, and taking the mixed solution as a reference substance solution.

(2) Respectively injecting the test solution and the impurity reference substance into a liquid chromatograph, recording a chromatogram, and calculating according to the peak area by an external standard method, wherein the chromatographic conditions are as follows:

a chromatographic column: firmometer Titank C18 column (150X4.6mm,3 μm);

detection wavelength: 200-400 nm, preferably 240 nm;

the column temperature was: 25-35 ℃, preferably 30 ℃;

the flow rate is: 0.6-1.0 ml/min, preferably 0.8 ml/min;

sample introduction amount: 5-20 mul, preferably 10 mul;

mobile phase A: a potassium dihydrogen phosphate buffer solution (6.8 g of potassium dihydrogen phosphate, 1g of sodium octane sulfonate, and 1000ml of water is added to dissolve the potassium dihydrogen phosphate buffer solution, and the pH value is adjusted to 3.1-3.5 by phosphoric acid), preferably, the pH value is adjusted to 3.3;

mobile phase B: methanol, gradient elution according to the following table:

the gas chromatography detection method of related substances in sulpiride bulk drug provided by the invention comprises the following operation steps:

(3) solution preparation:

taking a proper amount (about 0.1g) of sulpiride sample, precisely weighing, placing in a 10ml measuring flask, adding dimethyl sulfoxide to dilute to a scale, and shaking uniformly to obtain a test solution.

Accurately weighing 5mg of 2- (aminomethyl) -1-ethylpyrrolidine reference substance (impurity A), placing in a 50ml measuring flask, adding dimethyl sulfoxide to a constant volume to scale, shaking up, and using as reference substance stock solution. Precisely transferring 1ml of the reference stock solution into a 10ml measuring flask, adding dimethyl sulfoxide to dilute to scale, and shaking up to obtain the reference solution.

(4) Respectively injecting the test solution and the impurity reference substance into a gas chromatograph, recording a chromatogram, calculating by peak area according to an external standard method, and carrying out chromatographic column conditions as follows:

and (3) chromatographic column: CP-Volamine columns (60m 0.32 mm);

the column temperature raising program is: the initial column temperature is 158-162 ℃, the initial column temperature is maintained for 10-15 minutes, the initial column temperature is increased to 190-205 ℃ at the speed of 35-45 ℃/min, and the initial column temperature is maintained for 8-12 minutes; preferably; the temperature-raising program is as follows: the initial column temperature was 160 ℃ for 13 minutes, increased to 200 ℃ at 40 ℃/min for 10 minutes.

Sample inlet temperature: 190-205 ℃, preferably 200 ℃;

the split ratio is 5-10: 1, preferably 7: 1;

temperature of the detector: 240-260 ℃, preferably 250 ℃;

the flow rate is: 1.3-1.8 ml/min; preferably 1.5 ml/min;

by adopting the technical scheme of the invention, the advantages are as follows:

according to the detection method of the related substances in the sulpiride bulk drug, in the high performance liquid chromatography analysis process, a specific chromatographic column is selected, the elution gradient proportion and the column temperature are optimized, the types and the number of monitored impurities are large, the separation degree among the impurities and between the impurities and main components is good, the retention capacity of the main components and the impurities is high, the response of each component is high, and the content of 11 related impurities in the sulpiride bulk drug can be presented in one-time chromatographic behavior; meanwhile, the gas chromatography is adopted to accurately quantify the impurity A, so that related substances in the sulpiride bulk drug can be rapidly and accurately monitored, and the method is simple and easy to implement and high in accuracy and precision.

Drawings

FIG. 1 is a chromatogram of a mixed solution of impurities and a sample;

FIG. 2 is a chromatogram of a sample solution according to the present invention;

FIG. 3 is a line graph of impurities 2-7, impurities 12-16, and sulpiride;

FIG. 4 is a chromatogram of the impurity mixed solution in comparative example 1;

FIG. 5 is a chromatogram of a mixed solution of impurities and a control in comparative example 2;

FIG. 6 is a chromatogram of a mixed solution of impurities and a sample (impurity A);

fig. 7 is a linear graph of impurity a.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific examples described herein are intended to be illustrative only and are not intended to be limiting. The reagents, methods and apparatus employed in the present invention are conventional in the art, except as otherwise indicated.

Example 1: HPLC detection method of sulpiride related substances

First, experimental material and instrument

1. Drugs and reagents: sulpiride control (detector hospital), methyl 2-methoxy-5-sulfamoylbenzoate (impurity 2, AOCS), ethyl 2-methoxy-5-sulfamoylbenzoate (impurity 3, AOCS), 2-methoxy-5-sulfamoylbenzoic acid (impurity 4, AOCS), 2-methoxy-5-sulfamoylbenzamide (impurity 5, AOCS), sulpiride-N-oxide (impurity 6, AOCS), O-desmethylsulpiride (impurity 7, AOCS), 2-hydroxy-5-sulfamoylbenzoic acid (impurity 12, AOCS), N- [ (1-ethyl-2-pyrrolidinyl) methyl ] -2-methoxy-5-sulfonyl-benzamide (impurity 13, AOCS), 2-hydroxy-5-sulfonylbenzoic acid (impurity 14, AOCS), 2-methoxy-5-sulfonylbenzoic acid (impurity 15, AOCS), 3-oxo-2, 3-dihydrobenzo [ d ] isoxazole-5-sulfonamide (impurity 16, AOCS), methanol (chromatographically pure, shanghai seikagaku koku), monopotassium phosphate (analytically pure, chemicals of the national drug group limited), octane sulfonate (chromatographically pure, shanghai mclin biochemicals limited), phosphoric acid (chromatographically pure, alatin), ultrapure water (homemade, Millipore).

2. The instrument comprises the following steps: the names and specifications of the specific instruments are shown in table 2 below.

TABLE 2 name and Specification of specific instruments

Secondly, liquid phase chromatographic conditions

The chromatographic column adopts a Philomen Titank C18 column (150x4.6mm,3 mu m); taking potassium dihydrogen phosphate buffer solution (taking 6.8g of potassium dihydrogen phosphate and 1g of octane sodium sulfonate, adding 1000ml of water to dissolve, adjusting pH to 3.3 with phosphoric acid) as mobile phase A, taking methanol as mobile phase B, and performing linear gradient elution according to the following table; measuring the test solution and the reference solution respectively at a detection wavelength of 240nm, a flow rate of 0.8ml/min and a column temperature of 30 deg.C, precisely measuring 10 μ l each, injecting into a liquid chromatograph, and recording chromatogram.

Third, the experimental process

1. Detection of related substances in sulpiride raw material

Taking a sulpiride (batch number: S2003002) sample of about 10mg, precisely weighing, placing in a 10ml volumetric flask, adding a solvent [ potassium dihydrogen phosphate buffer solution (adjusting the pH to 3.3) -methanol (volume ratio of 90:10) ] for dissolving and diluting to a scale, and uniformly mixing to obtain a test solution. Respectively weighing a sulpiride reference substance and a proper amount of each impurity reference substance, adding a solvent to dissolve and quantitatively dilute into a mixed solution containing about 1 mu g of sulpiride and 1 mu g of sulpiride in each 1ml of each impurity, and uniformly mixing to obtain a reference substance solution. Precisely measuring 10 μ l of each of the sample solution and the reference solution, respectively injecting into a liquid chromatograph, and recording chromatogram. And quantifying the known impurities by adopting an external standard method, and measuring the unknown impurities by adopting a main component comparison method. The results are shown in Table 3. The samples (lot numbers S2003003 and S2003004) were tested according to the above test method, and the results are shown in Table 3.

TABLE 3 test results of different batches of test articles

2. Methodology validation

2.1 specificity

(1) Solvent: potassium dihydrogen phosphate buffer solution (adjusting its pH to 3.3) -methanol (volume ratio 90: 10);

(2) test solution: weighing about 10mg of sample (batch number: S2003002), placing in a 10ml volumetric flask, adding a solvent to dissolve and dilute to scale, and mixing uniformly.

(3) System applicability test control solutions: weighing and dissolving the reference substance of sulpiride and proper amount of reference substances of

impurities

2, 3, 4, 5, 6, 7, 12, 13, 14, 15 and 16 in a solvent, quantitatively diluting to obtain a mixed solution containing about 1 mu g of sulpiride and 1 mu g of sulpiride in each 1ml of impurities, and uniformly mixing.

(4) Impurity and sample mixed solution: appropriate amounts of samples and reference substances of

impurities

2, 3, 4, 5, 6, 7, 12, 13, 14, 15 and 16 are weighed, dissolved by a solvent and quantitatively diluted to form a mixed solution containing about 1 mu g of each impurity and 1mg of sulpiride in each 1 ml.

(5) Single impurity localization solution: taking a proper amount of the sulpiride reference substance and each impurity reference substance, respectively adding a solvent to dissolve and dilute the sulpiride reference substance and each impurity reference substance into a solution with a certain concentration, and uniformly mixing.

Precisely measuring 10 μ l of each solution, injecting into a liquid chromatograph, and recording chromatogram. The results are shown in Table 4, and the relevant spectra are shown in FIGS. 1-2.

TABLE 4 results of the specificity test

The result shows that under the chromatographic condition, the base line is stable, the blank solvent has no interference to the product determination, the peak shape of each substance in the impurity sample mixed solution is better, the theoretical plate number of the sulpiride main peak is 78570, the minimum separation degree of the main peak and the adjacent impurity peak is 3.01, and the minimum separation degree among all the impurities is more than 1.5, which indicates that the specificity is good.

2.2 destructive testing

In order to examine whether degradation products possibly generated by sulpiride can be detected under selected chromatographic conditions, the product is destroyed by violent conditions of high temperature, acid, alkali, oxidation, illumination and the like, the destroyed sample is dissolved by a solvent [ potassium dihydrogen phosphate buffer solution (the pH of the solution is adjusted to 3.3) -methanol (the volume ratio is 90:10) ] to prepare a test solution, 10 mu l of each solution is precisely measured, the solution is injected into a liquid chromatograph, and a chromatogram is recorded, wherein the specific method is shown in tables 5 and 6. The solvent mentioned in tables 5 and 6 was [ pH adjusted to 3.3) -methanol (volume ratio 90:10 ].

TABLE 5 destructive test results

TABLE 6 impurity condition in test sample solution under each destructive test

The result shows that the product has different degrees of degradation under the conditions of alkali heating, acid, oxidation, high temperature and illumination, the damage influence is larger under the conditions of alkali heating at 60 ℃ and oxidation, the product is stable under the conditions of acid, illumination and high temperature damage, degradation products generated by the damage under various conditions can be detected, the separation degree between a main component and adjacent impurities is larger than 1.5, the separation degree between the impurities is larger than 1.2, the f damage/f non-damage is in the range of 0.95-1.05, the main peak purity is more than 990.0, and the material is conserved.

2.3 determination of quantitation Limit, detection Limit

Taking a proper amount of the sulpiride reference substance and a proper amount of the impurity reference substance respectively, preparing a sample with a certain concentration, diluting gradually, precisely measuring 10 mu l, injecting into a liquid chromatograph, recording a chromatogram, and measuring by using a signal-to-noise ratio (S/N) of 3 and a signal-to-noise ratio (S/N) of 10, wherein the results are shown in a table 7.

TABLE 7 detection limit and quantitation limit results

The result shows that under the concentration and chromatographic conditions of related substances of the product, the quantitative limit of sulpiride and each known impurity is less than the report limit (0.05%), and the sensitivity is good.

2.4 sample solution stability test

Weighing about 10mg of sample, placing in a 10ml volumetric flask, adding a solvent [ potassium dihydrogen phosphate buffer solution (adjusting the pH to 3.3) -methanol (volume ratio of 90:10) ] to dissolve to scale, and mixing uniformly. After preparation, the sample is placed at room temperature for 0h, 3h, 6h, 9h, 12h, 15h, 18h, 21h and 24h for sample injection analysis, the stability of the sample solution is inspected, and the results are shown in Table 8.

TABLE 8 sample solution stability test

The results show that the sample solution is stable after being placed at room temperature for 24 hours after being prepared.

2.5 control solution stability test

Precisely weighing appropriate amount of each impurity and sulpiride reference substance, adding solvent [ potassium dihydrogen phosphate buffer solution (pH is adjusted to 3.3) -methanol (volume ratio is 90:10) ] to dissolve and dilute to obtain a mixed solution containing about 1 μ g of each impurity and 1 μ g of sulpiride per 1 ml. After the preparation, the sample is placed at room temperature for 0h, 3h, 6h, 9h, 12h, 15h, 18h, 21h and 24h for analysis, the stability of the reference solution is inspected, and the results are shown in Table 9.

TABLE 9 control solution stability test

The results show that the impurity control solution is stable after being prepared and placed at room temperature for 24 hours.

2.6 Linear and Range testing

Precisely weighing a proper amount of sulpiride reference substance and each impurity reference substance, adding a solvent [ potassium dihydrogen phosphate buffer solution (the pH value of the buffer solution is adjusted to 3.3) -methanol (the volume ratio is 90:10) ] for dissolving and diluting to prepare a stock solution with a certain concentration; precisely measuring the stock solution to obtain solutions with a series of gradient concentrations, wherein the solutions respectively comprise a quantitative limit concentration and 50%, 80%, 100%, 120% and 150% of the limit concentration. Taking the concentration C (μ g/ml) of the impurity control solution as the abscissa and the peak area of the impurity control as the ordinate, linear regression was performed and the regression equation was obtained, and the results are shown in Table 10 and FIG. 3.

TABLE 10 results of Linear examination

2.7 sample introduction precision test

According to the solution with 100% limit concentration prepared under the linear test item, sample introduction is continuously carried out for 6 times, chromatogram is recorded, and the sample introduction precision is examined, and the result is shown in table 11.

TABLE 11 test results of sample introduction precision

The result shows that the peak areas RSD of sulpiride and each impurity are less than 2.0%, the retention time RSD is less than 1.0%, and the sample injection precision of the instrument is good.

2.8 repeatability test

The product is precisely weighed and divided into 6 parts in parallel, and the same analyst samples for multiple times to carry out a series of tests to obtain discrete degrees between results, and then a repeatability test is carried out. The results are shown in Table 12.

TABLE 12 results of the repeatability tests

The results show that: and 6, the measurement of each impurity in the sample has good repeatability.

2.9 recovery test

Nine parts of sulpiride samples are precisely weighed, each part is about 10mg, impurities with limited amount of 80%, 100% and 120% are respectively added into a 10ml volumetric flask, a solvent [ potassium dihydrogen phosphate buffer solution (the pH value of the buffer solution is adjusted to 3.3) -methanol (the volume ratio is 90:10) ] is added to dilute to a scale, 10 mu l of the solution is precisely measured respectively, and the solution is injected into a liquid chromatograph for recovery rate determination. The results are shown in tables 13 to 23.

Table 13 accuracy test results for impurity 2

TABLE 14 accuracy test results for impurity 3

TABLE 15 accuracy test results for impurity 4

TABLE 16 accuracy test results for impurity 5

TABLE 17 accuracy test results for impurity 6

Table 18 accuracy test results for impurity 7

TABLE 19 test results for recovery of impurity 12

TABLE 20 test results for recovery of impurity 13

TABLE 21 test results for recovery of impurity 14

TABLE 22 test results on recovery of impurity 15

TABLE 23 test results for recovery of impurity 16

The conclusion shows that the method has good accuracy.

2.10 intermediate precision test

The product is taken and tested by different analysts at different times by using different instruments according to the method under the repeatability test item. The results are shown in Table 24.

TABLE 24 intermediate precision test results

Note: instrument 1 number: agilent1100, 100157A; instrument 2 numbering: agilent1100, 100149A

The results show that the method has good intermediate precision.

2.11 calibration factor determination

On 2 liquid chromatographs, 3 chromatographic columns were used, with P ³ ₂ Permutation and combination for 6 times in total, within the limit of quantitationTo within 200% of the specified limiting concentration, a total of 6 samples were prepared, the peak areas were regressed for each component concentration, and correction factors for impurities versus sulpiride were calculated, the results are shown in table 25.

TABLE 25 impurities correction factors for sulpiride

Note: a chromatographic column 1: firmore Titan column (150 mm. times.4.6 mm,3 μm), S/N: 130HA90084

And (3) chromatographic column 2: firmometer Titan column (150 mm. times.4.6 mm,3 μm), S/N: 130HA90083

A chromatographic column 3: firmometer Titan column (150 mm. times.4.6 mm,3 μm), S/N: 121ZA70110

An apparatus A: agilent1100 hplc, instrument number 100149 a;

an apparatus B: agilent1100 hplc, instrument No. 100157 a.

The results showed that the correction factor for impurity 2 was 0.78, the correction factor for impurity 3 was 0.85, the correction factor for impurity 4 was 0.75, the correction factor for impurity 5 was 0.72, the correction factor for impurity 6 was 1.60, the correction factor for impurity 7 was 1.90, the correction factor for impurity 12 was 0.89, the correction factor for impurity 13 was 1.74, the correction factor for impurity 14 was 1.43, the correction factor for impurity 15 was 1.23, and the correction factor for impurity 16 was 0.66.

2.12 durability examination

In order to examine the degree of resistance of the method to small changes in conditions, a durability test was conducted. The investigation items comprise the proportion of a mobile phase, the concentration and pH of potassium dihydrogen phosphate in a mobile phase buffer solution, the column temperature and different chromatographic columns, and the investigation indexes comprise the retention time of main components, the number of theoretical plates, the separation degree and the content of each impurity.

2.12.1 initial organic phase ratio Change of mobile phase

The durability was examined under the conditions of 9%, 10%, and 11% of the initial organic phase (methanol) ratio, respectively. The measurement results are shown in tables 26 to 30.

TABLE 26 durability (initial organic phase ratio of mobile phase) test results

The results show that when the initial organic phase (methanol) proportion is changed within the range of 9-11%, the retention time of the main peak, the number of theoretical plates and the separation degree are changed to a certain extent, and other chromatographic behaviors and sample detection results are not obviously changed.

2.12.2 variation of the concentration of Potassium dihydrogen phosphate in the Mobile phase buffer

The durability of the mobile phase buffer was examined at concentrations of 48mM, 50mM, and 52mM potassium dihydrogen phosphate, respectively. The results are shown in Table 27.

TABLE 27 durability (mobile phase salt concentration Change) test results

The results show that when the concentration of the potassium dihydrogen phosphate in the mobile phase buffer solution is changed within the range of 48 mM-52 mM, the retention time of the main peak, the number of theoretical plates and the separation degree are changed to a certain extent, and other chromatographic behaviors and sample detection results are not obviously changed.

2.12.3 change in pH of mobile phase buffer

The durability of the mobile phase buffer at pH 3.1, 3.3, and 3.5 was examined. The results are shown in Table 28.

TABLE 28 results of durability (variation in pH of mobile phase liquid) test

The result shows that when the pH value of the mobile phase buffer solution is changed within the range of 3.1-3.5, the retention time of the main peak, the number of theoretical plates and the separation degree are changed to a certain extent, and other chromatographic behaviors and sample detection results are not obviously changed.

2.12.4 Change in column temperature

The durability was examined at 25 deg.C, 30 deg.C, and 35 deg.C, respectively. The results are shown in Table 29.

TABLE 29 durability (column temperature Change) test results

The results show that when the column temperature is changed within the range of 25-35 ℃, the retention time of the main peak, the number of theoretical plates and the separation degree are changed to a certain extent, and other chromatographic behaviors and sample detection results are not obviously changed.

2.12.5 variations of the column

The durability of the different columns was examined separately. The results are shown in Table 30.

TABLE 30 durability (different columns) test results

Note: a chromatographic column 1: firmometer Titan C18 column (150 mm. times.4.6 mm,3 μm), S/N: 130HA 90084;

and (3) chromatographic column 2: firmometer Titan C18 column (150 mm. times.4.6 mm,3 μm), S/N: 130HA 90083;

a chromatographic column 3: agilent ZORBAX SB-C18 column (150 mm. times.4.6 mm, 3.5 μm), S/N: USEG 020693.

The results show that chromatographic columns of different manufacturers have great influence on impurity separation, the retention time of main peaks, the number of theoretical plates and the separation degree of chromatographic columns of the same manufacturer in different batches are changed to a certain extent, and other chromatographic behaviors and sample detection results are not obviously changed.

Comparative example 1 Effect of different gradients on the assay results during chromatography

Liquid chromatography conditions: the chromatographic column adopts a Philomen Titank C18 column (150mm multiplied by 4.6mm,3 mu m); using potassium dihydrogen phosphate buffer solution (6.8 g potassium dihydrogen phosphate and 1g sodium octane sulfonate, adding 1000ml water to dissolve, adjusting pH to 3.3 with phosphoric acid) as mobile phase A, using methanol as mobile phase B, and performing gradient elution according to the following table 31; the flow rate is 0.8 ml/min; the column temperature is 30 ℃; the detection wavelength was 240 nm.

TABLE 31 gradient elution procedure

Respectively taking appropriate amounts of

impurities

2, 3, 4, 5, 6, 7, 12, 13, 14 and 15, respectively placing in different measuring bottles, adding a solvent [ potassium dihydrogen phosphate buffer solution (the pH value of the buffer solution is adjusted to 3.3) -methanol (the volume ratio is 90:10) ] to dissolve and respectively preparing into a solution with the concentration of about 1.0mg/ml, taking each impurity mother liquor as each impurity mother liquor, respectively taking appropriate amounts of each impurity mother liquor, and preparing into an impurity mixed solution with the concentration of each impurity of 10 mu g/ml.

Precisely measuring 10 mul of each of blank solvent and impurity mixed solution, injecting into a liquid chromatograph, and recording chromatogram.

TABLE 32 influence of different gradient elution conditions on the results of the chromatographic analysis

As can be seen from fig. 4 and table 32, in the gradient elution process, the degree of separation between the

impurities

14 and 15 in the impurity mixed solution was 1.38, and the separation was not achieved at the baseline, but the degrees of separation of other impurities were good.

Comparative example 2 influence of different chromatography columns on the detection results during chromatography

Liquid chromatography conditions: the chromatographic column adopts an Agilent ZORBAX SB-C18 column (150mm multiplied by 4.6mm, 3.5 μm); potassium dihydrogen phosphate buffer solution (taking 6.8g of potassium dihydrogen phosphate and 1g of octane sodium sulfonate, adding 1000ml of water to dissolve, and adjusting pH to 3.3 with phosphoric acid) as mobile phase A, and methanol as mobile phase B; the flow rate is 0.8 ml/min; the column temperature is 30 ℃; the detection wavelength was 240 nm. The specific elution process is shown in Table 1.

Respectively taking appropriate amounts of

impurities

2, 3, 4, 5, 6, 7, 12, 13, 14, 15 and 16 and a sulpiride reference substance, adding a solvent [ potassium dihydrogen phosphate buffer solution (the pH value of the buffer solution is adjusted to be 3.3) -methanol (the volume ratio is 90:10) ] to dissolve and dilute the impurities and the reference substance to prepare a mixed solution of the impurities and the reference substance, wherein the concentration of each impurity of the reference substance is 1 mu g/ml. Precisely measuring 10 μ l of mixed solution of impurities and reference substances, injecting into a liquid chromatograph, and recording chromatogram.

TABLE 33 influence of different chromatography columns on the results of the chromatography

As is clear from fig. 5 and table 33, under the conditions of the column, the impurity 13 and the impurity 16 completely overlapped in the mixed solution of the impurities and the control, and the separation effect was not obtained.

Example 2: GC detection method for Perampanel related substances

First, experimental material and instrument

1. Drugs and reagents: 2- (aminomethyl) -1-ethylpyrrolidine (impurity A, AOCS), dimethyl sulfoxide (chromatographically pure, Shanghai Michelin Biochemical Co., Ltd.), and N, N-dimethylformamide (chromatographically pure, Shanghai Michelin Biochemical Co., Ltd.).

2. The instrument comprises: the names and specifications of the specific instruments are shown in Table 34 below.

TABLE 34 name and Specification of Instrument

sQP hundred thousand electronic balance	Sadoris scientific instruments Ltd
		XP6 million electronic balance	Mettler
6890N, 7890A gas chromatograph	Agilent
		LGA-5000 silent air generator	Shanghai Anpu Experimental Technology Co.,Ltd.
LGA-300Y hydrogen generator	Shanghai Anpu Experimental Technology Co.,Ltd.
		ECAA-LGB-0300W hydrogen-air integrated machine	SHANGHAI ANPEL SCIENTIFIC INSTRUMENT Co.,Ltd.

Second, gas chromatography conditions

The chromatographic column adopts Agilent CP-Volamine (60m 0.32 mm); the temperature rising procedure is as follows: the initial column temperature is 160 ℃, the temperature is kept for 13min, the temperature is raised to 200 ℃ at 40 ℃/min, and the temperature is kept for 10 min; sample inlet temperature: 200 ℃; temperature of the detector: 250 ℃; the split ratio is as follows: 7: 1; flow rate: 1.5ml/min, precisely measuring 1 mul of sample solution, injecting into a gas chromatograph, and recording chromatogram. Impurity A was measured by an external standard method, and samples (lot numbers: S2003002 and S2003004) were tested according to the above test method, and the results are shown in Table 35.

TABLE 35 results of detection of impurity A in different batches of test articles

Batch number	2- (aminomethyl) -1-ethylpyrrolidine (ppm)
		S2003002	Not detected out
S2003003	Not detected out
		S2003004	Not detected out

Third, the experimental process

1. Detection of related substances in sulpiride bulk drug

Taking about 0.1g of sulpiride raw material (batch number: S2003002), precisely weighing, placing in a 10ml volumetric flask, adding dimethyl sulfoxide to dilute to a scale, and shaking up to obtain a test solution. Accurately weighing 5mg of 2- (aminomethyl) -1-ethylpyrrolidine (impurity A), placing the 2- (aminomethyl) -1-ethylpyrrolidine (impurity A) in a 50ml measuring flask, adding dimethyl sulfoxide to a constant volume to scale, and shaking up to be used as a reference stock solution. Precisely transferring 1ml of the reference stock solution into a 10ml measuring flask, adding dimethyl sulfoxide to dilute to scale, and shaking up to obtain the reference solution. Directly injecting 1 μ l of each of the test solution and the reference solution, and recording chromatogram.

2. Methodology validation

2.1 specificity

(1) Solvent: dimethyl sulfoxide (DMSO).

(2) Control solution: accurately weighing 5mg of 2- (aminomethyl) -1-ethylpyrrolidine (impurity A), placing the 2- (aminomethyl) -1-ethylpyrrolidine (impurity A) in a 50ml measuring flask, adding dimethyl sulfoxide to a constant volume to scale, and shaking up to be used as a reference stock solution. Precisely transferring 1ml of the reference stock solution into a 10ml measuring flask, adding dimethyl sulfoxide to dilute to scale, and shaking up to obtain the reference solution.

(3) Positioning solution: 1ml to 1.5ml of the control stock solution was sampled into a vial for use.

(4) Test solution: the sulpiride raw material is about 0.1g, precisely weighed, placed in a 10ml volumetric flask, added with dimethyl sulfoxide to be diluted to a scale, and shaken up for standby.

(5) Impurity and sample mixed solution: 0.1g of sulpiride raw material is precisely weighed, placed in a 10ml volumetric flask, added with 1ml of reference substance storage solution and diluted to the scale by dimethyl sulfoxide, and shaken up for standby.

Directly injecting blank solvent, reference solution, sample solution, impurity and sample mixed solution, and positioning solution, and recording chromatogram, the results are shown in Table 36 and FIG. 6.

TABLE 36 results of the specificity test

The results show that: the impurity A in the reference solution has normal peak, the number of theoretical plates and the separation degree meet the requirements, the blank and the test solution do not interfere the detection, and the impurity A is not detected, so the method has good specificity.

2.2 sample introduction precision test

Taking 6 needles of reference substance solution for continuous sample injection under the specificity item, taking the retention time and the peak area as indexes, and investigating the sample injection precision of the impurity A of the method, wherein the result is shown in a table 37.

TABLE 37 sample introduction precision test results

The results show that: the precision of the instrument is good.

2.3 solution stability

Respectively taking a reference substance solution and a sample solution, injecting samples for 0h, 2h, 4h, 8h, 12h and 16h at room temperature, taking the peak area of the impurity A as an index, and inspecting the stability of the solution. The results are shown in tables 38 to 39.

TABLE 38 control solution stability results

Time (h)	0	2	4	8	12	16	RSD(％)
								Impurity A	8.3283	8.2854	8.0154	8.0139	8.5051	8.2844	2.3

TABLE 39 sample solution stability results

Time (h)	0	2	4	8	12	16	RSD(％)
								Impurity A	-	-	-	-	-	-	-

Remarking: "-" indicates no detection.

The results show that: the solution stability of the control solution and the sample solution is good within 16h under the condition of room temperature.

2.4 limit of detection of quantitative limit

Taking the reference stock solution under the specificity item, adding dimethyl sulfoxide to dilute the reference stock solution step by step, taking the concentration when the signal to noise ratio S: N is 10:1 and the signal to noise ratio S: N is 3:1 as the quantification limit and the detection limit respectively, and the experimental result is shown in tables 40 to 41.

TABLE 40 limit of detection of quantitative limit

TABLE 41 results of accuracy of quantitative limits

And (4) analyzing results: as can be seen from the above table, the detection sensitivity of the impurity A satisfies the requirements.

2.5 Linear and Range

Taking appropriate amount of stock solution of reference substance under the specificity, diluting with dimethyl sulfoxide, and preparing into a series of linear solutions with quantitative limit, 50%, 80%, 100%, 120%, and 150% of limit concentration (0.1%). Directly feeding the quantitative limiting solution and a series of linear solutions, recording a chromatogram, performing linear regression with the concentration C (mg/ml) of the reference solution as abscissa and the peak area A as ordinate, and performing a regression equation, wherein the experimental results are shown in Table 42 and FIG. 7.

TABLE 42 results of the Linear test

And (4) analyzing results: from the above results, it was found that the impurity A had a concentration in the range of 0.0034mg/ml to 0.0154mg/ml, r > 0.990, and exhibited a good linear relationship with the peak area.

2.6 repeatability test

Test solution: the sulpiride raw material is about 0.1g, precisely weighed, placed in a 10ml volumetric flask, added with 1ml of a reference substance storage solution under the special item, diluted to the scale by dimethyl sulfoxide, and shaken uniformly for later use. 6 parts of the mixture is prepared by the same method.

Control solution: precisely transferring 1ml of the reference stock solution under the specificity item, placing into a 10ml measuring flask, adding dimethyl sulfoxide to dilute to scale, and shaking up to obtain the reference solution. The results are shown in Table 43.

TABLE 43 repeatability test results

Number of	1	2	3	4	5	6	Average recovery (%)	RSD(％)
									Impurity A	96.54	97.99	96.11	93.32	102.23	103.13	98.22	3.9

The results show that: in 6 samples, the average recovery rate is 96.88%, the RSD is less than 10%, the method meets the requirement, and the repeatability is good.

2.7 recovery test

Weighing about 0.1g of sulpiride raw material, precisely weighing, paralleling 12 parts, respectively placing into 10ml volumetric flasks, and precisely adding solutions of control stock solutions under the special items of 0.8ml (3 parts), 1.0ml (6 parts) and 1.2ml (3 parts).

Preparing a reference solution: precisely transferring 1ml of the reference stock solution under the specificity to a 10ml volumetric flask, adding dimethyl sulfoxide to dilute to the scale to obtain the reference solution.

Directly sampling the solution, and recording the chromatogram. Calculated as peak area by external standard method, the experimental results are shown in table 44.

TABLE 44 results of recovery test

The results show that: the results show that the recovery rate of the impurity A is in the range of 90-108%, the RSD is less than 10.0%, the accuracy is high, and the requirement of quantitative analysis can be met.

2.8 intermediate precision test

In order to examine the discrete degree of the results of a series of tests carried out on the same homogeneous sample under the test condition by different analyzers, the standard recovery rate of the impurity A in the sample is determined according to the operation under the repeatability term, and an intermediate precision test is carried out. The results are shown in Table 45.

TABLE 45 intermediate precision test results

The results show that: the average recovery rate of the impurity A in 12 samples with intermediate precision is 97.6 percent, the RSD is less than 10.0 percent, and the intermediate precision is good.

2.9 durability test

In order to examine the degree of resistance of the method to which the measurement results are not affected when the measurement conditions are slightly changed, a durability test was conducted. The investigation factors comprise the column temperature, the injection port temperature, the detector temperature and the replacement of the chromatographic column, the investigation indexes are the retention time and the number of theoretical plates of the impurity A, and the experimental results are shown in tables 46 to 49.

TABLE 46 durability examination of replacement columns

Note: column 1 is CP-Volamine (60 m.times.0.32 mm), numbered: NLR0658239

Column 2 is CP-Volamine (60 m.times.0.32 mm), numbered: NLT0713245

Durability test results for column temperatures of Table 47

TABLE 48 results of durability examination of injection port temperatures

TABLE 49 durability examination of the detector temperature

And (4) conclusion: when the temperature of the column, the temperature of the sample inlet and the temperature of the detector are slightly changed or the chromatographic column is replaced, the recovery rate of the impurity A has no obvious difference, and all indexes meet the regulations. The method has good durability.

In conclusion, the invention adopts the high performance liquid chromatography, respectively screens and optimizes chromatographic conditions and other aspects, draws up a method for related substances, verifies the methodology, and quantitatively researches impurities 2-7 and 12-16 (process impurities and degradation impurities). The impurity A (2- (aminomethyl) -1-ethylpyrrolidine) which may be generated in the synthesis process was quantitatively investigated by gas chromatography. The detection method of the invention has the advantages of good linear relation between sulpiride and related substances, good accuracy and precision, strong specificity and high stability. The detection method has good reproducibility, can meet the detection requirements of related substances of the sulpiride bulk drug, and can be used for quality control of the sulpiride bulk drug.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: modifications of the technical solutions described in the foregoing embodiments are still possible, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A detection method for related substances in sulpiride bulk drug is characterized in that the detection method adopts high performance liquid chromatography and/or gas chromatography to carry out quantitative detection on sulpiride and related substances:

the high performance liquid chromatography conditions include: the chromatographic column is a Feilomen Titank C18 column; gradient elution is carried out by adopting a mobile phase A and a mobile phase B as a mixed mobile phase; the mobile phase A is a potassium dihydrogen phosphate aqueous solution, and the pH value of the mobile phase A is adjusted to 3.1-3.5; the mobile phase B is methanol; the initial ratio of the mobile phase A to the mobile phase B in the gradient elution process is 89-91: 11-9; the specific gradient elution procedure is as follows: the volume ratio of the mobile phase A and the mobile phase B is kept unchanged at the initial ratio within 0-14 minutes; the volume ratio of the mobile phase A to the mobile phase B is gradually changed from the initial ratio to 75:25 at a constant speed within 14-34 minutes; the volume ratio of the mobile phase A to the mobile phase B is kept constant at 75:25 within 34-75 minutes; the volume ratio of the mobile phase A to the mobile phase B is gradually changed from 75:25 to the initial ratio at a constant speed within 75-80 minutes; the volume ratio of the mobile phase A and the mobile phase B is kept unchanged in the initial ratio within 80-90 minutes;

the gas chromatography conditions include: the chromatographic column is a CP-Volamine column.

2. The method for detecting related substances in sulpiride bulk drug according to claim 1, wherein the initial ratio of mobile phase A to mobile phase B in the gradient elution process is 90: 10; the specific gradient elution procedure is as follows: the volume ratio of the mobile phase A to the mobile phase B is kept constant at 90:10 within 0-14 minutes; the volume ratio of the mobile phase A to the mobile phase B is uniformly graded from 90:10 to 75:25 within 14-34 minutes; the volume ratio of the mobile phase A to the mobile phase B is kept constant at 75:25 within 34-75 minutes; the volume ratio of the mobile phase A to the mobile phase B is gradually changed from 75:25 to 90:10 at a constant speed within 75-80 minutes; the volume ratio of mobile phase A to mobile phase B was kept constant at 90:10 for 80-90 minutes.

3. The method for detecting related substances in sulpiride bulk drug according to claim 1, characterized in that gas chromatography is adopted to quantitatively detect impurity 2- (aminomethyl) -1-ethylpyrrolidine; the gas chromatography conditions include: the length of the chromatographic column is 60m, and the diameter of the chromatographic column is 0.32 mm; the temperature-raising program is as follows: the initial column temperature is 158-162 ℃, the temperature is maintained for 10-15 minutes, the temperature is raised to 190-205 ℃ at 35-45 ℃/min, and the temperature is maintained for 8-12 minutes.

4. The method for detecting related substances in sulpiride bulk drug according to claim 3, wherein the gas chromatography conditions comprise: the temperature-raising program is as follows: the initial column temperature was 160 ℃ for 13 minutes, increased to 200 ℃ at 40 ℃/min for 10 minutes.

5. The method for detecting related substances in sulpiride bulk drug according to claim 3, wherein the gas chromatography conditions comprise: the temperature of the detector is 240-260 ℃, and the preferred temperature is 250 ℃; the temperature of a sample inlet is 190-205 ℃; preferably 200 ℃; the split ratio is 5-10: 1, preferably 7: 1; the flow rate is 1.3-1.8 ml/min; preferably 1.5 ml/min.

6. The method for detecting related substances in sulpiride bulk drug according to claim 1, wherein the preparation method of the mobile phase A is as follows: taking 6.8g of monopotassium phosphate and 1g of octane sodium sulfonate, adding 1000ml of water to dissolve, and adjusting the pH value to 3.1-3.5; preferably, the pH is adjusted to 3.3.

7. The method for detecting related substances in sulpiride bulk drug according to claim 1, wherein the high performance liquid chromatography conditions comprise: the length of the chromatographic column is 150mm, the diameter is 4.6mm, and the particle size of the filler is 3 mu m; the flow rate is 0.6-1.0 ml/min; the column temperature is 25-35 ℃; the detection wavelength is 200-400 nm; the sample injection amount is 5-20 mul.

8. The method for detecting related substances in sulpiride bulk drug according to claim 7, wherein the HPLC conditions comprise: the flow rate is 0.8 ml/min; the column temperature is 30 ℃; the detection wavelength is 240 nm; the amount of sample was 10. mu.l.

9. The method for detecting related substances in sulpiride bulk drug according to claim 1, wherein the related substances comprise the following substances: impurity 2: 2-methoxy-5-aminosulfonylbenzoic acid methyl ester; impurity 3: 2-methoxy-5-sulfamoylbenzoic acid ethyl ester; impurity 4: 2-methoxy-5-sulfamoylbenzoic acid, impurity 5: 2-methoxy-5-aminosulfonylbenzamide; impurity 6: sulpiride-N-oxide; impurity 7: o-desmethylsulpiride; impurity 12: 2-hydroxy-5-sulfamoylbenzoic acid; impurity 13: n- [ (1-ethyl-2-pyrrolidinyl) methyl ] -2-methoxy-5-sulfonyl-benzamide; impurity 14: 2-hydroxy-5-sulfonylbenzoic acid; impurity 15: 2-methoxy-5-sulfonylbenzoic acid; impurity 16: 3-oxo-2, 3-dihydrobenzo [ d ] isoxazole-5-sulfonamide; impurity A: 2- (aminomethyl) -1-ethylpyrrolidine.

10. The method for detecting related substances in sulpiride bulk drug according to claim 1, characterized in that the correction factor for impurity 2 is 0.78, the correction factor for impurity 3 is 0.85, the correction factor for impurity 4 is 0.75, the correction factor for impurity 5 is 0.72, the correction factor for impurity 6 is 1.60, the correction factor for impurity 7 is 1.90, the correction factor for impurity 12 is 0.89, the correction factor for impurity 13 is 1.74, the correction factor for impurity 14 is 1.43, the correction factor for impurity 15 is 1.23, and the correction factor for impurity 16 is 0.66.