Aromatic ester compound adsorbent as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of food science, and particularly relates to an aromatic ester compound adsorbent as well as a preparation method and application thereof. The preparation method of the aromatic ester compound adsorbent comprises the following steps: mixing and dispersing 1, 3, 5-tri (4-aminophenyl) benzene, 2, 3-dihydroxy terephthalaldehyde and Fe3O4 (Na3Cit); after dispersing, adding acetic acid to react to obtain an aromatic ester compound adsorbent; when the aromatic ester compound adsorbent is used for solid-phase extraction and detection of aromatic ester compounds in white spirit, the linear range is 0.01 mg / L-20 mg / L, the LOD is 0.11 mu g / L-0. 15 mu g / L, the LOQ is 0.35 mu g / L-0. 49 mu g / L, and the recovery rate is 85.55%-97.09%; compared with a liquid-liquid extraction and detection method, the method provided by the invention has the advantages of shorter extraction time, wider linear range and lower LOD and LOQ.

Description

Technical Field

[0001] The invention belongs to the field of food science and technology, and specifically relates to an aromatic ester compound adsorbent and a preparation method and application thereof. Background Art

[0002] Aromatic esters in liquor usually have unique aromas, including "rose", "honey", "sweet" or "fruity". Although their content in liquor is very small, they have a significant impact on the overall flavor of liquor due to their low threshold, strong aroma intensity and long aroma retention time. Aromatic esters, especially ethyl benzoate, ethyl phenylacetate, phenylethyl acetate and ethyl phenylpropionate, are important quality factors of liquor. They are not only important aroma compounds of liquor, but also provide a material basis for the identification of liquor production areas and ensure the authenticity of liquor. In addition, they also play an important role in the perception of aroma during the drinking process of liquor. Therefore, it is of great theoretical and practical significance to achieve accurate analysis of aromatic esters in liquor.

[0003] Among them, the proper extraction of trace components is a key step in the accurate analysis of aroma compounds in liquor. Due to the trace levels of aromatic esters in liquor and the complexity of the analytical matrix, in order to ensure the accuracy, precision, sensitivity and authenticity of its detection, appropriate pretreatment methods are required for extraction and enrichment before instrumental analysis. At present, a variety of pretreatment methods have been established to extract and enrich aromatic esters in liquor, but most of them have defects such as complex operation, long time consumption, lack of specificity or inaccurate quantification, such as liquid-liquid extraction method.

[0004] Magnetic solid-phase extraction (MSPE) technology has the advantages of being fast, green, simple, and targeted, and is a potential candidate method for the accurate detection of aromatic esters in liquor. Magnetic extraction materials are the core of MSPE technology and the key factor in determining the extraction and separation efficiency. Covalent organic frameworks (COFs) materials have become a hot topic in adsorbent research due to their excellent properties such as easy structural regulation, easy material modification, large specific surface area, good adsorption performance, high thermochemical stability, and low skeleton density. Summary of the invention

[0005] Based on this, the present invention has developed a covalent organic framework (COFs) material Fe3O4@TPB-Dha, which can be used as an adsorbent combined with GC-MS to achieve rapid and accurate detection of aromatic ester compounds (such as ethyl benzoate, ethyl phenylacetate, phenylethyl acetate and ethyl phenylpropionate) in liquor.

[0006] In order to achieve the above object, the present invention can adopt the following technical solutions:

[0007] On one hand, the present invention provides a method for preparing an aromatic ester compound adsorbent, comprising: mixing 1,3,5-tris(4-aminophenyl)benzene, 2,3-dihydroxyterephthalaldehyde and Fe3O4(Na3Cit), dispersing; adding acetic acid after dispersion to react to obtain the aromatic ester compound adsorbent; the preparation method of Fe3O4(Na3Cit) comprises: mixing FeCl3·6H2O, sodium citrate and sodium acetate in an ethanol environment; and then performing a hydrothermal reaction to obtain Fe3O4(Na3Cit).

[0008] Another aspect of the present invention provides an aromatic ester compound adsorbent, which is prepared by the preparation method of the present invention.

[0009] On the other hand, the present invention provides a method for extracting aromatic ester compounds in white wine, comprising: mixing white wine and the aromatic ester compound adsorbent of the present invention, extracting, separating and discarding the supernatant to obtain a reaction mixture; dispersing the reaction mixture in a desorption solvent for desorption, and separating the supernatant to obtain an aromatic ester compound extract.

[0010] Preferably, the aromatic ester compound comprises one or more of ethyl benzoate, ethyl phenylacetate, phenylethyl acetate and ethyl phenylpropionate.

[0011] Preferably, the above extraction method satisfies one or more of the following conditions: (a) before mixing the liquor and the aromatic ester compound adsorbent, the alcohol content of the liquor is adjusted to 6°-26°; (b) before mixing the liquor and the aromatic ester compound adsorbent, the pH of the liquor is adjusted to 3-10; (c) when the liquor and the aromatic ester compound adsorbent are mixed, the concentration of the aromatic ester compound adsorbent is 3mg / mL-7mg / mL; (d) the extraction is a vortex extraction; (e) the extraction time is 2min-20min; (f) the desorption solvent comprises ethyl acetate and formic acid, and the volume proportion of formic acid is 0.3%-3%; (g) the desorption time is 9min-18min.

[0012] More preferably, the above extraction method satisfies one or more of the following conditions: (i) before mixing the liquor and the aromatic ester compound adsorbent, the alcohol content of the liquor is adjusted to 15°; (ii) before mixing the liquor and the aromatic ester compound adsorbent, the pH of the liquor is adjusted to 4; (iii) when the liquor and the aromatic ester compound adsorbent are mixed, the concentration of the aromatic ester compound adsorbent is 5 mg / mL; (iv) the extraction time is 3 min-10 min; (v) the desorption solvent comprises ethyl acetate and formic acid, and the volume proportion of formic acid is 1%; (vi) the desorption time is 15 min.

[0013] More preferably, the extraction time is 4 minutes.

[0014] In another aspect, the present invention provides a method for detecting aromatic ester compounds in liquor, comprising: (1) extracting aromatic ester compounds from the liquor to be detected by the extraction method of the present invention to obtain an extract; (2) detecting the peak area of ​​the aromatic ester compounds in the liquor to be detected by the extract using a GC-MS method; and (3) calculating the concentration of the aromatic ester compounds in the liquor to be detected based on a standard curve of aromatic ester compound standards and peak areas.

[0015] Preferably, the gas chromatography conditions in the above-mentioned GC-MS method include: DB-WAX capillary column, 30m×0.25mm, 0.25μm; and / or temperature program: initial temperature 40°C, increased to 100°C at 15.0°C / min, and maintained for 3.0min; and / or increased to 240°C at 20.0°C / min, and maintained for 1.0min; and / or injection port temperature: 250°C; and / or carrier gas: He (99.999%); and / or constant flow: column flow rate is 1.0mL / min; and / or split ratio: 20:1; and / or injection volume: 1.0μL.

[0016] Preferably, the mass spectrometry conditions in the above GC-MS method include: the ionization mode is electron impact ionization; and / or the electron energy is 70 eV; and / or the mass spectrometer detector temperature is 250° C.; and / or the full scan mode (FullScan) is adopted; and / or the mass scan range is 50-500 m / z, and the dwell time is 0.2 s; and / or the solvent delay is 8 min; and / or the selected ion (SIM) mode is adopted; and / or the quantitative ions are as follows: 77, 105, 122, 150 for ethyl benzoate, 91, 164, 165 for ethyl phenylacetate, 104, 105, 164 for phenylethyl acetate, and 91, 104, 107, 178 for ethyl phenylpropionate.

[0017] The beneficial effects of the present invention include: solid phase extraction and detection of aromatic ester compounds in liquor based on the aromatic ester compound adsorbent provided by the present invention, with a linear range of 0.01 mg / L-20 mg / L, an LOD of 0.11 μg / L-0.15 μg / L, a LOQ of 0.35 μg / L-0.49 μg / L, and a recovery rate of 85.55%-97.09%; compared with the liquid-liquid extraction and detection method, the extraction time is shorter, the linear range is wider, and the LOD and LOQ are lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the process of magnetic solid phase extraction of the present invention;

[0019] Figure 2 The experimental results of Fe3O4@TPB-Dha addition in the extraction process of the present invention;

[0020] Figure 3 The test conditions of the pH value of the simulated wine sample during the extraction process of the present invention;

[0021] Figure 4 is the zeta potential of Fe3O4@TPB-Dha of the present invention;

[0022] Figure 5 This is the adsorption time test results during the extraction process of the present invention;

[0023] Figure 6 The test results of the desorption solvent type in the desorption process of the present invention;

[0024] Figure 7 The test results of the pH value of the desorption solvent in the desorption process of the present invention;

[0025] Figure 8 This is the desorption time test situation in the desorption process of the present invention. DETAILED DESCRIPTION

[0026] The examples are provided to better illustrate the present invention, but the present invention is not limited to the examples. Therefore, those skilled in the art may make non-essential improvements and adjustments to the implementation scheme according to the above invention content, which still fall within the protection scope of the present invention.

[0027] The terms used herein are only used to describe specific embodiments and are not intended to limit the present disclosure. Unless the context has a significantly different meaning, expressions in the singular include expressions in the plural. As used herein, it should be understood that terms such as "include", "have", "include" are intended to indicate the presence of features, numbers, operations, materials, or combinations. The terms of the present invention are disclosed in the specification, and are not intended to exclude the possibility that one or more other features, numbers, operations, materials, or combinations thereof may exist or may be added. As used herein, " / " may be interpreted as "and" or "or", depending on the circumstances.

[0028] The embodiment of the present invention provides a method for preparing an aromatic ester compound adsorbent, comprising: mixing 1,3,5-tris(4-aminophenyl)benzene, 2,3-dihydroxyterephthalaldehyde and Fe3O4(Na3Cit), and dispersing; adding acetic acid after dispersion to react to obtain the aromatic ester compound adsorbent; the preparation method of Fe3O4(Na3Cit) comprises: mixing FeCl3·6H2O, sodium citrate and sodium acetate in an ethanol environment; and then performing a hydrothermal reaction to obtain Fe3O4(Na3Cit).

[0029] It should be noted that the aromatic ester compound adsorbent in the present invention is magnetic, which can be more convenient during desorption; in addition, it should be understood that in the above preparation method, the temperature of the hydrothermal reaction can be 150°C-200°C, such as 160°C, 170°C, 180°C or 190°C, and the reaction time can be 10h-15h, such as 11h, 12h, 13h or 14h; in addition, after FeCl3·6H2O, sodium citrate and sodium acetate are mixed in an ethanol environment, they need to be washed with ethanol and ultrapure water respectively until neutral before hydrothermal reaction; in addition, dispersion can be carried out by stirring or the like; 1,3,5-tris(4-aminophenyl)benzene, 2,3-dihydroxyterephthalaldehyde and Fe3O4(Na3Cit) can be dissolved in dimethyl sulfoxide (DMSO) for dispersion and reaction.

[0030] In some specific examples, the preparation method of Fe3O4 (Na3Cit) includes: first, taking V1mL ethylene glycol and V1-2V1mg / mL FeCl3·6H2O particles to mix, then adding 0.25V1-0.5V1mg / mL anhydrous sodium citrate, stirring in a water bath above 70°C until dissolved. Continue to add V1-1.5V1mg / mL anhydrous sodium acetate, stir until dissolved, and react at 200°C for 10h. Then wash with ethanol and ultrapure water respectively until neutral, and vacuum freeze until dry to obtain Fe3O4 (Na3Cit) nanoparticles. Next, V1-1.5V1mg of Fe3O4(Na3Cit) powder, 0.02V1-0.1V1mg / mL of 1,3,5-tri(4-aminophenyl)benzene (TPB) powder and 0.03V1-0.1V1mg / mL of 2,3-dihydroxyterephthalaldehyde (Dha) powder were dispersed in 0.2V1-0.7V1ml of dimethyl sulfoxide (DMSO), and 0.01V1-0.1V1ml of acetic acid (99%, 17.5mol / L) was added dropwise. The mixture was incubated and separated with the aid of a magnet to obtain a solid product. The solid product was washed with tetrahydrofuran, methanol and ultrapure water until neutral, respectively, and vacuum frozen to dryness to obtain Fe3O4@TPB-Dha nanomaterials.

[0031] The embodiment of the present invention further provides an aromatic ester compound adsorbent, which is prepared by the preparation method of the present invention.

[0032] It should be noted that the aromatic ester compound adsorption has excellent adsorption capacity for aromatic ester compounds, and can efficiently and fully separate and enrich aromatic ester compounds, which is more conducive to the subsequent qualitative or quantitative detection of aromatic ester compounds in liquor.

[0033] An embodiment of the present invention also provides a method for extracting aromatic ester compounds in white wine, comprising: mixing white wine and the aromatic ester compound adsorbent of the present invention, extracting, separating and discarding the supernatant to obtain a reaction mixture; dispersing the reaction mixture in a desorption solvent for desorption, and separating the supernatant to obtain an aromatic ester compound extract.

[0034] It should be noted that the effect of extracting aromatic ester compounds in liquor by using the aromatic ester compound adsorbent of the present invention is better than the liquid-liquid extraction effect in the prior art.

[0035] In some specific examples, the aromatic ester compound includes one or more of ethyl benzoate, ethyl phenylacetate, phenylethyl acetate and ethyl phenylpropionate.

[0036] In some specific examples, the above extraction method satisfies one or more of the following conditions:

[0037] (a) Before mixing the liquor and the aromatic ester compound adsorbent, the alcohol content of the liquor is adjusted to 6°-26°, such as 7°, 10°, 15°, 20° or 25°, etc. Specifically, the alcohol content of the liquor refers to the volume percentage of ethanol;

[0038] (b) before mixing the liquor and the aromatic ester compound adsorbent, adjusting the pH of the liquor to 3-10, such as 4, 5, 6, 7, 8 or 9;

[0039] (c) mixing liquor and an aromatic ester compound adsorbent, wherein the concentration of the aromatic ester compound adsorbent is 3 mg / mL-7 mg / mL, such as 4 mg / mL, 5 mg / mL or 6 mg / mL;

[0040] (d) the extraction is vortex extraction; specifically, the extraction method;

[0041] (e) the extraction time is 2 min to 20 min, such as 5 min, 7 min, 10 min, 13 min, 15 min, 17 min or 19 min;

[0042] (f) the desorption solvent comprises ethyl acetate and formic acid, and the volume percentage of formic acid is 0.3%-3%, such as 0.6%, 0.8%, 1%, 1.3%, 1.5%, 1.7%, 2%, 2.3%, 2.5%, 2.7% or 2.9%;

[0043] (g) The desorption time is 9 min to 18 min, such as 10 min, 12 min, 15 min or 17 min.

[0044] In some specific examples, the above extraction method satisfies one or more of the following conditions:

[0045] (i) before mixing the liquor and the aromatic ester compound adsorbent, the alcohol content of the liquor is adjusted to 15°; specifically, the extraction effect when the alcohol content is adjusted to 15° is better than that of other ratios;

[0046] (ii) before mixing the liquor and the aromatic ester compound adsorbent, the pH of the liquor is adjusted to 4; specifically, the extraction effect of adjusting the pH of the liquor to 4 is better than that of other pH values;

[0047] (iii) liquor and aromatic ester compound adsorbent are mixed, and the concentration of the aromatic ester compound adsorbent is 5 mg / mL; specifically, at this concentration, the extraction effect is better than that at other concentrations;

[0048] (iv) the extraction time is 3 min to 10 min, such as 4 min, 5 min, 6 min, 7 min, 8 min or 9 min;

[0049] (v) the desorption solvent comprises ethyl acetate and formic acid, wherein the volume percentage of formic acid is 1%;

[0050] (vi) The desorption time is 15 min; specifically, the desorption effect of this desorption time is better than that of other desorption times.

[0051] In some specific examples, the extraction time is 4 minutes; specifically, an extraction time of 4 minutes can obtain an excellent extraction effect in a shorter time.

[0052] The embodiment of the present invention also provides a method for detecting aromatic ester compounds in white wine, comprising: (1) extracting aromatic ester compounds from the white wine to be detected by the extraction method of the present invention to obtain an extract; (2) using the extract to detect the peak area of ​​the aromatic ester compounds in the white wine to be detected by the GC-MS method; (3) calculating the concentration of the aromatic ester compounds in the white wine to be detected based on a standard curve of aromatic ester compound standards and peak areas.

[0053] It should be noted that in addition to the quantitative detection of aromatic ester compounds in liquor, qualitative detection can also be performed. Qualitative detection can be tested through the retention index and mass spectrometry fragmentation law of the analyte; in addition, the retention index is calculated using the improved Kovats method.

[0054] In some specific examples, the gas chromatography conditions in the above GC-MS method include: DB-WAX capillary column, 30m×0.25mm, 0.25μm; and / or temperature program: initial temperature 40°C, increased to 100°C at 15.0°C / min, and maintained for 3.0min; and / or increased to 240°C at 20.0°C / min, and maintained for 1.0min; and / or injection port temperature: 250°C; and / or carrier gas: He (99.999%); and / or constant flow: column flow rate is 1.0mL / min; and / or split ratio: 20:1; and / or injection volume: 1.0μL.

[0055] In some specific examples, the mass spectrometry conditions in the above GC-MS method include: the ionization mode is electron impact ionization; and / or the electron energy is 70 eV; and / or the mass spectrometer detector temperature is 250°C; and / or the full scan mode (FullScan) is adopted; and / or the mass scan range is 50-500 m / z, the dwell time is 0.2 s; and / or the solvent delay is 8 min; and / or the selected ion (SIM) mode is adopted; and / or the quantitative ions are as follows: ethyl benzoate is 77, 105, 122, 150, ethyl phenylacetate is 91, 164, 165, phenylethyl acetate is 104, 105, 164, and ethyl phenylpropionate is 91, 104, 107, 178.

[0056] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with specific examples, but the content of the present invention is not limited to the following examples.

[0057] 1. Preparation of Fe3O4@TPB-Dha

[0058] Example 1 Preparation of Fe3O4@TPB-Dha

[0059] 40 mL of ethylene glycol was measured and put into a 250 mL three-necked flask, and 54 mg / mL of FeCl3·6H2O particles were added and ultrasonically dissolved; after the FeCl3·6H2O was fully dissolved, 11 mg / mL of anhydrous sodium citrate was added, and the mixture was stirred in a water bath at a constant temperature of 80°C for 2 h to fully dissolve the sodium citrate and evenly disperse it in the ethylene glycol; then 49.25 mg / mL of anhydrous sodium acetate was continued to be added to the above system, and the mixture was fully stirred for 30 min to fully dissolve and disperse to obtain a uniform system, which was transferred to a 100 mL polytetrafluoroethylene stainless steel high-temperature and high-pressure reactor and fully reacted at 200°C for 10 h; after the reaction was completed, the reactor was cooled to room temperature, the pH of the supernatant was tested, the black product at the bottom of the reactor was collected, and it was ultrasonically cleaned 3-6 times with ethanol and ultrapure water respectively (until neutral), and vacuum dried at -50°C for 24 h to prepare Fe3O4 (Na3Cit) nanoparticles, which were ground using a grinder and set aside.

[0060] 50 mg of Fe3O4 (Na3Cit) powder, 1.8 mg / mL of 1,3,5-tri(4-aminophenyl)benzene (TPB) powder and 1.28 mg / mL of 2,3-dihydroxyterephthalaldehyde (Dha) powder were weighed into a 80 ml beaker, 20 ml of dimethyl sulfoxide (DMSO) was added, and the mixture was fully dispersed by ultrasonication for 5 min. 0.6 ml of acetic acid (99%, 17.5 mol / L) was added dropwise (5 s / drop) under ultrasonication. The whole process lasted for 10 min, and then incubated at room temperature for 10 min. The solid product was separated with the assistance of a magnet and washed with tetrahydrofuran, methanol and ultrapure water until neutral, respectively. Fe3O4@TPB-Dha nanomaterials were obtained by vacuum freeze-drying at -50 °C for 24 h.

[0061] 2. Experimental study on magnetic solid phase extraction parameters of aromatic esters in liquor

[0062] In the following experiment, the process diagram of magnetic solid phase extraction of aromatic esters in liquor is as follows: Figure 1 shown.

[0063] In the following experiments, the extraction efficiency is evaluated as follows: Enrichment factor (EF) is used as an evaluation index for the extraction efficiency of ester compounds by magnetic solid phase adsorbent, and its calculation formula is as shown in the formula:

[0064]

[0065] Among them, EF is the enrichment factor (%), C d is the concentration (mg / L) of ester compounds (ethyl benzoate, ethyl phenylacetate, phenylethyl acetate and ethyl phenylpropionate) in the desorption solution after magnetic solid phase extraction, and C0 is the initial concentration of ester compounds in the simulated wine sample (2.0 mg / L).

[0066] In the following experiments, the extraction of aromatic esters in liquor was carried out according to the following steps:

[0067] (1) Preparation of simulated wine sample: accurately pipette 15 mL of anhydrous ethanol (chromatographic grade) into a 100 mL volumetric flask, dilute to volume with ultrapure water and shake well to prepare a 15% volume fraction ethanol-water solution as a simulated wine sample, and adjust the pH of the simulated wine sample with 0.2 mol / L dilute hydrochloric acid solution and 1 mol / L ammonia solution, and store in a refrigerator at -4°C until use;

[0068] (2) Adsorption process of the analyte in the liquor sample: 5 mL of the liquor sample prepared in step (1) and 100 μL of a mixed standard solution of the target analyte (25 mg / L ethyl benzoate, 25 mg / L ethyl phenylacetate, 25 mg / L phenylethyl acetate and 25 mg / L ethyl phenylpropionate, the same below) with a concentration of 100 mg / L were taken in a 10 mL centrifuge tube, and the pH was adjusted to 4.0; then, the magnetic adsorbent Fe3O4@TPB-Dha was added, and the mixture was vortexed (2800 rpm, 30 s) at a speed of 2800 rpm to achieve adsorption equilibrium; after the extraction was complete, a strong magnet was used to separate the magnetic adsorbent Fe3O4@TPB-Dha from the supernatant under the action of an external magnetic field, and the supernatant was removed to obtain the Fe3O4@TPB-Dha composite material;

[0069] (3) Desorption process of the analyte in the liquor sample: The Fe3O4@TPB-Dha composite material treated in step (2) was redispersed and dissolved in 0.5 mL of a solution containing 1% desorption solvent, and desorbed. Under the action of an external magnetic field, a strong magnet was used to separate the magnetic adsorbent Fe3O4@TPB-Dha from the supernatant. The supernatant, which is the desorption solution containing the ester compounds, was taken and placed in an injection vial for GC-MS analysis to obtain the concentrations of different ester compounds.

[0070] (I) Experiment on different Fe3O4@TPB-Dha addition amounts during extraction

[0071] The amount of magnetic adsorbent Fe3O4@TPB-Dha used is of great significance for the extraction because it determines the total surface area available for adsorption of analytes.

[0072] In this experiment, aromatic esters were extracted according to the above-mentioned extraction method of aromatic esters in white wine, wherein the pH of the simulated wine sample in step (1) was adjusted to 4.0; the addition amount of the magnetic adsorbent Fe3O4@TPB-Dha in step (2) was set to 5 mg, 10 mg, 15 mg, 20 mg, 25 mg, 30 mg, 35 mg and 40 mg respectively, and the vortex extraction time was set to 4 min; in step (3), the desorption solvent was acidic ethyl acetate (formic acid and ammonia water, v ethyl acetate / v formic acid was 99:1), and the desorption time was 15 min; and the extraction efficiency of different addition amounts of magnetic adsorbent was tested.

[0073] The results are as follows Figure 2 As shown in the figure, the results show that when the mass of the adsorbent reaches 25 mg, the adsorption effect reaches the maximum value; when the amount of magnetic adsorbent exceeds 25 mg, the excess adsorbent cannot be completely desorbed under certain elution solvent conditions, resulting in a decrease in the enrichment factor. Therefore, 25 mg of Fe3O4@TPB-Dha magnetic adsorbent was selected as the preferred amount of adsorbent.

[0074] (II) Test on pH value of simulated wine sample during extraction

[0075] The pH value of the sample is considered to be a critical factor because the pH value can affect the ionization state of the target molecules and the surface properties of Fe3O4@TPB-Dha, thus affecting the extraction efficiency.

[0076] In this experiment, aromatic esters were extracted according to the above-mentioned extraction method of aromatic esters in white wine, wherein, in step (1), the pH value of the simulated wine sample was adjusted to 2, 4, 6, 8 and 10 respectively; in step (2), the addition amount of magnetic adsorbent Fe3O4@TPB-Dha was set to 25 mg, and the vortex extraction time was set to 4 min; in step (3), the desorption solvent was acidic ethyl acetate (formic acid and ammonia water, v ethyl acetate / v formic acid was 99:1), and the desorption time was 15 min; and the extraction efficiency of the simulated wine samples with different pH values ​​was tested.

[0077] The results are as follows Figure 3 As shown in the results, the adsorption efficiency of the target esters increased rapidly with the increase of the sample pH value from 2.0 to 4.0, and reached the maximum value at pH 4.0; above pH 4.0, the adsorption efficiency decreased with the further increase of pH value; when the pH value was 2 or increased from 8 to 10, the extraction efficiency of the target ester compounds decreased as a whole. In addition, Figure 4 As shown, the zero charge point (PZC) of Fe3O4@TPB-Dha is located at a pH value of 5.47. Therefore, at a pH value of 2.0 to 4.0, electrostatic adsorption will occur between the positively charged surface of Fe3O4@TPB-Dha and the negatively charged target ester analytes, ultimately improving the adsorption efficiency between the analytes and the adsorbent; in addition, when the pH value is higher than the PZC, the above-mentioned adsorbent and the analyte are both negatively charged, so electrostatic repulsion will occur, reducing the extraction efficiency. Therefore, in the present invention, the pH of the simulated wine sample is preferably adjusted to 4.0.

[0078] (III) Experiments on different adsorption (vortex extraction) time during extraction

[0079] In this experiment, aromatic esters were extracted according to the above-mentioned extraction method of aromatic esters in liquor, wherein, in step (1), the pH value of the simulated liquor sample was adjusted to 4; in step (2), the addition amount of magnetic adsorbent Fe3O4@TPB-Dha was set to 25 mg, and the vortex extraction time was set to 1 min, 2 min, 3 min and 4 min, respectively; in step (3), the desorption solvent was acidic ethyl acetate (formic acid and ammonia water, v ethyl acetate / v formic acid was 99:1), and the desorption time was 15 min; and the extraction efficiency of different vortex extraction times was tested.

[0080] The results are as follows Figure 5 As shown in the figure, the adsorption performance of the target esters improved with the increase of adsorption time, and then the adsorption efficiency reached the maximum at 4 min; however, the adsorption efficiency decreased with the further increase of adsorption time. Therefore, the optimal adsorption time was 4 min, and this rapid adsorption process can be attributed to the large specific surface area and many interactions between the target esters and the adsorbent.

[0081] (IV) Desorption solvent type test during desorption

[0082] In MSPE (magnetic solid phase extraction), the choice of elution solvent directly affects the recovery of the target analyte. A suitable elution solvent can effectively elute the target analyte from the adsorbent, thereby improving the efficiency of MSPE. In terms of the desorption solvent of MSPE, the important principle of "like dissolves like" can be used to achieve high desorption capacity of target ester substances.

[0083] In this experiment, aromatic esters were extracted according to the above-mentioned extraction method of aromatic esters in white wine, wherein, in step (1), the pH value of the simulated wine sample was adjusted to 4; in step (2), the addition amount of magnetic adsorbent Fe3O4@TPB-Dha was set to 25 mg, and the vortex extraction time was set to 4 min; in step (3), the desorption solvents were set to methanol, acetonitrile, ethyl formate (v ethyl acetate / v formic acid was 99:1), n-hexane, dichloromethane and carbon tetrachloride, and the desorption time was 15 min; and the extraction efficiency at different desorption times was tested.

[0084] The results are as follows Figure 6 As shown, the results show that when ethyl acetate is selected as the desorption solvent, the enrichment factor value is the highest. The reason may be that ethyl acetate has a similar structure to the esters to be tested, and ethyl acetate has a similar polarity to the target analyte, which can more effectively destroy the interaction between the esters to be tested and Fe3O4@TPB-Dha; on the contrary, n-hexane, dichloromethane, and tetrachloromethane have very different structures, and methanol and acetonitrile have different polarities from the target substance, and the desorption performance is poor; therefore, the present invention preferentially selects ethyl acetate as the desorption solvent.

[0085] (V) Desorption solvent pH test during desorption

[0086] In this experiment, aromatic esters were extracted according to the above-mentioned extraction method of aromatic esters in liquor, wherein, in step (1), the pH value of the simulated liquor sample was adjusted to 4; in step (2), the addition amount of magnetic adsorbent Fe3O4@TPB-Dha was set to 25 mg, and the vortex extraction time was set to 1 min, 2 min, 3 min and 4 min, respectively; in step (3), the desorption solvent was acidic ethyl acetate (formic acid and ammonia water), and the desorption time was 15 min; wherein the formic acid concentration and ammonia water concentration of the acidic ethyl acetate solution were set to 0.5% formic acid, 1% formic acid, 2% formic acid, 5% formic acid, ethyl acetate, 0.5% ammonia water, 1% ammonia water, 2% ammonia water and 5% ammonia water, respectively; and the extraction efficiency of different formic acid concentrations / ammonia water concentrations was tested.

[0087] The results are as follows Figure 7 As shown in the results, it can be clearly seen that when acidic ethyl acetate (99:1, v ethyl acetate / v formic acid, i.e. 1% formic acid) is selected as the desorption solvent, the desorption efficiency is the best; this is because when the formic acid content increases, the H + It will compete with the target for the active sites of the material, thereby reducing the adsorption of the target.

[0088] (VI) Desorption time test during desorption

[0089] Since the desorption efficiency of target ester compounds from the adsorbent is time-dependent, an appropriate desorption time is crucial for the desorption solvent to break the intermolecular hydrogen bonds and π-π interactions.

[0090] In this experiment, aromatic esters were extracted according to the above-mentioned extraction method of aromatic esters in liquor, wherein, in step (1), the pH value of the simulated liquor sample was adjusted to 4; in step (2), the addition amount of magnetic adsorbent Fe3O4@TPB-Dha was set to 25 mg, and the vortex extraction time was set to 1 min, 2 min, 3 min and 4 min, respectively; in step (3), the desorption solvent was an acidic ethyl acetate solution (formic acid and ammonia water, v ethyl acetate / v formic acid was 99:1), and the desorption time was set to 0, 5 min, 10 min, 15 min, 20 min and 25 min, respectively; and the extraction efficiency at different desorption times was tested.

[0091] The results are as follows Figure 8 As shown, the results show that a desorption time of 15 minutes is sufficient to release the target ester compounds from the adsorbent to the maximum extent; if the elution time is too long, the mass transfer equilibrium between the adsorbent and the elution solvent of the target ester substances will be destroyed; therefore, the present invention can select 15 minutes as the optimal desorption time.

[0092] 3. Construction and evaluation of GC-MS detection method

[0093] (I) Construction of qualitative detection method

[0094] (1) Preparation of simulated wine sample: Accurately pipette 15 mL of anhydrous ethanol (chromatographic grade) into a 100 mL volumetric flask, dilute to volume with ultrapure water and shake well to prepare a 15% volume fraction ethanol-water solution as a simulated wine sample, and store in a refrigerator at -4°C until use;

[0095] (2) Adsorption process of the test substance in liquor: 5 mL of the simulated liquor sample prepared in step (1) was added to a 10 mL centrifuge tube in sequence, and then 25 mg of the magnetic adsorbent Fe3O4@TPB-Dha prepared in Example 1 was added, and vortex extraction was performed at a speed of 2800 rpm for 4 min to achieve adsorption equilibrium; after the extraction was complete, a strong magnet was used to separate the magnetic adsorbent Fe3O4@TPB-Dha from the supernatant under the action of an external magnetic field, and the supernatant was removed;

[0096] (3) Desorption process of the test substance in liquor: The Fe3O4@TPB-Dha nanoparticles treated in step (2) were redispersed in 0.5 mL of 1% acidic ethyl acetate solution (formic acid and ammonia water, v ethyl acetate / v formic acid is 99:1) for desorption for 15 min. Under the action of an external magnetic field, a strong magnet was used to separate the magnetic adsorbent Fe3O4@TPB-Dha from the supernatant, and the supernatant was collected;

[0097] (4) subjecting the supernatant obtained in step (3) to GC-MS analysis;

[0098] The gas chromatography conditions were as follows: DB-WAX capillary column (30 m × 0.25 mm, 0.25 μm); temperature program: initial temperature 40 ° C, increased to 100 ° C at 15.0 ° C / min, maintained for 3.0 min; increased to 240 ° C at 20.0 ° C / min, maintained for 1.0 min; injection port temperature: 250 ° C; carrier gas: He (99.999%); constant flow: column flow rate is 1.0 mL / min; split ratio: 20:1; injection volume: 1.0 μL;

[0099] The mass spectrometry conditions were as follows: the ionization mode was electron impact ionization (EI); the electron energy was 70 eV; the mass spectrometer temperature was 250 °C; the qualitative determination was performed in full scan mode (Full Scan); the mass scan range was 50-500 m / z, the dwell time was 0.2 s; the solvent delay was 8 min, and the quantitative determination was performed in selected ion (SIM) mode;

[0100] (5) using chromatographic grade ethanol to prepare a mixed standard solution of normal alkanes (C8-C30), applying the same GC-MS analysis conditions as above to separate, and calculating the RI value (retention index) of the unknown analyte by obtaining the retention time of C8-C30, that is, calculating the RI according to the improved Kovats method;

[0101] (6) Result analysis: The NTST11.0 spectral library was used to analyze the nine higher fatty acid ethyl esters and the identification results were preliminarily determined. The RI values ​​calculated in step (5) were then compared with the RIs in the literature. The retention index and mass spectrometry fragmentation patterns of the analytes and the standards were compared and analyzed by GC-MS to obtain the final qualitative results.

[0102] (II) Construction of quantitative detection method

[0103] In the present invention, the external standard method, standard curve method and GC-MS are used to quantitatively analyze four aromatic ester compounds (ethyl benzoate, ethyl phenylacetate, phenylethyl acetate and ethyl phenylpropionate), comprising the following steps:

[0104] (1) Preparation of simulated wine samples

[0105] Accurately pipette 15 mL of anhydrous ethanol (chromatographic grade) into a 100 mL volumetric flask, dilute to volume with ultrapure water and shake well to prepare a 15% volume fraction ethanol-water solution as a simulated wine sample;

[0106] (2) Preparation of standard solution

[0107] Accurately weigh 100 mg of each standard into a 10 mL volumetric flask, dilute to volume with anhydrous ethanol (chromatographic grade), and prepare single standard solutions with a mass concentration of 10 g / L (ethyl benzoate single standard solution, ethyl phenylacetate single standard solution, phenylethyl acetate single standard solution, and ethyl phenylpropionate single standard solution); take the target ester compound solution in a 10 mL volumetric flask, dilute to 100 mg / L mixed standard solution with anhydrous ethanol as solvent; perform GC-MS analysis;

[0108] The gas chromatography conditions were as follows: DB-WAX capillary column (30 m × 0.25 mm, 0.25 μm); temperature program: initial temperature 40 ° C, increased to 100 ° C at 15.0 ° C / min, maintained for 3.0 min; increased to 240 ° C at 20.0 ° C / min, maintained for 1.0 min; injection port temperature: 250 ° C; carrier gas: He (99.999%); constant flow: column flow rate is 1.0 mL / min; split ratio: 20:1; injection The mass spectrometry conditions of GC-MS analysis were as follows: the ionization mode was electron impact ionization (EI); the electron energy was 70 eV; the mass spectrometer temperature was 250 °C; the qualitative analysis was performed in full scan mode (FullScan); the mass scan range was 50-500 m / z, and the dwell time was 0.2 s; the solvent delay was 8 min, and the quantitative determination was performed in selected ion (SIM) mode. The quantitative ion fragments are shown in Table 1.

[0109] Table 1 Retention time and quantitative ions of different aromatic ester compounds

[0110] No Retention time English name Chinese name CAS Number Quantitative ion 1 10.49 Ethylbenzoate Ethyl benzoate 93-89-0 77，105，122，150 2 11.4 Ethyl2-phenylacetate Ethyl phenylacetate 101-97-3 91，164，165 3 11.61 2-Phenylethylacetate Phenethyl acetate 103-45-7 104，105，164 4 12.08 Ethyl3-phenylpropionate Ethyl phenylpropionate 2021-28-5 91，104，107，178

[0111] (3) Drawing of standard curve:

[0112] The mass concentration of the analyte in each gradient standard mixed solution was used as the horizontal coordinate (x), and the peak area of ​​each quantitative ion detected was used as the vertical coordinate (y), and the linear regression equation y=ax+b of the standard curve was established; finally, the concentration of the target ester in each wine sample to be tested was calculated by the standard curve constructed above; the above experiments were carried out in parallel 3 times; the standard curves of ethyl benzoate, ethyl phenylacetate, phenylethyl acetate and ethyl phenylpropionate are as follows:

[0113] Ethyl benzoate: y = 1.08'10 7 x-28360;

[0114] Ethyl phenylacetate: y = 8.23'10 6 x+9604.2;

[0115] Phenyl acetate: y = 5.66'10 6 x+200430;

[0116] Ethyl phenylpropionate: y = 8.27'10 6 x-63100.

[0117] (4) Evaluation of quantitative detection methods

[0118] The evaluation parameters of GC-MS detection method mainly include linear relationship, detection limit (LOD), quantification limit (LOQ), recovery rate and precision.

[0119] 1) Linear relationship

[0120] The linear relationship of the standard curve is obtained by R 2 The results are shown in Table 2 below. The results show that within the corresponding concentration range, the four aromatic esters have a good linear relationship and the linear correlation coefficient (R 2 ) is 0.9998-0.9999.

[0121] Table 2 GC-MS detection method linear relationship

[0122]

[0123] 2) Limit of detection (LOD) and limit of quantification (LOQ)

[0124] The mass concentrations with signal-to-noise ratios greater than 3 and 10 were determined as LOD and LOQ, and the results are shown in Table 3 below. The results showed that the LOD and LOQ of ethyl benzoate, ethyl phenylacetate, phenylethyl acetate, and ethyl phenylpropionate were 0.11-0.15 μg / L and 0.35-0.49 μg / L, respectively.

[0125] Table 3 GC-MS detection method LOD and LOQ

[0126] Serial number Compound LOD (μg / L) LOQ (μg / L) 1 Ethyl benzoate 0.13 0.42 2 Ethyl phenylacetate 0.12 0.40 3 Phenethyl acetate 0.11 0.35 4 Ethyl phenylpropionate 0.15 0.49

[0127] 3) Recovery and precision of GC-MS detection method

[0128] Referring to Implementation Case 2, the optimal MSPE conditions were used to extract samples containing a certain mass concentration of target esters (four target esters at a 0.1 mg / L addition level), and the GC-MS method constructed above was used for detection to obtain the recovery rate; the above solution was sampled three times in succession, and the precision was evaluated by RSD; the recovery rate calculation formula was: Recovery rate % = (measured value of the added standard sample - measured value of the original sample) / spiked amount; the test results are shown in Table 4 below, the average recovery of the four target esters at a 0.1 mg / L addition level was 85.55%-97.09%, and the intra-day precision and inter-day precision were 0.69%-3.13% and 0.99%-6.60%, respectively.

[0129] Table 4 Recovery and precision of GC-MS detection method

[0130]

[0131]

[0132] In summary, the detection method constructed by the present invention is accurate and feasible for detecting the four target esters.

[0133] (5) Concentration test of aromatic ester compounds in the sample to be tested

[0134] The sample to be tested is subjected to the magnetic solid phase extraction described above, and then analyzed according to the GC-MS quantitative detection method described above, and then the concentrations of the four aromatic ester compounds in the sample to be tested are calculated using the standard curve obtained above.

[0135] 4. Actual sample testing

[0136] The GC-MS quantitative detection method constructed above was used to quantitatively detect aromatic ester compounds in 7 different real liquor samples. The quantitative results are shown in Table 5.

[0137] Table 5 Composition of aromatic esters in 7 different real liquor samples

[0138]

[0139] Continued from Table 5

[0140]

[0141] Next Table 5

[0142]

[0143]

[0144] It can be seen from Table 5 above that the four target aromatic esters can be accurately quantified, and the concentration ranges of ethyl benzoate, ethyl phenylacetate, phenylethyl acetate and ethyl phenylpropionate are 0.17 mg / L-0.43 mg / L, 0.10 mg / L-0.72 mg / L, 1.07 mg / L-2.40 mg / L and 0.34-1.49 mg / L, respectively.

[0145] In addition, the comparison between the method constructed by the present invention and other reported methods for determining aromatic esters in liquor is shown in Table 6 below.

[0146] Table 6 Comparison of the method constructed by the present invention with other reported methods for determining aromatic esters in liquor

[0147] Serial number Pretreatment method Extraction time Linear range LOD Recovery rate RSD (min) (mg / L) (μg / L) (％) (％) 1 VSLLME 10.5 0.09-12.5 1.2-27.3 73.3-120.9 - 2 HS-SPME 50 - - 85-106 0.9-5.0 3 LLE-1 >720 - 7.86-11.13 - 1.11-4.39 4 LLE-2 >720 - 5.31-7.03 102-112 5 LLE-3 >720 0.23-0.92 - - 6 LLE-4 >720 0.58-9.4 0.17 103 - 7 LLE-5 >720 0.149-3.049 85.63-101.27 5.56-9.86 8 LLE-6 >720 0.8-100 0.149-3.049 86.77-100.15 0.97-3.02 9 MSPE (the present invention) 4 0.01-20 0.11-0.15 85.55-97.09 0.69-6.6

[0148] V. Comparative test of the solid phase extraction (MSPE) of the present invention and the existing liquid-liquid extraction (LLE)

[0149] Comparative Example 1

[0150] The extraction of aromatic ester compounds in liquor by liquid-liquid extraction (LLE) method was compared, and the qualitative and quantitative analysis results of aromatic ester compounds (ethyl benzoate, ethyl phenylacetate, phenylethyl acetate and ethyl phenylpropionate) were obtained by GC-MS analysis, and the difference in extraction effect with magnetic solid phase extraction (Example 2) was expressed by extraction time, linear range, LOD, LOQ, and recovery rate; wherein, the liquid-liquid extraction method for extracting aromatic ester compounds in liquor comprises the following steps: accurately pipetting 15 mL of anhydrous ethanol (chromatographically pure) into a 100 mL volumetric flask, making up to volume with ultrapure water and shaking well, and preparing a volume fraction of 15% of ethanol-water solution as a simulated wine sample; and prepare a 100 mg / L mixed standard solution of the target analyte (25 mg / L ethyl benzoate, 25 mg / L ethyl phenylacetate, 25 mg / L phenylethyl acetate and 25 mg / L ethyl phenylpropionate); add octyl propionate to the standard solution and the white wine sample to obtain a concentration of 210.4 mg / L; saturate the diluted white wine with 50 g of sodium chloride, and then extract it with 50 mL of dichloromethane for 3 times; use anhydrous sodium sulfate to separate the organic phase from the water, and then use a Vigreux column to concentrate the organic phase to 500 μL, which is the extracted aromatic ester compound.

[0151] In addition, in Comparative Example 1, the GC-MS analysis conditions are:

[0152] (a) Gas phase conditions: GC-MS analysis was performed on a PerkinElmer Clarus 680 gas chromatograph with an SQ8C MS selective detector; helium was used as the carrier gas at a constant rate of 1.0 mL / min; the injector temperature was 250°C and set to splitless mode; a DB-5 column (30 m×0.25 mm×0.25 μm, Agilent) was used for separation; the oven was first set to 65°C and maintained for 2 min, then the temperature was increased to 280°C at a rate of 6°C / min and maintained for 5 min. The ion source temperature was heated to 300°C, and the transfer line was heated to 280°C;

[0153] (b) Mass spectrometry conditions: The ionization method was electron impact ionization; the ionization energy was 70 eV; the mass spectrometer detector temperature was 250°C; the full scan mode was used for qualitative analysis; the mass scan range of the mass spectrometer was 45 m / z to 300 m / z.

[0154] The extraction time, linear range, LOD, LOQ and recovery rate of the detection method of Comparative Example 1 were evaluated, and the results are shown in Table 7 below.

[0155] Table 7 Extraction time, linear range, LOD, LOQ and recovery of the detection method of Comparative Example 1

[0156]

[0157] In addition, the detection method in Comparative Example 1 was compared with the detection method in the present invention, and the results are shown in Table 8 below.

[0158] Table 8 Comparison of the detection method in comparative example 1 with the detection method in the present invention

[0159]

[0160] From the above analysis, it can be seen that the magnetic solid phase extraction method has a shorter extraction time, a wider linear range, a lower LOD and LOQ, and a comparable recovery rate for aromatic ester compounds in liquor compared with the liquid-liquid extraction method; therefore, the magnetic solid phase extraction method has a better adsorption effect on aromatic ester compounds in liquor and is more suitable for the extraction of aromatic ester compounds.

[0161] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be covered by the scope of the claims of the present invention.

Claims

1. A method for preparing an aromatic ester compound adsorbent, comprising: 1,3,5-tri(4-aminophenyl)benzene, 2,3-dihydroxyterephthalaldehyde and Fe3O4(Na3Cit) are mixed and dispersed; after dispersion, acetic acid is added to react to obtain an aromatic ester compound adsorbent; the preparation method of Fe3O4(Na3Cit) includes: FeCl3·6H2O, sodium citrate and sodium acetate are mixed in an ethanol environment; and then a hydrothermal reaction is performed to obtain Fe3O4(Na3Cit).

2. Aromatic ester compound adsorbent, characterized in that: The method is prepared according to claim 1.

3. A method for extracting aromatic ester compounds in liquor, characterized in that: include: The liquor and the aromatic ester compound adsorbent according to claim 2 are mixed, extracted, separated and discarded to obtain a reaction mixture; the reaction mixture is dispersed in a desorption solvent for desorption, and the supernatant is separated to obtain an aromatic ester compound extract.

4. The extraction method according to claim 3, characterized in that The aromatic ester compound comprises one or more of ethyl benzoate, ethyl phenylacetate, phenylethyl acetate and ethyl phenylpropionate.

5. The extraction method according to claim 3 or 4, characterized in that: The extraction method meets one or more of the following conditions: (a) Before mixing the liquor and the aromatic ester compound adsorbent, the alcohol content of the liquor is adjusted to 6°-26°; (b) before mixing the liquor and the aromatic ester compound adsorbent, adjusting the pH of the liquor to 3-10; (c) mixing liquor and an aromatic ester compound adsorbent, wherein the concentration of the aromatic ester compound adsorbent is 3 mg / mL-7 mg / mL; (d) extraction is vortex extraction; (e) The extraction time is 2 min to 20 min; (f) the desorption solvent comprises ethyl acetate and formic acid, wherein the volume proportion of formic acid is 0.3%-3%; (g) The desorption time is 9min-18min.

6. The extraction method according to claim 5, characterized in that The extraction method meets one or more of the following conditions: (i) Before mixing the liquor and the aromatic ester compound adsorbent, the alcohol content of the liquor is adjusted to 15°; (ii) before mixing the liquor and the aromatic ester compound adsorbent, adjusting the pH of the liquor to 4; (iii) mixing liquor and aromatic ester compound adsorbent, wherein the concentration of the aromatic ester compound adsorbent is 5 mg / mL; (iv) the extraction time is 3 min to 10 min; (v) the desorption solvent comprises ethyl acetate and formic acid, wherein the volume percentage of formic acid is 1%; (vi) The desorption time was 15 min.

7. The extraction method according to claim 6, characterized in that The extraction time is 4 min.

8. A method for detecting aromatic ester compounds in liquor, characterized in that: include: (1) extracting aromatic ester compounds from the liquor to be tested using the extraction method described in any one of claims 3 to 7 to obtain an extract; (2) The extract is used to detect the peak area of ​​aromatic ester compounds in the liquor to be tested using the GC-MS method; (3) The concentration of aromatic ester compounds in the liquor to be tested is calculated based on a standard curve of aromatic ester compound standards and peak area.

9. The detection method according to claim 8, characterized in that: The gas chromatography conditions in the GC-MS method include: DB-WAX capillary column, 30m×0.25mm, 0.25μm; and / or temperature program: initial temperature 40°C, increased to 100°C at 15.0°C / min, and maintained for 3.0min; and / or increased to 240°C at 20.0°C / min, and maintained for 1.0min; and / or injection port temperature: 250°C; and / or carrier gas: He (99.999%); and / or constant flow: column flow rate is 1.0mL / min; and / or split ratio: 20:1; and / or injection volume: 1.0μL.

10. The detection method according to claim 9, characterized in that: The mass spectrometry conditions in the GC-MS method include: the ionization mode is electron bombardment ionization; and / or the electron energy is 70 eV; and / or the mass spectrometer detector temperature is 250° C.; and / or the full scan mode (FullScan) is adopted; and / or the mass scan range is 50-500 m / z, and the dwell time is 0.2 s; and / or the solvent delay is 8 min; and / or the selected ion (SIM) mode is adopted; and / or the quantitative ions are as follows: 77, 105, 122, 150 for ethyl benzoate, 91, 164, 165 for ethyl phenylacetate, 104, 105, 164 for phenylethyl acetate, and 91, 104, 107, 178 for ethyl phenylpropionate.

Images