JP3120611U - Gas chromatograph - Google Patents

Abstract

A gas chromatograph capable of quickly replacing an insert in a sample vaporization chamber is provided.
A gas chromatograph is configured by providing an inert gas conduction path (10) for introducing an inert gas separately from a carrier gas in a sample vaporization chamber (20).
With this configuration, when the insert 3 is replaced, the insert replacement work can be performed in an inert gas atmosphere by blowing an inert gas from the inert gas conduction path 10 into the sample vaporizing chamber 20. Therefore, even if the insert 3 is replaced while the temperature of the sample vaporizing chamber 20 or the column 22 is maintained at a predetermined high temperature, there is no possibility that the insert 3 or the column 22 is deteriorated.
[Selection] Figure 1

Description

  The present invention relates to a gas chromatograph, and more particularly to a sample vaporization chamber of a gas chromatograph.

FIG. 2 shows a flow path configuration of a general gas chromatograph with a sample vaporizing chamber as a center.
In the figure, reference numeral 20 denotes a sample vaporizing chamber having a sample injection port 6 sealed with a septum 5 at the top, and a glass cylindrical insert 3 supported by a seal ring 4 inside. 21 is a flow controller used to control the flow rate of the carrier gas, 22 is a column that separates the vaporized sample fed from the sample vaporizing chamber 20 into components, and 23 is an electric signal that detects the separated components. It is a detector that outputs. Reference numeral 24 denotes a split flow path branched from the sample vaporizing chamber 20 and is opened and closed by a split valve 25.

The gas chromatograph configured as described above operates as follows.
The carrier gas is flow-controlled by the flow controller 21, supplied to the upper part of the sample vaporizing chamber 20 through the carrier gas introduction channel 2, passed through the insert 3 provided therein, and connected to the bottom part of the column. 22 to the detector 23. When the split valve 25 is open, a certain percentage of the carrier gas is discharged through the split flow path 24. The sample vaporization chamber 20 is heated to a temperature equal to or higher than the vaporization temperature of the sample by a heater (not shown).

Several methods are known as a sample introduction method. Among the most common splitless introduction methods, the split valve 25 is closed and a syringe (not shown) is used from the sample injection port 6. A liquid sample is injected into the insert 3 through the septum 5. The liquid sample is vaporized here and carried to the column 22 by the carrier gas. Since the sample is vaporized inside the insert 3, the sample vapor is introduced into the column 22 without contacting the metal inner wall of the sample vaporization chamber 20. Gas chromatography analysis is performed by detecting each component in the sample separated by the column 22 by the detector 23. The split valve 25 is opened by a timer device (not shown) at the timing when most of the sample moves to the column 22, and the solvent vapor remaining in the sample vaporizing chamber 20 is discharged through the split flow path 24, which hinders analysis. Reduces tailing of solvent vapor.
In the case of the split introduction method, the sample is injected with the split valve 25 always open.

Since the insert 3 is in direct contact with the sample as described above, the insert 3 tends to become dirty due to adhesion of a vaporization residue or the like of the sample. The insert 3 is configured to be detachable so that it can be replaced or cleaned when it becomes dirty. In addition, since the insert 3 should not have an adsorption action or a chemical action on the sample components, it is generally made of glass or quartz, but there is also an example in which the inner surface is coated with an inert material ( For example, see Patent Literature 1 and Patent Literature 2).
JP-A-11-101788 Japanese Patent Laid-Open No. 08-262003

Conventionally, when exchanging the insert, the temperature of the sample vaporizing chamber or column is lowered to near room temperature, and the exchange operation is performed after the supply of the carrier gas is stopped. This is also to prevent burns for the operator, but exposing the inner passivated insert to air (oxygen) at high temperatures will cause the deactivation coating to deteriorate. This is because the stationary phase film is oxidized and the column life is shortened by mixing.
However, it takes time to lower the temperature of the sample vaporization chamber, and it is necessary to expel the air that has entered the sample vaporization chamber before raising the temperature after replacing the insert. Met.
This invention is made | formed in view of such a situation, and it aims at providing the gas chromatograph which can replace | exchange the insert in a sample vaporization chamber rapidly.

In order to solve the above-mentioned problems, the present invention forms a gas chromatograph by providing an inert gas conduction path for conducting an inert gas separately from a carrier gas in a sample vaporizing chamber.
With this configuration, when the insert is replaced, the insert replacement operation can be performed in an inert gas atmosphere by blowing the inert gas from the inert gas conduction path into the sample vaporizing chamber.

  Since the present invention is configured as described above, even if the insert is replaced while the temperature of the sample vaporizing chamber or the column is maintained at a predetermined high temperature, the insert or the column is not deteriorated. In addition, since the time required for raising and lowering the temperature can be saved, the replacement work becomes efficient. Furthermore, as a secondary effect, the air mixing prevention function, which is a feature of the present invention, can be effectively utilized when replacing columns and septa.

The gas chromatograph provided by the present invention is characterized in that an inert gas is introduced into the sample vaporizing chamber separately from the carrier gas.
Therefore, the basic configuration of the best mode is a gas chromatograph provided with an inert gas conduction path for introducing an inert gas in addition to the carrier gas into the sample vaporizing chamber.

FIG. 1 shows a cross-sectional view of a sample vaporizing chamber 20 which is an embodiment of the present invention. FIG. 1 shows the sample vaporizing chamber 20 with a particular focus, and the overall flow path configuration as a gas chromatograph not shown in FIG. 1 is based on FIG.
In FIG. 1, reference numeral 1 denotes a metal vaporizing chamber main body which is a main structure of the sample vaporizing chamber 20, 8 a column nut for fixing the column 22, and 9 a seal nut for fastening the seal ring 4 to hold the insert 3. , 7 are septum nuts for fixing the septum 5 in place. Other components denoted by the same reference numerals as those in FIG. 2 are the same as those in FIG.

  A characteristic configuration of the present invention is an inert gas conduction path 10 provided in the lower part of the vaporizing chamber body 1. An inert gas (such as nitrogen) controlled by the electromagnetic valve 26 can be blown into the sample vaporizing chamber 20 through this flow path. Except when the insert 3 or the like is replaced, the electromagnetic valve 26 is closed, and the function of the sample vaporizing chamber 20 is not different from the conventional one, and the analysis can be performed as in the conventional case. Although the supply source of the inert gas is not shown, it may be branched from the supply source of the carrier gas, or a supply source such as a cylinder may be provided separately.

Next, a procedure for replacing the insert 3 in the present embodiment configured as described above will be described.
(1) The supply of the carrier gas is stopped, the electromagnetic valve 26 is opened, and the inert gas controlled to a pressure of about 10 kPa is introduced from the inert gas conduction path 10.
(2) Loosen and remove the seal nut 9, pull out the insert 3, and insert a new insert 3. During this time, since it is purged with an inert gas, air mixing does not occur or even if it is mixed.
(3) Next, the seal nut 9 is tightened. Before completely tightening, the inert gas is leaked from the gap of the seal nut 9 for a while, thereby expelling air that may have been mixed.
(4) Finally, the seal nut 9 is completely tightened, the solenoid valve 26 is closed, and a predetermined carrier gas is supplied to restore the state in which analysis is possible.

  The present invention functions effectively not only for the insert 3 but also for the replacement of the septum 5 and the column 22. The replacement procedure is the same as described above. When the septum 5 is replaced, the septum nut 7 may be loosened, and when the column 22 is replaced, the column nut 8 may be loosened.

  In addition, in order to control an inert gas, you may use not only the solenoid valve 26 shown in FIG. 1, but another control means, for example, an electronically controlled flow control device.

  The present invention can be used for gas chromatographs.

It is a figure which shows one Example of this invention. It is a figure which shows the conventional structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gasification chamber main body 2 Carrier gas introduction flow path 3 Insert 4 Seal ring 5 Septum 6 Sample inlet 7 Septum nut 8 Column nut 9 Seal nut 10 Inert gas conduction path 20 Sample vaporization chamber 21 Flow controller 22 Column 23 Detector 24 Split Flow path 25 Split valve 26 Solenoid valve

Claims (1)

A gas chromatograph having a sample vaporizing chamber for injecting and vaporizing a sample into a detachable insert and having a flow path configured so that a carrier gas flows through the sample vaporizing chamber and flows to a column. A gas chromatograph characterized in that an inert gas conduction path for conducting an inert gas is provided in the chamber separately from the carrier gas.

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