JPH0680423B2 - Thermal analyzer equipped with gas chromatograph and mass spectrometer - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus in which a gas chromatograph and a mass spectrometer are combined with a thermal analysis apparatus such as a thermogravimetric measuring apparatus or a differential thermal analysis apparatus.

(Prior Art) A thermal analyzer is a thermal decomposition reaction of an inorganic compound or an organic compound,
Alternatively, it is used in research fields such as physical properties of substances containing volatile components.

On the other hand, the mechanism of thermal decomposition can be further theoretically studied by analyzing the gas generated during thermal decomposition. Therefore, it is possible to analyze the gas generated during thermal decomposition by combining a thermal analyzer with an analyzer such as a gas chromatograph, gas chromatograph-mass spectrometer (GC / MS), mass spectrometer, or infrared spectrophotometer. Has been done.

(Problems to be Solved by the Invention) When a thermal analyzer is combined with a gas chromatograph or a gas chromatograph-mass spectrometer, the generated gas for a certain period of time during the thermal decomposition process in the thermal analyzer is trapped, and then the gas chromatograph is used. The analysis is carried out by a tograph or gas chromatograph-mass spectrometer. In that case, there is a problem that the relationship between the generated gas and the thermal decomposition temperature becomes unclear.

When a thermal analyzer is combined with a mass spectrometer or infrared spectrophotometer, the generated gas is generally a mixed gas, but a mass spectrometer or infrared spectrophotometer is not suitable for analyzing a mixture. is there.

This invention is a qualitative analysis of the pyrolysis temperature and evolved gas during pyrolysis.
Equipped with analytical means that can qualitatively and quantitatively measure the gas generated from the reactor of the thermal analysis device in order to clarify the quantification and obtain excellent information for studying the mechanism of the decomposition process. Another object of the present invention is to provide a thermal analysis device.

(Means for Solving Problems) In the apparatus of the present invention, referring to FIG. 1 showing an embodiment, a first carrier gas is flown into a reactor 6 containing a crucible 4, The temperature of the reactor 6 is changed so that the temperature and the physicochemical behavior of the sample in the crucible 4 are measured and the thermal analyzer 2 is connected to the reactor outlet of the thermal analyzer 2. A switching valve 24 for switching a plurality of flow paths, a second carrier gas flow path 28 connected to the switching valve 24, and a switching valve 24 having an inlet for the reactor 6
Alternatively, the trap 30 that is switched to and connected to the carrier gas channel 28 and the inlet by the switching valve 24 are the carrier gas channel 28.
Alternatively, it has a gas chromatograph column 32 switched and connected to the outlet of the trap 30, a mass spectrometer 36, a separator 44 provided between the outlet of the gas chromatograph column 32 and the mass spectrometer 36, and an opening / closing valve 46. And a flow path 34 connected to the reactor 6 by the switching valve 24 provided between the switching valve 24 and the separator 44.

(Operation) Generation from the reactor 6 is performed by switching the switching valve 24 so that the outlet of the reactor 6 of the thermal analysis device is connected to the flow path 34 and opening the open / close valve 46 of the flow path 34. The gas is introduced directly into the mass spectrometer 36 through the separator 44 and is analyzed moment by moment.

When the switching valve 24 is switched so that the outlet of the reactor 6 and the inlet of the trap 30 are connected, the gas generated from the reactor 6 is trapped in the trap 30.

Further, when the switching valve 24 is switched so that the inlet of the trap 30 is connected to the carrier gas flow path 28 and the outlet of the trap 30 is connected to the inlet of the gas chromatograph column 32, various compounds trapped in the trap 30 are obtained. Are separated by the gas chromatograph column 32 and detected by the mass spectrometer 36.

(Example) FIG. 1 shows an example in which a thermobalance, which is a thermogravimetric measuring device, is used as a thermal analyzer and a quadrupole mass spectrometer is used as a mass spectrometer.

A thermobalance 2 has a sample contained in the crucible 4, and the crucible 4 is housed in the reactor 6. A heating furnace 8 is provided outside the reactor 6, and the temperature of the heating furnace 8 is controlled by a temperature controller (not shown) connected to the heating furnace 8. A gas outlet is opened at the lower end of the reactor 6. 10 is a weight for balancing the thermobalance 2.

The thermobalance 2 is housed in a container 12 that is integral with the reactor 6,
A carrier gas inlet 14 is opened in this container 12, and helium or air as a carrier gas is supplied from a flow controller 16 through a valve 18. 20 is a safety valve.

The sample in the reactor 6 is heated in the heating furnace 8, and the gas generated from the sample flows together with the carrier gas supplied from the container inlet 14 from the outlet at the lower end of the reactor 6 through the flow path 22 to form a hexagonal switching valve. Channel 22 as directed to valve 24
The hexagonal valve 24 is connected to the outlet of the reactor 6. The channel 22 can be heated to a predetermined temperature from room temperature to 400 ° C. in order to prevent the gas generated from the sample from being adsorbed.

The hexagonal valve 24 is supplied with a carrier gas (helium) from the flow controller 26, a carrier gas passage 28, an inlet and an outlet of the trap 30, an inlet of the gas chromatograph column 32, and an inlet of a passage 34 connected to the mass spectrometer 36. Are connected. By this switching operation of the hexagonal valve 24, the channel 22 is connected to the inlet of the trap 30 or the inlet of the channel 34,
The carrier gas flow path 28 is connected to the inlet of the trap 30 or the inlet of the gas chromatograph column 32, and the outlet of the trap 30 is switched to be connected to the inlet of the gas chromatograph column 32 or the inlet of the flow passage 34.

The trap 30 passes the gas from the flow path 22 in a cooled state to adsorb and trap the generated gas component from the sample contained in the gas, and releases the adsorbed gas component by being heated.

The inlet portion 38 of the gas chromatograph column 32 is the second
As shown, the flow path 40 connected to the hexagonal valve 24.
And a sample introduction port that is sealed by a rubber stopper 42 and can be injected with a microsyringe. Again, the first
Returning to the figure, the outlet of the gas chromatograph column 32 is connected to the quadrupole mass spectrometer 36 via the separator 44. The separator 44 removes the carrier gas from the supplied gas and increases the concentration of the gas component to be analyzed.

Between the hexagonal valve 24 and the separator 44, there is also a flow path 34 for introducing the gas generated in the reactor 6 directly into the mass spectrometer 36.
An opening / closing valve 46 is provided in the flow path 34, and the opening / closing valve 46 is used to open / close the flow path 34.

Further, in the flow path 34, a splitter that can release the gas in the flow path 34 between the hexagonal valve 24 and the opening / closing valve 46.
48 is provided, and the carrier gas (for example, helium) is supplied from the flow controller 50 through the resistance tube 52. In this way, the carrier gas is added from the flow controller 50 by adjusting the gas flow rate to prevent the spread of the sample at the open / close valve 46 and the spread of the sample between the open / close valve 46 and the separator 44, and the separator 44. Is to improve the separation efficiency of.

Next, the operation of this embodiment will be described for each operation mode.

(A) Thermal analyzer-mass spectrometer direct coupling measurement mode (first
(Fig.) In the hexagonal valve 24, the flow passage 22 is connected to the flow passage 34, the carrier gas flow passage 28 is connected to the inlet of the trap 30, and the outlet of the trap 30 is connected to the inlet of the gas chromatograph column 32. Set valve 24. Also, the flow path 34
The open / close valve 46 is opened.

At this time, the gas generated from the sample flows along with the carrier gas to the reactor 6 → flow channel 22 → hexagonal valve 24 → flow channel 34 → open / close valve 46 → separator 44 → mass spectrometer 36. The flow is analyzed moment by moment.

The gas containing the gas generated from the sample in the flow path 34 is partially discharged from the splitter 48, and the carrier gas is added from the flow controller 50 through the resistance tube 52 to adjust the gas flow rate flowing through the flow path 34. To be done.

Further, the trap 30 and the gas chromatograph column 32 generally flow a carrier gas even when not in use, and in this case also, a small amount (for example, about 5 ml / min) of the carrier gas is indicated by a dashed arrow. Carrier gas flow path 28
→ Hexagon valve 24 → Trap 30 → Hexagon valve 24 → Gas chromatograph column 32 → Flows to separator 44.

(B) Trap mode (FIG. 3) The trap 30 is cooled, and the channel 22 is connected to the inlet of the trap 30 and the outlet of the trap 30 is channeled in the hexagonal valve 24.
The hexagonal valve 24 is set so that the carrier gas flow path 28 is connected to the inlet 34 of the gas chromatograph column 32. Further, the opening / closing valve 46 of the flow path 34 is closed.

At this time, the gas containing the gas generated from the sample flows through the channel 22 → hexagonal valve 24 → trap as shown by the solid line arrow.
The generated gas component is trapped by flowing to 30, and the residual gas flows and is discharged from the hexagonal valve 24 → the flow path 34 → the splitter 48.

In the trap mode, the open / close valve 46 is normally closed, but it may be opened occasionally to monitor the residual gas and led to the separator 44 → the mass spectrometer 36.

In addition, a small amount of carrier gas is flow controller 26-> carrier gas flow path 28-> hexagonal valve 24-> gas chromatograph column 32-> separator 44 as indicated by the dashed arrow.
Is being washed away.

(C) Gas chromatograph-mass spectrometer measurement mode (FIG. 4) The trap 30 is heated, the carrier gas flow path 28 from the flow controller 26 is connected to the inlet of the trap 30 in the hexagonal valve 24, and the outlet of the trap 30 is The hexagonal valve 24 is set so that it is connected to the inlet of the gas chromatograph column 32 and the channel 22 is connected to the channel 34. Further, the opening / closing valve 40 of the flow path 34 is closed.

At this time, the carrier gas from the flow controller 26 is flow channel 28 → hexagonal valve 24 →
Trap 30 → Hexagonal valve 24 → Gas chromatograph column
Flows from 32 to separator 44, and along with that trap 30
The gas generated from the sample trapped in the carrier also moves together with the carrier gas, is separated by the gas chromatograph column 32, is introduced into the mass spectrometer 36 through the separator 44, and is analyzed.

In addition, a small amount of carrier gas is also flown into the container 12 that houses the thermobalance 2, and the reactor 6 →
Flow path 22 → Hexagonal valve 24 → Flow path 34, splitter
Emitted from 48.

Next, FIG. 5 shows a measurement example in the thermal analyzer-mass spectrometer direct connection measurement mode using this embodiment.

60 is the temperature of the reactor 6 in the thermobalance, and 62 is the weight change of the sample corresponding to the temperature change of the reactor 6. Reference numeral 64 represents the total ion intensity detected by the quadrupole mass spectrometer 36, and corresponds to the total amount of gas generated from the sample. The total ionic strength 64 increases where the weight 62 decreases.

66-1 to 66-5 are mass chromatograms, which are the intensities of ions having different m / z (m is a mass number and z is a charge number). The values of m / z collected as the data of the mass chromatogram are the same as those in (B) trap mode and (C) above.
The gas chromatograph-mass spectrometer is separately measured in the measurement mode, the components contained in the generated gas are analyzed from the measurement result, and it is determined based on the analysis result.

By measuring such a mass chromatogram, the relationship between the weight change due to the temperature change and the evolved gas component at each weight change stage becomes clear.

(Effect of the Invention) According to the present invention, by switching the switching valve, the gas generated in the thermal analysis device is directly introduced into the mass spectrometer to measure the change in the generated gas every moment, and the generated gas, Can be once trapped and then switched to a mode in which the gas chromatograph-mass spectrometer separates and identifies. Therefore, by measuring the gas component contained in the generated gas in the measurement mode by the gas chromatograph-mass spectrometer and collecting the ionic strength of m / z of the measured component, the momentary change of the generated gas component can be measured. You will be able to measure.

In both measurement modes, since the flow path from the thermal analysis device to the switching valve is common, the measurement is performed under the same conditions.

As described above, according to the present invention in which both measurement modes are switched by the switching valve, the generated gas analysis at every moment can be correctly performed.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing one embodiment of the present invention as a thermal analyzer-mass spectrometer direct measurement mode, and FIG. 2 is a partial sectional view showing an inlet portion of a gas chromatograph column, FIGS. 3 and 4. 3 is a schematic diagram showing another operation mode of the embodiment, which is a trap mode and a gas chromatograph, respectively.
Corresponds to the mass spectrometer measurement mode. FIG. 5 is a graph showing an example of data measured using the same example. 2 ... Thermobalance, 4 ... Crucible, 6 ... Reactor, 8 ... Heating furnace, 12 ... Vessel, 16,26,50 ... Carrier gas flow controller, 22,34 ... Flow path, 24 …… Hexagon valve, 28
...... Carrier gas flow path, 30 …… Trap, 32 …… Gas chromatograph column, 36 …… Quadrupole mass spectrometer, 44 ……
Separator, 46 ... Open / close valve.

Claims (1)

[Claims] 1. A thermal analyzer for measuring the temperature and the physicochemical behavior of a sample by flowing a first carrier gas into a reactor containing a sample and changing the temperature of the reactor, and this thermal analysis. A switching valve connected to the reactor outlet of the apparatus for switching a plurality of channels, a second carrier gas channel connected to the switching valve, and the inlet by the switching valve to the reactor or the second channel. A trap that is switched to and connected to a carrier gas flow channel, a gas chromatograph column whose inlet is switched and connected to the second carrier gas flow channel or the outlet of the trap by the switching valve, a mass spectrometer, and the gas chromatograph. A separator provided between the outlet of the tograph column and the mass spectrometer; and an opening / closing valve provided between the switching valve and the separator. And a flow path connected to the reactor by a tube.