JP5120303B2 - Gas chromatograph and gas chromatograph mass spectrometer - Google Patents

Description

  The present invention relates to a gas chromatograph and a gas chromatograph mass spectrometer, particularly a sample vaporizing chamber thereof.

When split analysis is performed in the gas vaporization sample vaporization chamber, the sample is injected into the insert provided in the sample vaporization chamber with a microsyringe, and the sample is vaporized in the insert. A part of the vaporized sample is introduced into a capillary column and subjected to chromatographic analysis, but the remaining sample is discarded through a split vent.

In this case, in order to improve the reproducibility of the analysis, it is necessary to make the state of vaporization in the insert constant. Therefore, conventionally, silica wool is packed in the insert to make the state of vaporization in the insert constant and improve the reproducibility of analysis (for example, Patent Document 1).

Japanese Patent Laid-Open No. 10-073577

  However, when analyzing a sample containing a solvent with a large vaporization volume such as acetone or methanol, the vaporization volume of the sample injected into the insert may exceed the volume inside the insert. The reproducibility of the peak height will deteriorate. Therefore, in order to suppress vaporization of the sample, it is required to partially lower the temperature of the insert.

On the other hand, if the temperature of the insert is partially lower than the temperature of the heater, if a sample mainly composed of high-boiling components such as essential oils to be analyzed without being diluted with a solvent is vaporized in the insert, The high boiling point component of the sample injected from the syringe into the insert is not vaporized, and the sample remains in the insert, causing a decrease in the reproducibility of the analysis of the sample, and injecting the next sample into the insert for vaporization. In this case, the remaining sample is affected and detected as carry-over.

Therefore, in the prior art, there was no sample vaporization chamber capable of measuring both a sample containing a solvent having a large vaporization volume and a sample mainly composed of a high boiling point component with high reproducibility. Therefore, in the present invention, there is provided a sample vaporization chamber of a gas chromatograph or a gas chromatograph mass spectrometer capable of measuring both a sample containing a solvent having a large vaporization volume and a sample mainly composed of a high boiling point component with high reproducibility. The purpose is to do.

  The invention made in order to solve the above-mentioned problems is a gas chromatograph comprising a housing in which an insert is inserted and a sample vaporizing chamber having a heater block for heating the housing, wherein the insert of the housing and the heater block is provided. A sample introduction side to the housing, a gap provided between the housing and the heater block, and a shape that can be inserted into the gap, and is detachable to conduct heat generated from the heater block to the housing It is a gas chromatograph characterized by including a heat conductive spacer.

According to the invention, by providing a gap between the housing and the heater block, an air layer is formed between the housing and the heater block, and the heat of the heater is made difficult to be transmitted to the upper portion of the insert. It becomes possible to make it lower than the temperature of a heater. Therefore, vaporization of the sample can be suppressed, and a sample containing a solvent having a large vaporization volume can be analyzed with high reproducibility.

On the other hand, when measuring samples with high-boiling components as the main component, heat conduction spacers are installed in the gaps to improve heat conduction between the heater block and the housing where the gaps are provided. This suppresses the temperature drop at the top of the insert caused by this. And even when a space is provided, it becomes possible to prevent the high boiling point component of the sample from remaining in the insert without being vaporized. In addition, it is possible to prevent a decrease in reproducibility of analysis of the sample and to prevent carryover, and it is possible to analyze a sample having a high-boiling component as a main component with high reproducibility.

As described above, it is possible to provide a gas vaporization sample vaporization chamber capable of measuring both a sample containing a solvent having a large vaporization volume and a sample mainly composed of a high-boiling component with high reproducibility.

For users who only analyze samples containing a solvent with a large vaporization volume, a gas chromatograph is provided without a heat conducting spacer in the gap, while only analysis of samples containing high-boiling components as the main component. For users who do this, if a gas chromatograph is provided with a heat conducting spacer attached to the gap, both users can simply attach and remove the heat conducting spacer and do not change the design of other parts. In contrast, it is possible to provide a gas chromatograph with excellent reproducibility of analysis of a sample containing a solvent having a large vaporization volume or a sample mainly composed of a high boiling point component, and is excellent in cost and management. Can be manufactured.

In addition, for users who analyze both samples containing solvents with a large vaporization volume and samples containing high-boiling components as the main component, the user must attach and detach the heat-conducting spacer, depending on the nature of the sample to be analyzed Thus, it is possible to manufacture a gas chromatograph capable of measuring both a sample containing a solvent having a large vaporization volume and a sample containing a high-boiling component as a main component with good reproducibility.

It is the schematic of the state which removed the heat conductive spacer of the sample vaporization chamber of the gas chromatograph which concerns on this invention. It is a temperature distribution figure inside an insert in the state where a heat conduction spacer of a sample vaporization room of a gas chromatograph concerning the present invention was removed. It is the schematic of the state which mounted | wore the heat conductive spacer of the sample vaporization chamber of the gas chromatograph which concerns on this invention. It is a temperature distribution figure inside an insert in the state where a heat conduction spacer of a sample vaporization chamber of a gas chromatograph concerning the present invention was equipped.

Hereinafter, embodiments of a gas chromatograph according to the present invention will be described. FIG. 1 is a schematic view of a split / splitless sample vaporization chamber of a gas chromatograph according to the present invention.

A housing 1 is provided in the sample vaporization chamber of the gas chromatograph. An insert 2 is inserted into the housing 1 and the sample is vaporized in the insert 2. A carrier gas supply pipe 61 is provided in the upper part of the sample vaporization chamber, and a part of the carrier gas supplied from the carrier gas supply pipe 61 enters the capillary column 4, but the rest is the inner wall of the housing 1. And flow out of the system from the split vent 5 through a gap provided in the outer wall of the insert 2. Pyrex glass, quartz glass, or the like is used as the material for the insert 2.

The housing 1 is heated to an appropriate temperature (for example, 250 ° C.) by the heater 21 through the heater block 22.

In this manner, the housing 1 serves as a case for the insert 2, serves to form an inflow passage to the split vent 5, and serves to transfer heat generated by the heater 21 to the insert 2.

In addition, after the sample to be analyzed is placed in the microsyringe 6, the needle 7 of the microsyringe 6 penetrates the septum 8, and the tip of the needle 7 is introduced into the insert 2. Then, a sample is discharged from the tip of the needle 7 of the microsyringe 6 and is vaporized uniformly in the silica wool 9 disposed immediately below the sample. Part of the vaporized sample is introduced into the capillary column 4 along the flow of the carrier gas, and the rest flows out of the system from the split vent 5.

  According to the present invention, in the sample vaporization chamber of the gas chromatograph as described above, a space 31 provided between the housing 1 and the heater block 22 is provided on the sample introduction side of the housing 1 and the heater block 22 into the insert 2. As a result, an air layer is formed, and the heat of the heater 21 is hardly transmitted to the upper portion of the insert 2. In this way, the temperature of the upper part of the insert 2 can be made lower than the temperature of the heater 21.

  Since the air gap 31 forms an air layer between the housing 1 and the heater block 22 and makes it difficult for the heat of the heater 21 to be transmitted to the upper part of the insert 2, the thickness should be such that the air layer can be formed. There is no particular limitation. For example, when the length of the insert 2 is 100 mm, heat transfer can be sufficiently suppressed even if the thickness of the gap 31 is about 0.5 mm. The location of the gap 31 is not particularly limited as long as it is on the sample introduction side of the housing 1 and the heater block 22 into the insert 2.

  The height of the gap 31 is not particularly limited because the height of the gap 31 is proportional to the size of the portion where the temperature in the insert needs to be lowered in order to suppress the sample vaporized in the vaporization chamber. For example, when the length of the insert 2 is 100 mm, the amount of vaporization of the sample can be sufficiently suppressed even if the height of the gap 31 is about 10 mm.

  From the above, since the temperature of the upper portion of the insert 2 is lowered by providing the gap 31, the vaporization volume of the sample injected into the sample vaporization chamber can be suppressed. And when analyzing the sample containing a solvent with large vaporization volume, such as acetone and methanol, it becomes possible to prevent the volume of the sample to vaporize from exceeding the volume inside insert 2.

In this case, the temperature distribution inside the insert 2 is as shown in FIG. Comparing the temperature distribution 41 of the heater block with the temperature distribution 42 inside the insert when the heat conducting spacer is not installed, the gap 31 is provided, so that the upper portion of the insert 2 in the temperature distribution 42 inside the insert when the heat conducting spacer is not installed. This part is lower than the temperature distribution 41 of the heater block. In addition, since the temperature of the heater is high at the center and often decreases as it goes from the center to the upper end and the lower end, the temperature at both ends is lower than that at the center in FIG.

On the other hand, when analyzing a sample mainly composed of a high-boiling component, if the sample is injected into the insert 2 in a state where the gap 31 is provided and the temperature of the insert 2 is partially reduced, The high boiling point component is not vaporized and remains in the insert 2, causing a decrease in the analytical reproducibility of the sample, and when the next sample is injected into the insert 2 and vaporization is attempted, It will be affected and will be detected as carry-over.

Therefore, in the present invention, as shown in FIG. 3, when a sample mainly composed of a high boiling point component is measured, a heat conducting spacer 32 is attached to the gap 31 for analysis. When the heat conducting spacer 32 is attached to the gap 31, the heat conduction between the heater block 22 and the housing 1 in the gap 31 is improved, and the temperature drop at the upper portion of the insert 2 caused by providing the gap can be suppressed.

The shape of the heat conductive spacer 32 is not particularly limited as long as it can be inserted into the gap 31 provided between the housing 1 and the heater block 22. However, considering the ease of processing, it is considered that the shape of the air gap 31 is generally cylindrical, so that the shape of the heat conductive spacer 32 is also generally cylindrical. Conceivable.

The material of the heat conductive spacer 32 is not particularly limited as long as the material has better heat conductivity than air. For example, since metal has high thermal conductivity, it is conceivable to use stainless steel or aluminum.

However, if the same material is selected for the housing 1 and the heat conducting spacer 32, the contact surface between the heat conducting spacer 32 and the housing 1 may be welded when the heat conducting spacer 32 is inserted into the gap 31. Therefore, it is desirable to select different materials for the heat transfer spacer 32 and the housing 1.

As described above, by attaching the heat conductive spacer 32 to the gap 31, the temperature of the upper portion of the insert 2 can be increased to the same level as when the gap 31 is not provided, and the high boiling point component is the main component. The vaporization of the high boiling point component of the sample can be promoted, and the high boiling point component of the sample can be prevented from remaining in the insert 2. Therefore, it is possible to prevent a decrease in reproducibility of analysis of the sample and to prevent carry-over, and it is possible to analyze a sample having a high-boiling component as a main component with high reproducibility.

In this case, the temperature distribution inside the insert 2 is as shown in FIG. Comparing the temperature distribution 42 inside the insert when the thermal conductive spacer is not installed with the temperature distribution 43 inside the insert when the thermal conductive spacer is installed, the gap 31 is provided in the temperature distribution 42 inside the insert when the thermal conductive spacer is not installed. The temperature above the insert 2 that has been lowered due to this is approaching the heater block temperature 41 in the temperature distribution 43 inside the insert when the heat conducting spacer is mounted. Therefore, the temperature above the insert 2 is higher when the heat conductive spacer 32 is attached than when the gap 31 is provided and the heat conductive spacer 32 is not attached.

  Thus, when analyzing a sample containing a solvent having a large vaporization volume in a gas chromatograph including a sample vaporization chamber provided with a gap 31 above the housing 1 and the heater block 22 of the insert 2, the gap In the case where the analysis is performed with the heat conducting spacer 32 removed from the sample 31 and a sample mainly composed of a high boiling point component is analyzed, the vaporized volume is obtained by performing the analysis with the heat conducting spacer 32 mounted in the gap 31. It is possible to analyze both a sample containing a large solvent and a sample containing a high-boiling component as a main component with good reproducibility.

  In particular, high-accuracy analysis methods such as split analysis require reproducibility of the analysis, so the effect of the present invention is great. However, the present invention can also be used in other analysis methods such as splitless analysis. It is.

  Moreover, although the sample vaporization chamber used for a gas chromatograph has been described so far, the sample vaporization chamber according to the present invention can also be used for a sample vaporization chamber of a gas chromatograph mass spectrometer.

DESCRIPTION OF SYMBOLS 1 Housing 2 Insert 3 O-ring 4 Capillary column 5 Split vent 6 Micro syringe 7 Needle 8 Septum 9 Silica wool 21 Heater 22 Heater block 31 Air gap 32 Thermal conduction spacer 41 Temperature distribution of the heater block 42 Inside of the insert when the thermal conduction spacer is not installed Temperature distribution 43 Temperature distribution inside the insert when the heat conducting spacer is mounted 61 Carrier gas supply pipe

Claims (2)

In a gas chromatograph comprising a housing in which an insert is inserted and a sample vaporizing chamber having a heater block for heating the housing,
A sample introduction side of the housing and the heater block into the insert, and a gap provided between the housing and the heater block;
A gas chromatograph comprising a removable heat conducting spacer that is insertable into the gap and conducts heat generated from the heater block to the housing. A gas chromatograph mass spectrometer comprising the gas chromatograph according to claim 1.

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