A method for detecting ulamidocarp in ethanol-containing beverages

Abstract

This application relates to the field of food testing technology, specifically to a method for detecting ursotrine in ethanol-containing beverages. The method includes the following steps: taking an ethanol-containing beverage as a test sample; heating and vaporizing the test sample; passing the vaporized sample through an air carrier into a time-of-flight mass spectrometer using acetone dopant for detection; and determining whether the test sample contains ursotrine based on the detection results. This application has the advantages of accurate detection results and high detection efficiency, and can serve as a rapid detection technology to guide production.

Description

Technical Field

[0001] This application relates to the field of food testing technology, and in particular to a method for detecting oolong sugar in ethanol-containing beverages. Background Technology

[0002] Ulaiose is a compound that naturally occurs in fermented foods and alcoholic beverages, primarily formed during the heating and aging processes in alcoholic beverage production. Ulaiose has a significant impact on human health; therefore, it is necessary to test for ulaiose in high-ethanol-concentration beverages to ensure product quality.

[0003] Currently, for the detection of urethane in food, the national standard GB 5009.223-2014 "National Food Safety Standard - Determination of Ethyl Carbamate in Food" and the import and export commodity inspection industry standard SN / T 0285-2012 "Detection Method for Ethyl Carbamate Residue in Exported Wine - Gas Chromatography-Mass Spectrometry" (the detection limit of this method is 0.01 mg / kg) both use gas chromatography-mass spectrometry (GC-MS) as the standard detection method.

[0004] Although gas chromatography-mass spectrometry is a relatively accurate method for qualitative analysis of oolong sugar in food, it involves extremely complex pretreatment processes such as extraction, elution, and concentration. The operation is complicated and time-consuming, making it difficult to use as a rapid detection technology to guide production. Summary of the Invention

[0005] In order to enable a faster and more convenient detection of oolong sugar in ethanol-containing beverages, this application provides a method for detecting oolong sugar in ethanol-containing beverages.

[0006] The method for detecting oolong sugar in ethanol-containing beverages provided in this application adopts the following technical solution:

[0007] A method for detecting ursotrin in ethanol-containing beverages includes the following steps:

[0008] An ethanol-containing beverage was taken as the test sample. The test sample was heated and vaporized. The vaporized test sample was then carried by an air carrier and entered a time-of-flight mass spectrometer using acetone dopant for detection. The test results were used to determine whether the test sample contained oolong sugar.

[0009] This application uses acetone as a dopant to detect malachite in the test sample, thus eliminating the need for sample pretreatment. In time-of-flight mass spectrometry (TOF-MS), acetone undergoes photoionization under vacuum ultraviolet light irradiation, generating reactant ions. These reactant ions react chemically with malachite in the test sample entering the TOF-MS, producing stable characteristic product ions. This reduces interference from ethanol and other substances in the matrix, enabling the detection of malachite in ethanol-containing beverages by TOF-MS. This application can directly detect malachite in ethanol-containing beverages without requiring sample pretreatment, significantly shortening detection time and improving detection efficiency. It can serve as a rapid detection technology to guide production.

[0010] Preferably, the temperature for heating and vaporization is 150℃~170℃; and the air flow rate is 80mL / min~120mL / min.

[0011] When the temperature exceeds 170℃, the excessively high temperature can easily cause thermal decomposition of the target analyte, malachite, resulting in its undetectability. When the temperature is below 150℃, the excessively low temperature prevents the sample from effectively vaporizing, leading to a low detection response. This application controls the injection volume of the sample by controlling the injection flow rate, allowing the malachite in the sample to fully react with acetone to generate stable cluster characteristic ions, significantly reducing the influence of ethanol on the detection results during the detection process.

[0012] Preferably, the heating and vaporization temperature is 150°C; and the air flow rate is 100 mL / min.

[0013] Preferably, the parameters of the time-of-flight mass spectrometry using acetone dopant are set as follows: the ionization source is a vacuum ultraviolet lamp with an applied voltage of 1350V to 1450V; the pressure range of the high-pressure photoionization region is 100 to 1000 Pa; the carrier gas is air with an air flow rate of 80 mL / min to 120 mL / min; the concentration of acetone in air is 100 to 800 ppmv; and the detector is a microchannel plate detector with an applied voltage of 2800V to 3200V.

[0014] If the concentration of acetone in the air is below 100 ppmv, the concentration is too low, resulting in fewer characteristic cluster ions of oolong sugar, making it impossible to achieve high-sensitivity detection of oolong sugar. If the concentration of acetone in the air is above 800 ppmv, the concentration is too high, which can easily cause contamination of the vacuum ultraviolet lamp window, thus affecting the stability of the test.

[0015] Preferably, the parameters of the acetone-assisted time-of-flight mass spectrometry are set as follows: the ionization source is a vacuum ultraviolet lamp with an applied voltage of 1400V; the pressure range of the high-pressure photoionization region is 500Pa; the carrier gas is air with an air flow rate of 100mL / min; the concentration of acetone in air is 400ppmv; and the detector is a microchannel plate detector with an applied voltage of 3000V.

[0016] Preferably, determining whether the sample to be tested contains oolong sugar based on the detection results includes: determining whether the sample to be tested contains oolong sugar based on whether the detection results contain characteristic peaks related to oolong sugar.

[0017] Preferably, the characteristic peaks related to oolong sugar include: the cluster ion characteristic peaks generated by the reaction of acetone and oolong sugar.

[0018] Preferably, the cluster ion characteristic peaks generated by the reaction of acetone and oolong sugar include: a molecular ion characteristic peak with a mass-to-charge ratio of 147 and a molecular ion characteristic peak with a mass-to-charge ratio of 148.

[0019] In this application, the chemical name of urethane is ethyl carbamate. The relative molecular mass of ethyl carbamate is 89, the relative molecular mass of acetone is 58, the mass-to-charge ratio (m / z) of the characteristic peak of the cluster ion formed by the reaction of acetone ions and ethyl carbamate is 147, and the characteristic peak with a mass-to-charge ratio of 148 is the characteristic peak of the cluster ion formed by the reaction of acetone ions and ethyl carbamate introducing a hydrogen atom.

[0020] This application has the following beneficial technical effects:

[0021] This application utilizes time-of-flight mass spectrometry (TOF-MS) with acetone dopant to directly detect the sample. The detection results determine whether the sample contains malachite. Acetone enters a high-pressure photoionization region and undergoes photoionization under vacuum ultraviolet light, generating reactant ions. These reactant ions react chemically with malachite in the gaseous sample within the high-pressure photoionization region, producing stable characteristic product ions. This reduces interference from ethanol and other substances in the matrix, enabling the detection of malachite in ethanol-containing beverages via TOF-MS. The detection method in this application requires no sample pretreatment, offers short detection time, high efficiency, and accurate results, and can serve as a rapid detection technology to guide production. Attached Figure Description

[0022] Figure 1 This is a comparison of mass spectrometry results between Example 1 and Comparative Example 1 of this application. Detailed Implementation

[0023] Currently, the detection of ethyl carbamate (urethane) in food mainly relies on gas chromatography-mass spectrometry (GC-MS). However, GC-MS requires cumbersome sample pretreatment, is time-consuming, and complex, making it impractical for guiding actual factory production. Therefore, a rapid method for detecting ethyl carbamate in samples is needed. The inventors discovered that using acetone as a dopant allows for an ion-molecule reaction between acetone and gaseous ethyl carbamate in the sample during time-of-flight mass spectrometry (TOF-MS), significantly reducing the interference of ethanol in ethanol-containing beverages and enabling TOF-MS detection of ethyl carbamate in these beverages.

[0024] The present application will be further described below with reference to the embodiments.

[0025] Reagents: Acetone (chromatographic grade), ethanol (chromatographic grade), and urethane (chemical name: ethyl carbamate, concentration: 99%).

[0026] Instruments: Time-of-flight mass spectrometer (Dalian Institute of Chemical Physics, Chinese Academy of Sciences), gas sample preparation apparatus (Dalian Institute of Chemical Physics, Chinese Academy of Sciences).

[0027] This application provides a method for detecting ursotrine in ethanol-containing beverages, comprising the following steps:

[0028] An ethanol-containing beverage was taken as the test sample. The test sample was heated and vaporized. The vaporized test sample was then carried by an air carrier and entered a time-of-flight mass spectrometer using acetone dopant for detection. The test results were used to determine whether the test sample contained oolong sugar.

[0029] Specifically, 5-10 mL of ethanol-containing beverage is taken as the test sample; in this application, the specific volume of the test sample is 5 mL. The test sample is injected into the gas sample preparation device via a syringe pump at a flow rate of 10 μL / min. The sample is vaporized by heating using the gas sample preparation device at a temperature of 150℃~170℃. When the temperature exceeds 170℃, the excessively high temperature may cause thermal decomposition of the target analyte, ursolic acid, resulting in its undetectability. When the temperature is below 150℃, the excessively low temperature prevents the test sample from being effectively vaporized, leading to a low detection response.

[0030] This application's gas sample preparation device is connected to a time-of-flight mass spectrometer via a pipeline. Air is used as the carrier gas in the gas sample preparation device to carry the gaseous sample. The flow rate of the gaseous sample is controlled by the air flow rate within the device, thereby controlling the sample injection volume. This ensures that the malachite in the sample can fully react with acetone to generate stable cluster ions, significantly reducing the influence of ethanol on the detection results. The air carrier gas flow rate is 80 mL / min to 120 mL / min, specifically 100 mL / min in this application. The air carrier gas flow rate directly affects the concentration of the malachite sample gas. Too low a flow rate results in a too high concentration of malachite, preventing sufficient reaction with acetone; too high a flow rate results in a too low concentration, making the malachite undetectable.

[0031] The parameters for time-of-flight mass spectrometry in this application are set as follows: the ionization source is a vacuum ultraviolet lamp, and the applied voltage of the vacuum ultraviolet lamp is 1350V to 1450V; in this application, the applied voltage of the vacuum ultraviolet lamp is specifically selected as 1400V; the pressure range of the high-pressure photoionization region is 100 to 1000Pa; in this application, the pressure range of the high-pressure photoionization region is specifically selected as 500Pa; the carrier gas is air, and the air flow rate is 80mL / min to 120mL / min; in this application, the air flow rate is specifically selected as 100mL / min. The concentration of acetone in air is 100–800 ppmv. If the concentration is below 100 ppmv, the acetone concentration is too low, resulting in fewer characteristic ions of urethane clusters, making high-sensitivity detection of ethyl carbamate impossible. If the concentration is above 800 ppmv, the acetone concentration is too high, easily causing contamination of the vacuum UV lamp window, thus affecting the stability of the test. In this application, the acetone concentration in air is specifically chosen to be 400 ppmv. A microchannel plate detector is used, with an applied voltage of 2800 V–3200 V. In this application, the applied voltage is specifically chosen to be 3000 V. This application determines whether the sample contains urethane by analyzing the position of characteristic peaks in the mass spectrum detected by time-of-flight mass spectrometry.

[0032] In this application, acetone enters a high-pressure photoionization region and undergoes photoionization under vacuum ultraviolet light irradiation, generating reaction reagent ions. These ions react chemically with malachite in the gaseous sample within the high-pressure photoionization region to produce stable characteristic product ions. This reduces interference from ethanol and other substances in the matrix, enabling the detection of malachite in ethanol-containing beverages by time-of-flight mass spectrometry. The detection method in this application does not require sample pretreatment and offers short detection time, high efficiency, and accurate results, making it a rapid detection technology that can guide production.

[0033] Example 1

[0034] For ease of detection, first prepare a 50% ethanol solution by mixing ethanol and water. Then, dissolve 2 mg of maltose in 1 L of the ethanol solution to prepare a 2 mg / L maltose standard solution. Use the 2 mg / L maltose standard solution as the sample to be tested.

[0035] Take 5 mL of the sample to be tested and inject it into the gas sample preparation device using a syringe pump at a flow rate of 10 μL / min. The sample is then vaporized using the gas sample preparation device at a heating temperature of 150 °C. The gaseous sample is then transported to a time-of-flight mass spectrometer (TOF-MS) for detection using air as the carrier gas at a flow rate of 100 mL / min. The presence of ursotose in the sample is determined based on the position of the characteristic peaks in the mass spectrum.

[0036] The parameters for time-of-flight mass spectrometry were set as follows: the ionization source was a vacuum ultraviolet lamp with an applied voltage of 1400V; the pressure range of the high-pressure photoionization region was 500Pa; the carrier gas was air with an air flow rate of 100mL / min; the concentration of acetone in air was 400ppmv; and the detector was a microchannel plate detector with an applied voltage of 3000V.

[0037] Comparative Example 1

[0038] The difference between Comparative Example 1 and Example 1 is that no acetone dopant is added in the time-of-flight mass spectrometry, and the air carrier gas does not pass through the sample vial but directly enters the ionization region before the sample to be tested is detected to obtain the corresponding mass spectrum.

[0039] Figure 1 This is a comparison of the mass spectra obtained in Example 1 and Comparative Example 1. The upper part of the figure shows the mass spectrum corresponding to Example 1, and the lower part shows the mass spectrum corresponding to Comparative Example 1. From... Figure 1 As can be seen, when acetone is not added, i.e., in the mass spectrum corresponding to Comparative Example 1, only the characteristic ion peaks of matrix ethanol can be detected, including m / z 93 ([2ethanol+H)). + ) and m / z 139([3ethanol+H] + However, no characteristic peaks of ethyl carbamate were detected. The m / z value was 93 ([2ethanol + H+)). + The peak at m / z 139 ([3ethanol+H)) represents a cluster ion formed by the combination of two ethanol molecules and a hydrogen atom. + The peak is a characteristic peak of a cluster ion formed by the combination of three ethanol molecules and one hydrogen atom.

[0040] The mass spectrum after adding acetone, i.e., the mass spectrum corresponding to Example 1, shows characteristic peaks related to ethanol and acetone, including m / z 43 ([acetone-CH3]). + ), m / z 59 ([acetone + H] +m / z 87([acetone + C2H5]) + m / z 105 ([acetone + ethanol + H+)) + ), m / z 117([2acetone + H] + ), m / z 151([acetone + 2 ethanol + H] + ) and m / z 163 ([2acetone + ethanol + H] + Where m / z 43([acetone-CH3]) + The peak (m / z 59) represents the characteristic ion of an acetone molecule after ionization to release a methyl group. + The peak at m / z 87 ([acetone + C2H5]) represents the characteristic peak of an ion formed by the combination of an acetone molecule and a hydrogen atom. + The peak (m / z 105) represents the characteristic peak of a cluster ion formed by the combination of an acetone molecule and the ethyl group ionized from ethanol. ([acetone + ethanol + H)) + The peak at m / z 117 is characteristic of a cluster ion formed by the combination of an acetone molecule, an ethanol molecule, and a hydrogen atom. + The peak (m / z 151) is a characteristic peak of a cluster ion formed by the combination of two acetone molecules and one hydrogen atom. ([acetone + 2 ethanol + H)) + The peak at m / z 163 is a characteristic peak of a cluster ion formed by the combination of one acetone molecule, two ethanol molecules, and a hydrogen atom. + The peak is a characteristic peak of a cluster ion formed by the combination of two acetone molecules and one ethanol molecule with a hydrogen atom.

[0041] Two high-intensity characteristic peaks of ethyl carbamate were also found at m / z 147 ([acetone + ethyl carbamate)). + ) and m / z 148([acetone + ethyl carbamate + H] + ). Where m / z 147 ([acetone + ethyl carbamate]) + The peak (m / z 148) represents the characteristic peak of a cluster ion formed by the combination of an acetone molecule and a urethane molecule. + The peak () represents a cluster ion formed by the combination of an acetone molecule, an ethyl carbamate molecule, and a hydrogen atom. This demonstrates that, with the assistance of acetone, ionized acetone can form a stable cluster ion with ethyl carbamate, thereby eliminating the interference of ethanol and yielding the characteristic peak of ethyl carbamate. This enables time-of-flight mass spectrometry (TOF-MS) detection of urethane in ethanol-containing beverages.

[0042] In this application, acetone enters a high-pressure photoionization region and undergoes photoionization under vacuum ultraviolet light irradiation, generating reaction reagent ions. These ions react chemically with malachite in the gaseous sample within the high-pressure photoionization region to produce stable characteristic product ions. This reduces interference from ethanol and other substances in the matrix, enabling the detection of malachite in ethanol-containing beverages by time-of-flight mass spectrometry. The detection method in this application does not require sample pretreatment and offers short detection time, high efficiency, and accurate results, making it a rapid detection technology that can guide production.

[0043] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for detecting ursotrin in ethanol-containing beverages, characterized in that, Includes the following steps: An ethanol-containing beverage was used as the test sample. The sample was heated and vaporized, and then transported by air to a time-of-flight mass spectrometer (TOF-MS) using acetone dopant for detection. The presence of acetone in the sample was determined based on the detection results. The heating and vaporization temperature was 150 ℃~170 ℃; the air flow rate was 80 mL / min~120 mL / min; the parameters of the TOF-MS using acetone dopant were set as follows: the ionization source was a vacuum ultraviolet lamp with an applied voltage of 1350 V~1450 V; the high-pressure photoionization region pressure range was 100~1000 Pa; the carrier gas was air with an air flow rate of 80 mL / min~120 mL / min; and the concentration of acetone in the air was 100~800 ppmv. The detector is a microchannel plate detector, and the applied voltage is 2800 V to 3200 V. The step of determining whether the sample contains oolong sugar based on the detection results includes: determining whether the sample contains oolong sugar based on whether the detection results contain characteristic peaks related to oolong sugar. The characteristic peaks related to oolong sugar include: the cluster ion characteristic peaks generated by the reaction of acetone and oolong sugar.

2. The method for detecting ursotrine in ethanol-containing beverages according to claim 1, characterized in that, The heating and vaporization temperature is 150 °C; the air flow rate is 100 mL / min.

3. The method for detecting ursotrine in ethanol-containing beverages according to claim 1, characterized in that, The parameters of the acetone-assisted time-of-flight mass spectrometry were set as follows: the ionization source was a vacuum ultraviolet lamp with an applied voltage of 1400 V; the pressure range of the high-pressure photoionization region was 500 Pa; the carrier gas was air with an air flow rate of 100 mL / min; the concentration of acetone in air was 400 ppmv; and the detector was a microchannel plate detector with an applied voltage of 3000 V.

4. The method for detecting ursotrine in ethanol-containing beverages according to claim 1, characterized in that, The characteristic peaks of the cluster ions generated by the reaction of acetone and oolong sugar include: a cluster ion characteristic peak with a mass-to-charge ratio of 147 and a cluster ion characteristic peak with a mass-to-charge ratio of 148.

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