JPH0743355A - Gas sample introducing device - Google Patents

Abstract

PURPOSE:To provide a gas sample introducing device for controlling the fluctuation in the base line of chromatogram without drastically changing gas chromatography. CONSTITUTION:First and second 6-way cocks 3b and 4b are laid out in series at a sample introduction part of a carrier gas cylinder 1 of a gas chromatography 100 a sample introducing part 3 an isolation column 5 a line 11 for body, a sample metering pipe 3a and sample introduction/ delivery pipes 12a and 12b laid out at the first 6-way cock, a compensation pressure metering pipe 5a and a flow control valve 4c are laid out at the second 6-way cock, and a line 10 for compensation pressure of the carrier gas cylinder 1 second 6-way cock is provided. When metering samples, a line of the cylinder 1 the line 10 the cock 4b a metering pipe 4a the cock 4b the valve 4c outside of system and a line of the pipe 12a the cock 3b the metering pipe 3a the cock 3b the pipe 12b outside the system are formed when metering samples. Then, a line of the cylinder 1 the line 11 the cock 4b the metering pipe 4a the cock 4b the cock 3b the metering pipe 3a the cock 3b the column 5 a detector 7 is formed on analysis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas sample introduction device in a gas chromatograph, and more particularly to a gas sample introduction device for suppressing the fluctuation of the baseline of a gas chromatogram with a simple device configuration.

[0002]

[Technical background] When analyzing the composition of various gas samples (hereinafter sometimes referred to as "sample gas") on a gas chromatograph, for example, CO and C, which are trace components in hydrogen gas, are analyzed.
When analyzing O ₂ , it is generally performed as follows. First, by gas chromatography, C in the sample gas
The peak areas of CO and CO ₂ for a standard gas (concentration is known) close to the O and CO ₂ concentrations are obtained, and a calibration curve of the area and the concentration is prepared. Next, using the same gas chromatograph, the peak areas of CO and CO ₂ in the sample gas are obtained, and the CO and CO ₂ concentrations are obtained from the above calibration curve.

When introducing the standard gas for obtaining such a calibration curve into the gas chromatograph and when introducing the sample gas into the gas chromatograph during the actual analysis of the sample, it is generally switched to the measuring tube. An introduction means consisting of a cook is used. That is, first, a desired amount of sample gas or standard gas is sampled through the cock into the measuring pipe. Next, by switching the cock, the sample gas or standard gas in the measuring pipe is introduced into the separation column of the gas chromatograph.

This introduction operation will be described in more detail with reference to FIG. Note that FIG. 2 shows the state when the actual analysis of the sample gas is performed, but it is similarly shown when the analysis of the standard gas is performed.

In FIG. 2, reference numeral 100 denotes a gas chromatograph main body, and a hexagonal cock 3b of a sample introducing section 3 which is composed of a measuring pipe 3a and a switching hexagonal cock 3b at the time of sampling (measurement) is shown by a black line. Switching is performed so that such a flow path is formed. At this time, the carrier gas is sent from the carrier gas cylinder 1 through the pressure regulator 2 and the pressure gauge by the line 11 for charging the line and peripheral devices, and the opening of the cock 3b → the passage of the opening. Flows through the separation column 5 → reactor 6 → detector 7. If the pressure of the carrier gas is ^{1.7kgf / cm 2 (0.7kgf / cm} 2 in gauge pressure, hereinafter the same), the system (i.e., the line for analysis), the particular separation column 5, 1. A pressure of 7 kgf / cm ² will be applied.

On the other hand, the sample gas is introduced from the line 12 and flows through the flow path of the opening of the cock 3b → the opening →
A predetermined amount is measured (collected) by the measuring pipe 3a, and the rest flows through the flow path of → opening → opening into the atmosphere. At this time, a water bottle was placed at the outlet, and the outflow of the sample gas was confirmed by fluff in the water. At the time when the fluff generation stopped (at atmospheric pressure), the cock 3b was switched to the white line. The flow path is as shown.

This channel serves as a channel for introducing the sample into the gas chromatograph. That is, the sample is entrained by the carrier gas from the cylinder 1, flows through the flow path of the opening of the cock 3b → the opening → the measuring pipe 3a → the opening → the opening and is introduced into the separation column 5.

By the way, before the sample is introduced into the separation column 5, as described above, 1.
Although a pressure of 7 kg / cm ² is applied, the introduction of the sample at atmospheric pressure causes a pressure drop. Due to this pressure drop, the flow rate of the carrier gas after the pressure regulator 2 changes. This fluctuation in the flow rate of the carrier gas causes, for example, fluctuations in the baseline of the gas chromatogram shown in FIG. 4 (α in FIG. 4). It takes about 3 to 6 minutes for the baseline to be eliminated and the baseline to be stabilized (about 5 to 6 minutes in the example of FIG. 4).

If a peak appears before the baseline stabilizes, the peak area will be integrated in the changing baseline, and the peak area cannot be accurately measured (integration processing). Explaining with the example schematically shown in FIG. 5, the peak area of the i component is originally only the portion a, but if the baseline exists in the portion indicated by the dotted line, the portion indicated by b Is integrated more than that (that is, the baseline indicated by the dotted line does not appear in the actual chromatogram, so the peak area of the i component is a + b
Will be integrated as an area).

As described above, if there is a change in the baseline, the peak area cannot be accurately integrated and the analysis accuracy of the gas chromatograph is reduced. In particular,
If there is such a variation when obtaining the calibration curve with the standard gas, the reliability of the calibration curve itself is lowered, and the significance of the calibration curve is lost.

To eliminate this baseline fluctuation,
A method in which the pressure of the carrier gas at the time of sample measurement is atmospheric pressure and a method in which the pressure of the sample gas is the pressure of the carrier gas can be considered. However, if the former method is adopted,
Atmosphere may leak into the gas chromatograph, making it impossible to perform accurate analysis. Further, the latter method requires a large amount of sample gas, and therefore cannot be applied to a gas chromatograph which requires the introduction of a small amount of sample gas.

[0012]

SUMMARY OF THE INVENTION Under the above circumstances, the present invention is a gas sample introduction device in a gas chromatograph used not only for the above-mentioned hydrogen gas but also for the analysis of various gas samples, which is a chromatogram base. An object of the present invention is to provide the apparatus that does not cause line fluctuations without requiring a significant change in the apparatus configuration of a conventional gas chromatograph.

[0013]

To achieve this object, the gas sample introduction device of the present invention is a gas chromatograph equipped with a main body line from a carrier gas cylinder to a detector through a sample introduction part and a separation column. A sample metering tube with a first hexagonal cock and a second hexagonal cock arranged in series in the main body line of the sample introduction part, and a flow path connected to the first hexagonal cock on the downstream side, and for gas sample introduction / discharge A sample is arranged by arranging a pipe, a compensating pressure measuring pipe having a flow path connected to a second hexagonal cock on the upstream side and a flow control valve, and a compensating pressure line from the carrier gas cylinder to the second hexagonal cock. At the time of measurement, carrier gas cylinder → compensation line → second hexagonal cock → complementary pressure measuring tube → second hexagonal cock → flow control valve → outside system line and sample introduction tube → first six Forming a line to cock → sample metering pipe → first hexagonal cock → sample discharge pipe → outside of the system,
At the time of analysis, carrier gas cylinder → main unit line → second
6-way cock → Complementary pressure measuring tube → Second hexagonal cock → First hexagonal cock → Sample measuring tube → First hexagonal cock → Separation column → Detector line And

[0014]

In the gas sample introducing device of the present invention, the first hexagonal cock has the same function as the switching cock in the gas sample introducing means in the conventional gas chromatograph described above, and is provided on the upstream side of the first hexagonal cock. The second hexagonal cock and its peripherals (ie,
The compensating pressure measuring pipe, the flow rate adjusting valve, and the compensating line from the carrier gas cylinder) act to suppress the fluctuation of the baseline when introducing the gas sample.

The fluctuation of the baseline is as described above.
This is a phenomenon caused by the pressure drop in the separation column when the sample gas at the atmospheric pressure is introduced into the separation column under a pressure higher than the atmospheric pressure, and this pressure drop. Therefore, if the pressure drop of the separation column at the time of introducing the sample is suppressed, the fluctuation of the baseline can be eliminated. In the apparatus of the present invention, the pressure drop in the separation column at the time of introducing the sample is suppressed by the second hexagonal cock and its peripheral devices.

That is, first, at the time of measuring a sample gas (including a standard gas, the same applies hereinafter), the carrier gas is sent from the carrier gas cylinder through the pressure compensation line to the second hexagonal cock to reach the second hexagonal cock. By switching, the pressure is measured by the pressure compensation measuring tube through the flow path formed in the cock and collected. Then, the remaining carrier gas that has not been collected in the supplementary pressure measuring pipe passes through the flow path in the second hexagonal cock again and is discharged to the outside of the system via the flow rate adjusting valve.

On the other hand, the sample gas is fed from the sample introduction tube to the first
To the hexagonal cock, and by also switching the cock, the sample is weighed and collected in the sample measuring tube through the flow path formed in the cock. Then, the remaining sample gas that is not collected in the sample measuring pipe passes through the flow path in the first hexagonal cock again and is discharged from the system through the sample discharging pipe.

Further, at the time of measuring the sample, the main body line from the carrier gas cylinder to the detector via the second hexagonal cock, the first hexagonal cock and the separation column is also
When the carrier gas for charging is introduced, the pressure in the main body line, and thus the pressure in the separation column, is the same as the carrier gas pressure (1.7 kgf /
cm ² and thus held in) "0.7 kgf / ^cm 2 in gauge pressure".

When the measurement operation of the sample gas is completed in this way, the first and second hexagonal cocks are switched,
Move on to analysis of sample gas. During this analysis, the pressure compensation line is not used, but the main body line is used exclusively.

That is, the carrier gas is sent from the carrier gas cylinder through the line for the main body to the second hexagonal cock, and when the cock is switched, the carrier gas passes through the flow path formed in the cock, and the sample weighing described above is performed. From the opposite direction of time (that is, the side that was the outlet of the carrier gas at the time of sample measurement), enter the pressure compensation measuring tube. Then, at the time of measuring the sample, the carrier gas for pressure compensation (measured) in the measuring pipe is accompanied, and again passes through the flow path in the second hexagonal cock to reach the first hexagonal cock.

In the first hexagonal cock, the cock is also switched to pass through the flow path formed in the cock, and also in the direction opposite to that in the above sample measurement (that is, the sample gas outlet during sample measurement). Enter the inside of the sample measuring tube. Then, at the time of measuring the sample, the sample gas for analysis measured (collected) in the measuring tube is accompanied, and again passes through the flow path in the first hexagonal cock to reach the separation column.

As described above, in the apparatus of the present invention, the sample gas introduced into the separation column is entrained by the carrier gas sent from the carrier gas cylinder during analysis and the carrier gas for pressure compensation in the pressure compensation measuring pipe. The Rukoto. That is, the pressure of the sample gas introduced into the separation column is adjusted by the pressure possessed by this carrier gas for pressure compensation, and suppresses the pressure drop in the separation column during the transition to the analysis operation.

Further, by switching between the first and second hexagonal cocks, the flow control valve whose flow path is connected to the second hexagonal cock can be used when shifting from the weighing operation to the analytical operation.
If the carrier gas for pressure compensation in the pressure compensation metering pipe is made to flow little by little, the pressure can be adjusted and the pressure fluctuation at the time of switching the cock can be suppressed as much as possible.

In the gas sample introducing device of the present invention having the above-mentioned operation, when the size of the sample measuring tube is changed, in other words, when the amount of the sample for analysis is changed, the pressure compensation measurement is performed. It is not always necessary to change the size of the tube, and it can be dealt with by adjusting the pressure of the carrier gas for pressure compensation. However, when the size of the sample measuring pipe is changed significantly, it may be necessary to change the size of the supplementary pressure measuring pipe.

[0025]

EXAMPLE FIG. 1 shows an example of the gas sample introducing device of the present invention. 1, the same reference numerals as those in FIG. 2 denote the same functional units as those in FIG. In FIG. 1, a first hexagonal cock 3b and a second hexagonal cock 3b are provided in the sample introduction part 3 of the main body line 11 from the carrier gas cylinder 1 of the gas chromatograph main body 100 to the detector 7 through the sample introduction part 3 and the separation column 5. The hexagonal cock 4b is placed in series.

On the first hexagonal cock 3b located on the downstream side of the main body line 11, the sample measuring pipe 3a and the sample introducing / exhausting pipes 12a, 12b are arranged with their respective flow paths connected, and at the same time, upstream. To the second hexagonal cock 4b located on the side of the auxiliary pressure measuring pipe 4a and the flow rate adjusting valve 4c.
Are arranged by connecting the respective flow paths. In addition to the main body line 11, a pressure compensation line 10 from the carrier gas cylinder 1 to the second hexagonal cock 4b is provided.

In such a structure, by switching the first hexagonal cock 3b and the second hexagonal cock 4b, a channel shown by a black line is formed in both cocks 3b and 4b during sample weighing. . That is, one is carrier gas cylinder 1-> pressure regulator 2-> compensating line 10-> second hexagonal cock 4b (opening->opening)-> compensating pressure measuring pipe 4a-> second hexagonal cock 4b (opening-> opening). Part)
-> Flow control valve 4c-> Line outside the system. This line supplies the carrier gas for pressure compensation for suppressing the pressure drop of the separation column 5 at the time of transition to the analysis operation, to the measuring pipe 4a for pressure compensation.
This is a line for measuring (collecting).

The other is a sample introducing tube 12a → first hexagonal cock 3b (opening → opening) → sample measuring tube 3
a → first hexagonal cock 3b (opening → opening) → sample discharge tube 12b → line outside the system. This line is a line for measuring (collecting) the sample to be analyzed in the sample measuring pipe 3a.

When measuring the sample, together with these two lines, the carrier gas cylinder 1 → second hexagonal cock 4b (opening → opening) → first hexagonal cock 3b.
A line of (opening → opening) → separation column → reactor 6 → detector 7 is also formed. This line is used for the main body line 11 and various equipments installed in the line (the flow paths during the analysis operation in the first and second hexagonal cocks 3b, 4b, the separation column 5, the reactor 6, the detector). This is a line for charging 7) with a carrier gas.

Also, at the time of analysis, the first hexagonal cock 3b
And by switching the second hexagonal cock 4b, in FIG.
Flow paths shown by white lines in both cocks 3b and 4b, that is, carrier gas cylinder 1 → pressure regulator 2 → main body line 11 → second hexagonal cock 4b (opening → opening)
→ Complementary pressure measuring pipe 4a → Second hexagonal cock 4b (opening →
(Opening part) → first hexagonal cock 3b (opening part → opening part) → sample metering pipe 3a → first hexagonal cock 3b (opening part → opening part) → separation column 5 → reactor 6 → detector 7 line Is formed.

The first hexagonal cock 3b and the second hexagonal cock 4b may have the same structure, the same capacity and the same material, or different hexagonal cocks may be used. . In this example, the first hexagonal cock 3b
Is used in the conventional gas chromatograph, and the second hexagonal cock 4b is a commercially available product.

The compensating pressure measuring pipe 4a is the sample measuring pipe 3a.
The same structure and the same material may be used, or different materials may be used. The capacity of the supplementary pressure measuring pipe 4a is appropriately selected and used from the range of about 0.1 to 10 mL in capacity according to the operating conditions.
It has an important role in the device of the present invention,
It is necessary to strictly select it based on the calculation formula described later.

The pressure compensating line 10 can be made of any material and size, and the same material as the main body line 11 can be used.
They may have the same size or may have different sizes. In this example, a stainless steel pipe with an outer diameter of 2
mm, inner diameter 1.5 mm is used.

Pressure regulator 2 provided in the compensating line 10
Has a pressure adjustment range of about 0 to 10 kgf / cm ² (gauge pressure), and the pressure gauge has a pressure scale range of 0 to 10 kg.
of about f / cm ² (gauge pressure) is used, respectively, also flow control valve 4c is of a flow rate of about 1-10 mL / min is used.

Incidentally, the first hexagonal cock 3b and the second
The switching with the hexagonal cock 4b may be performed by hand and separately, for example, the “simple type universal joint device” previously proposed by the present inventor (Japanese Patent Application No. 4-59974). See also). In the example of FIG. 1, the first hexagonal cock 3b and the second hexagonal cock
The hexagonal cock 4b of the device is connected to the universal joint device 21 via the interlocking line 20.
It employs a method that activates and switches at once.

In the above-mentioned structure, first, in order to perform the sample weighing operation, the first and second hexagonal cocks 3b and 4b are switched at once by the universal joint device 21, and the above-mentioned sample is sampled. Three lines at the time of weighing (a line around the first hexagonal cock 3b, a line around the second hexagonal cock 4b, and a line for charging the main body line and peripheral devices with a carrier gas) are formed.

In the line around the first hexagonal cock 3b among these three lines, the sample gas to be analyzed passes from the introduction tube 12a through the flow path (→) in the first hexagonal cock 3b to the sample. It is introduced into the measuring pipe 3a and a predetermined amount is measured (collected). The remaining sample gas passes through the flow path (→) in the first hexagonal cock 3b again and the exhaust pipe 1
It is discharged from the system 2b.

Simultaneously with the measurement (collection) of this sample gas, in the line around the second hexagonal cock 4b, the carrier gas for pressure compensation passes from the carrier gas cylinder 1 through the pressure compensation line 10 and is supplied to the pressure regulator 2 and the pressure gauge. While adjusting the pressure, the pressure is sent to the second hexagonal cock 4b, introduced into the pressure compensation measuring pipe 4a through the flow path (→) in the cock 4b, and a predetermined amount is measured (collected). The remaining carrier gas passes through the flow path (→) in the second hexagonal cock 4b again, reaches the flow rate control valve 4c, and is discharged to the outside of the system.

In the above charging line, the carrier gas is sent from the carrier gas cylinder 1 through the main body line 11 while the pressure is adjusted by the pressure regulator 2 and the pressure gauge, and the carrier gas is stored in the second hexagonal cock 4b. Channel (→)
And the flow path (→) in the first hexagonal cock 3b,
After passing through the separation column 5, the reactor 6 and the detector 7, it is discharged to the outside of the system.

When the sample weighing operation is completed in this way, the first and second hexagonal cocks 3b and 4b are switched again by the universal joint device 21 to form the above-described analysis line. At the time of forming this line, that is, when shifting from the sample measuring operation to the analyzing operation, the carrier gas for pressure compensation in the pressure compensation measuring pipe 4a is supplied to the flow rate adjusting valve 4.
The pressure fluctuation in the system is suppressed by gradually flowing from c to the outside of the system.

In order to carry out an analysis operation in this analysis line, the carrier gas is sent from the carrier gas cylinder 1 through the main body line 11 while the pressure is adjusted by the pressure regulator 2 and the pressure gauge. The flow path in the cock 4b (
→) to the compensating pressure measuring pipe 4a, and the carrier gas for compensating pressure inside the measuring pipe 4a is entrained again through the flow path (→) in the second hexagonal cock 4b to reach the first hexagonal cock. Three
sent to b.

In the first hexagonal cock 3b, the cock 3b
Through the internal flow path (→) to the sample measuring pipe 3a,
The sample gas in the metering tube 3a is entrained and again sent through the flow path (→) in the first hexagonal cock 3b to the separation column 5, and by the column 5 and the detector 7 in the downstream thereof. , The sample gas is analyzed.

Since CO and CO ₂ separated in the separation column 5 cannot be detected by the hydrogen flame ionization detector, they are reacted with hydrogen as a carrier gas in the reactor 6 to produce methane (CH ₄ ) and the detector Sent to 7.

In such an analytical operation, in the separation column 5, in addition to the sample gas entrained in the carrier gas from the carrier gas cylinder 1, the supplementary pressure measuring pipe 4a at the time of measuring the sample.
The carrier gas that has been measured (collected) is introduced into the inside. The carrier gas in the supplementary pressure measuring pipe 4a acts as a supplementary pressure, and the pressure applied to the separation column 5 due to the carrier gas introduced for charging the sample is not lowered.

As described above, in the apparatus of the present invention, the pressure and amount of the carrier gas measured (collected) in the supplementary pressure measuring pipe 4a achieves the purpose of the present invention (the separation column 5 at the time of shifting to the analytical operation). It is an important factor in preventing pressure drop). The pressure of this carrier gas is adjusted by the pressure regulator 2 arranged in the pressure compensation line 10, and the amount is adjusted by the capacity of the pressure compensation measuring pipe 4a.

The method for obtaining the capacity of the pressure compensation measuring pipe 4a will be described below. First, the capacity of the supplementary pressure measuring pipe 4b is obtained by the equation (1) of the equation 1.

[0047]

[Equation 1]

[0048]

[Equation 2]

Next, how to specifically determine the capacity of the supplementary pressure measuring pipe 4a will be described. The preconditions at this time are as shown in Table 1.

[0050]

[Table 1]

Under the preconditions of Table 1, the sample measuring pipe 3a
Introduce 10 mL of atmospheric pressure sample gas into the measuring tube 3
The pressure in a is the inlet pressure of the separation column 5 (pressure of 1.7 kg sent for charging when measuring the sample).
It is 1.7 k in order to raise the pressure to the same pressure as 1.7 kgf / cm ² with a carrier gas of f / cm ^2.
A carrier gas with a pressure of gf / cm ² requires 4.1 mL.

The carrier gas of 4.1 mL is supplied by the carrier gas in the supplementary pressure measuring pipe 4a. This 4.
1 mL is the pressure of the supplementary pressure measuring pipe 4a of 6.2 kgf / cm ²
In this case, since the volume is 1.1 mL, 1.1 mL of carrier gas for pressure compensation may be measured in the pressure compensation metering pipe 4a.

However, in order to prevent the pressure drop in the separation column 5, it is necessary to maintain (ie, self-hold) the same pressure as the inlet pressure of the separation column 5 in the supplementary pressure measuring pipe 4a. The self-holding amount of this supplementary pressure measuring pipe 4a is 6.2k.
Assuming that the pressure is gf / cm ² and the volume is xmL, the pressure compensation measuring tube 4a
The amount of gas inside, and the capacity of the compensating pressure measuring pipe 4a is 6.2.
At a pressure of kgf / cm ² , 1.1 + x (mL) is enough.

From the above, the equation (4) of the equation 3 is established.

[0055]

[Equation 3]

When this equation (4) is rearranged, the equation (5) of the equation 4 is obtained.
When the expression (5) is expressed by a parameter, the expression (1) of the expression 1 is obtained.

[0057]

[Equation 4]

By rearranging the equation (5), x = 0.42. Therefore, the capacity of the supplementary pressure measuring pipe 4a is 6.2 kg.
1.1+ when operating at f / cm ² pressure
0.42 = 1.5 mL is enough.

In this way, the capacity of the supplementary pressure measuring pipe 4a can be obtained. This relationship is shown in Table 2, and the calculated value and the actual value are almost the same.

[0060]

[Table 2]

Specific Example By a gas chromatograph employing the gas sample introduction device of the present invention shown in FIG. 1 and a conventional gas chromatograph shown in FIG. 2, under the conditions shown in Table 3, hydrogen gas (hydrogen, C
O: 10.2 ppm and CO ₂ : 10.0 ppm) were used for each analysis 4 times. The results are as shown in Table 4. In Table 4,
The results obtained by the gas chromatograph employing the apparatus of the present invention shown in FIG. 1 are shown as examples, and the results obtained by the conventional gas chromatograph shown in FIG. 2 are shown as comparative examples.

[0062]

[Table 3]

The chromatogram obtained by the gas chromatograph using the apparatus of the present invention shown in FIG. 1 is shown in FIG. Figure 2
The chromatogram from the conventional gas chromatograph of
It was the one shown in FIG. As is apparent from FIG. 3, when the device of the present invention is adopted, the baseline does not fluctuate, and therefore the accurate integration processing of the peak area can be performed.

[0064]

[Table 4]

Table 4 shows No. 1 to 4 are the same tester,
The results are obtained with the same sample and the same area treatment parameter, and the standard deviation and the coefficient of variation are almost the same in the example and the comparative example, but the CO component in the comparative example is about 35% higher than that in the example. The CO ₂ component in the comparative example is about 18% higher than that in the example. Further, as described above, in FIG. 3, the baseline is stable and the peak of the CO component is clearly visible, so the value of the example can be regarded as the true value of the CO component. The value of the embodiment is C
Assuming the true value of O component, the comparative example is about 35% from this value.
It can be seen that the values in the examples are accurately integrated only for the peak area of the CO component.

[0066]

As described in detail above, according to the gas sample introduction device of the present invention, a hexagonal cock, a pressure regulator, a flow rate control valve, and these and a gas chromatograph can be used without requiring a drastic change in the conventional gas chromatograph. By using a simple member such as a pipe connecting the main body or a carrier gas cylinder, it is possible to suppress the fluctuation of the baseline during analysis. As a result, it is possible to provide a gas chromatograph capable of performing highly accurate analysis at extremely low cost.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing an example of a gas chromatograph adopting the gas sample introduction device of the present invention.

FIG. 2 is a schematic explanatory view showing a conventional gas chromatograph.

FIG. 3 is a chromatogram when hydrogen gas is analyzed by a gas chromatograph that employs the apparatus of the present invention shown in FIG.

FIG. 4 is a chromatogram when hydrogen gas is analyzed by the conventional gas chromatograph shown in FIG.

5 is a diagram schematically showing a state of integration processing by the chromatogram shown in FIG.

[Explanation of symbols]

100 gas chromatograph main body 1 carrier gas cylinder 2 pressure regulator 3 sample introduction part 3b first hexagonal cock 3a sample measuring pipe 4b second hexagonal cock 4a pressure compensation measuring pipe 4c flow control valve 5 separation column 6 reactor 7 detector 10 auxiliary Pressure line 11 Main body line 12a Sample introduction line 12b Sample discharge line 20 Line for interlocking the first 6-way cock and the second 6-way cock 21 Simple proposed universal joint device

Claims (1)

[Claims] 1. A gas chromatograph equipped with a main body line from a carrier gas cylinder to a detector via a sample introduction section and a separation column, wherein a first hexagonal cock and a second hexagonal cock are provided on the main body line of the sample introduction section. A sample metering pipe and a sample introducing / discharging pipe, which are arranged in series and have a flow path connected to the first hexagonal cock on the downstream side, are arranged, and a flow path is connected to a second hexagonal cock on the upstream side. In addition to arranging the pressure measuring pipe and flow rate control valve, a pressure compensation line from the carrier gas cylinder to the second hexagonal cock is provided. When measuring the sample, the carrier gas cylinder → pressure compensation line →
Second hexagonal cock → Complementary pressure measuring tube → Second hexagonal cock → Flow control valve → External system line and sample introduction tube → First hexagonal cock → Sample measuring tube → First hexagonal cock → Sample discharge Forming a line from the system to the outside of the system, and at the time of analysis, carrier gas cylinder → line for main body → second
6-way cock → Complementary pressure measuring tube → Second hexagonal cock → First hexagonal cock → Sample measuring tube → First hexagonal cock → Separation column → Detector line Gas sample introduction device.