CN114236002A - Method for detecting volatile impurities of anhydrous sodium carbonate - Google Patents
Method for detecting volatile impurities of anhydrous sodium carbonate Download PDFInfo
- Publication number
- CN114236002A CN114236002A CN202111536023.0A CN202111536023A CN114236002A CN 114236002 A CN114236002 A CN 114236002A CN 202111536023 A CN202111536023 A CN 202111536023A CN 114236002 A CN114236002 A CN 114236002A
- Authority
- CN
- China
- Prior art keywords
- sodium carbonate
- anhydrous sodium
- sample
- detecting
- impurities
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/26—Conditioning of the fluid carrier; Flow patterns
- G01N30/28—Control of physical parameters of the fluid carrier
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/50—Conditioning of the sorbent material or stationary liquid
- G01N30/52—Physical parameters
- G01N30/54—Temperature
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/86—Signal analysis
- G01N30/8675—Evaluation, i.e. decoding of the signal into analytical information
- G01N30/8679—Target compound analysis, i.e. whereby a limited number of peaks is analysed
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Engineering & Computer Science (AREA)
- Library & Information Science (AREA)
- Sampling And Sample Adjustment (AREA)
Abstract
The invention discloses a method for detecting volatile impurities in anhydrous sodium carbonate, which comprises the following steps: firstly, preparing at least 7 groups of reference substance standard solutions containing anhydrous sodium carbonate, wherein the concentrations of reference substances in the reference substance standard solutions are different, and the concentrations of impurities in the reference substance standard solutions are different; performing temperature programming detection on the reference standard solution by using a gas chromatography, drawing a standard curve of the reference standard solution according to the obtained peak area, and obtaining a concentration-peak area linear regression equation of the impurity reference in the anhydrous sodium carbonate according to the standard curve; and thirdly, providing a sample to be detected, detecting the sample to be detected under the same condition, substituting the obtained peak area into a concentration-peak area linear regression equation, and calculating the content of impurities in the sample to be detected. The method has the advantages of high detection sensitivity, low detection limit and accurate recovery rate, accurately and quantitatively detects the impurities in the anhydrous sodium carbonate, improves the detection accuracy, and is suitable for detecting the volatile impurities of the anhydrous sodium carbonate.
Description
Technical Field
The invention belongs to the technical field of detection of volatile impurities, and particularly relates to a method for detecting anhydrous sodium carbonate volatile impurities.
Background
The anhydrous sodium carbonate is a pharmaceutic adjuvant and is a pH regulator.
At present, anhydrous sodium carbonate can be industrially produced in a mature way, intermediate products and finished products need to be sampled to detect the volatile impurity conditions in the actual production of the anhydrous sodium carbonate, and an external standard method is adopted for detection in the past, so that the recovery rate is high, and the detection result is inaccurate.
Disclosure of Invention
The invention provides a detection method for anhydrous sodium carbonate volatile impurities, which solves the problems of high recovery rate and inaccurate detection result of the anhydrous sodium carbonate volatile impurities detected by an external standard method.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a method for detecting anhydrous sodium carbonate volatile impurities comprises the following steps:
step one, preparing at least 7 groups of reference substance standard solutions containing anhydrous sodium carbonate, wherein the concentrations of reference substances in the reference substance standard solutions are different, and the concentrations of impurities in the reference substance standard solutions are different;
step two, performing temperature programming detection on the reference standard solution by using a gas chromatography, respectively drawing a standard curve of the reference standard solution according to the obtained peak areas, and obtaining a concentration-peak area linear regression equation of the impurity reference in the anhydrous sodium carbonate according to the standard curve;
and step three, providing a sample to be detected, detecting the sample to be detected under the same conditions of the step two, substituting the obtained peak area into a concentration-peak area linear regression equation, and calculating the content of impurities in the sample to be detected.
Further, the impurity in the first step is ethanol.
Further, in the second step, the temperature is raised to 40 ℃ for 8 minutes, and then raised to 150 ℃ at the speed of 20 ℃/min for 10 minutes.
Further, the chromatographic conditions for the temperature programmed detection in the gas chromatography in the step two are as follows:
a chromatographic column: a capillary column taking 6% of cyanopropylphenyl-94% of dimethyl polysiloxane as a stationary liquid is taken as a chromatographic column;
the temperature of a sample inlet is 200 ℃; the temperature of the detector is 250 ℃;
headspace conditions: sample equilibrium temperature: 75 ℃; the balance time is as follows: 30 minutes;
mobile phase: nitrogen, the concrete content is as follows:
hydrogen flow rate: 40 ml/min; air flow rate: 400 ml/min;
nitrogen tail blowing: 32.2 ml/min; constant mainstream + tail-blown: 33 ml/min;
the split ratio is as follows: 20:1.
Further, in the step one, the concentration range of impurities in the standard solution of the reference substance is 0.0015-0.1 mg/L.
Further, the solvent of the reference substance standard solution in the step one is the solution of the to-be-detected substance.
As the invention adopts the invention, compared with the prior art, the invention has the technical progress that:
(1) the method adopts the gas chromatography to detect the anhydrous sodium carbonate, can more accurately detect whether the variety to be detected has impurities or not, can also detect the specific content of the impurities, and has the advantages of high detection sensitivity, low detection limit, accurate detection result and convenient analysis and control of production;
(2) the invention adopts the gas chromatography to detect a plurality of samples in the same time, thereby greatly improving the working efficiency;
(3) the programmed temperature rise can ensure that both low-boiling point components and high-boiling point components are properly reserved in a chromatographic column, chromatographic peaks are uniformly distributed, and the peak types are more symmetrical;
(4) the invention adopts the solution of the object to be tested as the solvent, which can eliminate the influence of matrix effect caused by the difference between the matrix of the solution of the object to be tested and the matrix of the solution of the reference object.
In conclusion, the method has the advantages of high detection sensitivity, low detection limit and accurate recovery rate, can be used for accurately and quantitatively detecting the impurities in the anhydrous sodium carbonate, improves the detection accuracy, and is suitable for detecting the volatile impurities of the anhydrous sodium carbonate.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.
In the drawings:
FIG. 1 is a gas chromatogram of a control solution of example 1 according to the present invention;
FIG. 2 is a gas chromatogram of a solution of a test substance of example 1 according to the present invention;
FIG. 3 is a standard curve of example 2 of the present invention.
Detailed Description
The following description is given in conjunction with preferred embodiments of the present invention. It should be understood that the preferred embodiments described herein are for purposes of illustration and explanation only and are not intended to limit the present invention.
Example 1
Method for detecting volatile impurities of anhydrous sodium carbonate
Step one, comparing a sample stock solution: accurately weighing 0.5g of pure absolute ethyl alcohol, adding water to dissolve and dilute to 100ml, and shaking up to obtain the product.
Stock solution of the sample to be tested: accurately weighing 40g of the product in a volumetric flask of 200ml, adding water to dilute to the scale, and shaking up to obtain the product.
Precisely measuring 5.0ml of the reference stock solution and 25ml of the sample stock solution into the same 50ml volumetric flask, adding water to dilute to scale, and shaking up to obtain the standard solution.
Step two, detecting the prepared standard solutions by using a gas chromatography respectively, wherein the chromatographic conditions are as follows: taking a capillary blood column taking 6% cyanopropylphenyl-94% dimethylpolysiloxane as a stationary liquid as a chromatographic column;
the temperature of a sample inlet is 200 ℃; the temperature of the detector is 250 ℃; the temperature programming is that the column temperature is kept for 8 minutes at 40 ℃, and then the temperature is raised to 150 ℃ at the speed of 20 ℃/min and kept for 10 minutes;
headspace conditions: sample equilibrium temperature: 75 ℃; the balance time is as follows: 30 minutes;
mobile phase: nitrogen, the concrete content is as follows:
hydrogen flow rate: 40 ml/min; air flow rate: 400 ml/min;
nitrogen tail blowing: 32.2 ml/min; constant column flow + tail blow: 33 ml/min;
the split ratio is as follows: 20:1.
And (3) detecting in the second step as shown in figure 1, comparing the peak area of the obtained reference substance solution with that shown in figure 2, and calculating the impurity content by using an external standard method according to the sample peak area.
Example 2
Method for detecting volatile impurities of anhydrous sodium carbonate
Step one, comparing a sample stock solution: accurately weighing 0.5g of pure absolute ethyl alcohol, adding water to dissolve and dilute to 100ml, and shaking up to obtain the product.
Stock solution of the sample to be tested: precisely weighing 40g of the product in a volumetric flask of 200ml, adding water to dissolve the product to a scale, and shaking up to obtain the product.
Precisely measuring 5.0ml of the reference stock solution and 25ml of the sample stock solution into the same 50ml volumetric flask, adding water to dilute to scale, and shaking up to obtain the final product.
Standard solutions of 0.0015mg/L, 0.005mg/L, 0.01mg/L, 0.025mg/L, 0.0751mg/L and 0.1001mg/L are prepared by the same method.
Step two, detecting the prepared standard solutions by using a gas chromatography respectively, wherein the chromatographic conditions are as follows: a capillary column with 6% cyanopropylphenyl-94% dimethylpolysiloxane as a stationary liquid was used as a chromatographic column:
the temperature of a sample inlet is 200 ℃; the temperature of the detector is 250 ℃; the temperature programming is that the column temperature is kept for 8 minutes at 40 ℃, and then the temperature is raised to 150 ℃ at the speed of 20 ℃/min and kept for 10 minutes;
headspace conditions: sample equilibrium temperature: 75 ℃; the balance time is as follows: 30 minutes;
mobile phase: nitrogen, the concrete content is as follows:
hydrogen flow rate: 40 ml/min; air flow rate: 400 ml/min;
nitrogen tail blowing: 32.2ml/min, constant column flow + tail blow: 33 ml/min;
the split ratio is as follows: 20:1.
And (5) drawing a standard curve for the content of the anhydrous sodium carbonate impurity reference substance obtained by respectively detecting in the step two, and obtaining a linear regression equation as shown in figure 3.
The correlation coefficient R and the linear regression equation were obtained from the relationship between the peak area and the concentration obtained in example 2, and the results are shown in Table 1 below.
Table 1 example 2 peak area and corresponding concentration
| Serial number | Peak area | Impurity concentration ug/ml |
| 1 | 29.884 | 1.5 |
| 2 | 94.294 | 5.0 |
| 3 | 183.963 | 10.0 |
| 4 | 450.077 | 25.0 |
| 5 | 908.884 | 50.0 |
| 6 | 1350.945 | 75.1 |
| 7 | 1884.772 | 100.1 |
The detection results in table 1 were subjected to linear analysis to obtain a linear regression equation shown in table 2.
Table 2 linear regression equation and correlation coefficient of test results of example 2
| Name (R) | Linear regression equation | Correlation coefficient |
| Impurities | Y＝18551x-5.9496 | r＝0.9995 |
Detecting a sample to be detected:
stock solution of the sample to be tested: precisely weighing 5.0g of the product in a 25ml volumetric flask, adding water to dissolve the product to a scale, and shaking up to obtain a stock solution of a to-be-detected product;
precisely measuring a to-be-measured stock solution in a volumetric flask of 5ml to 10ml, adding water to a constant volume to reach a scale, shaking up to obtain a solution, precisely measuring 5ml in a headspace flask, sealing, and preparing into a to-be-measured solution of 100 mg/ml;
dissolving a proper amount of reference substance with solvent, and diluting to obtain a solution containing 500ug of ethanol per 1ml as reference substance solution;
a capillary column taking 6% of cyanopropylphenyl-94% of dimethyl polysiloxane as a stationary liquid is taken as a chromatographic column;
the temperature of a sample inlet is 200 ℃; the temperature of the detector is 250 ℃; the temperature programming is that the column temperature is kept for 8 minutes at 40 ℃, and then the temperature is raised to 150 ℃ at the speed of 20 ℃/min and kept for 10 minutes;
headspace conditions: sample equilibrium temperature: 75 ℃; the balance time is as follows: 30 minutes;
mobile phase: nitrogen, the concrete content is as follows:
hydrogen flow rate: 40 ml/min; air flow rate: 400 ml/min;
nitrogen tail blowing: 32.2 ml/min; constant column flow + tail blow: 33 ml/min;
the split ratio is as follows: 20:1.
Operating according to the detection standard program of a gas chromatograph, measuring the peak area of the ethanol to be 18.3, and showing the gas chromatogram of the solution to be measured in figure 2. And calculating the ethanol content of the anhydrous sodium carbonate in the sample to be detected to be 0.0013mg/ml according to the theoretical linear regression equation, so that the ethanol content in the sample to be detected is 0.0013%.
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.
Claims (6)
1. A detection method of anhydrous sodium carbonate volatile impurities is characterized by comprising the following steps: the method comprises the following steps:
step one, preparing at least 7 groups of reference substance standard solutions containing anhydrous sodium carbonate, wherein the concentrations of reference substances in the reference substance standard solutions are different, and the concentrations of impurities in the reference substance standard solutions are different;
step two, performing temperature programming detection on the reference standard solution by using a gas chromatography, respectively drawing a standard curve of the reference standard solution according to the obtained peak area, and obtaining a concentration-peak area linear regression equation of the impurity reference in the anhydrous sodium carbonate according to the standard curve;
and step three, providing a sample to be detected, detecting the sample to be detected under the same conditions of the step two, substituting the obtained peak area into a concentration-peak area linear regression equation, and calculating the content of impurities in the sample to be detected.
2. The method for detecting anhydrous sodium carbonate volatile impurities according to claim 1, characterized in that: in the first step, the impurity is ethanol.
3. The method for detecting anhydrous sodium carbonate volatile impurities according to claim 1, characterized in that: in the second step, the temperature is raised to 40 ℃ for 8 minutes, and then raised to 150 ℃ at the speed of 20 ℃/min for 10 minutes.
4. The method for detecting anhydrous sodium carbonate volatile impurities according to claim 1, characterized in that: in the second step, the chromatographic conditions for the temperature programmed detection by the gas chromatography are as follows:
a chromatographic column: a capillary column taking 6% of cyanopropylphenyl-94% of dimethyl polysiloxane as a stationary liquid is taken as a chromatographic column;
the temperature of a sample inlet is 200 ℃; the temperature of the detector is 250 ℃;
headspace conditions: sample equilibrium temperature: 75 ℃; the balance time is as follows: 30 minutes;
mobile phase: nitrogen, the concrete content is as follows:
hydrogen flow rate: 40 ml/min; air flow rate: 400 ml/min;
nitrogen tail blowing: 32.2 ml/min; constant mainstream + tail-blown: 33 ml/min;
the split ratio is as follows: 20:1.
5. The method for detecting anhydrous sodium carbonate volatile impurities according to claim 1, characterized in that: in the step one, the concentration range of impurities in the standard solution of the reference substance is 0.0015-0.1 mg/L.
6. The method for detecting anhydrous sodium carbonate volatile impurities according to claim 1, characterized in that: in the step one, the solvent of the standard solution of the reference substance is the solution of the to-be-detected substance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111536023.0A CN114236002A (en) | 2021-12-15 | 2021-12-15 | Method for detecting volatile impurities of anhydrous sodium carbonate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111536023.0A CN114236002A (en) | 2021-12-15 | 2021-12-15 | Method for detecting volatile impurities of anhydrous sodium carbonate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114236002A true CN114236002A (en) | 2022-03-25 |
Family
ID=80756432
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111536023.0A Pending CN114236002A (en) | 2021-12-15 | 2021-12-15 | Method for detecting volatile impurities of anhydrous sodium carbonate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114236002A (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103487519A (en) * | 2013-09-05 | 2014-01-01 | 上海新亚药业有限公司 | Method for detecting multiple residual solvents in medicament |
| CN103487541A (en) * | 2013-09-05 | 2014-01-01 | 上海新亚药业有限公司 | Method for simultaneously detecting multiple residual solvents in ceftriaxone sodium |
| CN104090060A (en) * | 2014-07-28 | 2014-10-08 | 广州天赐高新材料股份有限公司 | Method for detecting residual solvent in electrolyte lithium salt |
| CN106153749A (en) * | 2015-04-07 | 2016-11-23 | 江苏宝众宝达药业有限公司 | The method of residual solvent in inspection chlophedianol hydrochloride Starting material medicine |
| CN108318615A (en) * | 2018-03-16 | 2018-07-24 | 湖北亿诺瑞生物制药有限公司 | The method that headspace gas chromatography detects residual solvent in heparin sodium |
| CN108344811A (en) * | 2017-01-24 | 2018-07-31 | 北京泰德制药股份有限公司 | The detection method of organic solvent residual in a kind of Injectable liposomal |
| CN111855837A (en) * | 2020-06-29 | 2020-10-30 | 武汉九州钰民医药科技有限公司 | Detection method and application of residual solvent in cefotaxime sodium |
| CN112710752A (en) * | 2020-12-18 | 2021-04-27 | 卓和药业集团有限公司 | Detection method of residual solvent of meclofenoxate sodium |
| CN113607843A (en) * | 2021-07-30 | 2021-11-05 | 河北省药品医疗器械检验研究院(河北省化妆品检验研究中心) | Method for detecting residual solvent in sirolimus raw material medicine |
-
2021
- 2021-12-15 CN CN202111536023.0A patent/CN114236002A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103487519A (en) * | 2013-09-05 | 2014-01-01 | 上海新亚药业有限公司 | Method for detecting multiple residual solvents in medicament |
| CN103487541A (en) * | 2013-09-05 | 2014-01-01 | 上海新亚药业有限公司 | Method for simultaneously detecting multiple residual solvents in ceftriaxone sodium |
| CN104090060A (en) * | 2014-07-28 | 2014-10-08 | 广州天赐高新材料股份有限公司 | Method for detecting residual solvent in electrolyte lithium salt |
| CN106153749A (en) * | 2015-04-07 | 2016-11-23 | 江苏宝众宝达药业有限公司 | The method of residual solvent in inspection chlophedianol hydrochloride Starting material medicine |
| CN108344811A (en) * | 2017-01-24 | 2018-07-31 | 北京泰德制药股份有限公司 | The detection method of organic solvent residual in a kind of Injectable liposomal |
| CN108318615A (en) * | 2018-03-16 | 2018-07-24 | 湖北亿诺瑞生物制药有限公司 | The method that headspace gas chromatography detects residual solvent in heparin sodium |
| CN111855837A (en) * | 2020-06-29 | 2020-10-30 | 武汉九州钰民医药科技有限公司 | Detection method and application of residual solvent in cefotaxime sodium |
| CN112710752A (en) * | 2020-12-18 | 2021-04-27 | 卓和药业集团有限公司 | Detection method of residual solvent of meclofenoxate sodium |
| CN113607843A (en) * | 2021-07-30 | 2021-11-05 | 河北省药品医疗器械检验研究院(河北省化妆品检验研究中心) | Method for detecting residual solvent in sirolimus raw material medicine |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111579689A (en) | Method for measuring content of dimethyl sulfate in clopidogrel hydrogen sulfate | |
| CN103344725B (en) | Method for simultaneously and quantitatively detecting content of ethyl carbamate and phthalate in distilled white wine | |
| CN110687223B (en) | Method for measuring content of sodium valproate raw material methyl acetoacetate | |
| CN112129855A (en) | Method for measuring chloroacetic acid concentration in air by gas chromatography and application thereof | |
| CN114236002A (en) | Method for detecting volatile impurities of anhydrous sodium carbonate | |
| CN110895264A (en) | Method for determining ethyl bromide in tenofovir alafenamide | |
| CN102297913A (en) | Method for measuring harmful substance-hexanolactam in air of workplace | |
| CN112147261A (en) | High performance liquid detection method for R-4-chloro-3-hydroxy ethyl butyrate in L-carnitine reaction solution | |
| CN113030323A (en) | Method for detecting residual solvent in nilotinib bulk drug | |
| CN114236003A (en) | Detection method of volatile impurities in calcium pantothenate | |
| CN107179370B (en) | Method for detecting gluconic acid content in fermentation liquor of vitamin C two-step fermentation method by adopting high performance liquid chromatography | |
| CN112763585A (en) | Method for determining benzene impurity content in sulfadiazine or sulfadiazine derivative | |
| CN116879428B (en) | High performance liquid analysis method for residual content of phosphorylcholine in L-alpha-phosphorylcholine | |
| CN115184529B (en) | Detection method of N-methylbenzylamine related substances | |
| CN112014507B (en) | Method for measuring content of 2-aminoacetophenone in high fructose corn syrup by headspace gas chromatography | |
| CN113777204B (en) | Detection method of p-hydroxyacetophenone related substances | |
| CN112034058B (en) | Method for detecting isomer impurities in vincamine | |
| CN114705790B (en) | Detection method of ethyl (2R, 4R) -4-methyl-2-piperidinecarboxylate isomer | |
| CN110824063A (en) | Method for detecting methyl formate residue in hydroxypropyl betacyclodextrin | |
| CN112526052A (en) | Method for measuring caprylyl glycol in cosmetic preservative by gas chromatography | |
| CN115711958A (en) | Method for detecting cyclohexanone in fluconazole sodium chloride injection | |
| CN114216985A (en) | Method for testing diisopropyl sulfate in isosorbide | |
| CN117571872A (en) | Method for measuring nitrate in vitamin B1 | |
| CN114965844A (en) | Method for detecting content of acetate in low-molecular-weight heparin | |
| CN117741025A (en) | Method for detecting impurities in ethyl 2,3-dibromopropionate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |