Method for detecting 1, 4-butanediol in tropine

Abstract

The invention provides a method for detecting 1, 4-butanediol in tropine, and relates to the field of pharmaceutical analysis. The detection method provided by the invention comprises the following steps: dissolving a to-be-detected sample, carrying out derivatization reaction, and then carrying out gas chromatography detection; wherein the reagent used for derivatization comprises trimethylsilylimidazole. The method has the characteristics of strong specificity, high sensitivity, high accuracy and good durability, can effectively detect 1, 4-butanediol in tropine, makes up for the technical blank of detection of 1, 4-butanediol in tropine, is beneficial to quality control of tropine, is further beneficial to quality control of atropine sulfate, and ensures clinical medication safety of atropine sulfate. Meanwhile, the method is also suitable for determining 1, 4-butanediol in other alkaline samples.

Description

Technical Field

[0001] The present invention relates to the field of pharmaceutical analysis, and more particularly, to a method for detecting 1,4-butanediol in tropine. Background Art

[0002] Tropine is an important starting material for the synthesis of atropine sulfate, and 1,4-butanediol is a process impurity that may be introduced during the preparation process of tropine. To ensure the quality of atropine sulfate, great attention is paid to the residual amount of 1,4-butanediol in the starting material tropine during drug control and review, and a quantitative analysis method needs to be established according to the general impurity limit of 0.15% for detection.

[0003] According to existing research reports, 1,4-butanediol has no ultraviolet absorption, a boiling point of about 230 °C, and an aqueous solution is neutral; tropine has no ultraviolet absorption, a boiling point of about 233 °C, and an aqueous solution is strongly alkaline. There are few research reports on the analysis method of 1,4-butanediol in the prior art, and there is no report in domestic and foreign literature on the method for detecting the residual amount of 1,4-butanediol in strongly alkaline samples of tropine. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for detecting 1,4-butanediol in tropine based on the above existing problems. The method derivatizes the sample to be tested and then performs gas chromatography detection. After verification, the method has strong specificity, high sensitivity, high accuracy, and good durability, can effectively detect 1,4-butanediol in tropine, and is also applicable to the determination of 1,4-butanediol in other alkaline samples.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A method for detecting 1,4-propanediol in tropine, which comprises the following steps: dissolving the sample to be tested, performing a derivatization reaction, and then performing gas chromatography detection; wherein, the reagent for derivatization includes trimethylsilylimidazole.

[0007] In a preferred embodiment of the present invention, the reagent for derivatization contains 0.5%-2% of trimethylchlorosilane by volume percentage.

[0008] In a preferred embodiment of the present invention, the reagent for derivatization consists of trimethylsilylimidazole containing 0.5%-2% of trimethylchlorosilane and toluene in a volume ratio of 1:6-15.

[0009] In a preferred embodiment of the present invention, the detection chromatographic column is a capillary column with polyethylene glycol as the stationary liquid or a capillary column with similar polarity.

[0010] In a preferred embodiment of the present invention, gas chromatography detection is performed using an FID detector; the injection port temperature is 210-230 °C, and the detector temperature is 245-260 °C.

[0011] In the preferred embodiment of the present invention, the gas chromatography temperature programming is as follows:

[0012]

[0013]

[0015] In the preferred embodiment of the present invention, the gas chromatography temperature programming is as follows:

[0016] Rate °C / min Value °C Holding time min - 50 - 20 230 5 。

[0017] In the preferred embodiment of the present invention, the carrier gas used is an inert gas, preferably nitrogen.

[0018] In the preferred embodiment of the present invention, the carrier gas flow rate is 1.5 - 3.0 mL / min.

[0019] In the preferred embodiment of the present invention, the injection mode is split injection, and the split ratio is 10 - 40:1.

[0020] The present invention provides a method for detecting 1,4 - butanediol in tropine. This method has the characteristics of strong specificity, high sensitivity, high accuracy, and good durability. It can effectively detect 1,4 - butanediol in tropine, filling the technical gap in the detection of 1,4 - butanediol in tropine, facilitating the quality control of tropine, and further facilitating the quality control of atropine sulfate to ensure the safety of its clinical use. At the same time, this method is also applicable to the determination of 1,4 - butanediol in other basic samples. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be described by way of examples with reference to the accompanying drawings, wherein:

[0022] Figure 1-4 is the gas chromatogram of Comparative Example 1;

[0023] Figure 5 is the gas chromatogram of Comparative Example 2;

[0024] Figure 6 is the gas chromatogram of Example 1;

[0025] Figure 7 is the gas chromatogram of Comparative Example 3;

[0026] Figure 8-9 is the gas chromatogram of Comparative Example 4. DETAILED DESCRIPTION OF THE INVENTION

[0027] The following is a further detailed description of the above content of the present invention in the form of specific embodiments by way of examples. However, this should not be construed as limiting the scope of the above subject matter of the present invention to the following examples. All technologies implemented based on the above content of the present invention fall within the scope of the present invention.

[0028] Comparative Example 1

[0029] Solution preparation method:

[0030] Blank solution: Methanol

[0031] Reference solution: Take about 30 mg of 1,4-butanediol, accurately weigh it, place it in a 10 ml volumetric flask, dilute it to the scale with methanol, and shake well; accurately measure 1 ml, place it in a 50 ml volumetric flask, dilute it to the scale with methanol, and shake well to obtain. (It can be scaled proportionally according to the actual situation)

[0032] Test solution: Take about 200 mg of tropine, accurately weigh it, place it in a 5 ml volumetric flask, dissolve it with methanol and dilute it to the scale, and shake well to obtain.

[0033] Spiked test solution: Take about 200 mg of tropine, accurately weigh it, place it in a 5 ml volumetric flask, dissolve it with the reference solution and dilute it to the scale, and shake well to obtain.

[0034] Take 1.0 μL of each of the above solutions and perform gas chromatography analysis under the following chromatographic conditions.

[0035] Chromatographic column: CP-Sil 8CB (30 m × 0.32 mm) (a capillary chromatographic column with 5% phenyl-methyl polysiloxane as the stationary liquid);

[0036] Split ratio: 10:1;

[0037] Injection mode: Direct liquid injection;

[0038] Injection port temperature: 220 °C;

[0039] Detector temperature: 250 °C, Detector: FID;

[0040] Column flow rate: 1.5 mL / min;

[0041] Carrier gas: Nitrogen;

[0042] The temperature programming is shown in Table 1.

[0043] Table 1 Temperature programming of Comparative Example 1

[0044] Rate °C / min Value °C Holding time min - 80 5 10 160 0 40 240 8

[0045] The test results using this method Figure 1 are shown as follows. Figure 1As shown, the peak shape of the component to be measured is good, but 1,4-butanediol in the spiked test solution degrades, and the unknown impurities generated by the degradation are not baseline-separated from the 1,4-butanediol chromatographic peak; under the same gas chromatography conditions, when the diluent is changed to toluene, the test results are as Figure 2 shown. The phenomenon is basically the same as that with methanol as the diluent, that is, 1,4-butanediol degrades, and the unknown impurities generated by the degradation are not baseline-separated from the 1,4-butanediol chromatographic peak. It can be seen that changing the diluent cannot meet the test requirements. Under the same gas chromatography conditions, different amounts of phosphoric acid are added to the diluent methanol. 1,4-butanediol in the reference solution still shows a degradation phenomenon, and the response of 1,4-butanediol is significantly reduced compared with that in pure organic solvents. The baseline of the peak position is uneven. At the same time, as the acid concentration increases, the response of the unknown peak gradually decreases, but the response of 1,4-butanediol does not show a gradually increasing trend. For details, see the appendix Figure 3 . In this case, the phenomena of the spiked test solution and the reference solution are basically the same. For details, see Figure 4 . It can be seen that adding acid to the diluent cannot meet the test requirements under this detection method.

[0046] Comparative Example 2

[0047] Solution preparation method:

[0048] Derivatization test solution: Trimethylsilylimidazole (containing 1% trimethylchlorosilane)-toluene (1:49). That is, take 1 volume of trimethylchlorosilane and 99 volumes of trimethylsilylimidazole and mix them evenly to obtain trimethylsilylimidazole (containing 1% trimethylchlorosilane); take 1 volume of trimethylsilylimidazole (containing 1% trimethylchlorosilane) and 49 volumes of toluene and mix them evenly to obtain trimethylsilylimidazole (containing 1% trimethylchlorosilane)-toluene (1:49).

[0049] Blank solution: The same as the derivatization test solution.

[0050] Reference solution: Take about 24 mg of 1,4-butanediol, accurately weigh it, place it in a 10 ml volumetric flask, dilute it to the mark with the derivatization test solution, and shake well; accurately measure 1.25 ml, place it in a 100 ml volumetric flask, and dilute it to the mark with the derivatization test solution, and shake well to obtain. (It can be scaled proportionally according to the actual situation)

[0051] Test solution: Take about 100 mg of tropine, accurately weigh it, place it in a 5 ml volumetric flask, dilute it to the mark with the derivatization test solution, and shake well to obtain.

[0052] (It can be scaled proportionally according to the actual situation)

[0053] Spiked test solution: Take about 100 mg of tropine, accurately weigh it, place it in a 5 ml volumetric flask, dilute it to the mark with the reference solution, and shake well to obtain.

[0054] Take 1.0 μL of each of the above solutions and perform gas chromatography analysis under the following chromatographic conditions.

[0055] Chromatographic column: DB-1 (30 m × 0.32 mm × 1.00 μm) (a capillary chromatographic column with 100% dimethylpolysiloxane as the stationary liquid).

[0056] The temperature programming is shown in Table 2.

[0057] Table 2 Temperature programming of Comparative Example 2

[0058] Rate °C / min Value °C Holding time min - 40 - 20 280 5

[0059] The remaining conditions are the same as those in Comparative Example 1.

[0060] The test results by this method are as Figure 5 shown. Figure 5 It shows that there is no interference in the chromatogram of the blank solution; the tailing factor of the 1,4-butanediol derivative in the reference solution (about 30 μg / ml) is 1.0, but the baseline at its peak position is lifted, affecting the integration calculation, and it cannot be improved by adjusting the column flow rate and temperature programming. At the same time, it is found that crystals precipitate in the test solution after standing at room temperature for about 15 h. Thus, it can be seen that this method cannot meet the detection requirements of 1,4-butanediol.

[0061] Example 1

[0062] Solution preparation method:

[0063] Derivatization test solution: Trimethylsilylimidazole (containing 1% trimethylchlorosilane)-toluene (1:9). That is, take 1 volume of trimethylchlorosilane and mix it evenly with 99 volumes of trimethylsilylimidazole to obtain trimethylsilylimidazole (containing 1% trimethylchlorosilane); take 1 volume of trimethylsilylimidazole (containing 1% trimethylchlorosilane) and mix it evenly with 9 volumes of toluene to obtain trimethylsilylimidazole (containing 1% trimethylchlorosilane)-toluene (1:9).

[0064] Blank solution: The same as the derivatization test solution.

[0065] Reference solution: Take about 24 mg of 1,4-butanediol, weigh it accurately, place it in a 10 ml volumetric flask, dilute it to the mark with the derivatization test solution, and shake well; accurately measure 1.25 ml, place it in a 100 ml volumetric flask, dilute it to the mark with the derivatization test solution, and shake well, that is obtained. (It can be scaled proportionally according to the actual situation)

[0066] Test solution: Take about 100 mg of tropine, weigh it accurately, place it in a 5 ml volumetric flask, dilute it to the mark with the derivatization test solution, and shake well, that is obtained.

[0067] (It can be scaled proportionally according to the actual situation)

[0068] Spiked test solution: Weigh accurately about 100 mg of tropine, place it in a 5-ml volumetric flask, dilute it to the mark with the reference solution, and shake well to obtain the solution.

[0069] System suitability solution: Weigh accurately about 24 mg of 1,4-butanediol and 2,5-dimethyltetrahydrofuran, place them in a 10-ml volumetric flask, dilute it to the mark with the derivatization test solution, and shake well; accurately measure 0.125 ml, place it in a 10-ml volumetric flask, dilute it to the mark with the derivatization test solution, and shake well to obtain the solution.

[0070] Take 1.0 μL of each of the above solutions after the derivatization reaction and perform gas chromatography detection under the following chromatographic conditions.

[0071] Chromatographic column: DB-WAX (30 m × 0.320 mm × 0.50 μm) (capillary chromatographic column with polyethylene glycol as the stationary liquid).

[0072] Split ratio: 20:1;

[0073] Injection mode: direct liquid injection;

[0074] Injection port temperature: 220 °C;

[0075] Detector temperature: 250 °C, detector: FID;

[0076] Column flow rate: 2.0 mL / min;

[0077] Carrier gas: nitrogen;

[0078] The temperature programming is shown in Table 3:

[0079] Table Temperature programming for Example 1

[0080] Rate °C / min Value °C Holding time min - 50 - 20 230 5

[0081] Figure 6As shown in [Figure / Table], there are no impurity peaks interfering with the detection of the 1,4-butanediol derivative in the blank solution, reference solution, system suitability solution, test solution, and spiked test solution. As shown in Table 4, the method quantification limit is 0.9 μg / ml, indicating good sensitivity. As shown in Table 5, within the concentration range of 0.9 μg / ml to 60 μg / ml, there is a good linear relationship between the peak area of the 1,4-butanediol derivative and its concentration (r = 0.9999). As shown in Table 6, the recovery rate of the 1,4-butanediol derivative in the spiked solution is 94.71% - 96.86%, and the maximum RSD of the recovery rate at all concentration levels is 1.0%. As shown in Table 7, under various changing chromatographic conditions (initial column temperature ±5°C, injection port temperature ±5°C, different batches of chromatographic columns of the same model and specification), the method specificity and the reproducibility of the test component detection results are good, indicating good durability of the method. Moreover, at room temperature, no crystals precipitate in the test solution after standing for more than 72 hours. Within the 24-hour inspection period, the RSD of the peak area of the 1,4-butanediol derivative in the limit concentration reference solution (about 30 μg / ml) at each inspection time point is 0.7% (details are shown in Table 8), and the RSD of the detected amount of 1,4-butanediol in the spiked test solution at each inspection time point is 1.1%, indicating good solution stability. The results show that using trimethylsilylimidazole (containing 1% trimethylchlorosilane) as the derivatization reagent can instantaneously react 1,4-butanediol to form a silyl-containing compound under the above concentration ratio, and it has good stability, meeting the detection requirements.

[0082] Table 4 Results of Detection Limit and Quantification Limit Tests in Example 1

[0083]

[0084] Table 5 Results of Linearity and Range Tests in Example 1

[0085]

[0086] Table 6 Results of Accuracy Tests in Example 1

[0087]

[0088]

[0089] Table 7 Results of Durability Tests of Chromatographic Conditions in Example 1

[0090]

[0091] Note: " / " in the table represents that the content is not involved.

[0092] Comparative Example 3

[0093] In this comparative example, the effects of different silylation derivatization reagents on the detection of 1,4-butanediol were investigated.

[0094] Silanization reagent ①: N-O-bis(trimethylsilyl)acetamide (BSM);

[0095] Derivatization test solution: BSM (containing 1% trimethylchlorosilane)-toluene (1:9). That is: take 1 volume of trimethylchlorosilane and mix it with 99 volumes of BSM to obtain BSM (containing 1% trimethylchlorosilane); take 1 volume of BSM (containing 1% trimethylchlorosilane) and mix it with 9 volumes of toluene to obtain BSM (containing 1% trimethylchlorosilane)-toluene (1:9).

[0096] Blank solution: same as the derivatization test solution.

[0097] Reference solution: Precisely pipette 1.5 μl of 1,4-butanediol into a 10 ml volumetric flask, dilute to the mark with the derivatization test solution, and shake well; precisely measure 1 ml and place it in a 5 ml volumetric flask, dilute to the mark with the derivatization test solution, and shake well to obtain. (Can be scaled proportionally according to the actual situation) Silanization reagent ②: hexamethyldisiloxane (HMDSO);

[0098] Derivatization test solution: HMDSO (containing 1% trimethylchlorosilane)-toluene (1:9). That is: take 1 volume of trimethylchlorosilane and mix it with 99 volumes of HMDSO to obtain HMDSO (containing 1% trimethylchlorosilane); take 1 volume of HMDSO (containing 1% trimethylchlorosilane) and mix it with 9 volumes of toluene to obtain HMDSO (containing 1% trimethylchlorosilane)-toluene (1:9).

[0099] Blank solution: same as the derivatization test solution.

[0100] Reference solution: Precisely pipette 1.5 μl of 1,4-butanediol into a 10 ml volumetric flask, dilute to the mark with the derivatization test solution, and shake well; precisely measure 1 ml and place it in a 5 ml volumetric flask, dilute to the mark with the derivatization test solution, and shake well to obtain. (Can be scaled proportionally according to the actual situation)

[0101] Silanization reagent ③: N-O-bis(trimethylsilyl)trifluoroacetamide (BSTFA).

[0102] Derivatization test solution: BSTFA (containing 1% trimethylchlorosilane)-toluene (1:9). That is: take 1 volume of trimethylchlorosilane and mix it with 99 volumes of BSTFA to obtain BSTFA (containing 1% trimethylchlorosilane); take 1 volume of BSTFA (containing 1% trimethylchlorosilane) and mix it with 9 volumes of toluene to obtain BSTFA (containing 1% trimethylchlorosilane)-toluene (1:9). Blank solution: same as the derivatization test solution.

[0103] Reference solution: Precisely pipette 1.5 μl of 1,4-butanediol into a 10-ml volumetric flask, dilute to the mark with the derivatization test solution, and shake well; precisely measure 1 ml and place it in a 5-ml volumetric flask, dilute to the mark with the derivatization test solution, and shake well to obtain. (It can be scaled proportionally according to the actual situation.) Respectively take 1.0 μL of each of the above solutions after the derivatization reaction and perform gas chromatography detection under the chromatographic conditions in Example 1.

[0104] The detection results are as Figure 7 shown in Table 8. When the derivatizing reagent is BSM, the specificity is good. However, it was found during the experiment that the reference solution (about 30 μg / ml) needs to be placed at room temperature for at least 1 hour after preparation to make the response of the 1,4-butanediol derivative stable, and the response after stabilization is about 75% of the response when trimethylsilylimidazole is used as the derivatizing reagent, indicating that the derivatization rate and yield of BSM (containing 1% trimethylchlorosilane) are both inferior to those of trimethylsilylimidazole (containing 1% trimethylchlorosilane). When the derivatizing reagent is HMDSO, there is no chromatographic peak of the 1,4-butanediol derivative in the reference solution (about 30 μg / ml) within 2 hours of investigation at room temperature, indicating that using HMDSO as the derivatizing reagent cannot meet the detection requirements of 1,4-butanediol. When the derivatizing reagent is BSTFA, the specificity is good, but the response of the 1,4-butanediol derivative in the limit concentration reference solution (about 30 μg / ml) shows a gradually increasing trend within 2 hours of investigation at room temperature, and the response of the 1,4-butanediol derivative in the reference solution (about 30 μg / ml) after standing for 2 hours is about 65% of the response when trimethylsilylimidazole is used as the derivatizing reagent, indicating that the derivatization rate and yield of BSTFA (containing 1% trimethylchlorosilane) are both inferior to those of trimethylsilylimidazole (containing 1% trimethylchlorosilane). When using trimethylsilylimidazole (containing 1% trimethylchlorosilane), no crystal precipitation phenomenon occurs in the test solution after standing at room temperature for more than 72 hours. Within 24 hours of investigation, the RSD of the peak area of the 1,4-butanediol derivative at each investigated time point in the reference solution (about 30 μg / ml) is 0.7%, and the RSD of the detected amount of 1,4-butanediol at each investigated time point in the spiked test solution is 1.1%, indicating good solution stability.

[0105] Table 8 Investigation results of different silylation derivatizing reagents

[0106]

[0107]

[0108] Note: In the table, "\ " represents that the stability was not investigated at this time point.

[0109] Comparative Example 4

[0110] In this comparative example, the effects of different esterification derivatization methods on the detection of 1,4-butanediol were investigated.

[0111] Esterification derivation method ①: The derivation test solution is a toluene solution containing 0.3% formic acid.

[0112] Derivation test solution: A toluene solution containing 0.3% formic acid. That is, 0.3 volumes of formic acid are mixed with 99.7 volumes of toluene to obtain it.

[0113] Blank solution: The same as the derivation test solution.

[0114] Reference solution: Precisely pipette 1.5 μl of 1,4-butanediol, place it in a 10 ml volumetric flask, dilute it to the mark with the derivation test solution, and shake well; precisely measure 1 ml, place it in a 5 ml volumetric flask, dilute it to the mark with the derivation test solution, and shake well to obtain it. (It can be scaled proportionally according to the actual situation)

[0115] Esterification derivation method ②: The derivation test solution is a toluene solution containing 0.3% acetic acid.

[0116] Derivation test solution: A toluene solution containing 0.3% acetic acid. That is, 0.3 volumes of acetic acid are mixed with 99.7 volumes of toluene to obtain it.

[0117] Blank solution: The same as the derivation test solution.

[0118] Reference solution: Precisely pipette 1.5 μl of 1,4-butanediol, place it in a 10 ml volumetric flask, dilute it to the mark with the derivation test solution, and shake well; precisely measure 1 ml, place it in a 5 ml volumetric flask, dilute it to the mark with the derivation test solution, and shake well to obtain it. (It can be scaled proportionally according to the actual situation)

[0119] Esterification derivation method ③: The derivation test solution is an aqueous solution containing 10% formic acid and 0.02% p-toluenesulfonic acid, and the extraction agent is toluene.

[0120] Blank solution: Weigh about 10 mg of p-toluenesulfonic acid, place it in a 50 ml volumetric flask, dissolve it with water and make up to the mark, and shake well; precisely measure 4.5 ml, add 0.5 ml of formic acid, then add 5 ml of toluene, shake, let it stand to separate layers, and inject the toluene layer for analysis.

[0121] Reference solution: Weigh about 10 mg of p-toluenesulfonic acid, place it in a 50 ml volumetric flask, add an appropriate amount of water to dissolve it, precisely add 1.7 μl of 1,4-butanediol, dilute it to the mark with water, and shake well; precisely measure 4.5 ml, add 0.5 ml of formic acid, shake, then add 5 ml of toluene, shake, let it stand to separate layers, and inject the toluene layer for analysis.

[0122] Esterification derivation method ④: The derivation test solution is an aqueous solution containing 10% acetic acid and 0.02% p-toluenesulfonic acid, and the extraction agent is toluene.

[0123] Blank solution: Weigh about 10 mg of p-toluenesulfonic acid, place it in a 50-ml volumetric flask, dissolve it with water and dilute to the mark, and shake well; accurately measure 4.5 ml, add 0.5 ml of acetic acid, then add 5 ml of toluene, shake, let stand to separate layers, and inject the toluene layer for analysis.

[0124] Reference solution: Weigh about 10 mg of p-toluenesulfonic acid, place it in a 50-ml volumetric flask, add an appropriate amount of water to dissolve it, accurately add 1.7 μl of 1,4-butanediol, dilute to the mark with water, and shake well; accurately measure 4.5 ml, add 0.5 ml of formic acid, shake, then add 5 ml of toluene, shake, let stand to separate layers, and inject the toluene layer for analysis.

[0125] Take 1.0 μL of each of the above solutions after the derivatization reaction respectively, and perform gas chromatography detection according to the chromatographic conditions in Example 1.

[0126] The detection results are as Figure 8 - Figure 9 shown. Figure 8-9 shown in that when the esterification derivatization methods ① - ④ are used, there are no chromatographic peaks of the 1,4-butanediol derivative product in the reference solution (about 30 μg / ml), indicating that this esterification derivatization method cannot meet the detection requirements of 1,4-butanediol.

Claims

1. A method for detecting 1,4-propanediol in tropine, characterized in that, It includes the following steps: dissolving the sample to be tested, performing a derivatization reaction, and then conducting gas chromatography detection; among them, the reagent for derivatization includes trimethylsilylimidazole.

2. The detection method according to claim 1, wherein The reagent for derivatization contains 0.5%-2% of trimethylchlorosilane by volume percentage.

3. The detection method according to claim 2, wherein The reagent for derivatization consists of trimethylsilylimidazole containing 0.5%-2% of trimethylchlorosilane and toluene in a volume ratio of 1:6-15.

4. The detection method according to any one of claims 1 to 3, characterized in that, The detection chromatographic column is a capillary column with polyethylene glycol as the stationary liquid or a capillary column with similar polarity.

5. The detection method according to claim 4, wherein Gas chromatography detection uses an FID detector; the injection port temperature is 210-230 °C, and the detector temperature is 245-260 °C.

6. The detection method according to claim 4, wherein The gas chromatography temperature program is:

7. The detection method according to claim 6, wherein The gas chromatography temperature program is:

8. The detection method according to claim 6, characterized in that, The carrier gas used is an inert gas, preferably nitrogen.

9. The detection method according to claim 8, wherein The carrier gas flow rate is 1.5-3.0 mL / min.

10. The detection method according to any one of 6-9, characterized in that, The injection method is split injection, and the split ratio is 10-40:1.

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