Qualitative analysis method for phenolic compounds and aldehyde compounds in fresh bamboo juice and application

Abstract

The invention discloses a qualitative analysis method for phenolic compounds and aldehyde compounds in fresh bamboo juice and application, and relates to the technical field of traditional Chinese medicine detection. Comprising the following steps: carrying out headspace sampling on a fresh bamboo juice sample, and analyzing by adopting a gas chromatograph-mass spectrometer. According to the method, headspace sampling is matched with a gas chromatograph-mass spectrometer to analyze a fresh bamboo juice sample, and heating conditions in a chromatographic process are matched, so that phenolic compounds and aldehyde compounds in the fresh bamboo juice can be detected at the same time, and at most seven phenolic compounds can be detected; components such as guaiacol, syringaldehyde and syringol which are considered to have potential pharmacological effects can be detected, and a more sufficient detection method is provided for quality evaluation of the fresh bamboo juice.

Description

Technical Field

[0001] The present invention relates to the technical field of traditional Chinese medicine detection, and more particularly, to a method for qualitative analysis and application of phenolic compounds and aldehyde compounds in fresh bamboo juice. Background Art

[0002] Fresh bamboo juice is a pale yellow clarified juice flowing out after heating the fresh stems of Phyllostachys nigra and its related plants of the same genus in the Gramineae family. The active ingredients of fresh bamboo juice mainly include sugars, amino acids, phenolic acids, alcohols, lignans, vitamins, and trace elements, etc. Among them, components such as guaiacol, syringaldehyde, and syringol are considered to have potential pharmacological effects. In order to determine that the curative effect of fresh bamboo juice is at a better level, it is crucial to detect the types of active ingredients in fresh bamboo juice.

[0003] However, different processing methods have a great impact on the chemical components in fresh bamboo juice. For example, during the preparation of fresh bamboo juice by the water boiling method and the steam extraction method, the process temperature is difficult to crack the lignan components, resulting in the inability to detect some active ingredients. At the same time, the existing detection methods for the types of active ingredients in fresh bamboo juice are limited, and only some active ingredients in fresh bamboo juice can be detected, which limits the comprehensive quality evaluation of fresh bamboo juice.

[0004] In view of this, the present invention is specifically proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for qualitative analysis and application of phenolic compounds and aldehyde compounds in fresh bamboo juice.

[0006] The present invention is implemented as follows:

[0007] In the first aspect, the present invention provides a method for qualitative analysis of phenolic compounds and aldehyde compounds in fresh bamboo juice, including subjecting a fresh bamboo juice sample to headspace injection and then analyzing it using a gas chromatography-mass spectrometry instrument.

[0008] The chromatographic conditions of the gas chromatography-mass spectrometry instrument include: the chromatographic column uses programmed temperature rise, the initial temperature is 30 - 40°C and is maintained for 4 - 6 min; it is heated to 40°C at a rate of 3°C / min and maintained for 3 - 6 min; it is heated to 50 - 60°C at a rate of 4 - 6°C / min and maintained for 2 - 4 min; it is heated to 110 - 125°C at a rate of 10 - 15°C / min and maintained for 3 - 6 min; it is heated to 115 - 125°C at a rate of 4 - 7°C / min and maintained for 1 - 4 min; it is heated to 140 - 145°C at a rate of 4 - 7°C / min and maintained for 0 - 4 min; it is heated to 160 - 180°C at a rate of 2 - 5°C / min and maintained for 0 - 4 min.

[0009] In an alternative embodiment, the chromatographic conditions of the gas chromatography - mass spectrometry instrument further include: the inlet temperature is 160 - 200 °C, and the split ratio of the chromatography is 8 - 12:1.

[0010] Preferably, the carrier gas for chromatographic analysis includes any one of helium and hydrogen; the carrier gas is in a constant - flow mode, and the carrier gas flow rate is 0.8 - 1.2 mL / min.

[0011] Preferably, the chromatographic column is an HP - 5MS chromatographic column.

[0012] Preferably, the specifications of the chromatographic column are 30 m × 250 μm × 0.25 μm.

[0013] In an alternative embodiment, the chromatographic conditions of the gas chromatography - mass spectrometry instrument further include: the inlet temperature is 170 - 190 °C, and the split ratio of the chromatography is 9 - 11:1.

[0014] Preferably, the carrier gas is in a constant - flow mode, and the carrier gas flow rate is 0.9 - 1.1 mL / min.

[0015] In an alternative embodiment, the parameters of headspace injection include: the sample equilibrium temperature is 60 - 100 °C, the sample equilibrium time is 110 - 130 min, and the sample loop filling time is 5 - 15 min.

[0016] Preferably, the specifications of the sample loop are 0.5 - 2.0 mL, and the sample loop equilibrium time is 0.3 - 0.7 min.

[0017] Preferably, the temperature of the transfer line is 120 - 160 °C.

[0018] Preferably, the injection time is 0.1 - 1.0 min.

[0019] In an alternative embodiment, the parameters of headspace injection include: the sample equilibrium temperature is 115 - 125 °C, and the sample equilibrium time is 8 - 12 min.

[0020] Preferably, the specifications of the sample loop are 0.5 - 1.5 mL, and the sample loop equilibrium time is 0.4 - 0.6 min.

[0021] Preferably, the temperature of the transfer line is 130 - 150 °C.

[0022] Preferably, the injection time is 0.3 - 0.7 min.

[0023] In an alternative embodiment, the mass spectrometry conditions of the gas chromatography - mass spectrometry instrument include: the auxiliary interface temperature is 250 - 290 °C, the ionization mode is EI, the ion source temperature is 200 - 250 °C, the ionization energy is 50 - 100 eV, the quadrupole temperature is 120 - 180 °C, and ion scanning is used.

[0024] In an alternative embodiment, the mass spectrometry conditions of the gas chromatography-mass spectrometry instrument include: the auxiliary interface temperature is 260-280 °C, the ionization mode is EI, the ion source temperature is 220-240 °C, the ionization energy is 60-80 eV, the quadrupole temperature is 130-160 °C, and ion scanning is used.

[0025] In an alternative embodiment, the gas chromatography-mass spectrometry instrument is an Agilent 7890A / 5975C gas chromatography-mass spectrometry instrument.

[0026] In a second aspect, the present invention provides an application of the method according to any one of the foregoing embodiments in distinguishing different processing techniques of fresh bamboo juice.

[0027] In an alternative embodiment, the phenolic compounds in fresh bamboo juice include at least one of guaiacol, 4-ethylphenol, 4-methylguaiacol, 4-ethylguaiacol, p-vinylguaiacol, syringol, and dihydroeugenol.

[0028] The aldehyde compounds in fresh bamboo juice include 5-methylfurfural or vanillin.

[0029] The present invention has the following beneficial effects:

[0030] The present invention provides a qualitative analysis method and application of phenolic compounds and aldehyde compounds in fresh bamboo juice. By using headspace injection in combination with a gas chromatography-mass spectrometry instrument to analyze fresh bamboo juice samples and combining with the temperature rising conditions during the chromatographic process, phenolic compounds and aldehyde compounds in fresh bamboo juice can be detected simultaneously, and up to 7 phenolic compounds can be detected. Components such as guaiacol, syringaldehyde, and syringol, which are considered to have potential pharmacological effects, can also be detected, providing a more comprehensive detection method for the quality evaluation of fresh bamboo juice. Moreover, this method is simple to operate, has strong repeatability, and has good application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0032] Figure 1 It is the total ion chromatogram obtained by detecting the mixed standard sample using the method of Example 1;

[0033] Figure 2 It is the total ion chromatogram obtained by detecting the fresh bamboo juice sold by a certain production enterprise 1 in Jiangxi using the method of Example 1;

[0034] Figure 3 The total ion chromatogram obtained by detecting the fresh bamboo extract sold by a production enterprise 2 in Jiangxi using the method of Example 1;

[0035] Figure 4 The total ion chromatogram obtained by detecting the fresh bamboo extract sold by a production enterprise 3 in Jiangxi using the method of Example 1;

[0036] Figure 5 The total ion chromatogram obtained by detecting the fresh bamboo extract sold by a production enterprise 4 in Jiangxi using the method of Example 1;

[0037] Figure 6 The total ion chromatogram obtained by detecting the fresh bamboo extract sold by a production enterprise 5 in Jiangxi using the method of Example 1;

[0038] Figure 7 The total ion chromatogram obtained by detecting the self-made fresh bamboo extract in the laboratory using the method of Example 1;

[0039] Figure 8 The total ion chromatogram obtained by detecting the fresh bamboo extract sold by a production enterprise 6 in Jiangxi using the method of Example 1;

[0040] Figure 9 The total ion chromatogram obtained by detecting the fresh bamboo extract sold by a production enterprise 7 using the method of Example 1;

[0041] Figure 10 The total ion chromatogram obtained by detecting the fresh bamboo extract sold by a production enterprise 8 using the method of Example 1;

[0042] Figure 11 The total ion chromatogram obtained by detecting the fresh bamboo extract sold by a production enterprise 9 using the method of Example 1;

[0043] Figure 12 The total ion chromatogram obtained by detecting the fresh bamboo extract sold by a production enterprise 10 using the method of Example 1;

[0044] Figure 13 The total ion chromatogram obtained by detecting the fresh bamboo extract sold by a production enterprise 11 using the method of Example 1;

[0045] Figure 14 The total ion chromatogram obtained by detecting the fresh bamboo extract sold by a production enterprise 12 using the method of Example 1;

[0046] Figure 15 The total ion chromatogram obtained by detecting the fresh bamboo extract sold by a production enterprise 13 using the method of Example 1;

[0047] Figure 16 The GC-MS total ion chromatogram obtained by detecting the fresh bamboo juice sold by a certain production enterprise 14 in Jiangxi using the method of Example 1;

[0048] Figure 17 The GC-MS total ion chromatogram obtained by detecting the fresh bamboo juice sold by a certain production enterprise 15 using the method of Example 1;

[0049] Figure 18 The GC-MS total ion chromatogram obtained by detecting the fresh bamboo juice sold by a certain production enterprise 16 in Jiangxi using the method of Example 1;

[0050] Figure 19 The GC-MS total ion chromatogram obtained by detecting the self-made fresh bamboo juice in the laboratory using the method of Comparative Example 1;

[0051] Figure 20 The GC-MS total ion chromatogram obtained by detecting the self-made fresh bamboo juice in the laboratory using the method of Comparative Example 2. Detailed implementation manners

[0052] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. For those not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. Those reagents or instruments not specified by the manufacturer can be obtained as conventional products through commercial purchase.

[0053] The features and properties of the present invention will be further described in detail below in conjunction with the embodiments.

[0054] Due to defects such as high temperature and too fast heating rate in the existing detection methods for the types of active ingredients in fresh bamboo juice, the number of detected types of active ingredients is limited, and only a small number of phenolic compounds can be detected, such as phenol, guaiacol, 4-methylguaiacol, 4-ethylguaiacol and 6-methoxyguaiacol. It is difficult to comprehensively evaluate the quality of fresh bamboo juice to determine the processing method of fresh bamboo juice. Therefore, the inventor proposes the following solutions.

[0055] In a first aspect, the present invention provides a qualitative analysis method for phenolic compounds and aldehyde compounds in fresh bamboo juice, including analyzing the fresh bamboo juice sample by headspace injection and then using a gas chromatography-mass spectrometry instrument.

[0056] The chromatographic conditions of the gas chromatography-mass spectrometry (GC-MS) instrument include: The chromatographic column uses programmed temperature rising. The initial temperature is 30 - 40 °C and is maintained for 4 - 6 min; it is heated to 40 °C at a rate of 3 °C / min and maintained for 3 - 6 min; it is heated to 50 - 60 °C at a rate of 4 - 6 °C / min and maintained for 2 - 4 min; it is heated to 110 - 125 °C at a rate of 10 - 15 °C / min and maintained for 3 - 6 min; it is heated to 115 - 125 °C at a rate of 4 - 7 °C / min and maintained for 1 - 4 min; it is heated to 140 - 145 °C at a rate of 4 - 7 °C / min and maintained for 0 - 4 min; it is heated to 160 - 180 °C at a rate of 2 - 5 °C / min and maintained for 0 - 4 min.

[0057] By using headspace injection in combination with GC-MS to analyze the fresh bamboo extract sample and matching the temperature rising conditions during the chromatographic process, phenolic compounds and aldehyde compounds in the fresh bamboo extract can be detected simultaneously, and up to 7 phenolic compounds can be detected. Components such as guaiacol, syringaldehyde, and syringol, which are considered to have potential pharmacological effects, can also be detected, providing a more comprehensive detection method for the quality evaluation of fresh bamboo extract.

[0058] In an alternative embodiment, the chromatographic conditions of the GC-MS instrument further include: The inlet temperature is 160 - 200 °C, and the split ratio of the chromatography is 8 - 12:1.

[0059] Preferably, the carrier gas for chromatographic analysis includes any one of helium and hydrogen; the carrier gas is in a constant flow mode, and the carrier gas flow rate is 0.8 - 1.2 mL / min.

[0060] Preferably, the chromatographic column is an HP-5MS chromatographic column.

[0061] Preferably, the specification of the chromatographic column is 30 m × 250 μm × 0.25 μm.

[0062] In an alternative embodiment, the chromatographic conditions of the GC-MS instrument further include: The inlet temperature is 170 - 190 °C, and the split ratio of the chromatography is 9 - 11:1.

[0063] Preferably, the carrier gas is in a constant flow mode, and the carrier gas flow rate is 0.9 - 1.1 mL / min.

[0064] By controlling the chromatographic parameters within the above ranges, the detection accuracy of phenolic components and aldehyde components can be improved, and the types and quantities of detected components can be increased.

[0065] In an alternative embodiment, the parameters of headspace injection include: The sample equilibrium temperature is 60 - 100 °C, the sample equilibrium time is 110 - 130 min, and the sample agitation time is 5 - 15 min.

[0066] Preferably, the specification of the sample loop is 0.5 - 2.0 mL, and the sample loop equilibration time is 0.3 - 0.7 min.

[0067] Preferably, the temperature of the transfer line is 120 - 160 °C.

[0068] Preferably, the injection time is 0.1 - 1.0 min.

[0069] In an alternative embodiment, the parameters of headspace injection include: sample equilibration temperature 115 - 125 °C, sample equilibration time 8 - 12 min.

[0070] Preferably, the specification of the sample loop is 0.5 - 1.5 mL, and the sample loop equilibration time is 0.4 - 0.6 min.

[0071] Preferably, the temperature of the transfer line is 130 - 150 °C.

[0072] Preferably, the injection time is 0.3 - 0.7 min.

[0073] By adopting headspace injection, the sample pretreatment process can be simplified, the analysis efficiency of the sample can be improved, and the sensitivity and accuracy of sample analysis can be enhanced. At the same time, controlling the sample initial temperature and heating rate parameters within the above ranges can effectively prevent component loss. The types and contents of detected components can be increased. When the parameters are too high, the components will be lost.

[0074] In an alternative embodiment, the mass spectrometry conditions of the gas chromatography - mass spectrometry instrument include: auxiliary interface temperature 250 - 290 °C, ionization mode EI, ion source temperature 200 - 250 °C, ionization energy 50 - 100 eV, quadrupole temperature 120 - 180 °C, and ion scanning is adopted.

[0075] In an alternative embodiment, the mass spectrometry conditions of the gas chromatography - mass spectrometry instrument include: auxiliary interface temperature 260 - 280 °C, ionization mode EI, ion source temperature 220 - 240 °C, ionization energy 60 - 80 eV, quadrupole temperature 130 - 160 °C, and ion scanning is adopted.

[0076] By controlling the mass spectrometry conditions within the above ranges, it can be ensured that the analyte (fresh bamboo juice sample) can be vaporized without decomposition during vaporization.

[0077] In an alternative embodiment, the gas chromatography - mass spectrometry instrument is an Agilent 7890A / 5975C type gas chromatography - mass spectrometry instrument.

[0078] In a second aspect, the present invention provides an application of the method according to any one of the foregoing embodiments in differentiating different processing techniques of fresh bamboo juice.

[0079] In an alternative embodiment, the phenolic compounds in fresh bamboo juice include at least one of guaiacol, 4-ethylphenol, 4-methylguaiacol, 4-ethylguaiacol, p-vinylguaiacol, syringol, and dihydroeugenol.

[0080] The aldehyde compounds in fresh bamboo juice include 5-methylfurfural or vanillin.

[0081] Example 1

[0082] This example provides a qualitative analysis method for phenolic and aldehyde compounds in fresh bamboo juice, including the following steps:

[0083] S01. Headspace injection: Take a fresh bamboo juice sample and perform headspace injection. The sample equilibrium temperature is 120 °C, and the sample equilibrium time is 10 min. The specification of the sample loop is 1.0 mL, and the sample loop equilibrium time is 0.5 min. The temperature of the transfer line is 140 °C, and the injection time is 0.5 min.

[0084] S02. Gas chromatography-mass spectrometry (GC-MS) analysis: Use an Agilent 7890A / 5975C type GC-MS instrument to perform chromatographic analysis and mass spectrometry analysis on the fresh bamboo juice sample.

[0085] S021. Chromatography: The chromatographic column is an HP-5MS chromatographic column with a specification of 30 m × 250 μm × 0.25 μm. The carrier gas is helium, and the constant flow mode is adopted. The carrier gas flow rate is 1.0 mL / min. The injection port temperature is 180 °C, and the chromatographic split ratio is 10:1. The chromatographic column is programmed to increase the temperature. The initial temperature is 30 - 40 °C and is maintained for 4 - 6 min; the temperature is increased to 40 °C at a rate of 3 °C / min and maintained for 3 - 6 min; the temperature is increased to 60 °C at a rate of 5 °C / min and maintained for 2 min; the temperature is increased to 1150 °C at a rate of 10 °C / min and maintained for 3 min; the temperature is increased to 120 °C at a rate of 6 °C / min and maintained for 4 min; the temperature is increased to 125 °C at a rate of 6 °C and maintained for 4 min; the temperature is increased to 145 °C at a rate of 6 °C / min and maintained for 0 min; the temperature is increased to 160 °C at a rate of 3 °C / min and maintained for 4 min.

[0086] S022. Mass spectrometry: The auxiliary interface temperature is 270 °C, the ionization mode is electron impact source (EI), the ion source temperature is 230 °C, the ionization energy is 70 eV, the quadrupole temperature is 150 °C, and ion scanning is adopted.

[0087] Test Example 1

[0088] Sample preparation

[0089] 1) Prepare a mixed standard sample containing aldehyde and phenolic compounds in fresh bamboo juice.

[0090] Prepare a mixed standard sample using the reference standards of the following substances:

[0091] Guaiacol (batch number: 111510 - 202205, content calculated as 100%), 4 - Ethylphenol (Chengdu Kloma Biotechnology Co., Ltd., batch number: CHB240123; content calculated as 98%), 4 - Methylguaiacol (Chengdu Kloma Biotechnology Co., Ltd., batch number: CHB210223; content calculated as 98%), 4 - Ethylguaiacol (Chengdu Kloma Biotechnology Co., Ltd., batch number: CHB220407; content calculated as 98%), p - Vinylguaiacol (Chengdu Kloma Biotechnology Co., Ltd.; batch number: CHB240303, content calculated as 98%), Syringol (National Institutes for Food and Drug Control, batch number: 112114 - 202401, content for identification), Dihydroeugenol (Chengdu Kloma Biotechnology Co., Ltd., batch number: CHB240308, content calculated as 98%), 5 - Methylfurfural (Chengdu Kloma Biotechnology Co., Ltd., batch number: CHB210222, content calculated as 98%) and Vanillin (National Institutes for Food and Drug Control, batch number: 100491 - 202203, content calculated as 99.3%).

[0092] The preparation method of the mixed standard sample includes: accurately weigh Guaiacol, p - Vinylguaiacol, 4 - Ethylguaiacol, 4 - Methylguaiacol, 4 - Ethylphenol, Dihydroeugenol, Syringol, 5 - Methylfurfural and Vanillin and dissolve them in an ethanol solution to obtain the mixed standard sample. Among them, the concentration of each component is: Guaiacol 4.06 mg / ml, p - Vinylguaiacol 54.60 mg / ml, 4 - Ethylguaiacol 9.60 mg / ml, 4 - Methylguaiacol 11.50 mg / ml, 4 - Ethylphenol 71.0 mg / ml, Dihydroeugenol 12.00 mg / ml, Syringol 9.60 mg / ml, 5 - Methylfurfural 9.06 mg / ml and Vanillin 100.20 mg / ml. Store it in a refrigerator at 4°C for future use.

[0093] 2) Fresh Bamboo Juice prepared in the laboratory: Prepare fresh bamboo juice according to "Jiangxi Province Traditional Chinese Medicine Decoction Pieces Processing Specification (2023 Edition)" compiled by Jiangxi Provincial Drug Administration. Use the dry distillation method to cut fresh bamboo stalks into bamboo sections with both ends removed of joints, break them into pieces, wash, and drain; place them in a dry distillation tank body, heat, collect bamboo juice,

[0094] filter it, boil it, and add an appropriate amount of preservative to obtain it.

[0095] 3) Purchase 16 kinds of fresh bamboo juice sold by different enterprises in the market as fresh bamboo juice samples.

[0096] The mixed standard sample, the self-made fresh bamboo juice in the laboratory, and the commercially available fresh bamboo juice were all used as the fresh bamboo juice samples to be detected, and the method of Example 1 was used for determination.

[0097] Among them, 7 phenolic compounds including guaiacol, 4-ethylphenol, 4-methylguaiacol, 4-ethylguaiacol, p-vinylguaiacol, syringol, and dihydroeugenol, and 2 aldehyde compounds including 5-methylfurfural and vanillin were detected in the mixed standard sample, and the detection results are as Figure 1 shown.

[0098] The detection results of the self-made fresh bamboo juice in the laboratory and the commercially available fresh bamboo juice were compared with the detection results of the mixed standard sample, and the types of phenolic compounds and aldehyde compounds contained in the self-made fresh bamboo juice in the laboratory and the commercially available fresh bamboo juice were analyzed to obtain the results shown in Table 1 and Figures 2 to 18 shown.

[0099] Table 1 Types of phenolic compounds and aldehyde compounds in different fresh bamboo juice samples

[0100]

[0101]

[0102] As Figure 1 can be seen, the method provided by the embodiment of the present invention can detect 7 phenolic compounds including guaiacol, 4-ethylphenol, 4-methylguaiacol, 4-ethylguaiacol, p-vinylguaiacol, syringol, and dihydroeugenol, and 2 aldehyde compounds including 5-methylfurfural and vanillin, and the evaluation of the active ingredients in fresh bamboo juice is more comprehensive.

[0103] As Figures 2 to 18 well as Table 1 shows, by using the same method as in the embodiment of the present invention to detect the types of phenolic compounds and aldehyde compounds in the fresh bamboo juice prepared by different processing techniques, the obtained component types are significantly different, which can be used to distinguish the processing techniques of different fresh bamboo juices and can also be used as a supplementary proof of the efficacy and effectiveness of fresh bamboo juice.

[0104] Comparative Example 1

[0105] This comparative example provides a qualitative analysis method for phenolic compounds and aldehyde compounds in fresh bamboo juice. The specific steps are similar to those of Example 1, except that: the chromatographic column uses programmed temperature rise, the initial temperature is 80 °C, and the holding time is 0 min; it is heated to 100 °C at a rate of 5 °C / min and held for 5 min; it is heated to 120 °C at a rate of 10 °C / min and held for 2 min; it is heated to 150 °C at a rate of 5 °C / min and held for 5 min; it is heated to 170 °C at a rate of 5 °C / min and held for 1 min.

[0106] Comparative Example 2

[0107] This comparative example provides a qualitative analysis method for phenolic compounds and aldehyde compounds in fresh bamboo juice. The direct injection method is adopted, and the chromatographic column is programmed to increase the temperature. It is 30 - 40 °C and maintained for 4 - 6 min; the temperature is increased to 40 °C at a rate of 3 °C / min and maintained for 3 - 6 min; the temperature is increased to 60 °C at a rate of 5 °C / min and maintained for 2 min; the temperature is increased to 115 °C at a rate of 10 °C / min and maintained for 3 min; the temperature is increased to 145 °C at a rate of 6 °C / min and maintained for 0 min; the temperature is increased to 160 °C at a rate of 3 °C / min and maintained for 4 min; the temperature is increased to 300 °C at a rate of 5 °C / min and maintained for 0 min.

[0108] Test Example 2

[0109] The methods of Example 1, Comparative Example 1 and Comparative Example 2 were respectively used to detect the self-made fresh bamboo juice samples in Test Example 1, and the results are shown in Table 2 and Figures 19 to 20 as shown.

[0110] Table 2 Types of compounds detected in fresh bamboo juice samples by different methods

[0111]

[0112] From Table 2 and Figures 19 to 20 it can be seen that more types of phenolic compounds and / or aldehyde compounds can be detected in the fresh bamboo juice samples detected by the method provided in this example. While for the same fresh bamboo juice samples detected by the methods of the comparative examples, the types of phenolic compounds and / or aldehyde compounds detected are less than those of the method of the example. This shows that the method provided by the embodiment of the present invention can detect more active ingredients in fresh bamboo juice, can be used to evaluate the quality of fresh bamboo juice, and can also be used as a means to distinguish the processing techniques of commercially available fresh bamboo juice.

[0113] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A qualitative analysis method for phenolic compounds and aldehyde compounds in fresh bamboo juice, characterized in that, It includes analyzing the fresh bamboo juice sample by headspace injection and then using a gas chromatography-mass spectrometry (GC-MS) instrument. The chromatographic conditions of the GC-MS instrument include: the chromatographic column uses programmed temperature rise. The initial temperature is 30 - 40 °C and is maintained for 4 - 6 min; it is heated to 40 °C at a rate of 3 °C / min and maintained for 3 - 6 min; it is heated to 50 - 60 °C at a rate of 4 - 6 °C / min and maintained for 2 - 4 min; it is heated to 110 - 125 °C at a rate of 10 - 15 °C / min and maintained for 3 - 6 min; it is heated to 115 - 125 °C at a rate of 4 - 7 °C / min and maintained for 1 - 4 min; it is heated to 140 - 145 °C at a rate of 4 - 7 °C / min and maintained for 0 - 4 min; it is heated to 160 - 180 °C at a rate of 2 - 5 °C / min and maintained for 0 - 4 min.

2. The method according to claim 1, characterized in that The chromatographic conditions of the GC-MS instrument also include: the inlet temperature is 160 - 200 °C, and the split ratio of the chromatography is 8 - 12:1; Preferably, the carrier gas for chromatographic analysis includes any one of helium and hydrogen; the carrier gas is in a constant flow mode, and the carrier gas flow rate is 0.8 - 1.2 mL / min; Preferably, the chromatographic column is an HP-5MS chromatographic column; Preferably, the specification of the chromatographic column is 30 m × 250 μm × 0.25 μm.

3. The method according to claim 1, characterized in that, The chromatographic conditions of the GC-MS instrument also include: the inlet temperature is 170 - 190 °C, and the split ratio of the chromatography is 9 - 11:1; Preferably, the carrier gas is in a constant flow mode, and the carrier gas flow rate is 0.9 - 1.1 mL / min.

4. The method according to claim 1, wherein The parameters of the headspace injection include: the sample equilibrium temperature is 110 - 130 °C, and the sample equilibrium time is 5 - 15 min; Preferably, the specification of the sample loop is 0.5 - 2.0 mL, and the sample loop equilibrium time is 0.3 - 0.7 min; Preferably, the temperature of the transfer line is 120 - 160 °C; Preferably, the injection time is 0.1 - 1.0 min.

5. The method according to claim 1, wherein The parameters of the headspace injection include: the sample equilibrium temperature is 115 - 125 °C, and the sample equilibrium time is 8 - 12 min; Preferably, the specification of the sample loop is 0.5 - 1.5 mL, and the sample loop equilibrium time is 0.4 - 0.6 min; Preferably, the temperature of the transfer line is 130 - 150 °C; Preferably, the injection time is 0.3 - 0.7 min.

6. The method according to claim 1, wherein The mass spectrometry conditions of the GC-MS instrument include: the auxiliary interface temperature is 250 - 290 °C, the ionization mode is EI, the ion source temperature is 200 - 250 °C, the ionization energy is 50 - 100 eV, the quadrupole temperature is 120 - 180 °C, and ion scanning is used.

7. The method according to claim 1, characterized in that The mass spectrometry conditions of the GC-MS instrument include: the auxiliary interface temperature is 260 - 280 °C, the ionization mode is EI, the ion source temperature is 220 - 240 °C, the ionization energy is 60 - 80 eV, the quadrupole temperature is 130 - 160 °C, and ion scanning is used.

8. The method according to any one of claims 2 to 7, characterized in that, The GC-MS instrument is an Agilent 7890A / 5975C type GC-MS instrument.

9. Application of the method according to any one of claims 1 - 8 in differentiating different processing techniques of fresh bamboo juice.

10. The application according to claim 9, characterized in that The phenolic compounds in the fresh bamboo juice include at least one of guaiacol, 4-ethylphenol, 4-methylguaiacol, 4-ethylguaiacol, p-vinylguaiacol, syringol, and dihydroeugenol; The aldehyde compounds in the fresh bamboo juice include 5-methylfurfural or vanillin.

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