Method for separating and detecting folic acid and folic acid optical isomer in folic acid
阅读说明：本技术 分离检测叶酸中叶酸及叶酸光学异构体的方法 (Method for separating and detecting folic acid and folic acid optical isomer in folic acid ) 是由 周书荣 李冰洁 陈雯 杜帅 兰昌云 刘阔 于 2020-12-02 设计创作，主要内容包括：本发明属于药物分析技术领域,具体涉及一种分离检测叶酸及其光学异构体的方法,该方法采用的色谱柱是以硅胶表面共价键合O-9-(叔丁基氨基甲酰)奎宁为填料,采用有机溶剂、有机酸和三乙胺进行梯度洗脱,将叶酸和/或叶酸光学异构体进行分离；流动相流速为0.4～0.6ml/min；色谱柱柱温为20～30℃；检测器波长设定为280±10nm；使用的稀释剂为四氢呋喃、甲醇、水、醋酸、三乙胺的混合溶液,利用峰面积归一化法测得叶酸及其光学异构体的含量。该方法叶酸及其光学异构体出峰时间快,20分钟内即可完成,峰型对称,能将其从多种杂质中分离出来,得到准确的含量,方法简单、快速、有效。(The invention belongs to the technical field of pharmaceutical analysis, and particularly relates to a method for separating and detecting folic acid and optical isomers thereof, wherein a chromatographic column adopted by the method takes silica gel surface covalent bonding O-9- (tert-butyl carbamoyl) quinine as a filler, and adopts an organic solvent, organic acid and triethylamine to carry out gradient elution so as to separate folic acid and/or folic acid optical isomers; the flow rate of the mobile phase is 0.4-0.6 ml/min; the temperature of the chromatographic column is 20-30 ℃; the wavelength of the detector is set to 280 +/-10 nm; the used diluent is a mixed solution of tetrahydrofuran, methanol, water, acetic acid and triethylamine, and the content of folic acid and the optical isomer thereof is measured by a peak area normalization method. The method has the advantages of fast peak emergence time of folic acid and optical isomers thereof, complete peak emergence within 20 minutes, symmetrical peak shape, capability of separating folic acid and optical isomers from various impurities to obtain accurate content, and simple, fast and effective method.)
1. The method for separating folic acid and/or folic acid optical isomers from folic acid and related impurities is characterized in that a chromatographic column adopted by the method takes O-9- (tert-butyl carbamoyl) quinine covalently bonded on the surface of silica gel as a filler, and the folic acid and/or folic acid optical isomers are separated from the folic acid and the related impurities by adopting a mobile phase A and a mobile phase B; the mobile phase A is an organic solution; the mobile phase B is a mixed solution of organic acid and triethylamine; the related impurities are one or more of impurities A-I, an impurity SM1d, an impurity SM1k and a folic acid optical isomer; the structural formula of the folic acid and related impurities is as follows:
2. the method according to claim 1, wherein the volume ratio of the mobile phase A to the mobile phase B is 80-120: 4-8.
3. The method according to claim 1, wherein the organic solution is a mixed solution of methanol and acetonitrile, and the volume ratio of the mixed solution is 40-60: 40-60.
4. The method according to claim 1, wherein the mobile phase B is a mixed solution of acetic acid and triethylamine, and the volume ratio of the mixed solution is 2-4: 2-4.
5. The method of claim 1, wherein the mobile phase flow rate is 0.4 to 0.6 ml/min.
6. The method according to claim 1, wherein the column temperature of the chromatographic column is 20 to 30 ℃.
7. A method for identifying folic acid and/or folic acid optical isomers in folic acid and related impurities is characterized in that folic acid and/or folic acid optical isomers in a detected object are separated from folic acid and related impurities by the method in claim 1, the folic acid and/or folic acid optical isomers are introduced into a detector for detection, a chromatogram obtained by the detection is compared with a chromatogram of a known folic acid and/or folic acid optical isomer reference substance, and whether the folic acid and/or folic acid optical isomers are contained in the detected object is judged; the relevant impurities are the relevant impurities in claim 1; the detector wavelength was set to 280 ± 10 nm.
8. A method for determining the content of folic acid and/or folic acid optical isomers in folic acid and related impurities, characterized in that a chromatogram is obtained by the method of claim 7; and measuring the content of the folic acid and/or the folic acid optical isomer by using a peak area normalization method.
9. The method of claim 8, comprising the steps of:
1) preparing a detection product solution and a reference product solution;
dissolving a detection product in a diluent to obtain a detection product solution; dissolving the folic acid and/or the folic acid optical isomer standard substance by using a diluent to prepare a reference substance solution;
2) separating;
separating folic acid and/or an optical isomer of folic acid from folic acid and related impurities in a test sample by the method of claim 1;
3) identifying;
identifying whether said test article contains said folic acid and/or an optical isomer of folic acid using the method described in claim 7;
4) calculating the content;
and according to the chromatogram obtained in the identification process, determining the content of the folic acid and/or the folic acid optical isomer in the detection product solution according to a peak area normalization method.
10. The method as claimed in claim 9, wherein the diluent in step 1) is a mixed solution of tetrahydrofuran, methanol, water, acetic acid and triethylamine, and the volume ratio of the mixed solution is 10:80:10:2:4: 3.
Technical Field
The invention belongs to the technical field of pharmaceutical analysis, and particularly relates to a method for separating and detecting folic acid and folic acid optical isomers in folic acid by an HPLC method.
Background
Folic acid is a water-soluble vitamin with the molecular formula of C19H19N7O6Molecular weight 441.40, chemical name N- [4- [ (2-amino-4-oxo-1, 4-dihydro-6-pteridine) methylamino]Benzoyl radical]-L-glutamic acid. The green leaf is named because it is rich in pteroylglutamic acid. There are several forms in nature, the parent compound of which is a combination of 3 components of pteridine, p-aminobenzoic acid and glutamic acid, and the structural formula of which is as follows:
folic acid is yellow or orange thin sheet or needle crystal, odorless and tasteless, and is heated to about 250 deg.C to gradually darken to form black jelly. Is not easy to dissolve in water and ethanol, and is easy to dissolve in acidic or alkaline solution. Antianemia medicine has effect of promoting normal erythrocyte formation. In the metabolism of the tea plant material, methyl groups are involved in the transport. Also participates in the synthesis of amino acids and nucleic acids in vivo, and promotes the generation of erythrocytes together with vitamin B12. Can be used for treating megaloblastic anemia, especially megaloblastic anemia for pregnant women and infants. However, in the pharmaceutical field, a plurality of impurities appear when folic acid is prepared, wherein one of the impurities is an optical isomer of folic acid, and the chemical name is (2R) -2- [4- [ [ (2-amino-4-oxo-1, 4-dihydropteridine-6-yl) methyl]Amino group]Benzamido group]Glutaric acid of formula C19H19N7O6Molecular weight of 441.40, structural formula:
the substances are folic acid optical isomers, the properties and the structures of the substances are similar, the separation difficulty is higher, and related technologies do not disclose that the substances can be separated from a plurality of impurities at present, so that the analysis of the folic acid optical isomers is still a technical problem and has a barrier to the analysis of related medicines.
Disclosure of Invention
In view of the above, an object of the present invention is to provide a method for separating folic acid and/or its optical isomers from crude folic acid by high performance liquid chromatography, which can separate folic acid and its optical isomers and related impurities efficiently and rapidly.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a method for separating folic acid and/or folic acid optical isomers from folic acid and related impurities is characterized in that a chromatographic column adopted by the method takes O-9- (tert-butyl carbamoyl) quinine covalently bonded on the surface of silica gel as a filler, and the folic acid and/or folic acid optical isomers are separated from the folic acid and the related impurities by adopting a mobile phase A and a mobile phase B; the mobile phase A is an organic solution; the mobile phase B is a mixed solution of organic acid and triethylamine; the related impurities are one or more of impurities A-I, an impurity SM1d, an impurity SM1k and a folic acid optical isomer; the structural formula of the folic acid and related impurities is as follows:
impurity I: the EP standard indicates an unknown structure, but the related substances are detected, so that a standard product cannot be obtained, and peaks do not appear at the positions of optical isomers in the method, so that the detection of the optical isomer impurities is not interfered.
Further, the volume ratio of the mobile phase A to the mobile phase B is 80-120: 4-8.
Further, the organic solution is a mixed solution of methanol and acetonitrile, and the volume ratio of the organic solution to the acetonitrile is 40-60: 40-60.
Further, the mobile phase B is a mixed solution of acetic acid and triethylamine, and the volume ratio of the mixed solution to the mobile phase B is 2-4: 2-4.
Further, the flow rate of the mobile phase is 0.4-0.6 ml/min.
Further, the temperature of the chromatographic column is 20-30 ℃.
The invention also aims to provide a method for identifying whether folic acid and/or folic acid optical isomers exist in a detected object by an HPLC method, and the method can effectively determine whether folic acid and/or folic acid optical isomers exist in the detected object.
In order to achieve the purpose, the technical scheme of the invention is as follows:
the method for identifying folic acid and/or folic acid optical isomers in folic acid and related impurities comprises the steps of separating folic acid and/or folic acid optical isomers in a detection object from folic acid and related impurities by using the method in the first aim, introducing the separation object into a detector for detection, comparing a chromatogram obtained by detection with a chromatogram of a known folic acid and/or folic acid optical isomer reference substance, and judging whether the detection object contains the folic acid and/or folic acid optical isomers; the related impurities are the related impurities in the first aim; the detector wavelength was set to 280 ± 10 nm.
The invention also aims to provide a method for measuring the contents of the optical isomer of the calcium levofolinate and related substances by an HPLC method, and the method can be used for measuring the contents of folic acid and/or the optical isomer of the folic acid in a detected substance.
In order to achieve the purpose, the technical scheme of the invention is as follows:
determining the content of folic acid and/or folic acid optical isomer in folic acid and related impurities, and obtaining a chromatogram by using the method of the second objective; and measuring the content of the folic acid and/or the folic acid optical isomer by using a peak area normalization method.
Further, the method comprises the following steps:
1) preparing a detection product solution and a reference product solution;
dissolving a detection product in a diluent to obtain a detection product solution; dissolving the folic acid and/or the folic acid optical isomer standard substance by using a diluent to prepare a reference substance solution;
2) separating;
separating folic acid and/or optical isomers of folic acid from folic acid and related impurities in a test sample by using the method described in the first aim;
3) identifying;
identifying whether the test article contains the folic acid and/or the optical isomer of folic acid by using the method described in the second objective;
4) calculating the content;
and according to the chromatogram obtained in the identification process, determining the content of the folic acid and/or the folic acid optical isomer in the detection product solution according to a peak area normalization method.
Further, the diluent in the step 1) is a mixed solution of tetrahydrofuran, methanol, water, acetic acid and triethylamine, and the volume ratio of the mixed solution is 10:80:10:2:4: 3.
The invention has the beneficial effects that:
1. provides a method for effectively separating, identifying and measuring folic acid and optical isomers thereof.
2. According to the separation detection method, folic acid and optical isomers thereof can be separated from various related impurities in folic acid, and the impurities ABCDEFGHI, SM1d and SM1k in the EP standard do not interfere with the detection of the optical isomers.
3. According to the provided separation detection method, the peak emergence time of folic acid and the optical isomer thereof is short, the folic acid and the optical isomer thereof can finish within 20 minutes, the peak shapes are symmetrical, the calculation can be carried out by using an area normalization method, the accurate impurity content of the optical isomer can be obtained, and the method is simple, rapid and effective.
Drawings
FIG. 1: example 3 chromatogram of folic acid optical isomer and folic acid;
FIG. 2: example 3 chromatogram of all impurities of folic acid;
FIG. 3: example 3 chromatogram of other impurities of folic acid;
FIG. 4: example 4 limit detection chromatogram;
FIG. 5: example 4 detection limit detection chromatogram;
FIG. 6: example 5 run 2016010301 folate detection chromatogram;
FIG. 7: example 5 run 2018051201 folate detection chromatogram;
FIG. 8: example 5 run 2019061701 folate detection chromatogram;
FIG. 9: example 5 run 20190507 folate detection chromatogram;
FIG. 10: example 5 run 20190509 folate detection chromatogram;
FIG. 11: example 5 run 20190510 folate detection chromatogram;
FIG. 12: example 5 run 20190518 folate detection chromatogram;
FIG. 13: example 5 batch number FA-20190103 folate assay chromatogram;
FIG. 14: example 5 batch number FA-20190105 folate assay chromatogram;
FIG. 15: example 5 batch number FA-20190107 folate assay chromatogram.
Detailed Description
The examples are given for the purpose of better illustration of the invention, but the invention is not limited to the examples. Therefore, those skilled in the art should make insubstantial modifications and adaptations to the embodiments of the present invention in light of the above teachings and remain within the scope of the invention.
Example 1
The main apparatus is as follows: shimadzu LC-20A high performance liquid chromatograph.
Mobile phase:
mobile phase A: methanol: 40-60, acetonitrile: 40-60;
mobile phase B: acetic acid: 2-4, triethylamine: 2-4;
methanol-acetonitrile-acetic acid-triethylamine (40-60: 2-4), and the best effect group is 50:50:3: 3;
a chromatographic column: covalently bonding O-9- (tert-butyl carbamoyl) quinine on the surface of silica gel as a filler, wherein the thickness of the filler is 4.6mm, 150mm and 5 mu m;
flow rate: 0.4-0.6 ml/min;
detection wavelength: 280 +/-10 nm;
column temperature: 20-30 ℃, preferably 25 ℃;
diluent agent: tetrahydrofuran-methanol-water-acetic acid-triethylamine (10:80:10:2.4: 3);
sample introduction volume: 5 mu l of the solution;
test solution: 0.3 mg/ml;
the quantitative method comprises the following steps: peak area normalization.
Example 2
Solution preparation:
and (4) avoiding light.
Test solution: taking a proper amount of the product (folic acid), adding a diluent [ tetrahydrofuran-methanol-water-acetic acid-triethylamine (10:80:10:2.4:3) ] for ultrasonic dissolution and quantitative dilution to prepare a solution containing 0.3mg per 1ml, and shaking up to obtain the product.
System applicability solution: taking a proper amount of folic acid optical isomer system applicability reference substances (containing folic acid and optical isomers), adding a diluent, ultrasonically dissolving, diluting to obtain a solution containing 0.3mg per 1ml, and shaking up to obtain the final product.
Example 3
Test method
Precisely measuring 5 mu l of system applicability solution, injecting into a liquid chromatograph, recording chromatogram, wherein the peak emergence sequence comprises optical isomers and folic acid, and the separation degree of the optical isomers and adjacent peaks meets the requirement (see table 1 and attached figure 1).
TABLE 1 System suitability test integration results
All impurities of folic acid are mixed, and comprise impurities A, B, C, D, E, F, G, H and SM1d, SM1k in EP standard and folic acid optical isomer impurities (shown in figure 2).
The folic acid contains other impurities including EP A, B, C, D, E, F, G, H, SM1d, and SM1k (FIG. 3).
Precisely measuring 5 mu l of test solution, injecting into a liquid chromatograph, recording chromatogram until the retention time of main peak is 2.5 times, calculating the content of optical isomer according to peak area normalization method, wherein the content of optical isomer is not more than 0.15%.
Example 4
Quantitative and detection limits
Preparing an impurity SM1m stock solution: precisely weighing SM1m 5mg as an impurity, placing the impurity in a 25ml measuring flask, adding a diluent to perform ultrasonic dissolution and dilution to scale, shaking up, precisely weighing 3ml, placing the impurity in the 25ml measuring flask, adding the diluent to dilute to scale, and shaking up to obtain the product.
Sample stock solution: precisely weighing a test sample SM 15 mg into a 25ml measuring flask, adding a diluent, ultrasonically dissolving and diluting to scale, shaking up, precisely weighing 3ml into the 25ml measuring flask, adding the diluent, diluting to scale, and shaking up to obtain the test sample.
Standard stock solutions: precisely transferring 2.5ml of each of the SM1m impurity stock solution and the sample stock solution into a same 20ml measuring flask, adding a diluent to dissolve and dilute the solution to a scale, and shaking up to obtain a standard stock solution.
Quantitative limiting solution: precisely measuring 0.3ml of standard stock solution, placing into a 10ml measuring flask, adding diluent to dissolve and dilute to scale, and shaking up to obtain the final product. (0.02%)
Detection limiting solution: precisely measuring 3ml of the limiting solution, putting the limiting solution into a 10ml measuring flask, adding a diluent to dilute to a scale, and shaking up to obtain the product. (0.006%)
The determination method comprises the following steps: and taking the quantitative limit solution for continuous sample injection for 6 times, taking the detection limit solution for continuous sample injection for 3 times, and calculating the ratio (signal-to-noise ratio) of the main peak height to the noise. Recording chromatogram, and the test results are shown in Table 2 and figure 4; table 3, fig. 5.
TABLE 2 quantitative Limit determination results
TABLE 3 measurement results of detection limits
Example 5
Folate detection
Taking a proper amount of the product, adding a diluent [ tetrahydrofuran-methanol-water-acetic acid-triethylamine (10:80:10:2.4:3) ] for ultrasonic dissolution and quantitative dilution to prepare a solution containing 0.3mg per 1ml, and shaking uniformly to obtain a test solution. Methanol-acetonitrile-acetic acid-triethylamine (50:50:3:3) is used as a mobile phase; the detection wavelength is 280 nm; the flow rate was 0.5ml per minute; the column temperature was 25 ℃. Taking a proper amount of folic acid SM1m system applicability reference substance (containing folic acid and impurity SM1m), adding a diluent, ultrasonically dissolving and diluting to prepare a solution containing 0.3mg per 1ml, and shaking up to obtain the system applicability solution. And (5) injecting 5 mu l of the system applicability solution into a liquid chromatograph, and recording the retention time of the chromatogram to the main component peak to be 2.5 times. Optical isomers and folic acid are sequentially formed according to the peak appearance sequence; the degree of separation of the optical isomers from the adjacent peaks was satisfactory (FIG. 1). And (5) injecting 5 mu l of test solution into a liquid chromatograph, and recording the chromatogram.
Results of optical isomer detection in 10 batches of folic acid (Table 4, tables 5-14, FIGS. 6-15):
TABLE 410 batch folate assay profiles
Folic acid batch number
Content of optical isomer in folic acid%
2016010301
0.09
2018051201
0.07
2019061701
0.08
20190507
0.07
20190509
0.08
20190510
0.10
20190518
0.08
FA-20190103
0.07
FA-20190105
0.06
FA-20190107
0.08
TABLE 5 Integrated results of folic acid testing of lot 2016010301
TABLE 6 Integrated results of folic acid detection of lot No. 2018051201
TABLE 7 integration results of folic acid detection of batch No. 2019061701
TABLE 8 Integrated results of folic acid detection of batch No. 20190507
TABLE 9 integration results of folic acid detection of lot 20190509
TABLE 10 Integrated results of folic acid testing of lot No. 20190510
TABLE 11 Integrated results of folic acid testing of lot No. 20190518
TABLE 12 integral results of folic acid detection of lot No. FA-20190103
TABLE 13 integration results of folic acid detection of lot No. FA-20190105
TABLE 14 integration results of folic acid detection of lot No. FA-20190107
Finally, the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all of them should be covered in the claims of the present invention.