Method for separating and determining fulvestrant starting material SM1 and seven impurities thereof

Abstract

The invention belongs to the technical field of analytical chemistry, and particularly relates to a method for separating and determining a fulvestrant starting material SM1 and seven impurities thereof. The method comprises the following steps: carrying out gradient elution by taking octadecylsilane chemically bonded silica as a chromatographic column filler, taking purified water as a mobile phase A and taking an organic solvent as a mobile phase B, and then detecting in a detector with the detection wavelength of 240nm, wherein the flow velocity of the mobile phase is 0.9-1.1 ml / min, and the temperature of a column box of the chromatographic column is 28-32 DEG C. According to the method disclosed by the invention, the fulvestrant starting material SM1 and seven process impurities thereof can be simultaneously and completely separated and qualitatively or quantitatively detected, and the method is simple, convenient, feasible, good in reproducibility, strong in specificity and high in sensitivity. According to the method, the problem of separation and determination of the fulvestrant starting material SM1 and seven process impurities is solved, the quality of the fulvestrant starting material SM1 is ensured to be controllable, and the safety and effectiveness of the product are finally determined.

Description

Technical Field

[0001] The present invention belongs to the technical field of analytical chemistry, and in particular relates to a method for separating and determining a fulvestrant starting material SM1 and seven impurities thereof. Background Art

[0002] Fulvestrant is a new type of breast cancer drug, mainly used for the treatment of postmenopausal advanced breast cancer that is resistant to anti-estrogen therapy and has positive estrogen receptors. Fulvestrant's chemical name is 7α-[9-[(4,4,5,5,5-pentafluoropentyl)sulfinyl]nonyl]estra-1,3,5(10)-triene-3,17β-diol, and its molecular formula is C 32 H 47 F5O3S, the structural formula of Fulvestrant is shown in Formula Ⅰ.

[0003]

[0004] SM1 is the starting material for the synthesis of Fulvestrant. Its scientific name is (7α,17β)-17-(acetyloxy)-7-(9-bromononyl)estra-4-en-3-one, its English chemical name is (7α,17β)-17-(Acetyloxy)-7-(9-bromononyl)estra-4-en-3-one, and its structural formula is shown in Formula II. Studies have found that the impurity SM1 may exist in the preparation process of Fulvestrant starting material SM1. 1a 、Impurity SM 1b 、Impurity SM 1c 、Impurity SM 1d 、Impurity SM 1f 、Impurity SM 1g 、Impurity SM 1l There are 7 process impurities in total. Impurities generated or related substances introduced during the preparation of fulvestrant starting material SM1 need to be strictly controlled regardless of whether they are in the API or the drug product.

[0005] At present, no patent information or literature analysis methods for separating and detecting the starting material SM1 of Fulvestrant and its seven process impurities using high performance liquid chromatography have been retrieved. Therefore, developing an analytical method that can quickly and effectively separate and detect the starting material SM1 of Fulvestrant and seven impurities is of great significance for drug quality control and degradation pathway research. Summary of the invention

[0006] In view of this, one of the objects of the present invention is to provide a method for separating the fulvestrant starting material SM1 and its impurities using high performance liquid chromatography, which method can simultaneously achieve effective separation of the fulvestrant starting material SM1 and its seven process impurities, and the method has high sensitivity and good durability.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for separating the fulvestrant starting material SM1 and its impurities by high performance liquid chromatography, wherein the chromatographic column used in the high performance liquid chromatography is filled with octadecylsilane bonded silica gel, the mobile phases are mobile phase A and mobile phase B, the mobile phase A is purified water, and the mobile phase B is an organic solvent; the impurity SM1 is separated in sequence by gradient elution. 1b 、Impurity SM 1f 、Impurity SM 1g , Fulvestrant starting material SM1, impurity SM 1a 、Impurity SM 1l 、Impurity SM 1d 、Impurity SM 1c Separation; the structural formula of the fulvestrant starting material SM1 is shown in Formula II; the impurity is the impurity SM shown in Formula III 1a , impurity SM with the structural formula shown in Formula IV 1b , impurity SM having a structural formula as shown in Formula V 1c , impurity SM having a structural formula as shown in Formula VI 1d , impurity SM having a structural formula as shown in formula VII 1f , impurity SM having a structural formula as shown in formula VIII 1g and the impurity SM shown in the structural formula IX 1l Any one or more of;

[0009]

[0010]

[0011] Further, the fulvestrant starting material SM1 and the impurity SM 1b 、Impurity SM 1f 、Impurity SM 1g 、Impurity SM 1a 、Impurity SM 1l 、Impurity SM 1d and impurity SM 1c The separation time is 70 min.

[0012] Further, the gradient elution program is:

[0013] At 0 min, the volume ratio of the mobile phase A to the mobile phase B was set to 58-62:42-38;

[0014] At 20 min, the volume ratio of the mobile phase A to the mobile phase B was set to 3:97;

[0015] At 60 min, the volume ratio of the mobile phase A to the mobile phase B was set to 3:97;

[0016] At 60.1 min, the volume ratio of the mobile phase A to the mobile phase B was set to 60:40;

[0017] At 70 min, the volume ratio of the mobile phase A to the mobile phase B was set to 60:40.

[0018] Furthermore, the gradient elution program is:

[0019] At 0 min, the volume ratio of the mobile phase A to the mobile phase B was set to 60:40;

[0020] At 20 min, the volume ratio of the mobile phase A to the mobile phase B was set to 3:97;

[0021] At 60 min, the volume ratio of the mobile phase A to the mobile phase B was set to 3:97;

[0022] At 60.1 min, the volume ratio of the mobile phase A to the mobile phase B was set to 60:40;

[0023] At 70 min, the volume ratio of the mobile phase A to the mobile phase B was set to 60:40.

[0024] Preferably, the organic solvent is acetonitrile, and the organic solvent is chromatographically pure.

[0025] Preferably, the flow rate of the mobile phase is 0.9 ml / min-1.1 ml / min, more preferably 1.0 ml / min; the column box temperature of the chromatographic column is 28° C.-32° C., more preferably 30° C.

[0026] Preferably, the filler of the chromatographic column is Bston Prime C18-2.

[0027] Preferably, the chromatographic column has a specification of 4.6 mm×250 mm and 5 μm.

[0028] Preferably, the injection volume is 20 μl.

[0029] The second object of the present invention is to provide a method for qualitatively identifying the fulvestrant starting material SM1 and its impurities, which can achieve qualitative identification of the fulvestrant starting material SM1 and its seven impurities.

[0030] To achieve the above object, the present invention adopts the following technical solutions:

[0031] A method for qualitatively identifying the fulvestrant starting material SM1 and its impurities, comprising separating the fulvestrant starting material SM1 and its impurities by the method described in the first objective, and then entering a detector for detection; the detection wavelength of the detector is 240 nm.

[0032] As a preferred technical method, the mobile phase A is purified water, the mobile phase B is acetonitrile; the flow rate of the mobile phase is 1.0 ml / min; the column box temperature of the chromatographic column is 30°C; the specifications of the chromatographic column are 4.6 mm×250 mm×5 μm; the detection wavelength is 240 nm;

[0033] The elution was performed according to the following gradient elution program and the chromatogram was obtained:

[0034] At 0 min, the volume ratio of the mobile phase A to the mobile phase B was set to 60:40;

[0035] At 20 min, the volume ratio of the mobile phase A to the mobile phase B was set to 3:97;

[0036] At 60 min, the volume ratio of the mobile phase A to the mobile phase B was set to 3:97;

[0037] At 60.1 min, the volume ratio of the mobile phase A to the mobile phase B was set to 60:40;

[0038] At 70 min, the volume ratio of the mobile phase A to the mobile phase B was set to 60:40.

[0039] Furthermore, the impurity SM was found to have a retention time of 14.7 ± 0.5 min. 1b ; The impurity SM is the one with retention time of 20.7±0.5min 1f ; The impurity SM is the one with retention time of 22.9±0.5min 1g ; The retention time of 27.7±0.5min is the starting material SM1 of Fulvestrant; the retention time of 28.8±0.5min is the impurity SM 1a ; The impurity SM is the one with retention time of 29.8±0.5min 1l ; The impurity SM is the one with retention time of 38.9±0.5min 1d ; The impurity SM is at a retention time of 49.4±0.5min 1c .

[0040] The third object of the present invention is to provide a method for quantitatively determining the content of the fulvestrant starting material SM1 and its impurities, which can achieve the content determination of the fulvestrant starting material SM1 and its seven impurities.

[0041] To achieve the above object, the present invention adopts the following technical solutions:

[0042] The method for quantitatively determining the fulvestrant starting material SM1 and its impurities comprises the following steps:

[0043] (1) Separation: Separating the fulvestrant starting material SM1 and its impurities by the method described in Objective 1;

[0044] (2) Detection: The separated fulvestrant starting material SM1 and its impurities were detected using the method described in the second objective, and a chromatogram was obtained;

[0045] (3) Calculation of content: Based on the chromatogram obtained in step (2), the impurity content is calculated by peak area using an external standard method and / or a self-control method with a correction factor.

[0046] Furthermore, before separation, a diluent is used to prepare a reference solution and a sample to be tested; the diluent is acetonitrile.

[0047] The method for preparing the sample solution to be tested is as follows: take an appropriate amount of Fulvestrant starting material SM1, dissolve the sample in acetonitrile, and prepare a sample solution with a concentration of 1.0 mg / ml.

[0048] The beneficial effects of the present invention are:

[0049] 1. The present invention uses high performance liquid chromatography to separate and detect the fulvestrant starting material SM1 and 7 process impurities. The analytical method of the present invention can completely separate and detect the fulvestrant starting material SM1 and 7 process impurities within 70 minutes, significantly shortening the separation time. The method of the present invention has the advantages of strong specificity, high sensitivity, high accuracy and good durability. The present invention solves the problem of separation and determination of the fulvestrant starting material SM1 and 7 process impurities, thereby ensuring that the quality of the fulvestrant starting material SM1 is controllable, and ultimately determining the safety and effectiveness of the product.

[0050] 2. The analytical method of the present invention has a lower limit of quantification and detection limit, wherein the impurity SM 1a The limit of quantification is 0.1960μg / ml, and the limit of detection is 0.0980μg / ml; impurity SM 1b The limit of quantification is 0.2019μg / ml, and the limit of detection is 0.1010μg / ml; impurity SM 1c The limit of quantification is 0.2106μg / ml, and the limit of detection is 0.1053μg / ml; the impurity SM 1d The limit of quantification is 0.1826μg / ml, and the limit of detection is 0.0913μg / ml; the impurity SM 1f The limit of quantification is 0.2034μg / ml, and the limit of detection is 0.1017μg / ml; impurity SM 1gThe limit of quantification is 0.0199μg / ml, and the limit of detection is 0.0100μg / ml; the impurity SM 1l The limit of quantification was 0.1492 μg / ml, and the limit of detection was 0.0746 μg / ml; the limit of quantification of the fulvestrant starting material SM1 was 0.2001 μg / ml, and the limit of detection was 0.1001 μg / ml. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is the chromatogram of blank solvent;

[0052] Figure 2 is the chromatogram of the mixed solution;

[0053] Figure 3 is the chromatogram of the test solution;

[0054] Figure 4-Figure 5 is the chromatogram of the quantitation limit solution;

[0055] Figure 6-Figure 7 is the chromatogram of the detection limit solution;

[0056] Figure 8-Figure 9 This is a high performance liquid chromatogram of the accuracy determination of six process impurities in the fulvestrant starting material SM1;

[0057] Fig.10 It is the impurity SM in the starting material SM1 of Fulvestrant 1g HPLC chromatograms for accuracy determination;

[0058] Fig.11 This is the chromatogram under the conditions of durability-mixed solution 1-flow rate 0.9 ml / min;

[0059] Fig.12 This is the chromatogram under the conditions of durability-mixed solution 2-flow rate 0.9 ml / min;

[0060] Fig.13 This is the chromatogram under the conditions of durability-mixed solution 1-flow rate 1.1ml / min;

[0061] Fig.14 This is the chromatogram under the conditions of durability-mixed solution 2-flow rate 1.1 ml / min;

[0062] Fig.15 This is the chromatogram under the conditions of durability-mixed solution 1-column temperature 28°C;

[0063] Fig.16 This is the chromatogram under the conditions of durability-mixed solution 2-column temperature 28°C;

[0064] Fig.17This is the chromatogram under the conditions of durability-mixed solution 1-column temperature 32°C;

[0065] Fig.18 This is the chromatogram under the conditions of durability-mixed solution 2-column temperature 32°C;

[0066] Fig.19 This is the chromatogram under the conditions of durability-mixed solution 1-mobile phase initial ratio A:B=58:42;

[0067] Fig. 20 This is the chromatogram under the conditions of durability-mixed solution 2-mobile phase initial ratio A:B=58:42;

[0068] Fig.21 This is the chromatogram under the conditions of durability-mixed solution 1-initial ratio of mobile phase A:B=62:38;

[0069] Fig. 22 This is a chromatogram under the conditions of durability-mixed solution 2-initial mobile phase ratio A:B=62:38. DETAILED DESCRIPTION

[0070] The technical solution of the present invention will be further described clearly and completely in conjunction with specific embodiments below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the present invention.

[0071] In the embodiment of the present invention, the high performance liquid chromatograph used is Thermo Fisher Ultimate 3000.

[0072] In the embodiment of the present invention, the chromatographic conditions are as follows:

[0073] A Bston Prime C18-2 (4.6 mm × 250 mm, 5 μm) chromatographic column was used; purified water was used as mobile phase A, and acetonitrile was used as mobile phase B; the detector detection wavelength was 240 nm, the mobile phase flow rate was 1.0 ml / min, the column box temperature was 30°C, the injection volume was 20 μl, and mobile phase A and mobile phase B were linearly eluted with gradient according to Table 1.

[0074] Table 1. Gradient elution program

[0075] Time (min) Mobile phase A (%) Mobile phase B (%) 0 60 40 20 3 97 60 3 97 60.1 60 40 70 60 40

[0076] In the embodiment of the present invention, the diluent / solvent / blank solution is acetonitrile.

[0077] In the embodiments of the present invention, the calculation formulas for the quantitative limit and the detection limit are as follows:

[0078]

[0079]

[0080] In the embodiment of the present invention, due to the impurity SM 1g It is a genotoxic impurity and its control limit is even lower, at 0.0040%, so the accuracy is verified separately.

[0081] In the embodiment of the present invention, FUL-SM1 is the fulvestrant starting material SM1.

[0082] Example 1. Specificity

[0083] Impurity SM 1g Reference stock solution: Take impurity SM 1g Place 4 mg of the reference substance in a 100 ml volumetric flask, add acetonitrile to dissolve and dilute to the scale, shake well, accurately measure 5.0 ml, place in a 50 ml volumetric flask, add acetonitrile to dissolve and dilute to the scale, shake well, and the solution is obtained.

[0084] Impurity mixed stock solution: Take impurity SM separately 1a Reference substance: about 50 mg, impurity SM 1c Reference substance: about 15 mg, impurity SM 1b 、Impurity SM 1d 、Impurity SM 1f and impurity SM 1l Place about 10 mg of each reference substance in a 100 ml volumetric flask, add acetonitrile to dissolve and dilute to the scale, shake well, and the solution is ready.

[0085] Test solution: Weigh about 50 mg of the test sample, place it in a 50 ml volumetric flask, add acetonitrile to dissolve and dilute to the scale, shake well, and obtain.

[0086] Mixed solution: weigh about 50 mg of the test sample, place it in a 50 ml volumetric flask, and accurately pipette the impurity SM 1g Place 0.5 ml of reference substance stock solution and impurity mixed stock solution in the same volumetric flask mentioned above, add acetonitrile to dissolve and dilute to the scale, shake well, and obtain.

[0087] Take blank solution and mixed solution respectively, inject according to chromatographic conditions, and record the chromatogram.

[0088] Results: Figure 1-Figure 3 As shown in Table 2, Figure 2 and Figure 3 The integration results are shown in Table 3 and Table 4. The blank solution and the test sample did not interfere with the detection of the 7 process impurities. The separation between the 7 process impurities and the adjacent impurity peaks in the mixed solution was greater than 1.5. This result shows that the specificity of this method is good.

[0089] Table 2. Specificity test results

[0090]

[0091] Table 3. Figure 2 The integral result table

[0092]

[0093]

[0094] Table 4. Figure 3 The integral result table

[0095]

[0096] Example 2. Limit of quantitation and limit of detection

[0097] Quantitation limit solution: Accurately weigh the fulvestrant starting material SM1 and each impurity reference substance, prepare a solution of a certain concentration, and dilute it step by step to obtain the quantitation limit solution, as shown in Table 3.

[0098] Detection limit solution: Accurately weigh the fulvestrant starting material SM1 and each impurity reference substance to prepare a solution of a certain concentration, and dilute stepwise to obtain the detection limit solution, as shown in Table 4.

[0099] Determination method: Take the above quantitative limit solution and inject it continuously for 6 times, and the detection limit solution and inject it continuously for 3 times, calculate the ratio of the main peak height to the noise (signal-to-noise ratio), and record the chromatogram. Figure 4-Figure 8 As shown in Tables 5 and 6, the experimental results show that under this chromatographic system, the detection limit and quantification limit of the fulvestrant starting material SM1 and the seven process impurities meet the requirement of S / N=3(10):1.

[0100] Table 5. Quantitation limit determination results

[0101]

[0102]

[0103]

[0104] Table 6. Detection limit determination results

[0105]

[0106] Example 3. Basic study of the accuracy of six process impurities in the fulvestrant starting material SM1 by the chromatographic system

[0107] Reference substance stock solution: Take impurity SM separately 1a and impurity SM 1cReference substance, about 25 mg each, impurity SM 1l Reference substance 7.5mg, impurity SM 1b 、Impurity SM 1d and impurity SM 1f About 5 mg of each reference substance is accurately weighed and placed in a 25 ml volumetric flask. Add acetonitrile to dissolve and dilute to the scale. Shake well. Accurately measure 5 ml and place in a 50 ml volumetric flask. Dilute to the scale with acetonitrile and shake well.

[0108] Reference substance solution: Accurately measure 2.5 ml of reference substance stock solution, place in a 50 ml volumetric flask, add diluent to dilute to the scale, shake well, and obtain.

[0109] Test solution: Take about 50 mg of the product, accurately weigh it, and place it in a 50 ml volumetric flask (a total of 10 samples, one of which is dissolved in acetonitrile and diluted to the scale as the unspecified test solution); accurately measure 2 ml, 2.5 ml, and 3 ml of the reference stock solution, 3 portions each, respectively, place them in the above 50 ml volumetric flasks, add acetonitrile to dissolve and dilute to the scale, shake well, and obtain.

[0110] Control solution: Accurately pipette 0.5 ml of each test solution into a 100 ml volumetric flask, dilute to the mark with acetonitrile, and shake well.

[0111] Take the above unspiked test solution, reference solution, control solution and spiked test solution, inject them in sequence, and record the chromatograms. Use the reference solution as the standard, calculate the content and recovery of each impurity by the external standard method, and calculate the content and recovery of each impurity by the self-control method with correction factors.

[0112] Results: Figure 8-Figure 9 As shown in Table 7, under this chromatographic system, the accuracy of the six process impurities in the fulvestrant starting material SM1 all met the requirements of 90%-108%.

[0113] Table 7. Results of accuracy determination of 6 process impurities in fulvestrant starting material SM1

[0114]

[0115]

[0116] Example 4. Chromatographic system for the analysis of impurity SM in the fulvestrant starting material SM1 1g Basic research on accuracy

[0117] Reference stock solution: Take impurity SM 1g About 20 mg of the reference substance is accurately weighed and placed in a 50 ml volumetric flask. Add acetonitrile to dissolve and dilute to the scale. Shake well. Accurately measure 0.1 ml and place in a 100 ml volumetric flask. Dilute to the scale with acetonitrile and shake well.

[0118] Reference substance solution: Accurately measure 2.5 ml of reference substance stock solution, place in a 25 ml volumetric flask, dilute to the mark with acetonitrile, shake well, and obtain.

[0119] Test solution: Take about 25 mg of the product, weigh accurately, place in a 25 ml volumetric flask, add acetonitrile to dissolve and dilute to the scale, shake well, and obtain.

[0120] Standard addition solution: Take about 25 mg of this product, weigh accurately, place in a 25 ml volumetric bottle, add an appropriate amount of acetonitrile to dissolve, accurately add 2.5 ml of reference substance stock solution, dilute to scale with acetonitrile, shake well, and you are done. (Prepare 2 portions in parallel)

[0121] Take the reference solution, test solution and standard solution for injection respectively, record the chromatogram and calculate the impurity SM 1g Peak area recovery.

[0122] Results: Fig.10 As shown in Table 8, under this chromatographic system, the impurity SM 1g The accuracy meets the requirements of 90%-108%.

[0123] Table 8. Impurities SM in Fulvestrant starting material SM1 1g Accuracy test results

[0124]

[0125] Example 5. Durability

[0126] Mixed solution 1: Accurately weigh the product and each impurity reference substance in appropriate amounts to prepare a solution containing approximately 11.0 mg of FUL-SM and 11.0 mg of impurity SM per ml. 1a 5.0μg, impurity SM 1c 5.0μg, impurity SM 1b 、Impurity SM 1d and impurity SM 1f 1.0μg each, impurity SM 1g 0.04 μg of solution.

[0127] Mixed solution 2: Accurately weigh the product and impurity SM 1l The reference substance is appropriate, and each 1 ml contains about 11.0 mg of FUL-SM and impurity SM 1l 1.5 μg of solution.

[0128] Take mixed solution 1 and mixed solution 2, adjust the experimental conditions (flow rate ± 0.1 ml / min, column temperature ± 2°C, initial ratio ± 1%), and test them respectively after the instrument system is stable to examine the separation between the peaks.

[0129] Results: Figure 11-Figure 22 As shown in Table 9, under this chromatographic system, when the flow rate, column temperature and initial ratio of the mobile phase fluctuated, the separation between the fulvestrant starting material SM1 and the seven process impurities and the adjacent peaks all met the requirement of being greater than 1.5, demonstrating the good durability of this method.

[0130] Table 9. Durability test results

[0131]

Claims

1. A method for separating fulvestrant starting material SM1 and its impurities by high performance liquid chromatography, characterized in that: The chromatographic column used in the high performance liquid chromatography method is filled with octadecylsilane bonded silica gel, and the mobile phases are mobile phase A and mobile phase B, wherein the mobile phase A is purified water and the mobile phase B is an organic solvent; the impurities SM are removed in sequence by gradient elution. 1b 、Impurity SM 1f 、Impurity SM 1g , Fulvestrant starting material SM1, impurity SM 1a 、Impurity SM 1l 、Impurity SM 1d 、Impurity SM 1c Separation; the structural formula of the fulvestrant starting material SM1 is shown in Formula II; the impurity is the impurity SM shown in Formula III 1a , impurity SM with the structural formula shown in Formula IV 1b , impurity SM having a structural formula as shown in Formula V 1c , impurity SM having a structural formula as shown in Formula VI 1d , impurity SM having a structural formula as shown in formula VII 1f , impurity SM having a structural formula as shown in formula VIII 1g and the impurity SM shown in the structural formula IX 1l Any one or more of; 2. The method according to claim 1, characterized in that Simultaneous separation of fulvestrant starting material SM1 and impurity SM 1b 、Impurity SM 1f 、Impurity SM 1g 、Impurity SM 1a 、Impurity SM 1l 、Impurity SM 1d and impurity SM 1c The separation time is 70 min.

3. The method according to claim 1, characterized in that The gradient elution program was: At 0 min, the volume ratio of the mobile phase A to the mobile phase B was set to 58-62:42-38; At 20 min, the volume ratio of the mobile phase A to the mobile phase B was set to 3:97; At 60 min, the volume ratio of the mobile phase A to the mobile phase B was set to 3:97; At 60.1 min, the volume ratio of the mobile phase A to the mobile phase B was set to 60:40; At 70 min, the volume ratio of the mobile phase A to the mobile phase B was set to 60:

40.

4. The method according to claim 1, characterized in that: The organic solvent is acetonitrile.

5. The method according to claim 1, characterized in that The flow rate of the mobile phase is 0.9 ml / min-1.1 ml / min; The column box temperature of the chromatographic column is 28°C-32°C.

6. A method for qualitatively identifying the fulvestrant starting material SM1 and its impurities, characterized in that: The method according to any one of claims 1 to 5 is used to separate the fulvestrant starting material SM1 and its impurities, and then enters a detector for detection; the detection wavelength of the detector is 240 nm.

7. The method according to claim 6, characterized in that The mobile phase A is purified water, and the mobile phase B is acetonitrile; the flow rate of the mobile phase is 1.0 ml / min; the column box temperature of the chromatographic column is 30° C.; the specifications of the chromatographic column are 4.6 mm×250 mm×5 μm; and the detection wavelength is 240 nm; The elution was performed according to the following gradient elution program and the chromatogram was obtained: At 0 min, the volume ratio of the mobile phase A to the mobile phase B was set to 60:40; At 20 min, the volume ratio of the mobile phase A to the mobile phase B was set to 3:97; At 60 min, the volume ratio of the mobile phase A to the mobile phase B was set to 3:97; At 60.1 min, the volume ratio of the mobile phase A to the mobile phase B was set to 60:40; At 70 min, the volume ratio of the mobile phase A to the mobile phase B was set to 60:

40.

8. The method according to claim 7, characterized in that The impurity SM is the one with retention time of 14.7±0.5min. 1b ; The impurity SM is the one with retention time of 20.7±0.5min 1f ; The impurity SM is the one with retention time of 22.9±0.5min 1g ; The retention time of 27.7±0.5min is the starting material SM1 of Fulvestrant; the retention time of 28.8±0.5min is the impurity SM 1a ; The impurity SM is the one with retention time of 29.8±0.5min 1l ; The impurity SM is the one with retention time of 38.9±0.5min 1d ; The impurity SM is at a retention time of 49.4±0.5min 1c .

9. A method for quantitatively determining the fulvestrant starting material SM1 and its impurities, characterized in that: The following steps are involved: (1) separation: separating the fulvestrant starting material SM1 and its impurities by the method described in any one of claims 1 to 5; (2) Detection: Detecting the separated fulvestrant starting material SM1 and its impurities using the method described in any one of claims 6 to 8, and obtaining a chromatogram; (3) Content calculation: Based on the chromatogram obtained in step (2), the impurity content is calculated by peak area using an external standard method and / or a self-control method with a correction factor.

10. The method according to claim 9, characterized in that Before separation, a reference solution and a sample to be tested are prepared with a diluent; the diluent is acetonitrile.

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