JPH04274760A - Sample inlet device for gas chromatograph - Google Patents

Abstract

PURPOSE:To easily set a split ratio and also make it applicable not only to a capillary column but Also to a packed column. CONSTITUTION:A first sample vaporizing chamber 2 comprises a septum 4 of a sample injection port, a carrier gas inlet port 6, a split exhaust port 10 having a needle valve 8, a sample collection port 14 having a needle valve 12 and a heater 16 for vaporizing injected sample. A second sample vaporizing chamber 20 is coupled to the sample collection port 14 of the first sample vaporizing chamber 2 via a solenoid valve 22. The sample vaporizing chamber 2 comprises a carrier gas inlet port 24, a column attaching port 28 and a heater 30 for maintaining the sample sent from the first sample vaporizing chamber in a vaporized state.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a gas chromatograph sample introduction device used in a gas chromatograph or a gas chromatograph-mass spectrometer (GC-MS) used as a single analytical instrument, and particularly relates to a sample introduction device for a gas chromatograph used as a single analytical instrument, and particularly for a part of the injected sample. The present invention relates to a sample introduction device equipped with a split-type sample vaporization chamber that introduces only the sample gas into a column together with a carrier gas and discharges the remainder.

0002

[Prior Art] A gas chromatograph equipped with a capillary column is overloaded if all of the injected sample is introduced into the column, so a split-type sample vaporization chamber is provided to introduce only a portion of the injected sample into the column. There is. A conventional split-type sample introduction device is equipped with one sample vaporization chamber, which includes a sample injection port for injecting the sample from the outside, a carrier gas introduction port for supplying carrier gas from the outside, and a flow rate control valve. and a column attachment port for introducing a portion of the sample into the capillary column together with a carrier gas, and a heating means for vaporizing the sample. The split ratio of the sample introduced into the capillary column is controlled by adjusting the flow rate control valve at the split outlet.

0003

Problems to be Solved by the Invention Since the split ratio of the sample is adjusted only by the flow control valve at the split outlet, it is not easy to set the split ratio. The split method is sometimes used not only for capillary columns but also for packed columns to sharpen chromatogram peaks. A packed column requires a larger amount of carrier gas than a capillary column, so if you try to introduce the sample at a large split ratio, such as a 100:1 ratio between the unused amount and the used amount, sample vaporization The total amount of carrier gas introduced into the chamber becomes large, resulting in a large amount of waste, which creates a problem that makes it difficult to use the split method.

SUMMARY OF THE INVENTION An object of the present invention is to provide a split-type sample introduction device that facilitates setting of the split ratio and can be used not only for capillary columns but also for packed columns.

[0005]

[Means for Solving the Problems] In the present invention, two sample vaporization chambers, a first and a second sample vaporization chamber, are provided which are connected in series. The first sample vaporization chamber has a sample injection port for injecting a sample from the outside, a carrier gas inlet for supplying carrier gas from the outside, a split outlet having a first flow rate control valve, and a second flow rate control valve. A sample collection port is provided, and heating means for vaporizing the sample is also provided. The second sample vaporization chamber is connected to the sample collection port via an on-off valve, and is provided with a carrier gas inlet for supplying a carrier gas from the outside and a column attachment port for attaching a column, and is provided with a heating to maintain the vaporized state of the sample. Means are provided.

[0006]

[Operation] The split ratio of the sample mixed with the carrier gas in the first sample vaporization chamber is determined by the opening degree of the first flow rate control valve at the split outlet and the second flow rate control valve at the sample collection port. The sample is split and guided to the second sample vaporization chamber. When the mixed gas of carrier gas and sample is introduced into the second sample vaporization chamber, the on-off valve between both sample vaporization chambers is closed, and the required amount of carrier gas is introduced from the carrier gas inlet of the second sample vaporization chamber. The sample is sent into the column by the pressure of the carrier gas. The liquid sample injected into the first sample vaporization chamber is vaporized by the heating means of the first sample vaporization chamber, and the vaporized state of the sample is maintained in the second sample vaporization chamber by the heating means of the second sample vaporization chamber. Ru.

[0007]

Embodiment FIG. 1 shows an embodiment. 2 is a first sample vaporization chamber, which includes a sample injection port sealed with a septum 4 and a carrier gas inlet 6 to which carrier gas is supplied from the outside.
and a split outlet 10 with a needle valve 8 as a first flow rate regulating valve, and a sample collection port 14 with a needle valve 12 as a second flow rate regulating valve, for vaporizing the injected sample. is equipped with a heater 16. A sample is injected into the sample vaporization chamber 2 through the septum 4 with the microsyringe 18 .

Reference numeral 20 denotes a second sample vaporization chamber, which is connected to the sample sampling port 14 of the first sample vaporization chamber via an electromagnetic valve 22 serving as an on-off valve. The sample vaporization chamber 20 includes a carrier gas inlet 24 through which a carrier gas is supplied from the outside, a column attachment port 28 to which a column 26 is attached, and a heater for keeping the sample sent from the first sample vaporization chamber in a vaporized state. 30 are provided. As the column 26, either a capillary column or a packed column can be used. The outlet of column 26 is led to, for example, a mass spectrometer.

The first sample vaporization chamber 2 is used to split the injected sample, and the second sample vaporization chamber 20 is used to replenish the amount of carrier gas required by the column.

Next, the operation of this embodiment will be explained. The sample injected into the first sample vaporization chamber 2 using the microsyringe 18 is vaporized by heating by the heater 16, mixed with the carrier gas supplied from the carrier gas inlet 6, and the needle valve of the split outlet 10 is mixed with the carrier gas supplied from the carrier gas inlet 6. 8 and the needle valve 12 of the sample sampling port 14, the sample sampling port 14 is branched into a split discharge port 10 and a sample sampling port 14. The sample discharged from the split discharge port 10 is discharged outside the gas chromatograph system. The split ratio can be changed by adjusting the two needle valves 8,12.

When the electromagnetic valve 22 is kept open, a mixed gas of the sample and carrier gas is introduced into the sample vaporization chamber 20 from the sample sampling port 14 . When the sample is introduced into the sample vaporization chamber 20, the electromagnetic valve 22 is closed, and carrier gas is supplied to the sample vaporization chamber 20 from the carrier gas inlet 24. By closing the electromagnetic valve 22, the sample vaporization chamber 20
This prevents the sample from flowing back into the sample vaporization chamber 2.

[0012] In the sample vaporization chamber 20, the carrier gas inlet 24
The sample mixed with the carrier gas from is sent to the column 26 under the pressure of the carrier gas. In the sample vaporization chamber 20, the sample is heated by a heater 30 and maintained in a vaporized state. The present invention is not limited to what is shown in the embodiment of FIG. 1, and each part can be modified in various ways.

[0013]

[Effect of the invention] In the present invention, the sample vaporization chamber is separated into two,
The sample was split using two flow rate control valves in the first sample vaporization chamber, and the carrier gas necessary for the column was replenished in the second sample vaporization chamber. Since the split ratio is set using two flow control valves, the split ratio can be easily set. Since only splitting is performed in the first sample vaporization chamber, a large amount of carrier gas is not required, and the necessary carrier gas is introduced in the second sample vaporization chamber, so the overall amount of carrier gas used is reduced, and the capillary column Split-type sample introduction can be performed not only for a packed column but also for a packed column.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing one embodiment.

[Explanation of symbols]

2 First sample vaporization chamber 4
Sample injection port septum 6
Carrier gas inlet 8, 12 Needle valve 10 Split outlet 14
Sample collection port 18 Micro syringe 16, 30
Heater 20 Second sample vaporization chamber 22
Solenoid valve 24 Carrier gas inlet 26
column

Claims (1)

[Claims] [Claim 1] A sample injection port for injecting a sample from the outside;
Carrier gas inlet for supplying carrier gas from outside,
a first sample vaporization chamber provided with a split discharge port having a first flow rate control valve, a sample collection port having a second flow rate control valve, and a heating means for vaporizing the sample; and an on-off valve in the sample collection port. A second sample vaporization chamber connected via a carrier gas inlet for supplying a carrier gas from the outside, a column attachment port for attaching a column, and a heating means for maintaining a vaporized state of the sample. Gas chromatograph sample introduction device.