JPS5895259A - Sample injecting device of gas chromatograph - Google Patents

Abstract

PURPOSE:To perform a continuous analysis by injecting a sample without disturbing the flow and controlled temperature of a carrier gas and, by providing a stopper storing chamber between a sample vaporizing chamber for gas chromatograph and a column connecting part and connecting a changeover valve to the flow path of the carrier gas. CONSTITUTION:A top purging gas introducing port 8 is provided at the upper side surface of a sample vaproizing chamber 6 and at the same time a stopper storing chamber 15 is provided between an outlet 11 and a column connecting part 7 and a bottom purging gas introducing port 9 is connected thereto. A stopper 10, the conical surface of which is set upward and rises to seal the outlet 11 of the chamber 6 when the inside of the chamber 15 is pressurized, is provided in the chamber 15. The stopper 10 has paths in the upper and lower directions and in the state expressed by figure, the carrier gas passed through the outlet 11 can flow into the part 7. The carrier gas has a branch 16 and is changed over to a carrier gas introducing port 5 and purging gas introducing parts 8, 9 through needle valves 13, 14 by a changeover valve 12. By this way, in case of exchanging a glass insert 4, the exchange can be performed without interrupting an analysis by switching of the valve 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a sample injection device for a gas chromatograph.

FIG. 1 is a sectional view of a conventional sample injection device.

An injection rubber septum 1 is fixed to the opening of the injection robot 3 by a cap 2, and a carrier gas inlet 5 is provided at the bottom of the injection robot 3. A cylindrical glass insert 4 is inserted into the injection port/body 3, that is, into the sample vaporization chamber 6, and the lower part of the insert 4 is connected to a column connection part 7 via an outlet 11.

When introducing a liquid sample into a gas chromatograph, a small syringe is generally used, and the needle penetrates the injection rubber septum 1 and injects the sample into the sample vaporization chamber 6. Since this sample vaporization chamber 6 is heated by a tape heater or the like wound around the injection robot 3, the poured liquid sample is instantaneously vaporized and exits to the column connection section 7 via the outlet 11. The sample gas that has entered the column in this manner is inserted into a carrier gas and its components are separated as it passes through the column. Note that the glass insert 4 installed in the sample vaporization chamber 6 is used to attach high boiling point residues in the sample, and is replaceable.

When replacing the glass insert 4, stop the flow of carrier gas, remove the cap 2 and injection rubber septum 1 after the injection robot 3 has cooled down, take out the glass insert 4 with a bottle set, etc., and clean it at the outlet, or Or replaced it with a new one.

Therefore, it was necessary to protect the column by stopping the carrier gas and lowering the temperature of the column oven. In addition, after replacement, it is necessary to restart the analysis after the column oven has risen to the set temperature and the baseline of the chromatogram has stabilized, which requires a large amount of waiting time each time the glass insert 4 is replaced. was. This has been a major cause of lowering the analytical efficiency of the gas chromatograph.

An object of the present invention is to provide a sample introduction device for a gas chromatograph that allows the glass insert to be replaced without disturbing the carrier gas flow and temperature control conditions of the gas chromatograph by a relatively simple improvement.
Its feature is that a stopper is housed in a stopper housing chamber formed between the sample vaporization chamber and the column connection section, and a switching valve is connected to the carrier gas flow path.

FIG. 2 is a sectional view of a sample injection device which is an embodiment of the present invention, and the same parts as in FIG. 1 are given the same reference numerals. The main point of this invention is that after a -1J sample is injected into the sample introduction device and sent to the column, the carrier gas is transferred to the sample vaporization chamber 6.
It is supplied directly to the column light end without passing through the sample vaporization chamber 6.
The outlet of the sample vaporization chamber 6 is sealed with a stopper 10 so that a separate carrier gas flow path can be provided inside.

A top purge gas inlet 8 is provided on the upper side of the sample vaporization chamber 6, and a space is provided between the outlet 11 and the column connection part 7.
- A buckwheat storage chamber 15 is provided and connected to the bottom purge gas inlet 9. A stopper 10 is installed in the stopper storage chamber 15 so that its conical surface faces upward and can rise to seal the outlet 11 when the inside of the stopper storage chamber 15 is pressurized.

Note that this stopper 10 has a vertical passage as shown in FIG. 2, and in this state, the carrier gas that has passed through the outlet 11 can flow to the column connecting portion 7.

The carrier gas flow path branches into three directions at the branching part 16, the first flow path connects to the top purge gas inlet 8 via the needle valve 13, which is an on-off valve, the second flow path connects to the switching valve 12, and the second flow path connects to the switching valve 12. The flow path 3 is a needle valve 1 which is an on-off valve.
4 through the bottom purge gas inlet 9 and the switching valve 12
The two-way switching valve 12 connected to the other passage is a sliding valve with a fixed part and a rotating part attached to each other, and has a central angle of 60°.
Three communication passages are formed at intervals. This communication path is shown as an actual line in FIG. 2, but it is constructed so that when the rotating part is rotated by 60 degrees, the communication path is switched to the communication path shown in broken lines. Note that this switching valve 12 is connected to the carrier gas inlet 5 and the outlet 18 at the locations shown in the figure.

Next, the operation of the sample introduction device configured as described above will be explained. Inject the sucked sample into the microringe and into the sample vaporization chamber 6 through an injection needle that penetrates the rubber septum 1.
Introduce it inside and vaporize it.

The vaporized sample vapor is transferred to the outlet 11 by the carrier gas flowing in from the carrier gas inlet 5. Stopper storage chamber 1
5 and column connection 7 into the column.

At this time, the switching valve 12 is in the state shown in FIG.
Both needle valves 13 and 14 form gas passages that are slightly opened, and a very small amount of carrier gas is introduced from the top purge gas inlet 8 and the bottom purge gas inlet 9, and the sample vapor is vaporized. It is made so that it does not remain in the chamber 6 or the bottom purge gas inlet 9.

Although the stopper 10 is lowered in the state shown in FIG. 2 due to its own weight and the flow of the carrier gas, the carrier gas is allowed to flow freely through the pores formed in the stopper 10 itself. That is, the sample introduction work can be performed without any trouble.

Next, when replacing the glass insert 4, the switching valve 12 is first rotated 60 degrees to switch to the flow path shown by the broken line. At this time, the carrier gas is supplied from the bottom purge gas inlet 9, so the pressure in the stopper storage chamber 15 increases, causing the stopper 10 to rise and sealing the outlet 11.

On the other hand, a small amount of carrier gas that has passed through the needling pulp 13 is introduced into the sample vaporization chamber 6 through the top purge gas inlet 8, but this gas flows back through the carrier gas inlet 5 and passes through the broken line passage of the switching valve 12. It is discharged from the discharge port 18.

If the camp 2 and the injection rubber septum 1 are removed in this state, the glass insert 4 can be taken out and replaced in the container. Furthermore, during this time, a small amount of carrier gas continues to flow from the top purge gas inlet 8, so that contamination within the sample vaporization chamber 6 is prevented, and trapped air can be easily discharged.

Furthermore, during this time, the carrier gas continues to flow through the column 2, so the next analysis can be performed immediately by switching the switching valve 12 to the solid line state after replacement.

The sample injection device of this example is configured so that the sample vaporization chamber is sealed so that the carrier gas can continue to flow.
Furthermore, by making the glass insert replaceable while the temperature of the column oven is being controlled, analysis efficiency can be significantly improved.

The sample injection device for a gas chromatograph of the present invention has the effect of making it possible to replace the glass insert without disturbing the operating state of the gas chromatograph through a relatively simple improvement, thereby further improving analysis efficiency.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional sample injection device, and FIG. 2 is a sectional view of a sample injection device which is an embodiment of the present invention. 1... Injection rubber septum, 2... Cap, 3...
・Inlet body, 4...Glass insert, 5...
Carrier gas inlet, 6...sample vaporization chamber, 7...
Column connection part, 8...Top burn gas inlet, 9.
...Bottom purge gas inlet, 10...Stopper, 1
1...Outlet, 12...Switching valve, 13114...
- Needle valve, 15...stopper accommodation chamber, 16.
17... Branch, 18... Outlet.

Claims (1)

[Claims] 1. In a gas chromatograph sample injection device having a sample vaporization chamber, a stopper is accommodated in a stopper storage chamber formed between the sample vaporization chamber and the column connection part, and a switching valve is connected to a carrier gas flow path. A sample injection device for a gas chromatograph, which is characterized by: