Method for detecting residual solvent in 1, 3, 5-trihydroxybenzene

Abstract

The invention relates to the technical field of chemical analysis, and particularly discloses a method for detecting a residual solvent in 1, 3, 5-trihydroxybenzene. A chromatographic column with 6% cyanopropyl benzene-94% dimethyl siloxane as a stationary liquid is adopted as a detection chromatographic column, the column temperature is set to be 35-45 DEG C and maintained for 4-6 min, then the temperature is increased to 195-205 DEG C at the rate of 8-12 DEG C / min and maintained for 4-6 min, the temperature of a constant-temperature furnace is 95-105 DEG C, the temperature of a detector is 255-265 DEG C, the split ratio is 8-12: 1, and the detection of 1, 3, 4-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5 The method can be used for simultaneously and quantitatively detecting the residual solvent 1, 3, 5-trihydroxybenzene, namely the 1, 3, 5-trihydroxybenzene, namely the 1, 3, 5-trihydroxybenzene, namely the 1, 3, 5-trihydroxybenzene, the methyl alcohol and the ethyl acetate, is more beneficial to reflecting the quality of the 1, 3, 5-trihydroxybenzene, and is of great significance for establishing a quality control system of the 1, 3, 5-trihydroxybenzene and ensuring the product quality and the medication safety of the 1, 3, 5-trihydroxybenzene.

Description

Technical Field

[0001] The invention relates to the technical field of chemical analysis, and in particular to a method for detecting residual solvents in 1,3,5-trihydroxybenzene. Background Art

[0002] 1,3,5-Trihydroxybenzene (1,3,5-Trihydroxy) directly acts on the smooth muscles of the gastrointestinal tract and urogenital tract. It is a non-opioid smooth muscle antispasmodic drug. It has the characteristics of not having anticholinergic effects. While relieving smooth muscle spasms, it does not produce anticholinergic drug side effects, does not cause symptoms such as hypotension, increased heart rate, and arrhythmia, and has no effect on cardiovascular function. It is clinically used for acute spasmodic pain caused by digestive system and biliary dysfunction, acute spasmodic urethra, bladder, renal colic, and gynecological spasmodic pain.

[0003] At present, 1,3,5-trihydroxybenzene is mostly produced with 2,6-dichlorophenol as the starting material and trimethylol as the solvent, and the intermediate is obtained by catalytic reaction, and then acidified and recrystallized to obtain 1,3,5-trihydroxybenzene. The 1,3,5-trihydroxybenzene product produced by this process will contain trimethylol, methanol and ethyl acetate residues. However, there is currently no detection method for residual solvents in 1,3,5-trihydroxybenzene. Therefore, in order to control the residual solvents in 1,3,5-trihydroxybenzene to ensure the quality of 1,3,5-trihydroxybenzene and thus ensure the safety of patients' medication, it is necessary to provide a detection method that can effectively measure the residual solvents in 1,3,5-trihydroxybenzene. Summary of the invention

[0004] In view of the lack of effective technical problem in the prior art for detecting residual solvents in 1,3,5-trihydroxybenzene, the present invention provides a method for detecting residual solvents in 1,3,5-trihydroxybenzene.

[0005] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0006] A method for detecting residual solvents in 1,3,5-trihydroxybenzene, the detection method being gas chromatography, comprising the following steps:

[0007] (1) Preparation of test solution and mixed reference solution:

[0008] Preparation of mixed reference solution: Take the reference substances of trimethylol, methanol and ethyl acetate and prepare a mixed reference solution with solvent;

[0009] Preparation of test solution: Take 1,3,5-trihydroxybenzene sample and prepare the test solution with solvent;

[0010] (3) Take the mixed reference solution and test solution and perform the test under the following gas chromatography conditions:

[0011] Detector: Hydrogen flame ionization detector;

[0012] Injection method: headspace injection;

[0013] Chromatographic column: 6% cyanopropylbenzene-94% dimethylsiloxane as the stationary phase;

[0014] Column temperature: 35℃-45℃ for 4min-6min, then increase the temperature to 195℃-205℃ at a rate of 8℃ / min-12℃ / min, and maintain for 4min-6min;

[0015] Constant temperature furnace temperature: 95℃-105℃;

[0016] Detector temperature: 255℃-265℃;

[0017] Split ratio: 8-12:1.

[0018] The residual solvent in 1,3,5-trihydroxybenzene in the present invention refers to trimethylol, methanol and ethyl acetate.

[0019] Compared with the prior art, the method for detecting residual solvents in 1,3,5-trihydroxybenzene provided by the present invention adopts gas chromatography, uses a 6% cyanopropylbenzene-94% dimethylsiloxane chromatographic column as a detection chromatographic column, cooperates with a specific programmed temperature rising method and specific constant temperature furnace temperature, detector temperature and split ratio and other gas chromatographic conditions, realizes the simultaneous quantitative detection of the residual solvents of 1,3,5-trihydroxybenzene, namely, trimethylol, methanol and ethyl acetate, is more conducive to reflecting the quality of 1,3,5-trihydroxybenzene, and is of great significance for establishing a quality control system for 1,3,5-trihydroxybenzene and ensuring its product quality and drug safety.

[0020] The method for detecting residual solvents in 1,3,5-trihydroxybenzene provided by the present invention has been verified by methodology to have high specificity, good accuracy, sensitivity, repeatability and stability, and is easy to operate. Qualitative and quantitative analysis of multiple residual solvents in 1,3,5-trihydroxybenzene can be achieved through one detection, which fills the gap that the prior art cannot effectively detect residual solvents in 1,3,5-trihydroxybenzene, is conducive to achieving quality control of 1,3,5-trihydroxybenzene products, and further helps to reduce the drug safety risk of 1,3,5-trihydroxybenzene products.

[0021] Preferably, the chromatographic column is DB-624, 30m×0.53mm×3.0μm.

[0022] Preferably, the column temperature is: maintained at 40°C for 5 min, then increased to 200°C at a rate of 10°C / min, and maintained for 5 min.

[0023] The preferred programmed temperature rising method combined with a specific chromatographic column can make the peak shapes of 1,3,5-trihydroxybenzene and residual solvents good, and is conducive to improving the separation between the components, thereby achieving qualitative and quantitative analysis of multiple residual solvents in 1,3,5-trihydroxybenzene.

[0024] Preferably, the temperature of the constant temperature furnace is 100°C.

[0025] Preferably, the detector temperature is 260°C.

[0026] Preferably, the split ratio is 10:1.

[0027] Preferably, the carrier gas is nitrogen with a flow rate of 2.8 mL / min-3.2 mL / min.

[0028] More preferably, the carrier gas flow rate is 3.0 mL / min.

[0029] Preferably, the injection volume is 1.0 μL.

[0030] Preferably, the solvent is a mixed solution of purified water and dimethyl sulfoxide in a volume ratio of 2:3.

[0031] Preferably, the concentration of trimethylol in the mixed reference solution is 0.1 mg / mL, the concentration of methanol is 0.3 mg / mL, and the concentration of ethyl acetate is 0.5 mg / mL.

[0032] Preferably, the concentration of the test solution is 100 mg / mL.

[0033] The preferred gas chromatography conditions are conducive to achieving sufficient detection of residual solvents in 1,3,5-trihydroxybenzene and achieving accurate quantitative detection of residual solvents in 1,3,5-trihydroxybenzene.

[0034] The gas chromatography detection method provided by the present invention can realize the effective detection of various residual solvents in 1,3,5-trihydroxybenzene, and through methodological research and verification, it is proved that the method of the present invention has good sensitivity, accuracy and reproducibility, which makes up for the gap that the prior art cannot realize the effective detection of residual solvents in 1,3,5-trihydroxybenzene, is beneficial to improving the quality of 1,3,5-trihydroxybenzene products, reducing the risk of drug use, and has high practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The gas chromatogram of the blank solvent under the specificity item in Example 2 of the present invention;

[0036] Figure 2 The gas chromatogram of the mixed reference solution under the specificity item in Example 2 of the present invention is shown in the figure, from left to right, methanol (3.370 min), ethyl acetate (8.437 min) and trimethylolbenzene (16.974 min);

[0037] Figure 3 The gas chromatogram of the test solution under the specificity item in Example 2 of the present invention is shown in the figure, from left to right, methanol (3.427 min), ethyl acetate (8.413 min) and trimethylolbenzene (17.000 min);

[0038] Figure 4 This is the gas chromatogram of the sample solution spiked under the specific property item in Example 2 of the present invention, from left to right are methanol (3.396 min), ethyl acetate (8.471 min) and trimethylolbenzene (16.996 min). DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0040] Example 1

[0041] 1.1 Solution preparation:

[0042] Blank solvent: Place chromatographic grade purified water and dimethyl sulfoxide in a clean bottle at a volume ratio of 2:3, mix well, and cool to room temperature to obtain a blank solvent.

[0043] Preparation of mixed reference solution: Accurately measure 100 mg of trimethylol, 300 mg of methanol, and 500 mg of ethyl acetate in a 100 mL volumetric flask containing 25 mL of blank solvent, and dilute to scale to prepare a mixed reference stock solution. Pipette 1 mL of the stock solution, add it to a 10 mL volumetric flask and dilute to scale to prepare a mixed reference solution.

[0044] Preparation of test solution: Accurately weigh 100 mg of 1,3,5-trihydroxybenzene raw material, place it in a headspace bottle, add 1 mL of blank solvent, and prepare a test solution with a concentration of 100 mg / mL after complete dissolution.

[0045] Preparation of spiked test solution: Accurately weigh 100 mg of 1,3,5-trihydroxybenzene raw material, place it in a headspace bottle, add 1 mL of the mixed reference solution prepared above, dilute to the scale with blank solvent, shake well, and obtain the spiked test solution.

[0046] 1.2 Gas chromatography conditions:

[0047] Detector: Hydrogen flame ionization (FID) detector;

[0048] Injection method: headspace injection;

[0049] Chromatographic column: DB-624, 30m×0.53mm×3.0μm;

[0050] Column temperature: 40°C for 5 min, then raised to 200°C at a rate of 10°C / min and maintained for 5 min;

[0051] Constant temperature furnace temperature: 100℃;

[0052] Detector temperature: 260°C;

[0053] Carrier gas: high-purity nitrogen (purity 99.99%), flow rate 3 mL / min;

[0054] Split ratio: 10:1;

[0055] Injection volume: 1.0 μL.

[0056] Example 2

[0057] Methodological validation:

[0058] 2.1 Exclusivity

[0059] Take blank solvent, the mixed reference solution and the spiked test solution and test them according to the above gas chromatography conditions, record the chromatogram, and the results are as follows: Figure 1-Figure 3 As shown, Figure 1 is the chromatogram of blank solvent, Figure 2 is the chromatogram of the mixed reference solution. Figure 3 is the chromatogram of the test solution, Figure 4 The chromatogram of the spiked test solution is shown in Table 1.

[0060] Table 1 Separation test results of each component in the mixed control solution

[0061]

[0062] It can be seen from the above table that the blank solvent in the detection method provided by this scheme does not interfere with the detection of each component, and the separation between the components meets the requirements, indicating that this method has good specificity.

[0063] 2.2 Limit of detection and limit of quantification

[0064] Accurately weigh 100 mg of trimethylol, 300 mg of methanol, and 500 mg of ethyl acetate as reference substances, respectively, and place them in 100 mL volumetric flasks containing 25 mL of blank solvent, and dilute to the scale. Then, draw 1 mL, add it to a 10 mL volumetric flask and dilute to the scale to obtain each reference substance solution.

[0065] Accurately measure each of the above-mentioned reference solution, perform serial dilution, inject into the gas chromatograph respectively, and record the chromatogram. When the chromatographic peak height is about 3 times the baseline noise, it is the detection limit; when the chromatographic peak height is about 10 times the baseline noise, it is the quantitative limit. The results are shown in Table 2. And prepare 6 portions of reference solution according to the quantitative limit concentration, test according to the above-mentioned gas chromatography conditions, and record the peak area of ​​each chromatographic peak. The results are shown in Table 3.

[0066] Table 2 Results of detection limit and quantification limit tests

[0067]

[0068] Table 3 Results of repeatability test of limit of quantitation

[0069] Element 1 2 3 4 5 6 RSD% Trimethylol 599 634 628 562 604 602 4.22 Methanol 2374 2401 2331 2193 2392 2405 3.46 Ethyl acetate 1306 1299 1443 1419 1352 1276 5.07

[0070] The test results showed that the RSD of the peak area of ​​each component measured 6 times was ≤5.07%, indicating that the method has high sensitivity and good repeatability of the limit of quantification.

[0071] 2.3 Linear range

[0072] Accurately weigh appropriate amounts of 1,3,5-trihydroxybenzene reference substance and unsymmetrical trimethylolbenzene, methanol and ethyl acetate reference substances, and prepare a series of linear solutions with blank solvent. Accurately measure 1.0 μL of each, inject and test according to the above gas chromatography conditions, record the chromatogram, determine the peak area, and draw a linear regression curve with concentration (μg / mL) as the horizontal axis and peak area as the vertical axis. The results are shown in Table 4.

[0073] Table 4 Linear test results of each component

[0074]

[0075]

[0076] The above results show that the linear relationship between the components is good, and r is greater than 0.9970, indicating that the method provided by this scheme has a good linear relationship.

[0077] 2.4 Recovery rate

[0078] According to the method under Example 1, take appropriate amounts of trimethylol, methanol and ethyl acetate reference substances, accurately weigh them, and quantitatively dilute them with blank solvent to prepare mixed reference substance stock solutions. Take 0.3mL, 1mL and 1.5mL respectively, place them in a 10mL volumetric flask, and dilute to volume with blank solvent to prepare reference substance stock solutions.

[0079] Accurately weigh 100 mg of 1,3,5-trihydroxybenzene test sample and place it in a headspace bottle. Prepare 9 portions in parallel, with three portions as a group. Add 1 mL of the above-mentioned reference substance stock solution of different concentrations to each group as the recovery spiked test solution.

[0080] The above 9 recovery solutions were taken and tested respectively according to the above gas chromatography conditions, the chromatograms were recorded, and the recovery rates were calculated. The results are shown in Table 5.

[0081] Table 5 Recovery test results

[0082]

[0083]

[0084] The test results show that the recovery rate of each component is between 90% and 100%, and the maximum RSD is 1.57%, indicating that the method provided by the present invention has good accuracy.

[0085] 2.5 Repeatability

[0086] Six samples of 1,3,5-trihydroxybenzene were taken and prepared into test solutions with a concentration of 100 mg / mL using blank solvent. The solutions were tested according to the above-mentioned gas chromatography conditions. The results are shown in Table 6.

[0087] Table 6 Repeatability test results

[0088]

[0089]

[0090] The test results show that the detection results of solvent residues in 6 samples of 1,3,5-trihydroxybenzene test solutions from the same batch are basically consistent, indicating that this method has good repeatability.

[0091] 2.6 Solution stability

[0092] Precisely weigh the unsymmetrical trimethylol, methanol, and ethyl acetate reference substances and prepare a mixed reference substance solution according to the method of Example 1. After being placed at room temperature for 0 h, 4 h, 8 h, 12 h, 16 h, and 24 h, the solution was tested according to the above-mentioned gas chromatography conditions. The stability results of the solution are shown in Table 7.

[0093] Table 7 Solution stability test results (peak area)

[0094] Element 0h 4h 8h 12h 16h 24h RSD% Methanol 560890 574677 570706 571747 563195 572509 0.98 Ethyl acetate 5667639 5784428 5791632 5763462 5557476 5724681 1.57 Trimethylol 2677107 2733667 2731662 2711950 2646012 2709175 1.26

[0095] The test results show that the reference solution of 1,3,5-trihydroxybenzene residual solvent prepared by the detection method of the present invention is placed at room temperature for 0h, 4h, 8h, 12h, 16h, and 24h, and then detected by the same method. The results obtained are basically consistent, and the relative standard deviation (RSD) is ≤1.57%, indicating that the solution prepared by this method has good stability.

[0096] 2.7 Durability

[0097] Take the mixed reference solution under Example 1, change the constant temperature furnace temperature, the initial temperature of the column temperature, and the heating rate, respectively, and perform detection according to the gas chromatography detection conditions of the present invention. The results are shown in Tables 8 to 10.

[0098] Table 8 Temperature separation of different constant temperature furnaces

[0099]

[0100]

[0101] Table 9 Separation of different column starting temperatures

[0102] Element Column temperature 35°C Column temperature 40℃ Column temperature 45°C Methanol 22.698 20.139 17.959 Ethyl acetate 14.450 14.717 16.116 Trimethylol 2.250 2.266 2.270

[0103] Table 10 Separation degree at different heating rates

[0104] Element Heating rate 8℃ / min Heating rate 10℃ / min Heating rate: 12℃ / min Methanol 20.191 20.139 20.233 Ethyl acetate 16.983 14.717 14.893 Trimethylol 2.433 2.266 2.114

[0105] It can be seen from the above table that by changing the conditions, the separation degree of each component meets the requirements, indicating that the method provided by this scheme has good durability.

[0106] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting residual solvents in 1,3,5-trihydroxybenzene, characterized in that: The detection method is gas chromatography, comprising the following steps: (1) Preparation of test solution and mixed reference solution: Preparation of mixed reference solution: Take the reference substances of trimethylol, methanol and ethyl acetate and prepare a mixed reference solution with solvent; Preparation of test solution: Take 1,3,5-trihydroxybenzene sample and prepare the test solution with solvent; (2) Take the mixed reference solution and test solution and perform the test under the following gas chromatography conditions: Detector: Hydrogen flame ionization detector; Injection method: headspace injection; Chromatographic column: 6% cyanopropylbenzene-94% dimethylsiloxane as the stationary phase; Column temperature: 35℃-45℃ for 4min-6min, then increase the temperature to 195℃-205℃ at a rate of 8℃ / min-12℃ / min, and maintain for 4min-6min; Constant temperature furnace temperature: 95℃-105℃; Detector temperature: 255℃-265℃; Split ratio: 8-12:

1.

2. The method for detecting residual solvent in 1,3,5-trihydroxybenzene according to claim 1, characterized in that: The chromatographic column is DB-624, 30m×0.53mm×3.0μm.

3. The method for detecting residual solvent in 1,3,5-trihydroxybenzene according to claim 1, characterized in that: The column temperature was maintained at 40°C for 5 min, then increased to 200°C at a rate of 10°C / min and maintained for 5 min.

4. The method for detecting residual solvent in 1,3,5-trihydroxybenzene according to claim 1, characterized in that: The constant temperature of the oven was 100°C and the detector temperature was 260°C.

5. The method for detecting residual solvent in 1,3,5-trihydroxybenzene according to claim 1, characterized in that: The split ratio is 10:

1.

6. The method for detecting residual solvent in 1,3,5-trihydroxybenzene according to claim 1, characterized in that: The carrier gas was nitrogen with a flow rate of 2.8 mL / min-3.2 mL / min.

7. The method for detecting residual solvent in 1,3,5-trihydroxybenzene according to claim 6, characterized in that: The carrier gas flow rate was 3.0 mL / min.

8. The method for detecting residual solvent in 1,3,5-trihydroxybenzene according to claim 1, characterized in that: The injection volume was 1.0 μL.

9. The method for detecting residual solvent in 1,3,5-trihydroxybenzene according to claim 1, characterized in that: The concentration of trimethylol in the mixed reference solution was 0.1 mg / mL, the concentration of methanol was 0.3 mg / mL, and the concentration of ethyl acetate was 0.5 mg / mL.

10. The method for detecting residual solvent in 1,3,5-trihydroxybenzene according to claim 1, characterized in that: The concentration of the test solution is 100 mg / mL.

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