Method for determining impurities in benzene series pure liquid by gas chromatography-mass spectrometry and gas chromatograph-mass spectrometer

Abstract

The invention is applicable to the technical field of chemical analysis and detection, and provides a method for determining impurities in benzene series pure liquid by gas chromatography-mass spectrometry, which comprises the following steps: connecting a passivation diverter to an outlet of a chromatographic column, and respectively connecting the passivation diverter to a sample inlet of a mass spectrometry detector and a sample inlet of a gas chromatography detector through two damping columns; injecting a pure liquid sample; a sample is separated by a chromatographic column, and then enters a mass spectrometry detector and a gas chromatography detector through a passivation flow divider respectively; according to the method for determining the impurities in the benzene series pure liquid through the gas chromatography-mass spectrometry, a passivation flow divider is installed at an outlet of a chromatographic column and is connected to a sample inlet of the mass spectrometry detector and a sample inlet of the gas chromatography detector respectively, and the mass spectrometry detector and the gas chromatography detector respond at the same time to conduct qualitative and quantitative analysis. And simultaneous response of a one-needle sample injection mass spectrum part and a gas chromatography part is realized, and the response time of each component impurity is consistent. The operation of replacing parts is reduced, and the working efficiency and the analysis quality are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical analysis and detection, and in particular relates to a method for determining impurities in a benzene series pure liquid by using gas chromatography-mass spectrometry. Background Art

[0002] When preparing gas standard substances, accurate qualitative and quantitative analysis of raw pure gas (liquid) and its impurities is crucial. Gas chromatograph can use area normalization method or external standard method to quantitatively analyze raw pure gas (liquid), but it cannot qualitatively analyze; mass spectrometer can qualitatively analyze raw pure gas (liquid), but it cannot accurately quantify; gas chromatography-mass spectrometry technology can combine the qualitative advantages of mass spectrometry and the quantitative advantages of gas chromatography, so as to accurately qualitatively and quantitatively analyze raw pure gas (liquid) and its impurities, and is widely used in environmental protection, medicine, pesticides and stimulants.

[0003] At present, when analyzing a certain component, the chromatographic column needs to be disassembled and assembled, and at least two injections are required to qualitatively and quantitatively analyze the pure gas (liquid) of the raw material. This operation is complicated, inefficient, time-consuming, inaccurate in qualitative and quantitative analysis, and shortens the service life of the instrument. Summary of the invention

[0004] The present invention provides a method for determining impurities in a benzene series pure liquid by gas chromatography-mass spectrometry, aiming to solve the above-mentioned problem.

[0005] The present invention is achieved by a method for determining impurities in a pure liquid of benzene series by gas chromatography-mass spectrometry, comprising the following steps: Prepare a gas chromatograph-mass spectrometer, connect a passivation splitter to the outlet of the chromatographic column and connect it to the inlet of the mass spectrometer detector and the inlet of the gas chromatograph detector respectively; Pure liquid injection: quantitatively deliver the prepared benzene series pure liquid sample into the chromatographic column through an automatic sample injector; The sample is separated by a chromatographic column and then enters a mass spectrometer detector and a gas chromatograph detector respectively through a passivation splitter; The mass spectrometer detector and gas chromatography detector respond simultaneously for qualitative and quantitative analysis.

[0006] Preferably, the injection volume of the pure liquid is 0.5 μL, the injection port temperature is 250° C., and the injection method is split (1:30) / (1:10).

[0007] Preferably, the chromatographic column is Rtx-1 MS (60m×0.32mm×0.5μm), the column temperature program is: column temperature 35°C for 2min, temperature program increased to 140°C at 20°C / min, temperature program increased to 300°C at 10°C / min, maintained for 10min, temperature program increased to 190°C at 20°C / min, maintained at constant temperature for 9min, the carrier gas is helium, the control mode is constant pressure mode 280kpa, the chromatographic column flow rate is 3.11ml / min, the tail blow flow rate is 10ml / min, the hydrogen flow rate is 40ml / min, and the air flow rate is 400ml / min.

[0008] Preferably, the ion source is an EI source and the temperature is 200°C, the interface temperature is 250°C, the FID detector temperature is 300°C, the detector voltage selection is relative to the tuning result, the qualitative acquisition mode is SCAN, the scanning range is M / Z 2-450, and the damping column×2: 0.5m×0.18mmID.

[0009] The present invention also provides a gas chromatography-mass spectrometry instrument, comprising a gas chromatography part and a mass spectrometry part, which is applied to the above-mentioned method for determining impurities in a pure liquid of benzene series by gas chromatography-mass spectrometry. The chromatographic column outlet of the gas chromatography unit is connected to a passivation splitter and is respectively connected to the mass spectrometry detector inlet and the gas chromatography detector inlet.

[0010] Preferably, the gas chromatograph-mass spectrometer further comprises an installation unit for installing the instrument body, and the installation unit comprises: A bottom plate, used to place the instrument body; Side panels are fixed at both ends of the bottom plate and located on both sides of the instrument body.

[0011] Preferably, an auxiliary component is installed on the side panel, and the auxiliary component includes: Mounting seats fixed to the outer side walls of the side panels at intervals up and down; A plurality of vertical rods are connected between the two mounting bases; A protective plate is arranged outside the vertical rod, and a compression spring is fixedly connected between the protective plate and the mounting seat; A cross rod group connected between the middle of the protective plate and the vertical rod, the cross rod group is composed of two cross-arranged support rods hinged in the middle, the ends of the two support rods close to the protective plate are hinged with sliders, the sliders are slidably connected to the protective plate, and the ends of the two support rods close to the vertical rod are hinged with movable sleeves, the movable sleeves are sleeved on the vertical rods, and the movable sleeves can move along the vertical rods; A tension spring between two movable sleeves connected to the same vertical rod.

[0012] Preferably, the vertical rod is rotatably connected to the mounting seat, and the vertical rod is provided with symmetrical bidirectional outer spiral rod sections, and the two outer spiral rod sections are respectively provided with inner spiral sleeves, and a third connecting rod is hinged on the side wall of the inner spiral sleeve, and one end of the third connecting rod away from the inner spiral sleeve is hinged to the protective plate, and the bottom end of the vertical rod can drive the connection moving mechanism for moving the instrument body.

[0013] Preferably, the moving mechanism comprises: A worm screw fixed to the bottom end of the vertical rod; A worm wheel is arranged on one side of the worm and can mesh with the worm, the worm wheel is rotatably mounted on the telescopic end of the electric push rod, the electric push rod is fixed to the side plate, and the worm wheel can be separated from or meshed with the worm by extending or shortening the electric push rod; A first connecting rod having one end hinged to the side plate, and a moving wheel rotatably mounted on the other end of the first connecting rod; A second connecting rod has one end eccentrically hinged to the worm gear, and the other end of the second connecting rod is hinged to the first connecting rod.

[0014] Preferably, a first synchronous wheel is fixed on all the worms, a second synchronous wheel is installed on each corner of the base plate, and a synchronous belt is connected between the first synchronous wheel and the second synchronous wheel.

[0015] Compared with the prior art, the embodiments of the present application have the following beneficial effects: The method for determining impurities in a pure liquid of benzene series by gas chromatography-mass spectrometry provided by the present invention comprises installing a passivation splitter at the outlet of a chromatographic column and connecting the mass spectrometer detector inlet and the gas chromatography detector inlet respectively, so that a mass spectrometer part and a gas chromatography part can respond simultaneously with one needle injection, and the response time of impurities of each component is consistent, thereby reducing the operation of replacing parts and components and improving work efficiency and analysis quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a flow chart of a method for determining impurities in a pure liquid of benzene series by gas chromatography-mass spectrometry provided in Example 1 of the present invention; Figure 2 It is a connection diagram of an automatic sampler, a chromatographic column, a passivation splitter, a gas chromatograph detector, and a mass spectrometer detector in a method for determining impurities in a pure liquid of benzene series by gas chromatography-mass spectrometry provided in Example 1 of the present invention; Figure 3 is a schematic diagram of a gas chromatography-mass spectrometer provided in Example 2 of the present invention; Figure 4 yes Figure 3 A partial enlarged view of the Figure 5 It is a top view of a first synchronous wheel, a second synchronous wheel and a synchronous belt in a gas chromatography-mass spectrometer provided in Example 2 of the present invention.

[0017] Notes on the figure markings: 100, automatic sample injector; 200, chromatographic column; 300, passivation splitter; 400, damping column; 500, gas chromatograph detector; 600, mass spectrometer detector; 1, bottom plate; 2, side plate; 3, first connecting rod; 4, moving wheel; 5, second connecting rod; 6, worm gear; 7, compression spring; 8, protective plate; 9, third connecting rod; 10, slide groove; 11, slider; 12, cross rod group; 13, tension spring; 14, movable sleeve; 15, mounting seat; 16, instrument body; 17, inner spiral sleeve; 18, vertical rod; 19, first synchronous wheel; 20, electric push rod; 21, worm; 22, second synchronous wheel; 23, synchronous belt. DETAILED DESCRIPTION

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0019] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0020] Example 1 The embodiment of the present invention provides a method for determining impurities in a pure liquid of benzene series by gas chromatography-mass spectrometry, such as Figure 1-Figure 2 As shown, the following steps are included: Prepare a gas chromatograph-mass spectrometer, connect a passivation splitter to the outlet of the chromatographic column, install the passivation splitter in the chamber where the chromatographic column is located, and connect the passivation splitter to the mass spectrometer detector inlet and the gas chromatograph detector inlet respectively through two damping columns; Pure liquid injection: quantitatively inject the prepared benzene series pure liquid sample into the chromatographic column through an automatic sample injector. In this embodiment, the sample is pure ethylbenzene liquid; The sample is separated by a chromatographic column and then enters a mass spectrometer detector and a gas chromatograph detector respectively through a passivation splitter; The mass spectrometer detector and gas chromatography detector respond simultaneously for qualitative and quantitative analysis.

[0021] In this embodiment, the injection volume of pure liquid injection is 0.5 μL, the injection port temperature is 250°C, the injection method is split (1:30) / (1:10), and the chromatographic column is Rtx-1 MS (60m×0.32mm×0.5μm), column temperature program: column temperature 35℃ for 2min, temperature program rise to 140℃ at 20℃ / min, temperature program rise to 300℃ at 10℃ / min, hold for 10min, temperature program rise to 190℃ at 20℃ / min, hold at constant temperature for 9min, carrier gas is helium, control mode is constant pressure mode 280kpa, column flow rate 3.11ml / min, tail flow rate 10ml / min, hydrogen flow rate 40ml / min, air flow rate 400ml / min, ion source is EI source and the temperature is 200℃, interface temperature 250℃, FID detector temperature 300℃, detector voltage selection is relative to the tuning result, qualitative acquisition mode SCAN, scanning range M / Z 2-450 damping column×2: 0.5m×0.18mmID.

[0022] The present invention installs a passivation splitter at the outlet of the chromatographic column and connects the mass spectrometer detector injection port and the gas chromatography detector injection port respectively, so that the mass spectrometer part and the gas chromatography part of one needle injection all respond simultaneously, the response time of impurities of each component is consistent, the operation of replacing parts is reduced, and the work efficiency and analysis quality are improved.

[0023] Example 2 An embodiment of the present invention provides a gas chromatograph-mass spectrometer. The instrument body can be a Shimadzu gas chromatograph-mass spectrometer (QP-2020NX), including a gas chromatography part and a mass spectrometer part, and is applied to the method for determining impurities in a pure liquid of benzene series by gas chromatography-mass spectrometry provided in Example 1. The outlet of the chromatographic column 200 of the gas chromatography unit is connected to a passivation splitter 300, and the passivation splitter 300 is respectively connected to the inlet of the mass spectrometer detector 600 and the inlet of the gas chromatograph detector 500 through two damping columns 400.

[0024] During operation, the prepared pure liquid sample of benzene series is quantitatively delivered to the chromatographic column 200 through the automatic sample injector 100, the sample is separated by the chromatographic column 200, and then enters the mass spectrometer detector 600 and the gas chromatography detector 500 respectively through the passivation splitter 300, and the mass spectrometer detector 600 and the gas chromatography detector 500 respond simultaneously to perform qualitative and quantitative analysis.

[0025] In this embodiment, Figure 3-Figure 5 As shown, the gas chromatograph-mass spectrometer further includes a mounting unit for mounting an instrument body 16 .

[0026] Wherein, the installation unit comprises: A bottom plate 1, used for placing an instrument body 16; The side panels 2 fixed at both ends of the bottom plate 1 and located at both sides of the instrument body 16 can be fixed by welding.

[0027] Furthermore, an auxiliary component is installed on the side panel 2, and the auxiliary component includes: Mounting seats 15 fixed to the outer side wall of the side plate 2 at intervals up and down; A plurality of vertical rods 18 are connected between the two mounting seats 15 and can be rotatably connected via bearings; A protective plate 8 is arranged outside the vertical rod 18, and a compression spring 7 is fixedly connected between the protective plate 8 and the mounting seat 15, which can be fixed by welding; A cross rod group 12 connected between the middle of the protective plate 8 and the vertical rod 18, the cross rod group 12 is composed of two cross-arranged support rods hinged in the middle, the ends of the two support rods close to the protective plate 8 are hinged with sliders 11, the sliders 11 are slidably connected to the protective plate 8, in this embodiment, the protective plate 8 is provided with a slide groove 10 for the slider 11 to be slidably connected, the ends of the two support rods close to the vertical rod 18 are hinged with movable sleeves 14, the movable sleeves 14 are sleeved on the vertical rod 18, and the movable sleeves 14 can move along the vertical rod 18; The tension spring 13 connected between the two movable sleeves 14 on the same vertical rod 18 can be hooked with the two movable sleeves 14 at both ends of the tension spring 13, and the tension spring 13 can be sleeved on the vertical rod 18; When a collision occurs, the protection plate 8 moves toward the vertical rod 18, the compression spring 7 is shortened, and at the same time, the protection plate 8 drives the two movable sleeves 14 to move away through the cross rods, and the tension spring 13 is stretched to play a role of buffer protection.

[0028] In this embodiment, the vertical rod 18 is rotatably connected to the mounting base 15, and the vertical rod 18 is provided with symmetrical bidirectional outer spiral rod sections, and the two outer spiral rod sections are respectively provided with inner spiral sleeves 17, and a third connecting rod 9 is hinged on the side wall of the inner spiral sleeve 17, and the end of the third connecting rod 9 away from the inner spiral sleeve 17 is hinged to the protective plate 8, and the bottom end of the vertical rod 18 can drive the connection moving mechanism for moving the instrument body 16.

[0029] In a specific implementation, the moving mechanism includes: The worm 21 fixed to the bottom end of the vertical rod 18 can be fixed in one piece; A worm wheel 6 is provided on one side of the worm 21 and can mesh with the worm 21. The worm wheel 6 is rotatably mounted on the telescopic end of the electric push rod 20. The electric push rod 20 is fixed on the side plate 2. The worm wheel 6 can be separated from or meshed with the worm 21 by extending or shortening the electric push rod 20. A first connecting rod 3 having one end hinged to the side plate 2, and a moving wheel 4 rotatably mounted on the other end of the first connecting rod 3; A second connecting rod 5 is eccentrically hinged to the worm gear 6 at one end, and the second connecting rod 5 is hinged to the first connecting rod 3 at the other end.

[0030] When there is no need to move the position of the instrument body 16, the electric push rod 20 is in an extension action, the electric push rod 20 drives the worm wheel 6 to separate from the worm 21, the moving wheel 4 contacts the table and cannot be supported, the bottom plate 1 is fully in contact with the table, the instrument body 16 cannot move, and the operation is kept stable. The protective plate 8, the compression spring 7, and the tension spring 13 play a buffering and protective role. When it is necessary to move the position of the instrument body 16, the electric push rod 20 is shortened, and the electric push rod 20 shortens to drive the worm wheel 6 to engage with the worm 21, and then the protective plate 8 is pushed toward the direction close to the instrument body 16 with both hands. The protective plate 8 drives the inner spiral sleeve 17 to move relative to the outer spiral rod segment through the third connecting rod 9, so that the outer spiral rod segment drives the vertical rod 18 to rotate, the vertical rod 18 drives the worm 21 to rotate, and the worm 21 drives the worm wheel 6 to rotate. The worm wheel 6 drives the first connecting rod 3 and the moving wheel 4 to rotate downward through the second connecting rod 5, and supports the table, which is convenient for moving the instrument body 16 and saving effort to adjust the position of the instrument body 16.

[0031] Preferably, a first synchronous wheel 19 is fixed on all the worm gears 21, a second synchronous wheel 22 is installed on each corner of the base plate 1, and a synchronous belt 23 is connected between the first synchronous wheel 19 and the second synchronous wheel 22. All the first synchronous wheels 19 are linked by the synchronous belt 23, so that all the worm gears 21 rotate synchronously, and thus all the worm wheels 6 rotate synchronously, so that all the moving wheels 4 rotate downward at the same angle, and all the moving wheels 4 are synchronously supported with the table top to avoid the situation where the instrument body 16 is tilted due to different heights of the moving wheels 4 when moving.

[0032] It should be noted that, for the above embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described order of actions, because according to the present invention, some steps may be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0033] In the embodiments provided in the present application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of the above-mentioned units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be in the form of telecommunication or other forms.

[0034] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0035] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the scope of protection of the invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on these embodiments, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in this field can still combine, add, delete or make other adjustments to the features in the various embodiments of the present invention according to the circumstances without conflict, without making creative work, so as to obtain different other technical solutions that do not deviate from the concept of the present invention in essence, and these technical solutions also belong to the scope of protection of the present invention.

Claims

1. A method for determining impurities in a pure liquid of benzene series by gas chromatography-mass spectrometry, characterized in that: The steps include: Prepare a gas chromatograph-mass spectrometer, connect a passivation splitter to the outlet of the chromatographic column and connect it to the inlet of the mass spectrometer detector and the inlet of the gas chromatograph detector respectively; Pure liquid injection: quantitatively deliver the prepared benzene series pure liquid sample into the chromatographic column through an automatic sample injector; The sample is separated by a chromatographic column and then enters a mass spectrometer detector and a gas chromatograph detector respectively through a passivation splitter; The mass spectrometer detector and gas chromatography detector respond simultaneously for qualitative and quantitative analysis.

2. The method for determining impurities in a pure benzene series liquid by gas chromatography-mass spectrometry as claimed in claim 1, characterized in that: The injection volume of pure liquid injection was 0.5 μL, the injection port temperature was 250 °C, and the injection mode was split (1:30) / (1:10).

3. The method for determining impurities in a pure benzene series liquid by gas chromatography-mass spectrometry as claimed in claim 2, characterized in that: The chromatographic column is Rtx-1 MS (60m×0.32mm×0.5μm), and the column temperature program is as follows: running at 35°C for 2min, heating to 140°C at a rate of 20°C / min, heating to 300°C at a rate of 10°C / min, maintaining for 10min, heating to 190°C at a rate of 20°C / min, and maintaining the constant temperature for 9min. The carrier gas is helium, and the control mode is the constant pressure mode of 280kpa. The chromatographic column flow rate is 3.11ml / min, the tail blow flow rate is 10ml / min, the hydrogen flow rate is 40ml / min, and the air flow rate is 400ml / min.

4. The method for determining impurities in a pure benzene series liquid by gas chromatography-mass spectrometry as claimed in claim 3, characterized in that: The ion source is EI source and the temperature is 200°C, the interface temperature is 250°C, the FID detector temperature is 300°C, the detector voltage selection is relative to the tuning result, the qualitative acquisition mode is SCAN, the scanning range is M / Z 2-450, and the damping column × 2: 0.5m×0.18mmID.

5. A gas chromatography-mass spectrometry instrument, comprising a gas chromatography part and a mass spectrometry part, characterized in that: The method for determining impurities in a pure liquid of benzene series by gas chromatography-mass spectrometry as described in any one of claims 1 to 4, wherein the outlet of the chromatographic column of the gas chromatography part is connected to a passivation splitter and connected to the inlet of the mass spectrometer detector and the inlet of the gas chromatography detector respectively.

6. The gas chromatograph-mass spectrometer according to claim 5, characterized in that: Also included is an installation unit for installing the instrument body, the installation unit comprising: A bottom plate, used to place the instrument body; Side panels are fixed at both ends of the bottom plate and located on both sides of the instrument body.

7. The gas chromatograph-mass spectrometer according to claim 6, characterized in that: The side plate is equipped with auxiliary components, which include: Mounting seats fixed to the outer side walls of the side panels at intervals up and down; A plurality of vertical rods are connected between the two mounting bases; A protective plate is arranged outside the vertical rod, and a compression spring is fixedly connected between the protective plate and the mounting seat; A cross rod group connected between the middle of the protective plate and the vertical rod, the cross rod group is composed of two cross-arranged support rods hinged in the middle, the ends of the two support rods close to the protective plate are hinged with sliders, the sliders are slidably connected to the protective plate, and the ends of the two support rods close to the vertical rod are hinged with movable sleeves, the movable sleeves are sleeved on the vertical rods, and the movable sleeves can move along the vertical rods; A tension spring between two movable sleeves connected to the same vertical rod.

8. The gas chromatograph-mass spectrometer according to claim 7, characterized in that: The vertical rod is rotatably connected to the mounting seat, and is provided with symmetrical bidirectional outer spiral rod sections. The two outer spiral rod sections are respectively provided with inner spiral sleeves, and a third connecting rod is hinged on the side wall of the inner spiral sleeve. One end of the third connecting rod away from the inner spiral sleeve is hinged to the protective plate, and the bottom end of the vertical rod can drive the connection moving mechanism for moving the instrument body.

9. The gas chromatograph-mass spectrometer according to claim 8, characterized in that: The moving mechanism comprises: A worm screw fixed to the bottom end of the vertical rod; A worm wheel is arranged on one side of the worm and can mesh with the worm, the worm wheel is rotatably mounted on the telescopic end of the electric push rod, the electric push rod is fixed to the side plate, and the worm wheel can be separated from or meshed with the worm by extending or shortening the electric push rod; A first connecting rod having one end hinged to the side plate, and a moving wheel rotatably mounted on the other end of the first connecting rod; A second connecting rod has one end eccentrically hinged to the worm gear, and the other end of the second connecting rod is hinged to the first connecting rod.

10. The gas chromatograph-mass spectrometer according to claim 9, characterized in that: A first synchronous wheel is fixed on all the worms, a second synchronous wheel is installed on each corner of the base plate, and a synchronous belt is connected between the first synchronous wheel and the second synchronous wheel.

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