A method for eliminating ammonia signals and / or volatile organic amines in ion mobility spectrometry and a method for detecting samples

Abstract

The present invention discloses a method for eliminating ammonia signals and / or volatile organic amines in an ion mobility spectrum and a method for detecting samples, and relates to the technical field of ion mobility spectrum analysis and detection. The elimination method comprises: treating the sample to be tested with a chemical reagent. A large amount of ammonia and / or volatile organic amines in the sample to be tested is fixed by a chemical method to form a stable compound to prevent ammonia or volatile organic amines from volatilizing and entering and contaminating the ion mobility spectrum system. The validity and ease of analysis of the sample collection data are guaranteed, and the efficiency of the detection is greatly improved. The present invention provides a new idea for suppressing the ammonia or volatile organic amine signals of the sample, and verifies the scientificity and validity of this idea through the trial of multiple reagents.

Description

Technical Field

[0001] The present invention relates to the technical field of ion mobility spectrometry analysis and detection, and in particular to a method for eliminating ammonia signals and / or volatile organic amines in an ion mobility spectrometry and a method for detecting a sample. Background Art

[0002] Gas phase ion mobility spectrometry (GC-IMS) is a combination of gas chromatography (GC) and ion mobility spectrometry (IMS). It is used to detect trace amounts of volatile substances. Chromatography is responsible for separating complex components, and ion mobility spectrometry can be used as a detector for chromatography. Ion migration occurs in the ion migration tube and is divided into two processes: one is ionization, which is to give the molecules of the analyte a certain charge; the other is migration, which is the movement of the ionized molecules of the analyte under the action of the electric field. The structure of the ion migration tube is as follows: Figure 1 shown.

[0003] Tritium source (T, β-ray) is one of the commonly used ionization sources in civilian GC-IMS. Its β-electron energy is small and cannot directly break chemical bonds and produce fragment ions. Under the irradiation of β-rays, nitrogen (GC carrier gas) and the trace amount of water contained in nitrogen undergo a series of chemical processes to eventually form hydrated protons H + (H2O) n , also called reactive ions. Reactive ions transfer hydrogen protons (H + ) is transferred to the analyte molecule, making the analyte molecule carry a unit of positive charge, H + (H2O) n The analyte molecules are ionized, which is the process of chemical ionization. Finally, the charged analyte molecules can complete migration under the action of the electric field and reach the detector to be detected. + (H2O) n Transfer protons to the analyte molecules to form analyte molecular ions (H + The process of ion mobility spectrometry (IMS) is the most basic premise for ion mobility spectrometry (IMS) detection.

[0004] Generally, the process of biological sample testing refers to Figure 2 As shown, the method mainly includes: firstly, placing the liquid or solid biological sample into a gas phase headspace bottle, sealing it with a bottle cap, and after a period of heating and shaking incubation, extracting a certain volume of headspace gas for sampling and detection to obtain information on the volatile substance components in the biological sample.

[0005] Biological samples generally contain a large amount of ammonia components and / or volatile organic amines (relative to other volatile components), which will affect GC-IMS data acquisition, increase the difficulty of data analysis and even cause data failure. At the same time, a large amount of ammonia and / or volatile organic amines will also contaminate the GC-IMS system, which is difficult to clean and greatly affects the experimental efficiency. Therefore, it is very necessary to inhibit ammonia and / or volatile organic amines in specific samples.

[0006] Gas phase ion mobility spectrometry usually uses high-purity nitrogen (99.999%) as the carrier gas. The carrier gas (containing trace water molecules) always flows through the entire GC-IMS system at a certain flow rate, so the hydrated protons H + (H2O) n The formation of H is continuous. In the GC-IMS spectrum, H + (H2O) n The signal peak of Figure 3 The "vertical line" indicated by the arrow, the bar signal, is H + (H2O) n The signal peak (also called reactive iron peak, or RIP peak for short) is in the dashed box, which is the signal of the analyte molecule that is ionized through the proton transfer process.

[0007] Since biological samples such as urine, saliva, and blood generally contain a large amount of ammonia components and / or volatile organic amines, which are easily accumulated in the chromatographic column, the chromatographic column cannot effectively separate them, resulting in the ammonia components and / or volatile organic amines being eluted into the migration tube simultaneously with the components to be tested, that is, there are a large number of "impurity" cations in the ion migration tube, such as Figure 4 The two "vertical lines" shown by the yellow short lines are parallel to the hydrated proton peak (RIP peak) and have high intensity. The presence of a large number of "impurity" cations will affect the normal proton transfer of other analyte molecules, thereby affecting the qualitative and quantitative analysis of the analyte molecules. Figure 4 As shown in the figure, when the tailing of ammonia is serious, a strip signal similar to the RIP peak is formed. At this time, in addition to the normal proton transfer process with the hydrated protons, the analyte will also undergo other side reactions. In the corresponding spectrum, multiple signals will appear for one analyte molecule, as shown in the dotted box in the figure. The signal on the left side of the box is a normal signal of the analyte molecule, and the signal on the right side of the box is a miscellaneous peak that appears in the side reaction process. The strength of the miscellaneous peak depends on the ammonia content in the sample and the residue in the chromatographic column, which increases the complexity of the spectrum and makes it uncontrollable. Even after the ammonia content reaches a certain level. The normal signal of the analyte molecule disappears, which greatly affects the qualitative and quantitative analysis of each component, making the obtained spectrum and data invalid.

[0008] In addition, the residual ammonia in the chromatographic column will continue to increase as the test progresses, and it is difficult to elute after the test. Therefore, after a certain number of biological samples are tested, the impact of the ammonia signal will become unacceptable and require thorough cleaning, which also greatly affects the efficiency of the test.

[0009] In view of this, the present invention is proposed. Summary of the invention

[0010] The object of the present invention is to provide a method for eliminating ammonia signals and / or volatile organic amines in ion mobility spectrometry and a method for detecting samples to prevent the influence of ammonia signals on other substances.

[0011] The influence of ammonia signal on biological sample detection is serious and must be solved. First, because its influence is uncontrollable, and second, because its accumulation will inevitably make its influence gradually aggravate, which will cause the collected spectrum to be unable to accurately describe the composition of volatile substances in the sample, thereby obtaining wrong conclusions. Therefore, the key to solving the problem is how to prevent or partially prevent the influence of ammonia signal on other substances. The inventors have found that the best way to eliminate the influence of ammonia on detection is to prevent ammonia from entering the ion mobility spectrometry system, such as for the gas phase ion mobility spectrometry (GC-IMS) system. It not only avoids the residue and accumulation in the chromatographic column, but also completely avoids the appearance of ammonia signals. For gas phase ion mobility spectrometry, the appearance of ammonia signals can be avoided.

[0012] The present invention is achieved in that:

[0013] The present invention provides a method for eliminating ammonia signals and / or volatile organic amines in ion mobility spectrometry, wherein a sample to be tested is treated with a chemical reagent to chemically fix the ammonia and / or volatile organic amines in the sample to be tested.

[0014] The inventors have found that by fixing ammonia and / or volatile organic amines in biological samples through certain reactions, ammonia will not volatilize and will be sucked up and injected by the injection needle. Ammonia molecules themselves easily combine with hydrogen protons to form ammonium ions (NH4 + ), so ammonia appears alkaline when dissolved in water, which is caused by the hydrolysis of ammonia. Ammonium ions are soluble cations, which stably dissolve in water in the form of ions under acidic conditions and no longer volatilize. By adjusting the pH value of the sample to be tested, the volatilization of ammonia can be effectively suppressed.

[0015] The inventors fix ammonia and / or volatile organic amines through a specific chemical process to prevent them from volatilizing to the headspace and entering the ion mobility spectrometry system (e.g., GC-IMS system). Ammonia and / or volatile organic amines have lone pairs of electrons and can act as electron donors. According to Lewis acid-base theory, they are alkaline compounds, so chemical reagents can act as electron acceptors to combine with ammonia to fix ammonia and / or volatile organic amines to prevent them from volatilizing. Volatile organic amines are, for example, selected from triethylamine, trimethylamine, and ethylenediamine.

[0016] In a preferred embodiment of the present invention, the chemical reagent is selected from at least one of the following chemical reagents: a non-volatile inorganic acid or a salt thereof, a non-volatile organic acid or a salt thereof, and a Lewis acid.

[0017] As for the selection of acid, the inventors found that the strength of the acid has a certain influence on the degree of elimination of ammonia and / or volatile organic amine signals.

[0018] When the acidity is as strong as possible, the elimination effect of ammonia and / or volatile organic amine signals is better. Chemical reagents with weaker acidity can also eliminate ammonia and / or volatile organic amine signals to a certain extent, as long as they can eliminate ammonia and / or volatile organic amine signals to a certain extent, they are within the protection scope of the present invention.

[0019] The selected acid itself should not be volatile, should not affect the volatilization of other substances, and should not destroy the components of other substances.

[0020] In an alternative embodiment, the non-volatile inorganic acid is selected from nitric acid, sulfuric acid or phosphoric acid;

[0021] In an alternative embodiment, the non-volatile organic acid is selected from aspartic acid or glutamic acid.

[0022] For example: Aspartic acid (Asp), isoelectric point pI = 2.97.

[0023] The salt of a non-volatile inorganic acid is selected from silver nitrate.

[0024] The salt of a non-volatile organic acid is selected from: oxalic acid tetraacetate.

[0025] In an optional embodiment, the Lewis acid is selected from ions, halides or Al(CH3)3 of elements of Groups Ib, IIb, IIIa, IIIb, IVa, IVb, Va, Vb, VIb, VIIb or VIII of the Periodic Table of Elements;

[0026] In an optional embodiment, the Lewis acid is selected from Cr ions, Hg ions, Co ions, Cu ions, Au ions, Ag ions or Pd ions. Ag has a better effect than Hg.

[0027] For example, the Lewis acid is selected from Cr 3+ , Hg 2+ 、Co 3+ , Cu + , Cu 2+ 、Au 3+ 、Ag + , Pd 2+ .

[0028] In an optional embodiment, the Lewis acid is selected from zinc chloride, zinc bromide, zinc iodide, manganese chloride, manganese bromide, cadmium chloride, cadmium bromide, stannous chloride, stannous bromide, stannous sulfate, stannous tartrate, indium trifluoromethanesulfonate, indium trifluoroacetate, zinc trifluoroacetate, chlorides or bromides of rare earth elements, cobalt chloride, ferrous chloride, yttrium chloride, aluminum chloride and mixtures thereof.

[0029] In an alternative embodiment, examples of Lewis acids include chlorides or bromides of rare earth elements such as lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, hafnium, erbium, thallium, ytterbium and lutetium.

[0030] It is also possible to use organometallic compounds such as triphenylborane, titanium isopropoxide as Lewis acids.

[0031] In an alternative embodiment, a mixture of two or more Lewis acids may of course be used.

[0032] Among the Lewis acids, for example, one is selected from zinc chloride, zinc bromide, stannous chloride, stannous bromide, triphenylborane and a mixture of zinc chloride / stannous chloride, indium trifluoromethanesulfonate, indium trifluoroacetate and zinc trifluoroacetate.

[0033] In a preferred embodiment of the present invention, the sample to be tested is a sample containing ammonia components.

[0034] In an optional embodiment, the sample to be tested is a biological sample or a food sample containing ammonia components.

[0035] In an alternative embodiment, the biological sample is urine, saliva, blood, serum or bile.

[0036] In an optional embodiment, the food sample is selected from tea, meat products, aquatic products, fermented products and animal tissues; for example, the animal tissues are selected from the fur or viscera of animals.

[0037] Meat products include but are not limited to: beef, pork, lamb, fish, shrimp, rabbit, chicken and duck.

[0038] In a preferred embodiment of the present invention, the elimination method comprises: mixing the sample to be tested with a chemical reagent, wherein the mass of the chemical reagent accounts for 0.1%-50% of the mass of the sample to be tested (e.g., a solid sample). For example, 5%-15%, 5%-10%, 6%-15%, 8%-12%, 1%-45%. In other embodiments, the mass of the chemical reagent exceeds 50% of the mass of the sample to be tested.

[0039] When the sample is in liquid form, it is measured by volume, and the amount (mass or volume) of the liquid sample added accounts for 0.1%-50% of the mass of the sample to be tested (eg, solid sample).

[0040] After mixing, if the chemical reagent is excessive, solid precipitation of the chemical reagent (such as amino acid) can be observed at the bottom of the bottle. In an optional embodiment, the amount of the added chemical reagent can be set to be excessive or not excessive as needed.

[0041] The present invention also provides a method for detecting samples using ion mobility spectrometry, the method comprising the following steps: fixing ammonia and / or volatile organic amines in the sample to be tested using the above-mentioned method for eliminating ammonia and / or volatile organic amine signals and / or volatile organic amines in the ion mobility spectrometer, then heating and incubating a sealed container containing the sample to be tested, and taking headspace gas to be tested by an ion mobility spectrometer.

[0042] In a preferred embodiment of the present invention, the heated incubation is performed by placing the sealed container at a temperature of 40-120°C for incubation.

[0043] For example, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C or 120°C.

[0044] In an optional embodiment, when the sample to be tested is a biological sample, the incubation is performed at 60°C-120°C.

[0045] In an optional embodiment, when the sample to be tested is a food sample, the incubation is performed at 40°C-100°C.

[0046] In a preferred embodiment of the present invention, the incubation time is 2-20 minutes, such as 2-8 minutes, 5-10 minutes.

[0047] In a preferred embodiment of the present invention, the single needle analysis time during detection is 5-40 minutes. The above single needle analysis time is 15-18 minutes, 15-19 minutes.

[0048] In a preferred embodiment of the present invention, the ion mobility spectrometry is: drift time ion mobility spectrometry, inhalation ion mobility spectrometry, traveling wave ion mobility spectrometry, high field asymmetric waveform ion mobility spectrometry, trapped ion mobility mass spectrometry.

[0049] In a preferred embodiment of the present invention, the ion mobility spectrometry is gas phase ion mobility spectrometry.

[0050] The present invention has the following beneficial effects:

[0051] The present invention fixes a large amount of ammonia and / or volatile organic amines in the sample to be tested by chemical methods to form stable compounds to prevent ammonia and / or organic amines from volatilizing and entering and contaminating the ion mobility spectrometry system, thereby ensuring the validity and ease of analysis of sample collection data and greatly improving the efficiency of detection.

[0052] The chemical reagents used can accept the lone pair electrons of ammonia, thereby chemically fixing the ammonia and / or volatile organic amines in the substance to be tested, which can effectively reduce the impact of the ammonia and / or volatile organic amine signals, while not affecting the volatilization of other substances in the sample, nor destroying other substances, and not having adverse effects on the instrument.

[0053] The present invention provides a new idea for suppressing the signal of ammonia and / or volatile organic amine in a sample, and verifies the scientificity and effectiveness of this idea through attempts with a variety of reagents. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0055] Figure 1 Schematic diagram of the structure of the ion transfer tube;

[0056] Figure 2 A flow chart for biological sample testing;

[0057] Figure 3 is the GC-IMS spectrum;

[0058] Figure 4 This is the result diagram of the influence of other reaction ions on the spectrum;

[0059] Figure 5 This is the result diagram of ammonia and volatile organic amine signals after three consecutive injections of untreated urine;

[0060] Figure 6 The result diagram of ammonia and volatile organic amine signals after 6 consecutive injections of urine spiked with aspartic acid (Asp);

[0061] Figure 7The figure is a comparison result of the Asp treatment group and the signal spectra of ammonia and volatile organic amines of different intensities;

[0062] Figure 8 The result graph of ammonia and volatile organic amine signals after 6 consecutive injections of blood with glutamate added;

[0063] Fig. 9 This is the result of 6 consecutive injections of ammonia and volatile organic amine signals of tea leaves added with sulfuric acid;

[0064] Fig.10 The result graph of ammonia and volatile organic amine signals after 6 consecutive injections of shrimp meat added with aspartic acid (Asp);

[0065] Fig.11 This is the result of 6 consecutive injections of ammonia and volatile organic amine signals in fish meat added with silver nitrate;

[0066] Fig.12 The result diagram of ammonia and volatile organic amine signals after continuous injection of proline-treated urine;

[0067] Fig.13 This is the result diagram of ammonia and volatile organic amine signals after three consecutive injections of untreated blood;

[0068] Fig.14 This is the result diagram of ammonia and volatile organic amine signals after three consecutive injections of untreated tea leaves;

[0069] Fig.15 This is the result diagram of ammonia and volatile organic amine signals after three consecutive injections of untreated shrimp meat;

[0070] Fig.16 The result diagram of ammonia and volatile organic amine signals after three consecutive injections of untreated fish meat;

[0071] Fig.17 The result diagram of ammonia and volatile organic amine signals after continuous injection of urine treated with mercuric chloride;

[0072] Fig.18 The result diagram of volatile organic amine signals after continuous sampling of crab meat treated with aspartic acid;

[0073] Fig.19 This is the result graph of volatile organic amine signals after continuous sampling of untreated crab meat. DETAILED DESCRIPTION

[0074] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0075] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0076] Example 1

[0077] In this embodiment, a urine sample is used as a test sample, and the test sample is treated with a chemical reagent.

[0078] Use a pipette to draw 2 mL of urine sample into a 20 mL headspace bottle, weigh and add 0.2 g of aspartic acid, shake slightly to mix, then the amino acid is in excess, and solid precipitation of amino acid can be observed at the bottom of the bottle, tighten the bottle cap for testing. Set the incubator temperature to 100 °C, incubation time to 5 min, headspace injection volume to 1000 μL, and single needle analysis time to 15 min.

[0079] The parameters of ion mobility spectrometry are as follows:

[0080]

[0081]

[0082] Time EPC1 (drift gas flow) EPC2 (Carrier gas flow) Record (record spectrum) 00:00,000 150mL / min 2ml / min -Rec (start collecting records) 02:00,000 150mL / min 2ml / min - 20:00,000 150mL / min 100ml / min -Stop (analysis of this sample ends)

[0083] Continuous 6-needle injection results reference Figure 6 As shown, at the same position in the spectrum, ammonia and volatile organic amine signals did not appear, the signal intensity at the corresponding position was very low, and there was no trend of cumulative signal increase.

[0084] Example 2

[0085] In this embodiment, a blood sample is used as a test sample, and the test sample is treated with a chemical reagent.

[0086] Use a pipette to draw 500 μL of blood sample into a 20 mL headspace bottle, weigh and add 0.1 g of glutamic acid, shake slightly to mix, then the amino acid is in excess and solid precipitation of amino acid can be observed at the bottom of the bottle, tighten the bottle cap for testing. Set the incubator temperature to 60°C, incubation time to 5 min, headspace injection volume to 1000 μL, and single needle analysis time to 15 min.

[0087] Apart from this, other parameters of the ion mobility spectrometry are the same as those in Example 1.

[0088] Continuous 6-needle injection results reference Figure 8As shown, at the same position in the spectrum, ammonia and volatile organic amine signals did not appear, the signal intensity at the corresponding position was very low, and there was no trend of cumulative signal increase.

[0089] Example 3

[0090] In this embodiment, tea samples are used as samples to be tested, and the samples to be tested are treated with chemical reagents.

[0091] Weigh 1g of tea sample on a balance and transfer it into a 20mL headspace bottle, weigh and add 2mL of 0.01M1 / 2H2SO4, shake slightly to mix, and tighten the bottle cap for testing. The incubator temperature is set to 80°C, the incubation time is 10min, the headspace injection volume is 500μL, and the single needle analysis time is 20min. In addition, the other parameters of the ion mobility spectrometry are the same as those in Example 1.

[0092] Continuous 6-needle injection results reference Fig. 9 As shown, at the same position in the spectrum, ammonia and volatile organic amine signals did not appear, the signal intensity at the corresponding position was very low, and there was no trend of cumulative signal increase.

[0093] Example 4

[0094] In this embodiment, shrimp meat is used as a sample to be tested, and the shrimp meat is treated with chemical reagents.

[0095] Weigh 2 g of shrimp sample on a balance and transfer it into a 20 mL headspace bottle, weigh and add 0.5 g of aspartic acid, add 2 mL of water, shake slightly to mix, and tighten the bottle cap for testing. The incubator temperature is set to 60°C, the incubation time is 15 min, the headspace injection volume is 500 μL, and the single needle analysis time is 30 min. In addition, the other ion mobility spectrometry parameters are the same as those in Example 1.

[0096] Continuous 6-needle injection results reference Fig.10 As shown, at the same position in the spectrum, ammonia and volatile organic amine signals did not appear, the signal intensity at the corresponding position was very low, and there was no trend of cumulative signal increase.

[0097] Example 5

[0098] In this embodiment, fish meat is used as a sample to be tested, and the fish meat is treated with chemical reagents.

[0099] Weigh 2g of fish sample on a balance and transfer it into a 20mL headspace bottle, weigh and add 0.2g of silver nitrate, add 2mL of water, shake slightly to mix, and tighten the bottle cap for testing. The incubator temperature is set to 60°C, the incubation time is 15min, the headspace injection volume is 500μL, and the single needle analysis time is 30min. In addition, the other ion mobility spectrometry parameters are the same as those in Example 1.

[0100] Continuous 6-needle injection results reference Fig.11 As shown, at the same position in the spectrum, ammonia and volatile organic amine signals did not appear, the signal intensity at the corresponding position was very low, and there was no trend of cumulative signal increase.

[0101] Example 6

[0102] In this embodiment, a urine sample is used as a test sample, and the test sample is treated with a chemical reagent.

[0103] A 2 mL urine sample was drawn by a pipette and injected into a 20 mL headspace bottle, 0.2 g of mercuric chloride was weighed and added, the mixture was slightly shaken, and the bottle cap was tightened for testing. The incubator temperature was set to 100°C, the incubation time was 5 min, the headspace injection volume was 1000 μL, and the single needle analysis time was 15 min. In addition, the other ion mobility spectrometry parameters were the same as those in Example 1.

[0104] Continuous 6-needle injection results reference Fig.17 As shown, at the same position in the spectrum, ammonia and volatile organic amine signals did not appear, the signal intensity at the corresponding position was very low, and there was no trend of cumulative signal increase.

[0105] Example 7

[0106] In this embodiment, crabs are used as samples to be tested, and the samples are treated with chemical reagents.

[0107] Weigh 1g crab meat sample on a balance and transfer it into a 20mL headspace bottle, weigh and add 0.2g aspartic acid, add 2mL water, shake slightly to mix, and tighten the bottle cap for testing. The incubator temperature is set to 60°C, the incubation time is 15min, the headspace injection volume is 500μL, and the single needle analysis time is 30min. In addition, the other ion mobility spectrometry parameters are the same as those in Example 1.

[0108] Continuous 6-needle injection results reference Fig.18 As shown, at the same position in the spectrum, dimethylamine and trimethylamine signals did not appear, the signal intensity at the corresponding position was very low, and there was no trend of increasing cumulative signals.

[0109] Comparative Example 1

[0110] This comparative example uses urine samples as the sample to be tested. Compared with Example 1, the difference is that the ammonia and volatile organic amine signals are not eliminated. Three injections are performed directly and continuously. In addition, the other ion mobility spectrometry parameters are the same as those in Example 1.

[0111] Results reference Figure 5 As shown in Figure 2, after continuous injection of untreated urine, very strong ammonia and volatile organic amine signals were observed on the left side of the RIP peak, such as Figure 5 As shown in the box, the signal strength increases gradually.

[0112] Comparative Example 2

[0113] Compared with Example 1, the difference is that neutral amino acid is used to eliminate the ammonia and volatile organic amine signals, and the other steps are the same. In addition, the other ion mobility spectrometry parameters are the same as those in Example 1.

[0114] Results reference Fig.12 As shown, after continuous injection of proline-treated urine, smaller ammonia and volatile organic amine signals were observed on the left side of the RIP peak, which were smaller than those of the untreated urine sample, but the signal intensity still gradually increased.

[0115] Comparative Example 3

[0116] This comparative example uses a blood sample as the sample to be tested. Compared with Example 2, the difference is that the ammonia and volatile organic amine signals are not eliminated. Three injections are performed directly and continuously. In addition, the other parameters of the ion mobility spectrometry are the same as those of Example 1.

[0117] Results reference Fig.13 As shown in Figure 2, after continuous injection of untreated blood, very strong ammonia and volatile organic amine signals were observed on the left side of the RIP peak, such as Fig.13 As shown in the box, the signal strength increases gradually.

[0118] Comparative Example 4

[0119] This comparative example uses tea samples as the samples to be tested. Compared with Example 3, the difference is that the ammonia and volatile organic amine signals are not eliminated. Three injections are performed directly and continuously. In addition, the other ion mobility spectrometry parameters are the same as those of Example 1.

[0120] Results reference Fig.14 As shown in Figure 2, after continuous sampling of untreated tea leaves, very strong ammonia and volatile organic amine signals were observed on the left side of the RIP peak, such as Fig.14 As shown in the box, the signal strength increases gradually.

[0121] Comparative Example 5

[0122] This comparative example uses shrimp meat samples as the sample to be tested. Compared with Example 4, the difference is that the ammonia and volatile organic amine signals are not eliminated. Three injections are performed directly and continuously. In addition, the other ion mobility spectrometry parameters are the same as those in Example 1.

[0123] Results reference Fig.15 As shown in Figure 2, after continuous sampling of untreated shrimp meat, very strong ammonia and volatile organic amine signals were observed on the left side of the RIP peak, such as Fig.15 As shown in the box, the signal strength increases gradually.

[0124] Comparative Example 6

[0125] This comparative example uses fish meat samples as the sample to be tested. Compared with Example 5, the difference is that the ammonia and volatile organic amine signals are not eliminated. Three injections are performed directly and continuously. In addition, the other ion mobility spectrometry parameters are the same as those of Example 1.

[0126] Results reference Fig.16 As shown in Figure 2, after continuous sampling of untreated fish meat, very strong ammonia and volatile organic amine signals were observed on the left side of the RIP peak, such as Fig.16 As shown in the box, the signal strength increases gradually.

[0127] Comparative Example 7

[0128] This comparative example uses crab meat samples as the sample to be tested. Compared with Example 7, the difference is that the volatile organic amine signal is not eliminated. Three injections are performed directly and continuously. In addition, the other ion mobility spectrometry parameters are the same as those in Example 1.

[0129] Results reference Fig.19 As shown in Figure 2, after continuous injection of untreated crab meat, very strong volatile organic amine signals (dimethylamine and trimethylamine) were observed on the left side of the RIP peak. Fig.19 As shown in the box, the signal strength increases gradually.

[0130] Experimental Example 1

[0131] This experimental example studies the effect of accumulated ammonia gas of different intensities on the signal detection of the analyte molecules.

[0132] like Figure 7 As shown, the first spectrum on the left is the Asp treatment group of Example 1, the middle is the spectrum with weaker ammonia and volatile organic amine signals, and the third is the spectrum with higher intensity after accumulation of ammonia and volatile organic amines. Figure 7 Below is a signal intensity graph. The signal intensity of ammonia and volatile organic amines can be quantified. See the Intensity column for the signal intensity of ammonia and volatile organic amines, in V volts. It is generally impossible to know the strength of ammonia and volatile organic amines before loading, and even if ammonia and volatile organic amines are weak, they will accumulate and affect subsequent detection, so they need to be suppressed as long as they exist. In this experimental example, the sample data of different ammonia intensities come from the first and last injections of the same ammonia-containing sample. It can be seen that the peak position and strength of the analyte signal between the first two spectra are similar. At this time, the ammonia and volatile organic amine signals are weak and do not significantly affect the peak signal of the analyte molecules. By comparing the third spectrum, it can be seen that after the ammonia intensity accumulates, the ammonia and volatile organic amine signals greatly affect the signal of the analyte molecules, and the peak position and intensity change significantly.

[0133] In summary, Asp has a very significant effect on inhibiting the volatilization and signal generation of ammonia and volatile organic amines, and preventing ammonia and volatile organic amines from entering and contaminating the GC-IMS system. In addition, Asp itself is not volatile, does not have strong oxidizing properties, does not affect the peaks of other substances, and does not destroy other volatile components. It is an effective method for suppressing ammonia and / or volatile organic amine signals in biological sample detection.

[0134] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for eliminating ammonia signals and / or volatile organic amines in ion mobility spectrometry, characterized in that: The method comprises the following steps: treating the sample to be tested with a chemical reagent to chemically fix ammonia and / or volatile organic amine in the sample to be tested; the chemical reagent is selected from at least one of the following: a non-volatile inorganic acid or its salt, a non-volatile organic acid or its salt and Lewis acid; and the amount of the chemical reagent added is 0.1%-50% of the mass of the sample to be tested.

2. The method for eliminating ammonia signals and / or volatile organic amines in ion mobility spectrometry according to claim 1, characterized in that: The non-volatile inorganic acid is selected from nitric acid, sulfuric acid or phosphoric acid; The non-volatile organic acid is selected from aspartic acid or its derivatives, glutamic acid or its derivatives; The Lewis acid is selected from Cr ions, Hg ions, Co ions, Cu ions, Au ions, Ag ions, Pd ions or halides; The salt of the non-volatile inorganic acid includes silver nitrate; the salt of the non-volatile organic acid is selected from: oxalic acid tetraacetate; The halide is selected from mercuric chloride, zinc chloride, zinc bromide, zinc iodide, manganese chloride, manganese bromide, cadmium chloride, cadmium bromide, stannous chloride, stannous bromide, stannous sulfate, stannous tartrate, indium trifluoromethanesulfonate, indium trifluoroacetate, zinc trifluoroacetate, chlorides or bromides of rare earth elements, cobalt chloride, ferrous chloride, yttrium chloride, aluminum chloride and mixtures thereof.

3. The method for eliminating ammonia signals and / or volatile organic amines in ion mobility spectrometry according to claim 2, characterized in that: The sample to be tested is a biological sample or a food sample containing ammonia components and / or volatile organic amines.

4. The method for eliminating ammonia signals and / or volatile organic amines in ion mobility spectrometry according to claim 3, characterized in that: The biological sample is urine, saliva, blood, serum or bile; The food sample is selected from tea, meat products, aquatic products, fermented products and animal tissues; the animal tissues are selected from animal fur or viscera.

5. A method for detecting a sample using ion mobility spectrometry, characterized in that: The method comprises the following steps: fixing ammonia and / or volatile organic amines in the sample to be tested by the method for eliminating ammonia signals and / or volatile organic amines in the ion mobility spectrum according to any one of claims 1 to 4, then heating and incubating the sealed container containing the sample to be tested, and taking the headspace gas to be tested by an ion mobility spectrometer.

6. The method for detecting a sample using ion mobility spectrometry according to claim 5, characterized in that: The heated incubation is to place the sealed container at a temperature of 40-120° C. for incubation.

7. The method for detecting a sample using ion mobility spectrometry according to claim 6, characterized in that: The incubation time is 2-20 minutes.

8. The method for detecting a sample using ion mobility spectrometry according to claim 5, characterized in that: The single needle analysis time during detection is 5-40min.

9. The method for detecting a sample using ion mobility spectrometry according to any one of claims 5 to 8, characterized in that: The ion mobility spectrometry includes drift time ion mobility spectrometry, inhalation ion mobility spectrometry, traveling wave ion mobility spectrometry, high field asymmetric waveform ion mobility spectrometry, and trapped ion mobility mass spectrometry.

10. The method for detecting a sample using ion mobility spectrometry according to any one of claims 5 to 8, characterized in that: The ion mobility spectrometry is: gas phase ion mobility spectrometry.

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