Method for detecting antioxidant in jet fuel

Abstract

The invention relates to the field of fuel, and discloses a method for detecting an antioxidant in jet fuel. The method comprises the following steps: (1) in the presence of a solvent, mixing the jet fuel to be detected with alkenyl-terminated sulfone; obtaining a chromatogram of a supernatant obtained after mixing; (2) taking the jet fuel with known antioxidant concentration, and processing according to the mode in the step (1) to obtain a corresponding standard chromatogram; and (3) comparing the standard chromatogram with the chromatogram obtained in the step (1) to obtain the type and / or content of the antioxidant in the jet fuel. By adopting the method, the content of the antioxidant in the fresh jet fuel can be measured, and particularly, the content of the antioxidant in the jet fuel stored for a long time can be accurately measured.

Description

Technical Field

[0001] The invention relates to the field of fuel, and in particular to a method for detecting an antioxidant in jet fuel. Background Art

[0002] There are three main production processes for jet fuel: straight run-non-hydrogenation, hydrofining, and hydrocracking. Usually, jet fuel produced by the straight run-non-hydrogenation process retains some natural antioxidant components such as mercaptans and phenolic compounds, and antioxidants are not required. However, in jet fuel produced by the hydrogenation process, most of the natural antioxidant components are removed, which is easy to oxidize and produce peroxides, and antioxidants need to be added to inhibit the oxidation process. Hindered phenol antioxidants are one of the important antioxidants. This type of antioxidant can combine with the free radicals formed during the oxidation process to terminate the chain reaction process and play a role in alleviating the oxidation deterioration of the fuel. GB 6537-2018 stipulates that the antioxidant 2,6-di-tert-butyl-4-methylphenol antioxidant (T501) allowed to be added to jet fuel should be added in an amount of 17.0-24.0 mg / L; ASTM D1655-21a (Jet A or Jet A-1) stipulates that the total amount of phenolic antioxidants added to jet fuel shall not exceed 24.0 mg / L. During the actual storage and use process, the antioxidants in jet fuel are constantly consumed. Studies have shown that peroxides only begin to form when the antioxidants are completely consumed. Therefore, tracking and analyzing the antioxidant content can predict the oxidation of the fuel and help relevant departments decide whether the oil can still be used normally and whether antioxidants need to be added. This requires accurate determination of the antioxidant content in jet fuel, and therefore the detection method of antioxidant content is particularly important.

[0003] Common methods for detecting the content of phenolic antioxidants in jet fuel include ultraviolet spectroscopy, electrochemical method, micellar electrokinetic capillary chromatography, high performance liquid chromatography (HPLC), etc., among which the most commonly used is high performance liquid chromatography (HPLC). This method has high accuracy for determining the content of 2,6-di-tert-butyl-p-cresol (T501) in fresh jet fuel and can meet production requirements. However, for jet fuel that has been stored for a long time, there will be interference from impurities when using this method to detect T501, resulting in peak overlap between T501 and impurities, affecting the accuracy of the results. The components of jet fuel stored for a long time are more complex, and it is also difficult to separate T501 and impurities. Therefore, the conventional high performance liquid chromatography method cannot determine the accurate content of its antioxidants. At present, there is also a technology that uses liquid-mass spectrometry technology to more accurately determine the content of phenolic antioxidants in jet fuel. However, liquid-mass spectrometry instruments are very expensive, at least millions of yuan, and refineries or general testing centers are not capable of equipping them, making them difficult to promote and apply. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned problems existing in the prior art and to provide a method for detecting antioxidants in jet fuel. By adopting this method, the antioxidant content in fresh jet fuel can be determined, and in particular, the antioxidant content in long-term stored jet fuel can be accurately determined.

[0005] In order to achieve the above object, the present invention provides a method for detecting antioxidants in jet fuel, the method comprising:

[0006] (1) mixing a jet fuel to be tested and a terminal olefin sulfone in the presence of a solvent; obtaining a chromatogram of a supernatant obtained after the mixing;

[0007] wherein the mixing is carried out in the presence of an organic base, and the organic base contains a nitrogen-containing heterocycle;

[0008] (2) taking a jet fuel with a known antioxidant concentration and treating it in the manner of step (1) to obtain a corresponding standard chromatogram;

[0009] (3) Comparing the above standard chromatogram with the chromatogram obtained in step (1) to obtain the type and / or content of the antioxidant in the jet fuel.

[0010] By adopting the technical solution provided by the present invention, the peak of the substance corresponding to the antioxidant can be fully separated from the peak of other substances, and the content of the antioxidant in fresh jet fuel can be accurately determined, and the content of the antioxidant in jet fuel stored for a long time can also be accurately determined. In addition, the method does not rely on overly expensive instruments, and ordinary refineries or testing centers can also detect antioxidants in jet fuel with relatively low-cost instruments. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is the standard curve constructed in the examples. DETAILED DESCRIPTION

[0012] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0013] The present invention provides a method for detecting an antioxidant in jet fuel, the method comprising:

[0014] (1) mixing a jet fuel to be tested and a terminal olefin sulfone in the presence of a solvent; obtaining a chromatogram of a supernatant obtained after the mixing;

[0015] wherein the mixing is carried out in the presence of an organic base, and the organic base contains a nitrogen-containing heterocycle;

[0016] (2) taking a jet fuel with a known antioxidant concentration and treating it in the manner of step (1) to obtain a corresponding standard chromatogram;

[0017] (3) Comparing the above standard chromatogram with the chromatogram obtained in step (1) to obtain the type and / or content of the antioxidant in the jet fuel.

[0018] The inventors of the present invention have found in their research that the above method can fully separate the peak of the substance corresponding to the antioxidant from the peak of other substances, and can accurately determine the antioxidant content in the jet fuel. The method provided by the present invention is not only applicable to fresh jet fuel, but also particularly suitable for long-term stored jet fuel that is difficult to determine by conventional methods. The method provided by the present invention can accurately determine the antioxidant content in such jet fuel. It can be understood that the terminal olefin group refers to a double bond located at one end of the molecule.

[0019] In the case of fresh or long-term stored jet fuel, the peak positions of antioxidants and other impurities may overlap in the chromatographic peaks, so it is difficult to confirm the amount of antioxidants. After mixing with terminal olefin sulfone, the peak brought by the antioxidant will disappear, and a new peak will appear at an earlier retention time. Generally, the retention time of the new peak will be advanced by a certain time T (such as 0.5-1min) relative to the antioxidant (especially 2,6-di-tert-butyl-p-methylphenol). The amount of antioxidant originally contained is confirmed by the area of ​​the peak. For the type of antioxidant (especially 2,6-di-tert-butyl-p-methylphenol), if the chromatogram obtained in step (1) has a chromatographic peak at a position where the peak position of the antioxidant standard substance is separated by T (earlier), it can be considered that the antioxidant in the jet fuel to be tested is the same as the antioxidant standard substance. In order to further improve the accuracy of the method of the present invention, the method can also further include directly comparing the chromatographic peak of the jet fuel to be tested that is not mixed with the terminal olefin sulfone with the chromatographic peak of the antioxidant standard substance for confirmation. Currently, GB 6537-2018 stipulates that the antioxidant allowed to be added to jet fuel is 2,6-di-tert-butyl-4-methylphenol antioxidant (T501).

[0020] Wherein, at least one of an infrared spectrometer, a gas chromatograph, a liquid chromatography-mass spectrometer, a gas chromatography-mass spectrometer, and a high performance liquid chromatograph can be used to obtain a corresponding chromatogram, and in particular, a high performance liquid chromatograph can be used to obtain a more accurate result. According to a particularly preferred embodiment of the present invention, the chromatogram is a high performance liquid chromatograph. The parameters and specific operating conditions of the high performance liquid chromatograph can be conventional conditions in the art, for example, the high performance liquid chromatograph can be configured with a diode array detector (DAD detector), a 1260 Infinity VL type quaternary pump, an injector 0.1-900 μL, and an increment of 0.1 μL; a quaternary pump pressure range of 0-200 bar, a flow rate of up to 5 ml / min, a flow rate setting value from 0.001 to 10.0 mL / min, and an increment of 0.001 ml / min; a diode array detector detection wavelength of 0-800 nm. Analytical conditions: The chromatographic column is a normal phase silica gel column, the injection volume is 10 μL, the mobile phase is degassed and dehydrated chromatographic grade n-hexane, the mobile phase flow rate is 1 mL / min, and the detection wavelength of the DAD detector is 280 nm.

[0021] According to the present invention, preferably, the jet fuel is selected from at least one of straight-run jet fuel, hydrofined jet fuel and hydrocracking jet fuel. It can be understood that jet fuel is jet engine fuel, also known as aviation turbine fuel. For hydrofined jet fuel containing a large amount of oxygen-containing, nitrogen-containing, sulfur-containing and other heteroatom compounds, it is also difficult to accurately obtain the content of antioxidants therein by conventional methods. Generally, the composition of jet fuel is mainly chain alkanes and cycloalkanes, and may also include antioxidants, antistatic agents, antiwear agents, metal passivators, anti-icing agents, etc. Relative to the total mass of jet fuel, chain alkanes and cycloalkanes account for nearly 90wt%, and the composition and physical properties are similar to those of n-hexane, and n-hexane is usually used to simulate jet fuel.

[0022] According to the present invention, preferably, the antioxidant is a phenolic antioxidant, preferably at least one of 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-p-methylphenol and 2,6-di-tert-butylphenol. The antioxidant allowed to be added to the jet fuel specified in GB 6537-2018 is 2,6-di-tert-butyl-p-methylphenol, and general jet fuel uses 2,6-di-tert-butyl-p-methylphenol (also known as T501). The method of the present invention is also particularly suitable for the accurate determination of T501.

[0023] According to the present invention, preferably, in step (1), the content of antioxidant in the jet fuel is not less than 10 mg / L, preferably not less than 12 mg / L (for example, it can be 12-100 mg / L). Within the above range, a more accurate effect can be achieved.

[0024] According to the present invention, preferably, the terminal alkenyl sulfone is a vinyl sulfone, preferably at least one of a chain alkyl vinyl sulfone, a cycloalkane vinyl sulfone and an aromatic vinyl sulfone, more preferably at least one of a phenyl vinyl sulfone, a tolyl vinyl sulfone, a xylyl vinyl sulfone and a tritolyl vinyl sulfone. The inventors of the present invention have found in their research that when the above alkenyl sulfone is used, a more accurate effect can be obtained.

[0025] According to the present invention, preferably, in step (1), the mass ratio of terminal alkenyl sulfone to the jet fuel to be tested is (0.03-1):1, preferably (0.1-0.4):1. The amount of antioxidant added in jet fuel is strictly regulated (GB 6537-2018), ranging from 17-24 mg / L. The inventors of the present invention have found in their research that excessive addition of terminal alkenyl sulfone does not affect the accuracy of the measurement results. Adding terminal alkenyl sulfone according to the above conditions can further ensure the accuracy of the effect when the amount is small.

[0026] According to the present invention, preferably, in step (1), the solvent is selected from at least one of acetone, ethyl acetate, tetrahydrofuran, chloroform, dichloromethane, methanol and acetonitrile.

[0027] According to the present invention, preferably, in step (1), the volume ratio of the jet fuel to be tested and the solvent is (0.1-2):1, preferably (0.3-1):1.

[0028] According to the present invention, preferably, in step (1), the organic base is selected from pyridines (i.e. substituted or unsubstituted pyridine) and / or piperidines (i.e. substituted or unsubstituted piperidine), more preferably 2,6-dimethylpiperidine (DMP) and / or 4-dimethylaminopyridine (DMAP). Under the above conditions, the accuracy of the measurement result can be further guaranteed.

[0029] Preferably, in step (1), the mass ratio of the organic base to the jet fuel to be tested is (0.05-0.5):1, more preferably (0.1-0.3):1.

[0030] According to the present invention, preferably, in step (1), the mixing conditions include: temperature of 15-60°C, preferably 20-40°C (for example, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, and the range formed by any two of the above values ​​and the value within the range); time of 0.1-5 (for example, 0.1, 1, 1.5, 2, 2.3, 2.5, 3, 3.5, 4, 4.5, 5, and the range formed by any two of the above values ​​and the value within the range) min. Oscillation can be performed during the mixing process to make the system more uniform.

[0031] After the mixing is completed, the material can be left to stand for 8-15 min to cool (to room temperature) and obtain a supernatant.

[0032] It is understood that jet fuels with different known antioxidant concentrations can be taken and processed in the manner of step (1) to obtain standard chromatograms, and then a standard curve is constructed using the peak area of ​​the chromatogram and the known concentration. Then, the content of the antioxidant in the jet fuel to be tested is determined by combining the standard curve and the peak area of ​​the chromatogram obtained in step (1).

[0033] The present invention will be described in detail by way of examples below. In the following examples and comparative examples, the parameters and operating conditions of the high performance liquid chromatograph include: the high performance liquid chromatograph is equipped with a diode array detector (DAD detector), a 1260 Infinity VL quaternary pump, an injector of 0.1-900 μL, and an increment of 0.1 μL; the quaternary pump pressure range is 0-200 bar, the flow rate is up to 5 ml / min, the flow rate setting value is from 0.001 to 10.0 mL / min, and the increment is 0.001 ml / min; the diode array detector detection wavelength is 0-800 nm. Analysis conditions: the chromatographic column is a normal phase silica gel chromatographic column, the injection volume is 10 μL, the mobile phase is chromatographic grade n-hexane that has been degassed and dehydrated, the mobile phase flow rate is 1 mL / min, and the DAD detector detection wavelength is 280 nm.

[0034] In the following examples, the room temperature is about 25°C.

[0035] Preparation Example 1

[0036] Preparation of simulated oil containing T501 antioxidant (as mentioned above, the composition of jet fuel is mainly alkanes and cycloalkanes, accounting for nearly 90%, and the composition and physical properties are similar to n-hexane, and n-hexane is usually used to simulate jet fuel):

[0037] Take 0.1g T501 antioxidant (2,6-di-tert-butyl-p-methylphenol) and dissolve it in n-hexane, and use a 1000ml volumetric flask to quantify and prepare a 100mg / L mother solution. By diluting the mother solution, prepare n-hexane solutions containing antioxidants at different concentrations of 10mg / L, 20mg / L, 30mg / L, 40mg / L, and 50mg / L for the next step.

[0038] Example 1

[0039] Take 1 ml of the n-hexane solution with an antioxidant concentration of 50 mg / L obtained in Preparation Example 1, add 3 mL of dichloromethane as a solvent, add 0.1680 g of phenyl vinyl sulfone (PVS) and 0.1220 g of 4-dimethylaminopyridine (DMAP) in sequence, and then oscillate and mix the system at room temperature for a total mixing time of 2 min.

[0040] After the mixture was mixed and allowed to stand for 10 minutes, the supernatant sample 5 was taken and analyzed by high performance liquid chromatography. Compared with the chromatogram of the simulated oil before mixing with the terminal olefin sulfone, the peak corresponding to the original antioxidant disappeared, and a new characteristic peak with a retention time of 12.21 minutes appeared. The detection results are shown in Table 1.

[0041] Example 2

[0042] Take 1 ml of the n-hexane solution with an antioxidant concentration of 50 mg / L obtained in Preparation Example 1, add 3 mL of dichloromethane as a solvent, add 0.1680 g of phenyl vinyl sulfone (PVS) and 0.1220 g of triethylamine (TEA) in sequence, and then oscillate and mix the system at room temperature for a total mixing time of 2.3 min.

[0043] After the mixing was completed, the mixture was allowed to stand for 10 minutes, and the supernatant sample 5-1 was taken for high performance liquid chromatography analysis. The peak corresponding to the original antioxidant disappeared, and a new characteristic peak close to the position in Example 1 appeared. The test results are shown in Table 1.

[0044] Example 3

[0045] Take 1 ml of the n-hexane solution with an antioxidant concentration of 50 mg / L obtained in Preparation Example 1, add 3 mL of dichloromethane as a solvent, add 0.1680 g of phenyl vinyl sulfone (PVS) and 0.1220 g of 2,6-dimethylpiperidine (DMP) in sequence, and then oscillate and mix the system at room temperature for a total mixing time of 1.8 min.

[0046] After the mixing was completed, the mixture was allowed to stand for 10 minutes, and the supernatant sample 5-2 was taken for high performance liquid chromatography analysis. The peak corresponding to the original antioxidant disappeared, and a new characteristic peak similar to that in Example 1 appeared. The test results are shown in Table 1.

[0047] Example 4

[0048] 1 ml of n-hexane solution with antioxidant concentrations of 10 mg / L, 20 mg / L, 30 mg / L and 40 mg / L obtained in Preparation Example 1 was taken respectively and treated according to the steps of Example 1 to obtain Sample 1, Sample 2, Sample 3 and Sample 4. In the HPLC of the above four samples, new characteristic peaks similar to those in Example 1 appeared.

[0049] Example 5

[0050] The concentration of the antioxidant in Example 4 and the area of ​​the corresponding new peak were used to construct a standard curve. The results are shown in Figure 1 The linear relationship between the characteristic peak area and the T501 concentration is: y = 2.266x + 4.1 (where x is the T501 concentration, unit: mg / L; y is the characteristic chromatographic peak area), and the correlation coefficient is R2 =0.9958, which shows that the concentration of T501 has a good linear relationship with the characteristic peak area using this method, and the linear correlation coefficient (R 2 ) is above 0.99.

[0051] Table 1

[0052] Standard solution concentration (mg / L) Retention time of new characteristic peak (min) Example 4 Sample 1 10 12.32 Example 4 Sample 2 20 12.28 Example 4 Sample 3 30 12.19 Example 4 Sample 4 40 12.20 Example 1 50 12.21

[0053] Example 6

[0054] Take 1 ml of a real hydrorefined jet fuel sample A, add 3 mL of dichloromethane as solvent, add 0.1680 g of phenyl vinyl sulfone (PVS) and 0.1220 g of 4-dimethylaminopyridine (DMAP) in sequence, and then shake and mix the system at room temperature for a total mixing time of 2.5 min.

[0055] After the mixing was completed, the mixture was allowed to stand for 10 minutes, and the supernatant sample 6 was taken for high performance liquid chromatography analysis. The detailed test results are shown in Table 2.

[0056] Embodiment 7:

[0057] Take 1 ml of a real hydrocracking jet fuel sample B, add 3 mL of dichloromethane as solvent, add 0.1680 g of phenyl vinyl sulfone (PVS) and 0.1220 g of 4-dimethylaminopyridine (DMAP) in sequence, and then mix the system at room temperature for a total mixing time of 3 min.

[0058] After the mixed reaction was completed, the mixture was allowed to stand for 10 minutes, and the supernatant sample 7 was taken. After entering the high performance liquid chromatography analysis, the peak corresponding to the original antioxidant disappeared, and a new characteristic peak similar to that in Example 1 appeared. The detailed test results are shown in Table 2.

[0059] Embodiment 8:

[0060] Take 1 ml of a jet fuel sample C stored for 5 years, add 3 mL of dichloromethane as solvent, add 0.1680 g of phenyl vinyl sulfone (PVS) and 0.1220 g of 4-dimethylaminopyridine (DMAP) in sequence, and then shake and mix the system at room temperature for a total mixing time of 2 min.

[0061] After the mixed reaction was completed, the mixture was allowed to stand for 10 minutes, and the supernatant sample 8 was taken. After entering the high performance liquid chromatography analysis, the peak corresponding to the original antioxidant disappeared, and a new characteristic peak similar to that in Example 1 appeared. The detailed test results are shown in Table 2.

[0062] Example 9

[0063] Take 1 ml of the n-hexane solution with an antioxidant concentration of 50 mg / L obtained in Preparation Example 1, add 2 mL of chloroform as a solvent, add 0.1820 g of tolyl vinyl sulfone and 0.1220 g of 4-dimethylaminopyridine in sequence, and then shake and mix the system at room temperature for a total mixing time of 2 min.

[0064] After the mixing was completed, the mixture was allowed to stand for 10 minutes, and the supernatant sample 9 was taken for high performance liquid chromatography analysis. New characteristic peaks similar to those in Example 1 appeared, and the test results are shown in Table 1.

[0065] Example 10

[0066] Take 1 ml of the n-hexane solution with an antioxidant concentration of 50 mg / L obtained in Preparation Example 1, add 1.2 mL of ethyl acetate as solvent, add 0.1960 g of ditolyl vinyl sulfone and 0.1830 g of 4-dimethylaminopyridine in sequence, and then shake and mix the system at room temperature for a total mixing time of 2 min.

[0067] After the mixing was completed, the mixture was allowed to stand for 10 minutes, and the supernatant sample 10 was taken for high performance liquid chromatography analysis. New characteristic peaks similar to those in Example 1 appeared, and the detection results are shown in Table 1.

[0068] Embodiment 11

[0069] The method of Example 1 is followed, except that the solvent of Example 1 is replaced by methanol.

[0070] New characteristic peaks similar to those in Example 1 appeared, and the detection results are shown in Table 1.

[0071] Comparative Example 1

[0072] 1 ml of hydrorefined jet fuel sample A, 1 ml of hydrocracking jet fuel sample B, and 1 ml of jet fuel sample C stored for 5 years were taken and directly analyzed by high performance liquid chromatography. The detailed test results are shown in Table 2.

[0073] Comparative Example 2

[0074] The method of Example 1 was followed, except that phenyl vinyl sulfone was replaced by phenyl propenyl sulfone (non-terminal vinyl sulfone). A new characteristic peak similar to that in Example 1 appeared, and the detection results are shown in Table 1.

[0075] The measured concentration of the antioxidant was calculated by the standard curve obtained above and the peak area corresponding to each sample, as shown in Table 2. The recovery rate refers to 100% × measured value of antioxidant content / actual value.

[0076] Table 2

[0077]

[0078]

[0079] Among them, for sample 5-1, triethylamine was used in the treatment of Example 2. It can be seen that the scheme outside the scope of the present invention cannot obtain a higher recovery rate, that is, the accuracy is obviously poor.

[0080] It can be seen that if the three jet fuel samples A, B, and C are not treated by the present invention and are directly detected by liquid chromatography, the measured contents are inaccurate, especially the peaks of the antioxidants in the long-term stored jet fuels overlap seriously with the impurities, and the measured antioxidant content is obviously too high. After the treatment of the present invention, the antioxidant derivatives can be completely separated from the impurities and do not affect the quantification of the antioxidant. In addition, by comparing the analysis results of samples 5, 5-1, and 5-2, it can be seen that the use of 4-dimethylaminopyridine is the best.

[0081] In addition, in the above table, for Examples 6, 7 and 8, the antioxidant concentrations therein were also determined by liquid-mass spectrometry, and as a reference, the corresponding high-performance liquid chromatography recovery rate was calculated as follows: 100% × the measured value of the method of the present invention / liquid-mass spectrometry measured value; wherein, the liquid-mass spectrometry method does not include the treatment method provided by the present invention, but the jet fuel is directly measured according to the method B liquid chromatography-mass spectrometry in the national standard GB / T40496-2021 "High-performance liquid chromatography method for the determination of antioxidant content in jet fuel". It can be seen that the quantitative results of samples 6, 7, and 8 treated by the method of the present invention on the chromatogram are consistent with the antioxidant content results measured by liquid-mass spectrometry, proving that the method is reliable. In addition, if the treatment method of the present invention is not used, the antioxidant content in the hydrocracked jet fuel B can be relatively accurately determined by liquid chromatography (the error is generally within 5%), but the results of the antioxidant content in the hydrofined jet fuel A and the long-term stored jet fuel C are inaccurate and differ greatly from the results of liquid-mass spectrometry. The method provided in the present invention can accurately measure the antioxidant content in the above various jet fuels.

[0082] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for detecting antioxidants in jet fuel, characterized in that: The method includes: (1) mixing a jet fuel to be tested and a terminal olefin sulfone in the presence of a solvent; obtaining a chromatogram of a supernatant obtained after the mixing; wherein the mixing is carried out in the presence of an organic base, and the organic base contains a nitrogen-containing heterocycle; (2) taking a jet fuel with a known antioxidant concentration and treating it in the manner of step (1) to obtain a corresponding standard chromatogram; (3) Comparing the above standard chromatogram with the chromatogram obtained in step (1) to obtain the type and / or content of the antioxidant in the jet fuel.

2. The method according to claim 1, wherein: The chromatography was high performance liquid chromatography.

3. The method according to claim 1, wherein: The jet fuel is selected from at least one of straight run jet fuel, hydrofined jet fuel and hydrocracked jet fuel.

4. The method according to claim 1 or 2, wherein: The antioxidant is a phenolic antioxidant, preferably at least one of 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-p-methylphenol and 2,6-di-tert-butylphenol.

5. The method according to claim 1 or 3, wherein: In step (1), the content of antioxidant in the jet fuel is not less than 10 mg / L, preferably not less than 12 mg / L.

6. The method according to claim 1, wherein: The terminal alkenyl sulfone is a vinyl sulfone, preferably at least one of alkyl vinyl sulfone, cycloalkyl vinyl sulfone and aromatic vinyl sulfone, more preferably at least one of phenyl vinyl sulfone, tolyl vinyl sulfone, xylyl vinyl sulfone and trisyl vinyl sulfone.

7. The method according to claim 1 or 6, wherein: In step (1), the mass ratio of the terminal alkenyl sulfone to the jet fuel to be tested is (0.03-1):1, preferably (0.1-0.4):

1.

8. The method according to claim 1, wherein: In step (1), the solvent is selected from at least one of acetone, ethyl acetate, tetrahydrofuran, chloroform, dichloromethane, methanol and acetonitrile.

9. The method according to claim 1 or 8, wherein: In step (1), the volume ratio of the jet fuel to be tested and the solvent is (0.1-2):1, preferably (0.3-1):

1.

10. The method according to claim 1 or 3, wherein: In step (1), the organic base is selected from pyridines and / or piperidines, more preferably 2,6-dimethylpiperidine and / or 4-dimethylaminopyridine.

11. The method according to claim 10, wherein: In step (1), the mass ratio of the organic base to the jet fuel to be tested is (0.05-0.5):1, preferably (0.1-0.3):

1.

12. The method according to claim 1 or 3, wherein: In step (1), the mixing conditions include: temperature of 15-60°C, preferably 20-40°C; time of 0.1-5 min.

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