JPH10206386A - Hydrogen flame ionization detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the effect of the fluctuation of the base line by fitting a molecular sheave to a part immediately before a nozzle of a detector body to reduce the pollution of a water flow passage. SOLUTION: The hydrogen gas to be fed from a pipe passage 2a passes through an opening 3c, passes molecular sheaves 12 filled in an outer hollow pipe of a column adapter 3a of double tubular structure, leads to a nozzle 4, and is blow out of a nozzle cap 5. The air fed into a detector from a pipe passage 2b is merged with the hydrogen gas to be blown out of the periphery of the nozzle cap 5, and ignited immediately above the nozzle cap 5 to form the hydrogen flame. The sample gas to flow out of the tip of the outlet of a column 1 inside the nozzle cap 5 is ionized in the hydrogen flame, and detected by a collector 8. Because the molecular sheaves 12 are fitted immediately before the nozzle 4, the pollution is completely eliminated by the molecular sheaves 12 even when any part of the hydrogen flow passage is polluted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame ionization detector for a gas chromatograph.

[0002]

2. Description of the Related Art A flame ionization detector used as a detector for a gas chromatograph discharges a sample gas from a nozzle cap provided downstream of an outlet of a column, mixes the hydrogen gas, and burns the mixture in an air atmosphere. It is made to let. FIG. 6 shows a configuration of a conventional hydrogen flame ionization detector. The outlet of the column 1 is configured to pass through the hollow inside of the column adapter 3 screwed to the base 2, pass through the hollow inside of the nozzle 4, and come inside the nozzle cap 5 at the tip of the nozzle. ing. The carrier gas passing through the column 1 and the separated sample are discharged from the nozzle cap 5. Further, a pipe 2a for introducing hydrogen gas and a pipe 2b for introducing air are connected to the side of the base 2, so that the nozzle cap 5 forms a hydrogen flame. Reference numeral 6 denotes an ignition device for igniting hydrogen gas, 7 denotes a high-voltage cable for applying a DC voltage between two electrodes provided on the nozzle cap 5, and a collector 8 is disposed above the nozzle cap 5. Have been. Pure carrier gas (nitrogen, helium, etc.)
When only a mixed gas of hydrogen and hydrogen gas is used, no current flows between the voltages, but when a sample such as an organic compound is mixed in the carrier gas, a current proportional to the amount of the organic compound flows between the electrodes. This is because, when the organic compound or the like burns in the hydrogen flame, ions are generated, and the ions are captured by the collector 8. The analysis is performed by extracting this ion current through the signal cable 11.

[0003]

When a sample is analyzed using a flame ionization detector, if the hydrogen flow path to the flame ionization detector is dirty, the baseline repeatedly fluctuates. The detection sensitivity becomes poor, resulting in poor sensitivity. Therefore, conventionally, in order to remove the contamination of the hydrogen flow path, a molecular sieve tube is provided in the middle of the hydrogen flow path from the hydrogen cylinder to the flame ionization detector as shown in FIG. ing.

[0004] However, in the method in which the molecular sieve pipe is provided in the hydrogen flow path, the dirt upstream of the molecular sieve pipe can be removed, but the influence of the dirt downstream of the molecular sieve pipe cannot be removed. Therefore, the baseline fluctuation due to the contamination of the hydrogen flow path cannot be completely removed.

Accordingly, an object of the present invention is to provide a hydrogen flame ionization detector capable of minimizing the contamination of the hydrogen flow path and removing the influence of the baseline fluctuation for measurement.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a hydrogen flame ionization detector according to the present invention has a molecular sieve built in a flame ionization detector main body.

That is, the hydrogen flame ionization detector of the present invention comprises:
Hydrogen gas and air are supplied to form a hydrogen flame on the nozzle cap of the nozzle provided inside the detector body, and the hydrogen flowing out of the column is introduced into the hydrogen flame to ionize and detect hydrogen. In the flame ionization detection device, a molecular sieve is built in a portion immediately before a nozzle of the detector main body.

In the flame ionization apparatus according to the present invention, by incorporating a molecular sieve in the flame flame ionization apparatus itself as shown in a schematic configuration as shown in FIG. It is one that can be removed.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. FIG. 3 is a configuration diagram of an ionization detection device according to one embodiment of the present invention, and FIGS. 1 and 2 are enlarged views of a portion related to a hydrogen flow path.

In the figure, the same components as those of the prior art shown in FIG. Column 1
Pass through the hollow interior of the adapter 3b screwed to the base 2. The column adapter 3a is located above the adapter 3b.
Is attached. The column adapter 3a has a double tube structure. The column 1 passes through the inner hollow tube of the column adapter 3a, and the molecular sieve 12 is filled in the outer hollow tube. An opening 3c is formed near the lower end of the outer tube wall of the column adapter 3a.
On the other hand, an outlet of a conduit 2a for hydrogen gas is formed in the base 2 at a position facing the opening 3c. Therefore, the hydrogen gas passes through the pipe 2 a, the opening 3 c and the molecular sieve 12, enters the hollow pipe of the nozzle 4, and is blown out from the nozzle cap 5. On the other hand, the air is sent into the detector from the pipe 2b and joins the hydrogen gas from around the nozzle cap 5. Therefore, a hydrogen flame is formed by igniting just above the nozzle cap 5. Since the sample gas is caused to flow out of the outlet end of the column 1 inside the nozzle cap 5, the sample is ionized in the hydrogen flame, and the formed ions are detected by the collector 8.

In this hydrogen flame ionization detector, the supplied hydrogen gas passes through a molecular sieve 12 attached immediately before the nozzle 4, then reaches the nozzle 4 immediately and is blown out from the nozzle cap 5. Therefore, no matter where the hydrogen flow path is contaminated, dirt in the middle of the flow path can be completely removed by the molecular sieve.

Hereinafter, embodiments of the present invention will be summarized. A hydrogen flame is formed on the nozzle cap of the nozzle provided inside the detector body by supplying hydrogen gas and air,
In a flame ionization detector for detecting a sample flowing out of a column by introducing the sample into the hydrogen flame and ionizing the same, a column adapter having a double-tube structure is detachably incorporated immediately before a nozzle of the detector body. Then, the column passes through the inner hollow of the column adapter so that the column outlet reaches the nozzle, the molecular sieve is filled in the outer hollow of the column adapter, and hydrogen gas is supplied near the end opposite the nozzle of the column adapter. A flame flame ionization detector, characterized in that an opening for introducing into a molecular sieve is provided, and a hydrogen flow path for supplying hydrogen to the opening is provided in the detector.

In this embodiment, not only the structure becomes very compact, but also the molecular sieve can be easily exchanged only by exchanging the column adapter.

[0014]

As described above, in the hydrogen flame ionization detector of the present invention, since the molecular sieve is built in immediately before the nozzle in the ionization detector, contamination of hydrogen gas due to contamination of the hydrogen gas flow path is achieved. Can be removed, and the fluctuation of the baseline due to contamination can be reduced.

Further, since the molecular sieve itself is incorporated in the components of the flame ionization detector, the number of components can be reduced and the apparatus can be made compact.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a main part of a column adapter part of a flame ionization detector according to one embodiment of the present invention.

FIG. 2 is a main part configuration diagram of a portion related to a hydrogen flow path inside a flame ionization detector according to one embodiment of the present invention.

FIG. 3 is a configuration diagram of a flame ionization detector main body according to an embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a flame ionization detector according to one embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of a conventional hydrogen flame ionization detector.

FIG. 6 is a configuration diagram of a detector main body of a conventional flame ionization detector.

[Explanation of symbols]

 1: Column 2: Base 2a: Pipe (hydrogen gas) 2b: Pipe (air) 3a: Column adapter 3b: Adapter 3c: Opening 4: Nozzle 5: Nozzle cap 12: Molecular sieve

Claims (1)

[Claims] 1. A hydrogen flame is formed in a nozzle cap of a nozzle provided inside a detector body by supplying hydrogen gas and air, and a sample flowing out of a column is introduced into the hydrogen flame to thereby ionize the sample. A flame ionization detection apparatus for detecting a flame ionization, wherein a molecular sieve is incorporated in a portion immediately before a nozzle of the detector main body.