CN112834634A

CN112834634A - Fast gas chromatograph

Info

Publication number: CN112834634A
Application number: CN202011581069.XA
Authority: CN
Inventors: 武杰; 刘军伟
Original assignee: Beijing Jieyu Guangpu Technology Co ltd
Current assignee: Hebei Panyi Analytical Instrument Co ltd
Priority date: 2020-12-28
Filing date: 2020-12-28
Publication date: 2021-05-25
Anticipated expiration: 2040-12-28
Also published as: CN112834634B

Abstract

An embodiment of the present invention provides a gas chromatograph (50) comprising: the sample injector is used for receiving a sample to be detected and the carrier gas; a chromatographic column connected to the sample injector; a detector (60), the detector (60) being connected to a chromatography column; the gas chromatograph (50) further comprises an electronic program boosting system and an electronic program heating system, wherein the pressure range of the electronic program boosting system is 0.1-2.0MPa, and the boosting rate is 0.001-0.1 MPa/min; the temperature range of the electronic temperature programming system is 30-400 ℃, the temperature rising rate is 1-60 ℃/min, and the detector is a mass detector. According to the gas chromatograph provided by the invention, the analysis speed can be improved by 3-5 times, and the resolution can be improved by 3-5 times.

Description

Fast gas chromatograph

Technical Field

The present disclosure relates to the field of analytical instruments, and in particular to a fast gas chromatograph, and more particularly to a high pressure fast gas chromatograph.

Background

Gas chromatographic analysis has become an important method for separating and analyzing mixed volatile organic compounds, is widely applied to many fields, and has a very important position in industrial, agricultural, national defense and scientific research. The conventional gas chromatograph has better separation efficiency and higher detection sensitivity, and along with the development of scientific technology, the gas chromatograph is rapidly developed as a new separation and analysis technology and becomes an indispensable means for analysis, detection, separation and purification.

The working principle of the gas chromatograph is that by using the distribution coefficient between the gas phase and the stationary liquid phase of each component in the sample, when the gasified sample is conveyed into the chromatographic column by the carrier gas, the components are located therein, and because of the different adsorption or dissolution capacities of the components, the components run at different speeds in the chromatographic column, and after a certain column length, they are separated from each other and flow out of the chromatographic column in sequence into the detector, and a current signal is generated and processed by the data processor.

Under the economic condition of big data, the analysis sample amount of environmental detection, food safety, petrifaction and the like is greatly increased, and the requirement for accelerating the analysis speed is met, but the current gas chromatograph cannot fully meet the requirement, for example, the analysis time of a large amount of samples is still maintained at 15-60 minutes, and the analysis time in some application occasions is far from meeting the social requirement. The analysis speed is accelerated, so that the labor cost can be greatly saved.

Moreover, in the existing gas chromatograph, the sample injection pad is adopted in the sample injection section, however, the service life of the sample injection pad is limited, and the sample injection pad needs to be replaced frequently, and about 50 times of sample injection operations need to be replaced, and if the sample injection pad is not replaced in time, the risk of gas leakage exists. In addition, the gas chromatograph in the prior art has the problem of high use cost.

Disclosure of Invention

It is an object of the present disclosure to provide a novel gas chromatograph.

It is also an object of the present disclosure to provide a gas chromatograph that at least partially overcomes the drawbacks of the prior art.

It is also an object of the present disclosure to provide a gas chromatograph with faster detection speed.

The present disclosure is also directed to a gas chromatograph, which solves the problem of frequent replacement of the sample injection pad.

It is also an object of the present disclosure to provide a gas chromatograph having a lower use cost.

In order to achieve one of the above purposes, the present disclosure provides the following technical solutions:

a gas chromatograph comprising:

the sample injector is used for receiving a sample to be detected and the carrier gas;

a chromatographic column connected to the sample injector;

a detector coupled to a chromatography column; and

a data acquisition and processing system for acquiring and processing data,

the gas chromatograph also comprises an electronic program boosting system and an electronic program heating system, wherein the pressure range of the electronic program boosting system is 0.1-2.0Mpa, and the boosting rate is 0.001-0.1 Mpa/min; the temperature range of the electronic temperature programming system is 30-400 ℃, the temperature rising rate is 1-60 ℃/min, and the detector is a mass detector.

According to a preferred embodiment of the invention, the sample injector is a self-closing sample injector, which comprises a sample injector main body and a self-closing valve;

the self-closing valve comprises a valve seat and a valve rod, wherein a sample inlet hole penetrating through the valve seat along the extension direction of the sample injector main body is formed in the valve seat, and the valve rod is arranged in the valve seat and penetrates through the sample inlet hole;

and a sealing ring is arranged at the joint surface of the sample injector main body and the self-closing valve.

According to a preferred embodiment of the invention, the self-closing valve is an electrically controlled normally closed valve, and is opened when a sample is injected, and is closed at the rest time, so as to ensure that the sample inlet is airtight.

According to a preferred embodiment of the present invention, the gas chromatograph further includes a carrier gas switching device and a carrier gas source, the carrier gas source including a nitrogen gas source and a helium gas source;

the nitrogen source and the helium source are respectively communicated with a carrier gas switching device through gas supply pipelines, and the carrier gas switching device is communicated with a carrier gas inlet of the self-closing sample injector;

wherein, a first valve is arranged on a gas supply pipeline communicated with the nitrogen source and the carrier gas switching device, a second valve is arranged on a gas supply pipeline communicated with the helium source and the carrier gas switching device, and the first valve and the second valve are respectively electronic switch valves;

wherein the carrier gas switching device is configured to switch between supplying gas from the nitrogen source to the auto-close injector and supplying gas from the helium source to the auto-close injector.

According to a preferred embodiment of the present invention, the carrier gas switching device is configured to supply the nitrogen gas source to the self-closed sample injector during the pre-and post-preparation process and post-column tail-blowing of the sample, and to supply the helium gas source to the self-closed sample injector during the sample analysis.

According to a preferred embodiment of the invention, the electronic program boost system consists of a digital program pressure controller and an electronic pressure flow control valve.

According to a preferred embodiment of the present invention, the data acquisition rate of the data acquisition processing system is 100 times/second and 200 times/second.

According to a preferred embodiment of the invention, the chromatography column is a photolithographic quartz plate chromatography column or a quartz capillary chromatography column.

According to a preferred embodiment of the invention, the silica plate chromatography column comprises a silica plate composed of a first plate and a second plate arranged in a stack, grooves formed by a photolithography process are respectively arranged on the opposite surfaces of the first plate and the second plate, and the grooves in the first plate and the grooves in the second plate combine to form capillary channels which are sinuously wound in the silica plate.

According to a preferred embodiment of the present invention, the gas chromatograph further comprises a column box, the photolithographic quartz plate chromatographic column is arranged in the column box, and a heater and a fan are further arranged in the column box;

wherein the volume of the column box is 3-5 liters, and the heating power of the heater is 1-2 kilowatts.

According to a preferred embodiment of the present invention, the inner wall of the capillary channel formed by the combination of the grooves in the first plate and the grooves in the second plate is coated with a mixed stationary phase of methylphenylpolysiloxane and polymethylsiloxane in a weight ratio of 1: 1.

According to a preferred embodiment of the invention, the lithographic quartz plate chromatography column is connected to the sample injector and the detector by means of joints.

According to a preferred embodiment of the invention, the capillary channel has a length of 5-20 meters and an internal diameter of between 50-150 micrometers.

According to a preferred embodiment of the present invention, a fan is provided in the column box to make the temperature in the column box uniform.

According to a preferred embodiment of the present invention, the column box further comprises an air inlet and an air outlet, and an exhaust fan is provided at an inner side of the column box near the air outlet for actively cooling the column box after the sample analysis is completed.

According to a preferred embodiment of the invention, the sample injector is a double-layer filtering structure comprising a quartz wool filter located upstream and a graphene filter located downstream.

According to the gas chromatograph provided by the embodiment of the invention, the analysis speed is higher by adopting the electronic program boosting system and the electronic program heating system. Because the self-closing sample injector is adopted, the sample injection pad does not need to be frequently replaced, gas leakage is avoided, the stability of detection is ensured, and the use cost is lower. Furthermore, the carrier gas switching device is arranged, so that helium is not used all the time in the analysis process, but is used in the sample analysis process, and helium is not used in the preparation process before and after the sample analysis and tail blowing after the column, so that nitrogen with lower price is used, and therefore, the gas chromatograph has lower use cost.

Drawings

Fig. 1 is a schematic structural diagram of a gas chromatograph according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a self-closing sample injector according to an embodiment of the invention;

FIG. 3 is an enlarged view showing the self-closing valve of the self-closing sample injector;

fig. 4 is a control relationship diagram of a gas chromatograph according to an embodiment of the present invention; and

FIG. 5 is a schematic illustration of a photolithographic quartz plate chromatography column according to an embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present disclosure are described in detail below with reference to the drawings, wherein like or similar reference numerals denote like or similar elements. Furthermore, in the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the disclosure. It may be evident, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in schematic form in order to simplify the drawing.

According to the general inventive concept of the present disclosure, there is provided a fast gas chromatograph including: a carrier gas source for providing a carrier gas; an injector configured to receive a sample to be tested and the carrier gas; a chromatographic column connected to the sample injector; a detector coupled to a chromatography column; the gas chromatograph also comprises an electronic program boosting system and an electronic program heating system, wherein the pressure range of the electronic program boosting system is 0.1-2.0Mpa, and the boosting rate is 0.001-0.1 Mpa/min; the temperature range of the electronic temperature programming system is 30-400 ℃, and the temperature rising rate is 1-60 ℃/min. The gas chromatograph of the invention is a high-pressure rapid gas chromatograph.

Fig. 1 is a schematic structural diagram of a gas chromatograph according to an embodiment of the present invention, and as shown in fig. 1, a gas chromatograph 50 includes: a carrier gas source for providing a carrier gas; a carrier gas switching device 56 for switching the carrier gas supplied from the carrier gas source; an injector configured to receive a sample to be measured and the carrier gas, where the injector employs a self-closing injector 57; a chromatographic column connected to the sample injector; a detector 60, the detector 60 being connected to a chromatography column; and a data acquisition processing system 61.

Specifically, the carrier gas source includes a nitrogen source 51 and a helium source 52, and in the embodiment of fig. 1, the nitrogen source 51 and the helium source 52 are respectively a high-pressure steel cylinder filled with a high-purity gas, i.e., nitrogen or helium, but the present invention is not limited thereto, and the nitrogen source 51 and the helium source 52 may be supplied with gas in other forms. The nitrogen source 51 and the helium source 52 are respectively communicated with a carrier gas switching device 56 through a gas supply pipeline 63, and the carrier gas switching device 56 is communicated with a carrier gas inlet 55 of the self-closing sample injector 57; wherein a first valve 53 is provided on a gas supply pipe 63 communicating the nitrogen gas source 51 and the carrier gas switching device 56, and a second valve 54 is provided on a gas supply pipe 63 communicating the helium gas source 52 and the carrier gas switching device 56, the first valve 53 and the second valve 54 being respectively electronic on-off valves, specifically, they are respectively coupled to an electronic pressure control line. The carrier gas switching device 56 is configured to switch between supplying gas from the nitrogen gas source 51 to the self-closed injector 57 and supplying gas from the helium gas source 52 to the self-closed injector 57.

In the sample analysis, a sample to be detected is added into the sample injector, helium or nitrogen is supplied to the sample injector through a carrier gas switching device according to needs, the pressure of the sample injector is boosted by an electronic program boosting system, and most of the filtered sample is discharged from a discharge port 58 of the sample injector; the other small part enters a chromatographic column of which the temperature is controlled by an electronic temperature programming system, a sample is separated by the chromatographic column and is detected by a detector 60, and then data is input into a data acquisition and processing system 61. The detector 60 is a hydrogen flame ionization detector.

In the embodiment of the present invention, the carrier gas switching device 56 is configured to cause the nitrogen gas source 51 to supply gas to the self-closed sample injector 57 during the preparation process before and after the sample analysis and at the time of post-column tail blowing, and to cause the helium gas source 52 to supply gas to the self-closed sample injector 57 during the sample analysis. The invention adds a carrier gas switching device, and uses N before and after analysis₂N for blowing gas and tail after column₂Gas, He gas was used only during the analysis. Because the price difference of the two carrier gases is 10 times, the use cost of the instrument can be reduced by controlling the use of the carrier gases by a program.

Alternatively, the nitrogen gas source and the helium gas source can be different parts of the same gas cylinder, the gas cylinder is divided into the nitrogen gas source and the helium gas source through an intermediate partition plate, a rotating assembly is arranged on the gas cylinder, a sealing element is arranged between the gas cylinder and the rotating assembly, a gas outlet is arranged on the rotating assembly, the rotating assembly can rotate around the gas cylinder under the action of an actuating element, the gas outlet is switched between the communication with the nitrogen gas source and the helium gas source, two carrier gases can be supplied to the gas outlet at different stages, and therefore only one pipeline is required to be connected with the carrier gas switching device.

Further, the carrier gas switching device may include a base and a rotating disk, the rotating disk abuts against the base, a first inlet and a second inlet are provided on the base, the first inlet and the second inlet are respectively connected with the nitrogen gas source and the helium gas source through pipes, an outlet is provided on the rotating disk, the outlet is connected with the carrier gas inlet of the sample injector, the rotating disk is configured to be rotatable under the action of the actuating element, so that the outlet of the rotating disk moves between a first position communicated with the first inlet and a second position communicated with the second inlet.

The gas chromatograph 50 further comprises an electronic program boosting system and an electronic program heating system, wherein the pressure range of the electronic program boosting system is 0.1-2.0Mpa, and the boosting rate is 0.001-0.1 Mpa/min; the temperature range of the electronic temperature programming system is 30-400 ℃, and the temperature rising rate is 1-60 ℃/min. The pressure control system adopting self-programming consists of a digital program pressure controller and an electronic pressure flow control valve; the temperature raising and lowering speed is accelerated and the analysis period is shortened by adopting a self-programming temperature raising control system which consists of a program controller, a low-pressure heater and a low-heat capacity column box, wherein the temperature precision reaches +/-0.05 ℃.

Referring to fig. 2, the structure of the sample injector of the present invention includes a main body 82, and a first nut 81 and a second nut 83 located at the upper and lower ends of the main body, the first nut 81 and the second nut 83 are screwed on the main body 82, a double-layered silica gel spacer 88 and a spacer support 89 located at the upper end are included in the main body 82, a vertical through hole and a horizontal through hole are provided in the spacer support 89, the horizontal through hole is communicated with a carrier gas inlet 55 of the sample injector, and a lining pipe 90 is further included in the main body 82. The upper end of the lining tube 90 is fixedly connected with the main body 82, a quartz cotton filter 84 and a graphene filter 85 are arranged in the lining tube from top to bottom, the length ratio of the quartz cotton filter 84 to the graphene filter 85 can be 3: 1, the filter is used for preventing impurities such as colloid or asphaltene in samples such as crude oil from polluting or damaging the chromatographic column and the detector, the filtering and collecting efficiency of graphene is higher, and the graphene has smaller pores. The double layer silica gel spacer 88 further ensures the air tightness of the sample injector at high pressure. A funnel-shaped sample injection port is formed at the center of the first nut 81, and a cylindrical hole is formed at the center of the second nut 82; a quartz capillary 87 is connected to the second nut 82 through the cylindrical bore.

It should be noted that the sample injector of the present invention is an auto-sampler 57, and the auto-sampler 57 includes a sample injector main body and an auto-closing valve 70; the self-closing valve 70 comprises a valve seat 71 and a valve rod 72, wherein a sample inlet hole 73 penetrating through the valve seat 71 along the extending direction of the sample injector main body is arranged in the valve seat 71, and the valve rod 72 is arranged in the valve seat 71 and penetrates through the sample inlet hole 73; the interface of the injector body and the self-closing valve 70 is provided with a sealing ring 74.

Wherein, the self-closing valve 70 is an electrically controlled normally closed valve, the self-closing valve 70 is opened when the sample is injected, and the self-closing valve 70 is closed in the rest time.

The invention innovatively develops a self-closing sample injector, the sample injector is opened only when a sample is injected, and the sample injector is automatically closed in the rest time, so that the problems of high pressure air leakage and frequent replacement of a silicon rubber sample injection pad in the repeated use process are solved.

As a preferred embodiment of the present invention, a tapered protrusion is provided on a side of the valve seat 71 facing the first nut 81, and a tapered recess is provided on a side of the valve seat 71 facing away from the first nut 81, a bottom end of the tapered recess being an extension starting point of the sampling hole 73, and the sampling hole 73 penetrates the tapered protrusion.

Preferably, the data collection rate of the data collection processing system 61 is 100-.

Fig. 4 is a control relationship diagram of a gas chromatograph according to an embodiment of the present invention, as shown in fig. 4, switching of a carrier gas switching system is realized by an instrument main control board, and auxiliary gas control is realized; in the sample introduction process, the instrument main control board performs self-closing control on the self-closing sample injector and controls the shunt by controlling the flow control valve at the discharge port; after sample introduction, the instrument main control board performs program pressure rise control and program temperature rise control; the instrument main control board also realizes the control of the detector board and the data acquisition control, and carries out display control and parameter control through the display panel and the control panel.

The chromatographic column of the present invention may be a fine-diameter quartz capillary chromatographic column, preferably a photolithographic quartz plate chromatographic column, having an inner diameter of 50-180 micrometers and internally coated with various analytical requirements stationary phases, which will be described in detail below with reference to fig. 5. the photolithographic quartz plate chromatographic column 59 includes a photolithographic quartz plate 94 composed of a first plate and a second plate arranged in a stacked manner, grooves formed by a photolithographic process are respectively provided on the opposite surfaces of the first plate and the second plate, the grooves in the first plate and the grooves in the second plate form capillary channels in combination, which are bent and coiled in the photolithographic quartz plate 94 to form an inner tube of the column having an inner diameter of 50-150 micrometers, and internally coated with various analytical requirements stationary phases. According to a preferred embodiment of the present invention, the inner walls of the capillary channel formed by the combination of the grooves in the first plate and the grooves in the second plate are coated with various stationary phases for analysis, such as a mixed stationary phase of methylphenylpolysiloxane and polymethylsiloxane in a weight ratio of 1: 1; the capillary channel has a length of 5-20 meters and an internal diameter of 50-200 microns. Specifically, the capillary channel extends from one long side edge of the photolithographic quartz plate 94 in a first direction perpendicular to the long side edge, curves to transition before reaching the opposite long side edge parallel to the long side edge, then extends in a second direction opposite to the first direction, curves to transition before reaching the long side edge, then extends in the first direction, and so on. Both ends of the capillary channel are located on the long side, alternatively both ends of the capillary channel are located on different sides of the quartz plate 94. According to a preferred embodiment of the present invention, the litho quartz plate column 59 is connected to the injector and detector 60 by a connector 92, and on the opposite side of the connector 92 from the litho quartz plate column 59 are an injector end 91 and a detector end 92, respectively, which are both quartz capillary columns. The present invention combines the new photoetching quartz plate chromatographic column with fine capillary column to make the column have inner diameter up to 50-180 micron and length of 5-20 m and various fixed phases coated inside.

The special photoetching quartz plate chromatographic column is used, the conventional quartz capillary chromatographic column is provided with polyimide with an outer coating, the heating can only be carried out to 320 ℃, the photoetching quartz plate chromatographic column does not need the outer coating and can be heated to 350 ℃, the analysis range is expanded, the carbon 45 hydrocarbon can be analyzed to the carbon 70 hydrocarbon, and a new analysis tool is provided for the research and utilization of the heavy and high wax oil in China.

Further, the gas chromatograph 50 further includes a column box 62, the photolithography quartz plate chromatographic column 59 is disposed in the column box 62, and a heater is further disposed in the column box 62; wherein the volume of the column box 62 is 3-5 liters, and the heating power of the heater is 1-2 kilowatts. The high heating power and the small column box can meet the high temperature rate, and the small column box can make the column box quickly return to the initial low temperature state after the analysis is completed, so as to start the next analysis. In addition, a fan is provided in the column box 62 to make the temperature in the column box 62 uniform; the column box 62 further comprises an air inlet and an air outlet, and an exhaust fan is arranged on the outer side, close to the air outlet, of the column box 62, and is used for actively cooling the column box 62 after the sample is analyzed, so that the column box can quickly recover to an initial low-temperature state after the analysis is finished.

According to the gas chromatograph provided by the embodiment of the invention, the electronic program boosting system and the electronic program heating system are adopted, so that the detection speed is higher. Because the self-closing sample injector is adopted, the sample injection pad does not need to be frequently replaced, gas leakage is avoided, the stability of detection is ensured, and the use cost is lower. Furthermore, the carrier gas switching device is arranged, so that helium is not used all the time in the analysis process, but only used in the sample analysis process, and helium is not used in the preparation process before and after the sample analysis and in the tail blowing process after the column, so that nitrogen with lower price is used.

The high-pressure rapid gas chromatograph has the advantages that the analysis speed is 3-6 times faster than that of the conventional gas chromatograph, the resolution ratio is improved by 3-6 times, the analysis time of a large number of samples is shortened to 5-10 minutes from the conventional 15-60 minutes, the high-pressure rapid gas chromatograph can be widely applied to the fields of environmental detection, petroleum, petrifaction, food safety, drug detection and the like, the high-pressure rapid gas chromatograph can become a novel instrument for replacing the conventional gas chromatograph, the application range is wide, the analysis speed is high, the social and economic benefits are obvious, and the instrument is not produced at home and abroad in the market at present.

Although embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure. The scope of applicability of the present disclosure is defined by the appended claims and their equivalents.

List of reference numerals:

50 gas chromatograph

51 Nitrogen gas source

52 helium source

53 first valve

54 second valve

55 carrier gas inlet

56 carrier gas switching device

57 self-closing sample injector

58 discharge port

59 photoetching quartz plate chromatographic column

60 detector

61 data acquisition and processing system

62 column box

63 gas supply duct

70 self-closing valve

71 valve seat

72 valve stem

73 sample inlet

74 sealing ring

81 first nut

82 main body

83 second nut

84 quartz cotton filter

85 graphite alkene filter

86 control valve

87 quartz capillary column

88 silica gel spacer

89 spacer support

90 inner lining pipe

91 sample injector end

92 joint

93 to the detector end

94 photoetching quartz plate

95 chromatographic column.

Claims

1. A gas chromatograph (50) comprising:

a chromatographic column connected to the sample injector;

a detector (60), the detector (60) being connected to a chromatography column; and

a data acquisition processing system (61) for acquiring and processing data,

the method is characterized in that: the gas chromatograph (50) also comprises an electronic program boosting system and an electronic program heating system, wherein the pressure range of the electronic program boosting system is 0.1-2.0Mpa, and the boosting speed is 0.001-0.1 Mpa/min; the temperature range of the electronic temperature programming system is 30-400 ℃, the temperature rising rate is 1-60 ℃/min, and the detector is a mass detector.

2. The gas chromatograph (50) of claim 1, wherein:

the sample injector is a self-closing sample injector (57), and the self-closing sample injector (57) comprises a sample injector main body and a self-closing valve (70);

the self-closing valve (70) comprises a valve seat (71) and a valve rod (72), wherein a sample inlet hole (73) penetrating through the valve seat (71) along the extending direction of the sample injector main body is formed in the valve seat (71), and the valve rod (72) is arranged in the valve seat (71) and penetrates through the sample inlet hole (73);

and a sealing ring (74) is arranged at the joint surface of the sample injector main body and the self-closing valve (70).

3. Gas chromatograph (50) according to claim 2, characterized in that:

the self-closing valve (70) is an electrically controlled normally closed valve, the self-closing valve (70) is opened when a sample is injected, and the self-closing valve (70) is closed at the rest of time to ensure that the sample inlet is airtight.

4. The gas chromatograph (50) of claim 3, wherein:

the gas chromatograph (50) further comprises a carrier gas switching device (56) and a carrier gas source, the carrier gas source comprising a nitrogen gas source (51) and a helium gas source (52);

the nitrogen source (51) and the helium source (52) are respectively communicated with a carrier gas switching device (56) through gas supply pipelines (63), and the carrier gas switching device (56) is communicated with a carrier gas inlet (55) of the self-closing sample injector (57);

wherein, a first valve (53) is arranged on a gas supply pipeline (63) which is communicated with the nitrogen source (51) and the carrier gas switching device (56), and a second valve (54) is arranged on the gas supply pipeline (63) which is communicated with the helium source (52) and the carrier gas switching device (56), and the first valve (53) and the second valve (54) are respectively electronic switch valves;

wherein the carrier gas switching device (56) is configured to switch between supplying gas from the nitrogen gas source (51) to the self-closed injector (57) and supplying gas from the helium gas source (52) to the self-closed injector (57).

5. Gas chromatograph (50) according to claim 4, characterized in that:

the carrier gas switching device (56) is configured to supply the nitrogen gas source (51) to the self-closed sample injector (57) during preparation before and after sample analysis and during post-column tail-blowing, and to supply the helium gas source (52) to the self-closed sample injector (57) during sample analysis.

6. Gas chromatograph (50) according to claim 5, characterized in that:

the electronic program boosting system consists of a digital program pressure controller and an electronic pressure flow control valve.

7. Gas chromatograph (50) according to claim 6, characterized in that:

the data acquisition rate of the data acquisition processing system (61) is 100-.

8. Gas chromatograph (50) according to claim 7, characterized in that:

the chromatographic column is a photoetching quartz plate chromatographic column (59) or a quartz capillary chromatographic column.

9. Gas chromatograph (50) according to claim 8, characterized in that:

the photolithographic quartz plate chromatographic column (59) comprises a photolithographic quartz plate (94) consisting of a first plate and a second plate which are arranged in a stacked mode, grooves formed through photolithographic process are formed in the opposite surfaces of the first plate and the second plate respectively, and the grooves in the first plate and the grooves in the second plate are combined to form a capillary channel which is bent and coiled in the photolithographic quartz plate (94).

10. Gas chromatograph (50) according to claim 9, characterized in that:

the gas chromatograph (50) further comprises a column box (62), the photoetching quartz plate chromatographic column (59) is arranged in the column box (62), and a heater and a fan are further arranged in the column box (62);

wherein the volume of the column box (62) is 3-5 liters, and the heating power of the heater is 1-2 kilowatts.