CN115980201A

CN115980201A - Method for determining piperidine residue

Info

Publication number: CN115980201A
Application number: CN202111206257.9A
Authority: CN
Inventors: 王崇益; 严羽琦; 王艺
Original assignee: Jiangsu Chia Tai Qingjiang Pharmaceutical Co Ltd
Current assignee: Jiangsu Chia Tai Qingjiang Pharmaceutical Co Ltd
Priority date: 2021-10-16
Filing date: 2021-10-16
Publication date: 2023-04-18

Abstract

The invention discloses a method for measuring piperidine residue, which comprises the following steps: the solvent is 1~5% ethylenediamine DMSO solution, the chromatographic column of a gas chromatograph is a CP-Volamine capillary column, the initial temperature is 75-85 ℃, the initial temperature is maintained for 15 minutes, the temperature is increased to 240 ℃ at the rate of 30 ℃ per minute, and the temperature is maintained for 10 minutes; sample inlet temperature: 215 to 225 ℃, detector FID temperature: 245 to 255 ℃, column flow rate: 1.8 to 2.2ml/min, and the split ratio of 3:1. The method for determining the piperidine residue in the product by using the gas chromatography has the advantages of high separation efficiency, high recovery rate, high analysis speed and high detection sensitivity, and can better control the piperidine residue in the product.

Description

Method for determining piperidine residue

Technical Field

The invention relates to the technical field of analysis, in particular to a method for determining piperidine residue.

Background

Piperidine, also known as Piperidine, having the English name Piperidine and molecular formula C ₅ H ₁₁ N, it has strong irritation and toxicity to human body, small dose can stimulate sympathetic and parasympathetic ganglia, large dose can inhibit, can cause weakness, nausea, sialorrhea, dyspnea, muscle paralysis and asphyxia after being taken by mistake.

The piperidine is mainly used as a solvent, an organic synthesis intermediate, an epoxy resin cross-linking agent, a condensation catalyst and the like, has wide application in the field of medicines, and is an important raw material of products such as dipyridamole, cinacalcet, 3-fluoromethyllauric acid and the like. Therefore, it is necessary to effectively control the residual amount of piperidine in the product and realize separation and detection.

Disclosure of Invention

The invention aims to screen out a proper solvent, grope out a proper pretreatment method and establish a method for measuring the piperidine residue so as to better control the piperidine residue in a product.

The technical scheme of the method for determining the piperidine residue comprises the following steps:

blank solvent: 1% ethylenediamine DMSO solution;

test solution: precisely weighing about 1.0g of a sample to be tested, placing the sample in a 10ml measuring flask, adding a 1% ethylenediamine DMSO solution, carrying out ultrasonic dissolution, fixing the volume to a scale, and shaking up to be used as a test sample solution;

control solution: accurately weighing an appropriate amount of piperidine, respectively placing into corresponding measuring bottles, dissolving with 1% ethylenediamine DMSO solution, and diluting to obtain 0.02mg piperidine solution per 1ml, as a reference solution;

the chromatographic column is as follows: CP-Volamine capillary column (30 m 0.32mm 5 μm)

The chromatographic conditions are as follows: the initial temperature is 80 ℃, the temperature is maintained for 15 minutes, the temperature is increased to 240 ℃ at the rate of 30 ℃ per minute, and the temperature is maintained for 10 minutes; sample inlet temperature: 220 ℃, detector FID temperature: 250 ℃, column flow rate: 2.0ml/min, split ratio 3:1;

sampling the blank solvent, the solution sample and the solution reference substance solution by 1 mul respectively;

calculating linear regression equation of the concentration value of the reference solution and the corresponding peak area value, wherein the correlation coefficient is not less than 0.99, and the reference solution has symmetrical peak shape.

According to different pH values of samples to be detected, the concentration of the ethylamine DMSO solution can be adjusted between 1% and 5%, when the pH value is lower, higher concentration can be adopted, and when the pH value is higher, lower concentration can be adopted, so that better effect can be obtained.

The method for determining the piperidine residue in the product by using the gas chromatography has the advantages of high separation efficiency, high recovery rate, high analysis speed and high detection sensitivity, and can better control the piperidine residue in the product.

Drawings

FIG. 1 screening chromatogram of column of example 1

FIG. 2 example 2 screening chromatogram for a chromatography column

FIG. 3 example 3 screening chromatogram for chromatography column

FIG. 4 example 4 chromatographic column and solvent screening

FIG. 5 example 5 screening chromatogram for solvent

FIG. 6 screening chromatogram for solvent of example 6

FIG. 7 chromatogram for screening of solvent in example 7

FIG. 8 chromatogram for screening of solvent in example 8

FIG. 9 screening chromatogram of example 9 solvent

FIG. 10 chromatogram for solvent screening in example 10

FIG. 11 chromatogram for screening of solvent in example 11

FIG. 12 chromatogram for screening of solvent in example 12

FIG. 13 optimized chromatogram for solvent in example 13

FIG. 14 example 14 optimized chromatograms of solvents

FIG. 15 chromatogram of separation test solution

FIG. 16 Linear regression of isopropanol

FIG. 17 Linear regression of dichloromethane

FIG. 18 piperidine Linear regression plot

FIG. 19 is a graph comparing the results of flow rate variation tests

FIG. 20 is a graph showing a comparison of the results of column temperature change tests

FIG. 21 comparative graph of temperature variation test results of a detector

FIG. 22 is a graph comparing the test results of sample injector temperature change.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The present invention will be described in further detail below by way of examples, but it should not be construed that the scope of the subject matter of the present invention is limited to the examples. Such alterations and modifications are intended to be included herein by the scope of this disclosure, and such modifications are intended to be within the meaning of those skilled in the art.

EXAMPLE 1 screening of chromatography columns

Instruments and reagents

The instrument comprises the following steps: water bath, balance and gas chromatograph

Reagent: ethanol, pyridine, toluene and piperidine

A chromatographic column: TG-5MS, liquid sample introduction and ethanol as a solvent.

Column temperature: the initial temperature was 80 ℃ for 15 minutes, and the temperature was increased to 240 ℃ at a rate of 30 ℃ per minute for 10 minutes.

Sample inlet temperature: 220 ℃, detector FID temperature: 250 ℃, column flow rate: 2.0ml/min.

As a result: the toluene and pyridine peak shapes are good, the piperidine peak trailing is serious and is partially overlapped with a toluene peak reagent, separation cannot be realized, and the method is not applicable. See fig. 1.

EXAMPLE 2 screening of chromatography columns

The column was CD-BASEWAX and the procedure was otherwise the same as in example 1.

As a result: piperidine peak shape is poor, response is low, and the method is not applicable. See fig. 2.

EXAMPLE 3 screening of chromatography columns

The chromatographic column HP-5 is arranged on the chromatographic column, the other operations were the same as in example 1.

As a result: toluene, pyridine and piperidine have good peak shapes, but the peak time of the piperidine and toluene is partially overlapped, so the method is not applicable. See fig. 3.

Example 4 column and solvent screening

The column was a CP-Volamine capillary column, and the other operations were the same as in example 1.

As a result: the control solution had a good peak shape and the separation was satisfactory, but the recovery of piperidine was determined to be 0 after adding the standard solutions of dipyridamole, cinacalcet, 3-fluoromethyllauric acid to the sample in ethanol +3% ammonia as solvent, and pyridine, toluene, piperidine, and the method was not applicable. See fig. 4.

EXAMPLE 5 screening of solvents

The reagents were ethanol +0.2% ammonia, pyridine, toluene, piperidine, otherwise the procedure was as in example 4.

As a result: the recovery rate of the solution is not detected, the recovery rate cannot meet the requirement, and the method is not applicable. See FIG. 5

EXAMPLE 6 screening of solvents

The reagents were ethanol +3% ammonia, pyridine, toluene, piperidine, otherwise the procedure was as in example 5.

As a result: the recovery rate of the solution and piperidine can be detected, but the recovery rate cannot meet the requirement, and the method is not applicable. See fig. 6.

EXAMPLE 7 screening of solvents

The reagents were ethanol +1% diethylamine, pyridine, toluene, piperidine, otherwise the same procedure as in example 5 was followed.

As a result: the recovery rate of the solution and piperidine is not detected, the recovery rate cannot meet the requirement, and the method is not applicable. See fig. 7.

EXAMPLE 8 screening of solvents

The reagents were ethanol +10% diethylamine, pyridine, toluene, piperidine, otherwise the same procedure as in example 5 was followed.

As a result: the recovery rate of the solution is high, the detection of the impurity peaks is high, the recovery rate of piperidine is about 60 percent, the recovery rate cannot meet the requirement, and the method is not applicable. See fig. 8.

EXAMPLE 9 screening of solvents

The reagents are DMSO, pyridine, toluene and piperidine, and the other operations are the same as example 5.

As a result: the recovery rate of the solution is about 70 percent, the recovery rate of the piperidine does not meet the requirement, and the method is not applicable. See fig. 9.

EXAMPLE 10 screening of solvents

The reagents are DMSO, sodium phosphate, sodium hydroxide, pyridine, toluene, piperidine, and the other operations are the same as example 5.

As a result: the pH value of DMSO is adjusted by saturated sodium phosphate, the sodium phosphate is separated out in the DMSO, the separation degree of piperidine and toluene is deteriorated, a blank is interfered, and the method is not applicable; taking 0.1M sodium hydroxide as a solvent, introducing a sample in a headspace, and insolubilizing a dipyridamole, cinacalcet and 3-fluoromethyllauric acid sample, wherein the method is not applicable; 0.5M sodium hydroxide is used as a solvent, headspace sampling is carried out at 75 ℃ for 30min, the recovery rate of piperidine is 0, the requirement cannot be met, and the method is not applicable. See fig. 10.

EXAMPLE 11 screening of solvents

The reagents were ethylenediamine, pyridine, toluene, piperidine, and the other operations were the same as in example 5.

As a result: the reference substance has good peak shape, the dipyridamole, cinacalcet and 3-fluoromethyllauric acid samples take ethylenediamine as a solvent, piperidine is added, the detection recovery rate is over 95 percent, and the requirement is met, but the ethylenediamine has high corrosivity, and the method has to be optimized for large damage to chromatographic columns and detection equipment. See fig. 11.

EXAMPLE 12 screening of solvents

The reagents were 10% ethylenediamine DMSO solution, pyridine, toluene, and piperidine, and the recovery rates of piperidine were determined in the same manner as in example 11 except that 10%, 5%, and 1% ethylenediamine DMSO solutions were used as solvents.

As a result: the peak shape of the reference substance is good, the dipyridamole, the cinacalcet and the 3-fluoromethyllauric acid sample are added with piperidine by taking a 10% ethylenediamine DMSO solution as a solvent, and the detection recovery rate is over 95 percent, so that the requirement is met. See fig. 12.

EXAMPLE 13 solvent optimization

The reagents were 5% ethylenediamine DMSO solution and piperidine, and the procedure was otherwise the same as in example 12.

As a result: the recovery rate of the piperidine is more than 95 percent and meets the requirement. See fig. 13.

EXAMPLE 14 solvent optimization

The reagents were 1% ethylenediamine DMSO solution and piperidine, and the procedure was otherwise the same as in example 13.

As a result: the peak shape of the reference substance is good, the cinacalcet hydrochloride and the sample take 1% ethylenediamine DMSO solution as a solvent, piperidine is added, the detection recovery rate is over 95%, and the recovery rate meets the requirement.

And (4) conclusion: the ethylene diamine and DMSO with different proportions are adopted as solvent samples to be dissolved, the piperidine recovery rate meets the requirement, and in order to reduce the damage of the ethylene diamine to a chromatographic column, a 1% ethylene diamine DMSO solution is better used as the solvent. See fig. 14.

Example 15 establishment of detection method and System adaptability test

Blank solvent: DMSO;

test solution: precisely weighing about 1.0g of cinacalcet, placing the cinacalcet in a 10ml measuring flask, adding a 1% ethylenediamine DMSO solution, ultrasonically dissolving, fixing the volume to a scale, and shaking up to be used as a test solution;

control solution: diluting with 1% ethylenediamine DMSO solution to 1ml of mixed solution containing isopropanol 2.0mg, dichloromethane 2.0mg and piperidine 0.02mg as control solution;

sample application separation degree test solution: precisely weighing about 1.0g of cinacalcet, placing the cinacalcet in a 10ml measuring flask, precisely adding 1ml of a control solution stock solution, adding a 1% ethylenediamine DMSO solution, carrying out ultrasonic dissolution, fixing the volume to a scale, and shaking up to be used as a sample-adding separation degree test solution;

positioning test solution: accurately measuring 1ml of isopropanol and dichloromethane reference substance storage solution, placing the solution in a 100ml measuring flask, accurately measuring 1ml of piperidine reference substance storage solution, placing the solution in a 25ml measuring flask, diluting the solution to a scale by using 1% ethylenediamine DMSO solution, and taking the solution as each solvent positioning solution;

The chromatographic conditions are as follows: the initial temperature is 80 ℃, the temperature is maintained for 15 minutes, the temperature is increased to 240 ℃ at the rate of 30 ℃ per minute, and the temperature is maintained for 10 minutes; sample inlet temperature: 220 ℃, detector FID temperature: 250 ℃, column flow rate: 2.0ml/min, split ratio 3:1.

Separately taking each solution, injecting 1 μ l, recording chromatogram, and showing the resolution test solution in figure 15. The test results of the test sample and the reference solution are shown in table 1, and the specificity test results are shown in table 2.

TABLE 1 precision test results

TABLE 2 results of the specificity test

As a result: blank solvent is not interfered; the separation degree of each solvent is more than 1.5; 5 needles of isopropanol are continuously injected, the peak area RSD is 4.26 percent, and the main peak retention time RSD is 0.25 percent; 5 needles of dichloromethane are continuously injected, the peak area RSD is 2.90 percent, and the main peak retention time RSD is 0.18 percent; continuously injecting 5 needles of piperidine, wherein the peak area RSD is 2.99%, and the main peak retention time RSD is 0.15%; the result shows that the method has good system applicability and specificity.

EXAMPLE 16 Linear and Range test

Taking appropriate amounts of isopropanol, dichloromethane and piperidine, precisely weighing, adding 1% ethylenediamine DMSO solution to dissolve and dilute to prepare each control stock solution containing 100mg of isopropanol, 100mg of dichloromethane and 1.0mg of piperidine in each 1ml, precisely weighing 5ml of each control stock solution, placing in a 25ml measuring flask, and diluting with 1% ethylenediamine DMSO solution to obtain a control stock solution containing 20mg of isopropanol, 20mg of dichloromethane and 0.2mg of piperidine in each 1 ml. Measuring 1.0ml, 2.0ml, 1.0ml, 3.0ml and 2.0ml of the stock solution of the control solution, respectively placing the stock solution of the control solution in 50ml, 25ml, 10ml, 25ml and 10ml measuring bottles, adding 1% ethylenediamine DMSO solution to dilute to the scale, and shaking up to obtain the reagent. Mu.l of the sample is injected respectively, chromatogram is recorded, the result of the linear and range test is measured by taking the injection concentration (mu g/ml) as the abscissa (x-axis) and the peak area as the ordinate (y-axis), and is shown in tables 3, 4 and 5 and figures 16, 17 and 18.

TABLE 3 isopropanol linearity and range test results

TABLE 4 Dichloromethane Linearity and Range test results

TABLE 5 piperidine Linear and Range test results

The result shows that the isopropanol linear equation is y =0.0333x +0.8072, the peak area and the concentration are in good linear relation in the range of 39.38138 mu g/ml-3938.13800 mu g/ml, and R is ² =0.9995, y-axis intercept offset 0.012; the linear equation of the dichloromethane is y =0.0087x +0.0305, the peak area and the concentration have good linear relation in the range of 42.19376 mu g/ml-4219.37640 mu g/ml, and R is ² =0.9998, y-axis intercept offset 0.002; the linear equation of piperidine is y =0.0453x-0.0338, the peak area and the concentration are in good linear relation in the range of 4.15008 mu g/ml to 41.50080 mu g/ml, and R is ² =0.9975, y-axis intercept offset-0.037.

Example 17 detection Limit and quantitation Limit tests

The reference solution was diluted step by step, the detection limit of each solvent was calculated with a signal-to-noise ratio S/N of not less than 3, and the quantitation limit of each solvent was calculated with a signal-to-noise ratio S/N of not less than 10, the results are shown in tables 6 and 7.

TABLE 6 determination results of detection limit and quantitative limit of each solvent to be tested

TABLE 7 Limit of quantitation precision test results

The results show that: the quantitative limit concentration of the isopropanol is equivalent to 0.039 percent of the concentration of the test sample, and the RSD of a continuous 5-needle sample injection peak area is 8.83 percent; the quantitative limit concentration of the dichloromethane is equivalent to 0.042 percent of the concentration of the test sample, and the RSD of the continuous 5-needle sample injection peak area is 8.53 percent; the limit concentration of the piperidine quantification is equivalent to 0.004 percent of the concentration of the test sample, and the RSD of the continuous 5-needle sample injection peak area is 9.89 percent; the limit of quantitation under this chromatographic condition is satisfactory.

EXAMPLE 18 repeatability test

Taking 1.0g of the product, precisely weighing, placing 6 parts in parallel into 10ml measuring flasks respectively, adding 1% ethylenediamine DMSO solution, ultrasonically dissolving, and fixing the volume to a scale to obtain a test solution. Mu.l of sample was injected and the results are shown in tables 1.3.2-8. The isopropanol content and the dichloromethane content in the sample are respectively 0.601% and 0.353%, respectively, and piperidine is not detected; taking 1.0g of the product, precisely weighing, placing 6 parts in parallel into 10ml measuring flasks respectively, precisely adding 1ml of a control solution stock solution, adding a 1% ethylenediamine DMSO solution, ultrasonically dissolving, fixing the volume to a scale, shaking up, and using as a sample-adding repeatability test solution. Samples of 1. Mu.l were injected and the results are shown in tables 8 and 9. The absolute deviation of the content in the sample loading repeatability test solution is less than 20 percent of the limit of the quality standard.

TABLE 8 results of the repeatability tests

TABLE 9 sample Loading repeatability test results

And (4) conclusion: the same experimenter repeatedly measures the same batch of samples for 6 times, the number of solvent peaks of the measured results is consistent above the limit of quantitation, the detected content of isopropanol in 6 test solutions is 0.601%, the detected content of dichloromethane is 0.353%, and piperidine is not detected; the same experiment personnel repeatedly measure the same batch of samples with the concentration of the control solution for 6 times, the number of the solvent peaks of the measured result is consistent above the limit of quantification, the absolute deviation of the content in 6 test solutions is less than 20 percent of the limit of quality standard, the RSD (n = 6) of the total solvent content is 2.70 percent, the requirement is met, and the method has good repeatability.

Example 19 intermediate precision test

The influence of randomly varying factors on precision was examined and evaluated by different analysts, using different instruments, on different dates, on the same batch under the repeated test items. Taking 1.0g of the product, precisely weighing, placing 6 parts in parallel into 10ml measuring flasks respectively, precisely adding 1ml of a control solution stock solution, adding a 1% ethylenediamine DMSO solution, ultrasonically dissolving, fixing the volume to a scale, shaking uniformly, making an intermediate precision test solution, and injecting 1 mu l of the intermediate precision test solution, wherein the results are shown in Table 10.

TABLE 10 results of precision test

The absolute deviation is less than 20% of the limit of the quality standard, the RSD (n = 12) of the total solvent content is 3.82%, the method meets the requirement, and the method has good precision.

EXAMPLE 20 recovery test

Control stock solution: accurately weighing appropriate amounts of isopropanol, dichloromethane and piperidine, respectively placing into corresponding measuring bottles, dissolving and diluting with 1% ethylenediamine DMSO solution to obtain solutions containing 100mg of isopropanol, 100mg of dichloromethane and 1mg of piperidine per 1ml, and using the solutions as control stock solutions of each solvent. Precisely measuring the reference substance stock solution of each solvent in a volumetric flask from 5ml to 25ml respectively, and adding a 1% ethylenediamine DMSO solution to dilute to a scale to obtain the stock solution of the recovery rate. 1ml of the recovery stock solution was precisely measured, placed in a 10ml measuring flask, and diluted with a 1% ethylenediamine DMSO solution to a mixed solution containing about 2mg of isopropyl alcohol, 2mg of methylene chloride and 0.02mg of piperidine per 1ml, as a control solution.

Quantitative limit recovery stock solution: taking 1ml of reference substance stock solutions of isopropanol and dichloromethane, respectively placing the reference substance stock solutions into a 10ml measuring flask, fixing the volume to the scale by using a 1% ethylenediamine DMSO solution, shaking up, taking 1ml of diluted isopropanol and 1ml of dichloromethane, placing the diluted isopropanol and 1ml of dichloromethane into the 10ml measuring flask, fixing the volume to the scale by using the 1% ethylenediamine DMSO solution, shaking up, and respectively using the solutions as stock solutions of isopropanol and dichloromethane with quantitative limit recovery rate.

Loading and recovering 80%, 100% and 120% concentration solution: precisely weighing 2.5g, 1.0g and 2.5g of the product, respectively placing the product in 25ml, 10ml and 25ml measuring bottles, adding a 1% ethylenediamine DMSO solution for ultrasonic dissolution, respectively precisely weighing 2ml, 1ml and 3ml of the recovery rate stock solution, placing the stock solution in 25ml, 10ml and 25ml measuring bottles, diluting the stock solution to a scale by using a 1% ethylenediamine DMSO solution, shaking the stock solution uniformly, and taking the stock solution as a solution with 80%, 100% and 120% concentration for sample recovery.

Isopropanol and dichloromethane are added to determine the concentration of the limiting solution: precisely weighing 2.5g of the product, placing the product into a 25ml measuring flask, adding a 1% ethylenediamine DMSO solution for ultrasonic dissolution, adding a proper amount of isopropanol and dichloromethane quantitative limit recovery stock solution, then using the 1% ethylenediamine DMSO solution for constant volume to a scale, shaking up, and using the solution as a solution of isopropanol and dichloromethane sampling quantitative limit concentration.

Piperidine loading solution with quantitative limiting concentration: precisely weighing 1.0g of the product, placing the product into a 10ml measuring flask, adding a 1% ethylenediamine DMSO solution for ultrasonic dissolution, adding an appropriate amount of a piperidine control solution, using the 1% ethylenediamine DMSO solution for constant volume to a scale, shaking up, and using the solution as a solution for piperidine sampling quantitative limit concentration.

3 parts of the extract are prepared according to the same method for each concentration level, the extract is measured according to the chromatographic conditions determined in example 15, the recovery rate is calculated according to the peak area of an external standard method, and the results are shown in tables 11, 12 and 13;

TABLE 11 isopropanol recovery test results

TABLE 12 methylene chloride recovery test results

TABLE 13 piperidine recovery test results

And (4) conclusion: the average recovery rates of four concentration levels of isopropanol quantitative limit, low, medium and high are 100.37%, 95.96%, 96.47% and 94.61 respectively, and the 4 horizontal recovery rates RSD are 7.47% and less than 10.0%; the average recovery rates of the dichloromethane quantitative limit, the low concentration level, the medium concentration level and the high concentration level are respectively 88.10%, 100.71%, 100.86% and 99.26%, the RSD of the 4 concentration levels is 6.12% and is less than 10.0%, the average recovery rates of the piperidine quantitative limit, the low concentration level, the medium concentration level and the high concentration level are respectively 88.14%, 100.20%, 95.86% and 94.38%, and the RSD of the 4 concentration levels is 5.11% and is less than 10.0%, and the result shows that the method has good accuracy.

EXAMPLE 21 durability test

The control solution and the 100% limit test solution were analyzed by the following chromatographic conditions, and the test results are shown in tables 14 and 15 in FIGS. 19, 20, 21 and 22, respectively.

TABLE 14 durability test results

TABLE 15 durability test

Results and discussion: the temperature of the injection port is changed within the range of 215-225 ℃, the flow rate is changed within the range of 1.8-2.2 ml/min, the temperature of the detector is changed within the range of 245-255 ℃, the initial column temperature is changed within the range of 75-85 ℃, the separation degree of each solvent in the contrast solution is more than 1.5 (when the temperature of the detector is 255 ℃, the separation degree of isopropanol and the adjacent impurity peak is slightly poor but does not influence the quantification), and the relative deviation of each solvent in the sample solution at the limit of 100% does not exceed 20% of the quality standard, which indicates that the method has good durability.

EXAMPLE 22 cinacalcet sample assay

Taking 3 batches of cinacalcet samples, precisely weighing about 1.0g, putting into a 10ml measuring flask, adding 1% ethylenediamine DMSO solution to a constant volume to a scale, and shaking to dissolve to obtain the cinacalcet. According to the residual solvent determination method, sample introduction is carried out on a test solution and a reference solution, a chromatogram is recorded, and the residual amount of each solvent to be determined is calculated according to the peak area by an external standard method, and the result is shown in Table 16.

TABLE 16 measurement results of each test solvent

EXAMPLE 23 Fluoromethyl lauric acid sample determination

3 batches of 3-fluoromethyl lauric acid (about 1.0 g) are taken, the structural formula of the 3-fluoromethyl lauric acid is shown in figure 16, the mixture is precisely weighed and placed in a 10ml measuring flask, 1% ethylenediamine DMSO solution is added to be constant volume to be calibrated, and the mixture is shaken to be dissolved, so that the fluorine-containing acrylic acid is obtained. Example 15 the method, sample test solution and reference solution, record chromatogram, according to the external standard method to calculate the solvent residue by peak area, the results are shown in table 17.

TABLE 17 measurement results of respective test solvents

Example 24 dipyridamole sample assay

Taking 3 batches of dipyridamole, precisely weighing about 1.0g, putting into a 10ml measuring flask, adding 1% ethylenediamine DMSO solution to a constant volume to a scale, and shaking to dissolve. According to the residual solvent determination method, sample introduction is carried out on a sample solution and a reference solution, a chromatogram is recorded, and the residual amount of each solvent to be determined is calculated according to the peak area by an external standard method, and the result is shown in Table 18.

TABLE 18 measurement results of respective test solvents

Claims

1. A method for determining piperidine residue is characterized by comprising the following steps:

preparation of control solution: accurately weighing an appropriate amount of piperidine, respectively placing into corresponding measuring bottles, dissolving and diluting with 1~5% ethylenediamine DMSO solution to obtain a solution containing about 0.02mg of piperidine per 1ml, and using the solution as a reference solution;

preparing a test solution: precisely weighing about 1.0g of a sample to be tested, placing the sample in a 10ml measuring flask, adding 1~5% ethylenediamine DMSO solution for ultrasonic dissolution, fixing the volume to a scale, and shaking up to be used as a test sample solution;

preparation of a blank solution: 1~5% ethylenediamine DMSO solution;

the chromatographic column comprises: CP-Volamine capillary column;

chromatographic conditions are as follows: the initial temperature is 75 to 85 ℃, the temperature is maintained for 15 minutes, the temperature is raised to 240 ℃ at the rate of 30 ℃ per minute, and the temperature is maintained for 10 minutes.

2. Sample inlet temperature: 215 to 225 ℃, detector FID temperature: 245 to 255 ℃, column flow rate: 1.8 to 2.2ml/min, and the split ratio of 3:1;

sample introduction: sampling the blank solvent, the solution sample and the solution reference solution respectively for 1 mul, and recording chromatogram by liquid sampling; piperidine residues were calculated by external standard method.

3. The method of claim 1 for determining piperidine residual, wherein: concentration of ethylenediamine DMSO solution 1%, starting temperature in chromatographic conditions: 80 ℃, injection port temperature: 220 ℃, detector FID temperature: 250 ℃, column flow rate: 2.0ml/min.

4. The method for measuring piperidine residue according to claim 1, wherein: ethylenediamine DMSO concentration of 2%, starting temperature in chromatographic conditions: 75 ℃, injection port temperature: 215 ℃, detector FID temperature: 245 ℃, column flow rate: 1.8ml/min.

5. The method for measuring piperidine residue according to claim 1, wherein: ethylenediamine DMSO concentration 5%, starting temperature in chromatographic conditions: 85 ℃, injection port temperature: 225 ℃, detector FID temperature: 255 ℃, column flow rate: 2.2ml/min.