Mass spectrometric detection method for trace cigarette ash in cigarette ash

Abstract

The invention relates to a mass spectrometric detection technology, in particular to a mass spectrometric detection method for trace cigarette ash in cigarette ash, and a specific structure comprises a sample bottle, a mass flow controller, a Nafion drying tube, a gas source, a flow control system and a mass spectrometer. Based on the strong qualitative analysis performance of the mass spectrum, the method can realize high-sensitivity detection of trace cigarette ash in a large amount of cigarette ash, and has the advantages of high detection speed and high accuracy.

Description

Technical Field

[0001] The present invention relates to mass spectrometry detection technology, and specifically to a mass spectrometry detection method for trace amounts of cigarette ash in cigarette ash. Based on the powerful qualitative and quantitative analysis capabilities of mass spectrometry, the method can achieve highly sensitive detection of trace amounts of cigarette ash in a large amount of cigarette ash, and has the advantages of fast detection speed and high accuracy. Background Art

[0002] Fire is a sudden disaster event that not only poses a huge threat to people's lives and property, but also causes serious pollution to the environment. In a fire, burning materials release a large amount of smoke, which contains toxic and harmful gases and particulate matter. Studying the composition of soot at the fire scene can help understand the characteristics of burning materials and the combustion process, thereby providing a scientific basis for guiding fire accident investigations.

[0003] The presence of cigarette ash in cigarette ash is a common phenomenon. The cigarette ash in cigarette ash mainly comes from the residues left by smokers during the smoking process, including burned cigarette butts, cigarette ash and incompletely burned substances in smoke. Studies have found that cigarette ash contains a large amount of harmful chemicals, such as heavy metals, polycyclic aromatic hydrocarbons and organic matter, which are potentially harmful to human health and the environment.

[0004] By studying the cigarette ash in the fire scene, we can gain a deeper understanding of the behavior and changes of cigarette ash during the fire process. Researchers can collect ash samples from the fire scene and conduct physical and chemical analysis and toxicological evaluation to determine the harmful components and toxicity levels. These research results can provide a basis for analyzing the causes and processes of fire accidents, and provide scientific references for fire prevention, fire fighting and environmental protection.

[0005] In conclusion, the research background of cigarette ash in fire scene is closely related to the fields of fire investigation, smoke toxicity assessment and environmental protection, and is of great significance for improving the level of prevention and treatment of fire accidents. Summary of the invention

[0006] The purpose of the present invention is to utilize the powerful qualitative and quantitative detection performance of mass spectrometry technology to detect trace amounts of cigarette ash in cigarette ash, thereby providing strong evidence for fire source tracing investigation.

[0007] To achieve the above object, the technical solution of the present invention is:

[0008] A mass spectrometry detection method for trace cigarette ash in cigarette ash, comprising a sample bottle, a mass flow controller, a Nafion drying tube, a mass spectrometer, a flow control system and a gas source, characterized in that:

[0009] A phosphoric acid solution is first added to a sample bottle, and then a ash sample to be tested is added. The mouth of the sample bottle is sealed with a rubber plug having a through hole in the middle, and then one end of a polytetrafluoroethylene tube is inserted from the through hole of the rubber plug into the sample bottle (1) above the liquid surface to draw out the sample gas in the headspace of the sample bottle; the other end of the polytetrafluoroethylene tube is connected to an interface of a three-way joint via a mass flow controller, the gas outflow speed of the sample gas released from the sample bottle is controlled by the mass flow controller, the second interface of the three-way joint is connected to a gas source via a flow control system, the third interface of the three-way joint is connected to one end of a Nafion drying tube, the other end of the Nafion drying tube is connected to a mass spectrometer inlet, the gas is mixed and diluted with the gas released from the gas source at the three-way joint, and finally, the gas is dehumidified by the Nafion drying tube and then enters the mass spectrometer for detection.

[0010] The sample bottle is a wide-mouth flask with a volume of 0.5-2L, and the flask mouth is equipped with a rubber stopper. The small holes on the rubber stopper can be punched with a puncher, and the diameter of the small holes is 3mm-4mm (such as: 3mm or 4mm); the concentration of the phosphoric acid solution is 1-10% (85% mass fraction of concentrated phosphoric acid is added to water, the dilution ratio is: V 磷酸 / (V 水 +V 磷酸 )), the usage amount is 100-500mL.

[0011] The gas flow control range of the mass flow controller is 0-20mL / min, and the gas outflow rate in the sample bottle is controlled at 5-10ml / min; the dilution gas flow rate released by the flow control system is 20-90mL / min, that is, the gas dilution volume multiple is 5-10 times.

[0012] The tee joint is made of stainless steel, and the inner diameter of the joint interface is 3mm-4mm; all pipelines use polytetrafluoroethylene tubes with an outer diameter of 3mm-4mm.

[0013] The gas source is a compressed air cylinder, and the compressed air is connected to the flow control system. The system consists of a cylinder filled with molecular sieve desiccant and two mass flow controllers. One end of the cylinder is connected to the gas outlet of the gas source, and the other end is connected to the second interface of the three-way joint and the backwash gas inlet of the Nafion drying tube through a three-way joint. The gas flow rate is controlled while ensuring that the air provided by the gas source is dry. The dried gas enters the detection pipeline through different outlets;

[0014] The Nafion drying tube is composed of an inner tube made of a material containing a sulfonic acid group and an outer sealed sleeve. The inner tube is inserted into the sleeve, and the two end faces or inner wall faces of the sleeve are tightly connected to the outer wall faces of the two ends of the inner tube. A gap is left between the inner wall face of the sleeve and the outer wall face of the inner tube to form a closed cavity. A backflush gas inlet and a backflush gas outlet are arranged near the two ends of the sleeve in the closed cavity. One end of the inner tube is connected to the third interface of the three-way joint, and the other end is connected to the mass spectrometer injection port. The moisture of the gas in the inner tube is transferred to the outer sleeve by relying on the chemical hydrophilicity of the sulfonic acid group, and the backflush air is blown into the outer sleeve. The backflush air is provided by a gas source and blown into the backflush gas inlet near one end of the mass spectrometer injection port at a flow rate of 1-2L / min.

[0015] The mass spectrometer is a time-of-flight mass spectrometer, a quadrupole mass spectrometer or a Fourier transform ion cyclotron resonance mass spectrometer.

[0016] Based on the powerful qualitative analysis performance of mass spectrometry, this method can achieve highly sensitive detection of trace amounts of cigarette ash in a large amount of cigarette ash, and has the advantages of fast detection speed and high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of an ion funnel-based vertical single-photon ionization source of the present invention;

[0018] Figure 2 The mass spectra of three types of cigarette ash;

[0019] Figure 3 This is the mass spectrum of three types of cigarette ash mixed in cigarette ash. DETAILED DESCRIPTION

[0020] See also Figure 1 , which is a schematic diagram of the structure of the present invention. It includes a sample bottle 1, a mass flow controller 2, a Nafion drying tube 4, a mass spectrometer 5, a flow control system 6 and a gas source 7, and is characterized in that:

[0021] A phosphoric acid solution is first added to the sample bottle 1, and then the ash sample to be tested is added. The mouth of the sample bottle 1 is sealed with a rubber stopper with a through hole in the middle, and then one end of a polyfluoro tube is inserted from the through hole of the rubber stopper into the sample bottle 1 above the liquid surface to draw out the sample gas in the headspace of the sample bottle; the other end of the polyfluoro tube is connected to an interface of a three-way joint 3 via a mass flow controller 2, and the sample gas released from the sample bottle 1 is controlled by the mass flow controller 2 to control the gas outflow speed, the second interface of the three-way joint 3 is connected to the gas source 7 via a flow control system 6, the third interface of the three-way joint 3 is connected to one end of a Nafion drying tube 4, and the other end of the Nafion drying tube 4 is connected to the inlet of a mass spectrometer 5, and the gas is mixed and diluted with the gas released from the gas source 7 at the three-way joint 3, and finally, the gas enters the mass spectrometer 5 for detection after being dehumidified by the Nafion drying tube 4.

[0022] Sample bottle 1 is a wide-mouth flask with a volume of 1L. The flask mouth is equipped with a rubber stopper. The small hole on the rubber stopper can be punched with a puncher. The diameter of the small hole is 4mm. The concentration of the phosphoric acid solution is 5% (250mL of concentrated phosphoric acid with a mass fraction of 85% is added to 4750mL of water, and the dilution ratio is: V 磷酸 / (V 水 +V 磷酸 )), the usage amount is 200mL.

[0023] The gas flow control range of the mass flow controller 2 is 0-20mL / min, and the gas outflow rate in the sample bottle 1 is controlled at 5ml / min; the dilution gas flow rate released by the flow control system 6 is 45mL / min, that is, the gas dilution volume multiple is 10 times.

[0024] The three-way joint 3 is made of stainless steel, and the inner diameter of the joint interface is 4 mm; all pipelines use polytetrafluoroethylene tubes with an outer diameter of 4 mm.

[0025] The gas source 7 is a compressed air cylinder, and the compressed air is connected to the flow control system 6. The system is composed of a cylinder filled with a molecular sieve desiccant and two mass flow controllers. One end of the cylinder is connected to the gas outlet of the gas source 7, and the other end is connected to the second interface of the three-way connector 3 and the backwash gas inlet of the Nafion drying tube 4 through a three-way connection. The gas flow rate is controlled while ensuring that the air provided by the gas source 7 is dry. The dried gas enters the detection pipeline through different outlets;

[0026] The Nafion drying tube 4 was purchased from Womei Bochun, model MD-110-12F-4. It consists of an inner tube made of a material containing a sulfonic acid group and an outer sealed sleeve, the inner tube is inserted into the sleeve, the two end faces or inner wall faces of the sleeve are tightly connected to the outer wall faces of the two ends of the inner tube, a gap is left between the inner wall face of the sleeve and the outer wall face of the inner tube, and a closed cavity is formed, and a backflush gas inlet and a backflush gas outlet are arranged near the two ends of the sleeve in the closed cavity, one end of the inner tube is connected to the third interface of the three-way connector 3, and the other end is connected to the injection port of the mass spectrometer 5; relying on the chemical hydrophilicity of the sulfonic acid group, the moisture of the gas in the inner tube is transferred to the outer sleeve, and the backflush air is blown into the outer sleeve, and the backflush air is provided by the gas source 7 and blown into the backflush gas inlet near one end of the injection port of the mass spectrometer (5), and the flow rate is 1L / min.

[0027] The mass spectrometer 5 is a time-of-flight mass spectrometer.

[0028] Example:

[0029] The above method was used to test the ashes of domestic cigarettes (e.g., ashes from burning Taishan and Lotus cigarettes, Y) and the mixture of ashes (e.g., ashes from burning waste paper shells, dry old branches, etc.) and ashes (the mass ratio of ashes to ashes is about 1:10000, H). The results are as follows: Figure 2 and Figure 3 As shown in the figure, there are several obvious characteristic peaks in the mass spectrum of cigarette ash, namely 42, 60, 75, 85, 89, 93 and 111, and these characteristic peaks are also obtained in the mass spectrum of mixed ash, indicating that trace amounts of cigarette ash are detected in the ash. That is, this method can well identify whether there is still cigarette ash in the ash.

Claims

1. A mass spectrometry method for detecting trace amounts of cigarette ash in cigarette ash, comprising a sample bottle (1), a mass flow controller (2), a Nafion drying tube (4), a mass spectrometer (5), a flow control system (6) and a gas source (7), characterized in that: A phosphoric acid solution is first added to a sample bottle (1), and then a ash sample to be tested is added. The mouth of the sample bottle (1) is sealed with a rubber stopper having a through hole in the middle, and then one end of a polytetrafluoroethylene tube is inserted from the through hole of the rubber stopper into the sample bottle (1) above the liquid surface to draw out the sample gas in the headspace of the sample bottle; the other end of the polytetrafluoroethylene tube is connected to an interface of a three-way joint (3) via a mass flow controller (2), the gas outflow speed of the sample gas released from the sample bottle (1) is controlled by the mass flow controller (2), the second interface of the three-way joint (3) is connected to a gas source (7) via a flow control system (6), the third interface of the three-way joint (3) is connected to one end of a Nafion drying tube (4), the other end of the Nafion drying tube (4) is connected to an inlet of a mass spectrometer (5), the gas is mixed and diluted with the gas released from the gas source (7) at the three-way joint (3), and finally, the gas is dehumidified by the Nafion drying tube (4) and enters the mass spectrometer (5) for detection.

2. The mass spectrometry detection method according to claim 1, characterized in that: The sample bottle (1) is a wide-mouth flask with a volume of 0.5-2L, and the flask mouth is equipped with a rubber stopper. The small hole on the rubber stopper can be punched with a puncher, and the diameter of the small hole is 3mm-4mm (such as: 3mm or 4mm); the concentration of the phosphoric acid solution is 1-10% (the mass fraction of concentrated phosphoric acid is 85%, and the dilution factor is V 磷酸 / V 水 +V 磷酸 ), the usage amount is 100-500mL.

3. The mass spectrometry detection method according to claim 1, characterized in that: The gas flow control range of the mass flow controller (2) is 0-20 mL / min, and the gas outflow rate in the sample bottle (1) is controlled to be 5-10 ml / min; the dilution gas flow rate released by the flow control system (6) is 20-90 mL / min, that is, the gas dilution volume multiple is 5-10 times.

4. The mass spectrometry detection method according to claim 1, characterized in that: The three-way joint (3) is made of stainless steel, and the inner diameter of the joint interface is 3mm-4mm; all pipelines use polytetrafluoroethylene tubes with an outer diameter of 3mm-4mm.

5. The mass spectrometry detection method for trace amounts of cigarette ash in cigarette ash according to claim 1 or 3, characterized in that: The gas source (7) is a compressed air cylinder, and the compressed air is connected to a flow control system (6). The system is composed of a cylinder filled with a molecular sieve desiccant and two mass flow controllers. One end of the cylinder is connected to the gas outlet of the gas source (7), and the other end is connected to the two mass flow controllers through a three-way joint (3) and the backwash gas inlet of the Nafion drying tube (4). The gas flow rate is controlled while ensuring that the air provided by the gas source (7) is dry. The dried gas enters the detection pipeline through different outlets.

6. The mass spectrometry detection method according to claim 1 or 5, characterized in that: The Nafion drying tube (4) is composed of an inner tube made of a material containing a sulfonic acid group and an outer sealed sleeve. The inner tube is inserted into the sleeve. The two end faces or inner wall faces of the sleeve are tightly connected to the outer wall faces of the two ends of the inner tube. A gap is left between the inner wall face of the sleeve and the outer wall face of the inner tube to form a closed cavity. A backflush gas inlet and a backflush gas outlet are arranged near the two ends of the sleeve in the closed cavity. One end of the inner tube is connected to the third interface of the three-way joint (3), and the other end is connected to the injection port of a mass spectrometer (5). The moisture in the gas in the inner tube is transferred to the outer sleeve by relying on the chemical hydrophilicity of the sulfonic acid group. Backflush air is blown into the outer sleeve. The backflush air is provided by a gas source (7) and blown into the backflush gas inlet near one end of the injection port of the mass spectrometer (5). The flow rate is 1-2 L / min.

7. The mass spectrometry detection method according to claim 1 or 2, characterized in that: The mass spectrometer (5) is a time-of-flight mass spectrometer, a quadrupole mass spectrometer or a Fourier transform ion cyclotron resonance mass spectrometer.

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