A high temperature thermal analysis sampling device for complex samples

Abstract

A high-temperature thermal analysis sampling device for complex samples, the complex sample high-temperature thermal analysis sampling device comprising a sample placement device (2), a tubular furnace heating device (5) and a sample conveying device (4) with a branch (7). The sample placement device (2) and the sample conveying device (4) are slidably sealed by an O-ring (3). The sampling device provided by the present invention can meet the sampling requirements of solid samples, complete the heating, sampling and analysis requirements of the samples in a short time, and meet the requirements of the mass spectrometer for on-site rapid analysis and detection. The high-temperature thermal analysis sampling device provided by the present invention can quickly analyze volatile and semi-volatile samples in solid samples, reduce the adsorption of samples on the tube wall, and can be used in conjunction with various gas analysis instruments.

Description

Technical Field

[0001] The invention relates to a sample injection device for a mass spectrometer, in particular to a sample injection device for converting a solid sample into gas. Background Art

[0002] Mass spectrometry has fast analysis speed, high resolution and sensitivity, and strong qualitative ability. Low-pressure photoionization mass spectrometry is suitable for rapid, online analysis of organic samples. However, mass spectrometry needs to work in a high vacuum environment and cannot be directly used for the analysis of solid samples. Solid samples usually need to be processed using solvent extraction, solid phase microextraction and other techniques before detection. However, these methods are relatively complicated and time-consuming.

[0003] Li Haiyang and others invented a thermal analysis sampling device with surface airflow purge (patent application number: 200710011082.X). It includes a fixed control device for controlling whether the sample attachment sheet is clamped or not, and a surface airflow purge device. The gap formed between the two is a sample slot for inserting a sample attachment sheet; the fixed control device and the surface airflow purge device are fixedly or movably connected. The general heating temperature is controlled between 100 and 300°C. It can be used for the analysis of solid or liquid samples.

[0004] Kong Qingyuan and others invented a thermal analysis sampling device (patent application number: 201010191307.6). It includes a carrier gas distribution three-way valve, a port sealing nut, a port sealing gasket, a cavity sealing jacket, a temperature control device, a furnace body, a cold trap, a sampling three-way valve, and a gas washing device; the carrier gas distribution three-way valve is at the near opening end of the furnace body, the port sealing nut and the port sealing gasket are at the opening end of the furnace body, the cavity sealing jacket is at both ends of the furnace body, the temperature control device is outside the furnace body, the furnace body is connected to the cold trap, the sampling three-way valve 8 is connected to the cold trap outlet, and the gas washing device is connected to the sampling three-way valve. It has the advantages of simple structure, convenient operation, small overall gas path dead volume, high sample recovery rate, and can realize multiple ways of sampling at the same time.

[0005] Zhao Xiaofeng and others invented a mass spectrometry thermal analysis sampling method and device (patent application number: 201710307716.X). It mainly includes two pieces of heat-conducting materials, a cavity formed by the two pieces of heat-conducting materials, a sample adsorption material, a purge air pipe, a vacuum pump pipe and a sampling pipe. The heat-conducting material contains a heating device and a cooling device in whole or in part, and is connected to the purge air pipe, the vacuum pump pipe and the sampling pipe.

[0006] However, the above-mentioned thermal analysis sampling devices, when used for tobacco sample detection, cannot solve the problem of adsorption of nicotine, glycerin and tar in tobacco samples.

[0007] The present invention designs a complex sample high-temperature thermal analysis sampling device, which can perform rapid thermal analysis on volatile and semi-volatile components in solid samples, avoid adsorption problems, and is suitable for on-site rapid analysis of mass spectrometry. Summary of the invention

[0008] The object of the present invention is to provide a high-temperature thermal analysis sampling device for complex samples, which can realize rapid thermal analysis and detection of volatile and semi-volatile components in solid samples. To achieve the above object, the technical solution adopted by the present invention is:

[0009] On the one hand, the present invention provides a high-temperature thermal analysis sampling device for complex samples, comprising: a sample placement device, a tubular furnace heating device, a sample conveying device and a resistance heating wire; the sample placement device and the sample conveying device are both cylindrical, such as a square tube, a round tube, etc., and one end of the sample placement device is embedded in the sample conveying device; a branch port is provided on the surface of the sample conveying device; the tubular furnace heating device is provided with a through hole, and the through hole is for the heated part of the sample conveying device to be embedded; the resistance heating wire is wound around the exposed surface of the sample conveying device; the materials of the sample placement device and the sample conveying device are both stainless steel or quartz glass.

[0010] Preferably, the sample placement device and the sample transport device are both in the shape of a circular tube; the sample transport device comprises a large diameter section and a small diameter section; one end of the sample placement device is nested into the large diameter section of the sample transport device; the sample placement device and the large diameter section of the sample transport device are sealed by an O-ring sliding.

[0011] Preferably, the branch port is located at the large diameter section of the sample delivery device and is used to pass the internal standard calibration gas. When the internal standard gas is not passed, the branch port is in a closed state.

[0012] Preferably, the non-embedded end of the sample placement device is used to introduce a purge gas, and a quartz wool or Cambridge filter for filtering is placed at the port of the embedded end; the purge gas is introduced from front to back, and along the direction of introduction of the purge gas, the solid sample to be tested is tightly placed at the front end of the quartz wool or Cambridge filter for filtering.

[0013] Preferably, the heating temperature of the tubular furnace heating device can be adjusted between 100 and 800° C.; the through hole is a circular hole located in the middle of the tubular furnace for being nested into the large diameter section of the sample conveying device; the solid sample to be tested is placed at the center of the heating of the tubular furnace heating device.

[0014] Preferably, along the direction of introduction of the purge gas, the surface of the right end of the sample conveying device located at the rear of the tubular furnace heating device is covered with insulating mica paper; the resistance heating wire is wound around the outer surface of the mica paper; the temperature of the resistance heating wire can be adjusted between 100 and 300°C.

[0015] On the other hand, the present invention provides an application of the above-mentioned complex sample high-temperature thermal analysis sampling device in an analytical instrument. During the application, the port of the small-diameter section of the sample delivery device is used to connect to the gas analyzer interface.

[0016] Preferably, the gas analyzer interface is a capillary interface for mass spectrometry sampling; the complex sample is a tobacco sample; during the analysis of the tobacco sample, the heating temperature of the tubular furnace heating device is 180-300°C; the heating temperature of the resistance heating wire (8) is 180-300°C; the ionization source of the mass spectrometer is a low-pressure photoionization mass spectrometer, the ionization source pressure is 1-100 Pa, and the ionization zone heating temperature is 180-300°C.

[0017] Preferably, during the analysis of the tobacco sample, the heating temperature of the tubular furnace heating device (5) is 100-800°C; the heating temperature of the resistance heating wire (8) is 180-200°C; the ionization source of the mass spectrometer is a low-pressure photoionization mass spectrometer, the ionization source pressure is 30-60 Pa, and the heating temperature of the ionization zone is 180-200°C.

[0018] Beneficial Effects

[0019] The high-temperature thermal analysis sampling device provided by the present invention can realize direct sampling detection of tobacco samples in mass spectrometry by improving the materials and heating methods of the sample placement device and the sample conveying device, and combining with the improvement of mass spectrometry detection conditions.

[0020] The present invention can avoid the serious adsorption problem existing in the detection of tobacco samples by designing the material of the sample placement device and the sample conveying device to be stainless steel or quartz glass and designing the heating temperature of the tobacco samples to be above 180°C;

[0021] By setting the mass spectrometry detection condition ionization zone pressure within the range of 1 to 100 Pa and heating the ionization zone to 180° C., the problem of the ionization zone can be solved and the rapid detection of key components in the tobacco sample can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of the high-temperature thermal analysis sampling device for complex samples.

[0023] 1. Purge gas; 2. Sample placement device; 3. O-ring; 4. Sample delivery device; 5. Tube furnace heating device; 6. Internal standard calibration gas; 7. Sample delivery device branch; 8. Resistance heating wire; 9. Mass spectrometer injection capillary; 10. Quartz wool or Cambridge filter; 11. Solid sample.

[0024] Figure 2 Schematic diagram of the high-temperature thermal desorption device for complex samples combined with low-pressure photoionization mass spectrometry.

[0025] Figure 3 This is the thermal decomposition mass spectrum of a certain brand of heat-not-burn cigarette tobacco sample.

[0026] Figure 4 These are the continuous test results of nicotine and glycerin for a single sample.

[0027] Figure 5 This is the mass spectrum obtained from the tobacco sample detection. DETAILED DESCRIPTION

[0028] The present invention will be further described below by way of examples in conjunction with the accompanying drawings.

[0029] Implementation Example 1

[0030] See also Figure 1 , a structural schematic diagram of a complex sample high temperature thermal analysis sampling device of the present invention. It includes: a sample placement device 2, a tubular furnace heating device 5, a sample conveying device 4 with a branch port 7 and a resistance heating wire 8. The material of the sample placement device 2 and the sample conveying device 4 is quartz glass. The branch port 7 has an inner diameter of 1.5 mm and an outer diameter of 3 mm.

[0031] The sample placement device 2 is in the shape of a circular tube, the left end of the sample delivery device 4 is a circular tube with a larger diameter, and the right end is contracted to a circular tube with a smaller aperture, and the outer diameter of the sample placement device 2 is just large enough to be embedded in the large diameter section of the circular tube-shaped sample delivery device 4. The sample placement device 2 and the sample delivery device 4 are slidably sealed by an O-ring 3.

[0032] The sample conveying device 4 has a branch port 7 at the right end of the larger diameter portion, and the branch port 7 can be passed through the internal standard calibration gas (the internal standard calibration gas is glycerin or nicotine when the cigarette tobacco is tested). The branch port 7 can be closed when the internal standard gas is not passed. The purge gas 1 enters from the left end of the sample placement device 2. The quartz wool or Cambridge filter 10 for filtering is tightly placed at the rightmost end of the sample placement device. The solid sample 11 is placed close to the quartz wool or Cambridge filter 10 for filtering.

[0033] The heating temperature of the tube furnace 5 is 300° C. There is a circular hole in the middle of the tube furnace, and the left end of the sample conveying device 4 with a large aperture can be tightly embedded in the circular hole. The position of the sample placement device 2 inserted into the sample conveying device 4 ensures that the sample 11 is exactly in the center of the tube furnace 5 heating.

[0034] The surface of the sample conveying device 4 at the right end of the tube furnace is covered with insulating mica paper, and the mica paper is wrapped with a resistance heating wire 8. The temperature of the resistance heating wire is set to 190°C.

[0035] The right end of the sample delivery device 4 can be connected to a capillary 9 for low-pressure photoionization mass spectrometry sampling.

[0036] Figure 2 This is a schematic diagram of the structure of the high-temperature thermal analysis device for the above-mentioned complex samples combined with the low-pressure photoionization mass spectrometry.

[0037] Figure 3 (a) For the use of Figure 2 A typical mass spectrum of a certain brand of heat-not-burn cigarette tobacco sample obtained with the device. Figure 3 (b) is a continuous monitoring spectrum of nicotine and glycerol in tobacco samples with different glycerol contents (glycerol contents are 0%, 10%, 20%, and 30%, respectively).

[0038] The detection conditions are as follows: the heating temperature of the tube furnace is 300°C, the heating temperature of the resistance wire and the heating temperature of the ionization zone are both 190°C, the gas pressure of the ionization zone is 40 Pa, and the spectrum acquisition time is 5s.

[0039] The device can complete the detection of a single tobacco sample within 1 minute, and the resulting mass spectrum is simple and convenient for qualitative and quantitative analysis.

[0040] Depend on Figure 3 It can be seen that the detection of tobacco samples provided by the present invention solves the adsorption problem of high-boiling point components in smoke, there is no memory effect, and the lower ionization zone pressure reduces matrix interference, and the obtained mass spectra of nicotine and glycerol are simple and easy to interpret.

[0041] Comparative Example 1

[0042] The experimental apparatus is the same as that of Example 1. The temperature of the resistance heating wire 8 wound around the mica paper is set to 100° C., and other operating conditions are the same as those of Example 1.

[0043] Figure 4 This is the continuous test result of nicotine and glycerin of a single sample. Due to the adsorption of nicotine and glycerin, there is a residue in the pipeline, so there is an obvious memory effect.

[0044] Comparative Example 2

[0045] The experimental apparatus is the same as that of Example 1, the gas pressure in the mass spectrometer ionization region is set to 532 Pa, and other operating conditions are the same as those of Example 1.

[0046] Figure 5 This is the mass spectrum of the tobacco sample. Although glycerol (MH + ) and nicotine (M + ) ion peaks, but the spectrum is very complex and the matrix effect is seriously affected.

[0047] It can be seen from Implementation Example 1 and Comparative Examples 1 and 2 that the detection operating conditions for key components in tobacco samples are that the sample placement device 2 and the sample conveying device 4 are made of quartz glass or stainless steel, the heating temperature of the sample conveying device 4 and the mass spectrometer ionization zone is above 180°C, and the gas pressure in the ionization zone is within 1 to 100 Pa. This can eliminate the memory effect of the smoke components, reduce the impact of matrix interference on detection, and achieve rapid detection of smoke components.

Claims

1. A complex sample high temperature thermal analysis sampling device, characterized in that: The thermal analysis sampling device comprises a sample placement device (2), a tubular furnace heating device (5), a sample conveying device (4) and a resistance heating wire (8); the sample placement device (2) and the sample conveying device (4) are both cylindrical, and one end of the sample placement device (2) is embedded in the sample conveying device (4); a branch opening (7) is provided on the surface of the sample conveying device (4); the tubular furnace heating device (5) is provided with a through hole, and the through hole is used for the heated part of the sample conveying device (4) to be embedded; the resistance heating wire (8) is wound around the exposed surface of the sample conveying device (4); the material of the sample placement device (2) and the sample conveying device (4) are both stainless steel or quartz glass; The sample placement device (2) and the sample transport device (4) are both in the shape of a circular tube, and the sample transport device (4) comprises a large diameter section and a small diameter section; one end of the sample placement device (2) is nested in the large diameter section of the sample transport device (4); an O-ring (3) is used to slide and seal between the sample placement device (2) and the large diameter section of the sample transport device (4); The branch port (7) is located at the large diameter section of the sample conveying device (4) and is used to introduce the internal standard calibration gas (6). When the internal standard gas is not introduced, the branch port (7) is in a closed state. The non-embedded end of the sample placement device (2) is used to introduce the purge gas. A quartz wool or Cambridge filter (10) for filtering is placed at the port of the embedded end. The purge gas is introduced from front to back. Along the direction of introduction of the purge gas, the solid sample (11) to be tested is placed at the front end of the quartz wool or Cambridge filter (10) for filtering. The heating temperature of the tubular furnace heating device (5) can be adjusted within the range of 100 to 800° C.; the through hole is a circular hole located in the middle of the tubular furnace and is used to be embedded in the large diameter section of the sample conveying device (4); the solid sample (11) to be tested is placed at the center of the heating of the tubular furnace heating device (5); Along the direction of the purge gas, the surface of the sample conveying device (4) at the rear end of the tubular furnace heating device (5) is covered with insulating mica paper; the resistance heating wire (8) is wound around the outer surface of the mica paper; the temperature of the resistance heating wire can be adjusted within the range of 100 to 300°C.

2. An application of the complex sample high-temperature thermal analysis sampling device according to claim 1 in an analytical instrument. During the application, the port of the small-diameter section of the sample conveying device (4) is used to connect to the gas analyzer interface.

3. The use according to claim 2, characterized in that: The gas analyzer interface is a capillary (9) interface for mass spectrometry sampling; the complex sample is a tobacco sample; during the analysis of the tobacco sample, the heating temperature of the tubular furnace heating device (5) is 100 to 800° C.; the heating temperature of the resistance heating wire (8) is 180 to 300° C.; the ionization source of the mass spectrometer is a low-pressure photoionization mass spectrometer, the ionization source pressure is 1 to 100 Pa, and the ionization zone heating temperature is 180 to 300° C.

4. The use according to claim 3, characterized in that: During the analysis of the tobacco sample, the heating temperature of the tubular furnace heating device (5) is 300-500°C; the heating temperature of the resistance heating wire (8) is 180-200°C; the ionization source of the mass spectrometer is a low-pressure photoionization mass spectrometer, the ionization source pressure is 30-60 Pa, and the heating temperature of the ionization zone is 180-200°C.

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