JPH09236591A - Gas chromatograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas chromatograph wherein separation analysis with the use of a large aperture column and a small aperture column whose flow rate are significantly different is performed with one sample injection. SOLUTION: Relating to a gas chromatograph wherein a column is connected to a sample gasification chamber 31 and the sample running through the column is detected, the sample gasification chamber 31 is provided with a split line 33 and line 34 which allow connection to a large aperture column 46 and a small aperture capillary column 47 whose flow rate are significantly different. Then, by branching the vaporized sample obtained from a common sample, and by supplying the large aperture column 46 and the small aperture capillary column 47 with the vaporized sample at a single sample injection at the same time, separation analysis with the large aperture column 46 and the small aperture column 47 whose flow rate are significantly different is performed at one sample injection, and separation and analysis are performed at the same time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an analyzer for separating and analyzing a sample, and more particularly to a gas chromatograph including a gas chromatograph mass spectrometer and a supercritical fluid chromatograph.

[0002]

2. Description of the Related Art In chromatography in which a mixture is separated by utilizing the difference in the moving speed in the column caused by the difference in the adsorptivity of the mobile phase with respect to the stationary phase and the difference in the partition coefficient, and qualitative and quantitative analysis of each component A gas chromatograph is known as an analyzer that uses gas as a mobile phase.

6 and 7 are schematic views for explaining the structure of a conventional gas chromatograph. 6 and 7, the gas chromatograph shows the carrier gas part 1
And a carrier gas flow rate control unit 2 for controlling the pressure, flow rate, or flow velocity of the carrier gas, a sample vaporization unit 3 for injecting or vaporizing a sample, a separation column unit 4, and a detection unit 5. The detection signal is recorded by the reading / recording unit 6.

The sample vaporized in the vaporization chamber 31 of the sample vaporization section 3 is passed through columns 46 and 47 installed in the separation column section 4 and detected by detectors 58 and 59. As this column, a small-diameter column with a small flow rate such as a capillary column and a large-diameter column with a large flow rate such as a packed column are known, and in general, there are fewer types of small-diameter columns than large-diameter columns. Therefore, some components cannot be analyzed unless a large-diameter column is used.In conventional gas chromatographs, the column to be used is selected according to the component to be separated and analyzed, and the column is replaced for analysis. .

For example, when separating oxygen-containing compounds in gasoline, there is a column suitable for good separation in a short time among large-diameter columns such as a packed column, and the separation of kerosene in gasoline. In this case, since there is a column capable of high separation among the small-diameter capillary columns, a large-diameter column is used for analysis of oxygen-containing compounds and a small-diameter capillary column is used for analysis of kerosene components.

[0006]

In the conventional gas chromatograph, columns having greatly different flow rates such as separation analysis by a small-diameter capillary column and separation analysis by a large-diameter column are used because of the relationship between analytical components and column characteristics. If necessary, prepare a gas chromatograph equipped with a small-diameter capillary column and a gas chromatograph equipped with a large-diameter column, and inject each sample separately for analysis, or for one gas chromatograph. The small-diameter capillary column and the large-diameter column are replaced, and samples are injected into each column for analysis. Therefore, there has been a problem that the labor and time required for the analysis are long.

FIG. 6 shows the configuration of a gas chromatograph using the large diameter column 46, and FIG. 7 shows the small diameter column 4.
It is a structure of a gas chromatograph when 7 is used. Since the flow rates of the large-diameter column and the small-diameter column are greatly different, the configurations of the sample vaporization section and the separation column section are different.
For example, when a large-diameter column is used, the sample and carrier gas delivered from the vaporization chamber, such as a packed column sample vaporization chamber, are directly delivered to the column. On the other hand, when using a small-diameter column, a part of the sample and carrier gas is sent to the column and a surplus is discharged from the split line 33, as in a split sample vaporization chamber. Therefore, it is difficult to perform separation analysis using two types of columns having greatly different flow rates at the same time, and it is necessary to perform analysis individually.

[0008] Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional gas chromatograph and to provide a gas chromatograph capable of performing separation analysis by columns having greatly different flow rates with a single sample injection. .

[0009]

The present invention relates to a gas chromatograph in which a column is connected to a sample vaporization chamber and a sample that has passed through the column is detected, and the sample vaporization chamber has a large-diameter column and a small-diameter column with greatly different flow rates. Can be connected, and a vaporized sample obtained from a common sample is branched and supplied to each connected column, so that separation and analysis by columns with greatly different flow rates can be performed with one sample injection. The sample vaporization chamber provided in the gas chromatograph of the present invention has a configuration capable of connecting a large-diameter column and a small-diameter column having greatly different flow rates, and a sample vaporized by one-time sample injection is simultaneously applied to a small-diameter capillary column. Can be supplied to a large-diameter column and a large-diameter column and a small-diameter column with different flow rates can simultaneously perform separation and analysis.

The gas chromatograph of the first embodiment of the present invention connects a small-diameter capillary column and a packed column (packing column) to the sample vaporization chamber, and the small-diameter capillary column and packed column can be injected once. Separation analysis can be performed using a column (packed column).

In the second embodiment of the present invention, a split sample vaporization chamber is used as the sample vaporization chamber, a small diameter capillary column is connected to the vaporization chamber, and a large diameter column is connected to the split line of the vaporization chamber. Yes, this makes it possible to connect a large diameter column and a small diameter column with greatly different flow rates.

Further, the third embodiment of the present invention uses a packed column sample vaporization chamber as the sample vaporization chamber, and has a flow passage to which a small diameter capillary column in addition to a large diameter column can be connected to the vaporization chamber. This is provided, and by doing so, it is possible to connect a large diameter column and a small diameter column with greatly different flow rates.

A fourth embodiment of the present invention is to provide a plurality of split lines in a vaporization chamber and connect a plurality of large diameter columns having different diameters to the split lines.
As a result, it is possible to perform an analysis in which the sample is simultaneously introduced into a plurality of large diameter columns having different diameters.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. A configuration example of the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram illustrating the configuration of an embodiment of the gas chromatograph of the present invention. In FIG. 1, the gas chromatograph is
As in the conventional case described above, the carrier gas section 1, the carrier gas flow rate adjusting section 2 for adjusting the pressure, flow rate or flow velocity of the carrier gas, the sample vaporizing section 3 for injecting or vaporizing the sample, and the separation column section 4 And the detection unit 5 and reading
The recording unit 6 is provided, and the configuration of the sample vaporization unit 3 and the separation column unit 4 is different from that of the conventional gas chromatograph.

The carrier gas section 1 depressurizes a carrier gas such as helium, hydrogen, nitrogen, and argon from a carrier gas cylinder 11 with a pressure reducing valve 12 and introduces the carrier gas into a carrier gas flow rate adjusting section 2. The carrier gas flow rate adjusting unit 2 adjusts the pressure by the flow meter 23, the fine adjustment valve 21 and the pressure gauge 22 so that the required flow rate or flow velocity can be obtained. In addition, instead of the carrier gas flow rate control unit,
A pressure regulator that regulates the pressure can also be used. The sample vaporization part 3 is a part for sending the vapor of the mixture of the sample and the carrier gas into the column, vaporizes the sample in the sample injection port and the vaporization chamber 31 which form a part of the flow path of the carrier gas, and the separation column part 4 A sample vapor is introduced together with the carrier gas. The sample vaporizer 3 is a vaporizer temperature controller 3
2, the temperature control can be performed.

The sample injection port and vaporization chamber 31 in FIG. 1 show the case of a split sample vaporization chamber used for a small diameter column. Usually, the split sample vaporization chamber has a line 34 for introducing sample vapor and carrier gas to the small diameter column,
A split line 33 is provided for discharging excess sample vapor and carrier gas. In the embodiment of the present invention, the split line 33 is used as a line for connecting a large diameter column.

The separation column section 4 is provided with a first GC (gas chromatograph) oven 41 and a second GC oven 43, and both GC ovens are connected through a through hole through which the line 34 passes. A large-diameter column 46 connected to the split line 33 is installed in the first GC oven 41, and a small-diameter capillary column 47 connected to the other line 34 and guided through the through-hole is installed in the second GC oven 43. The first detector 51 is connected to the other end of the large diameter column 46, and the second detector 52 is connected to the other end of the small diameter capillary column 47. Each detector has a column 46,
The outflow state of each component of the sample separated and sent out at 47 is detected. As the detector used in the detection unit 5, for example, in addition to the heat conduction type detector, a hydrogen flame ionization detector, an electron capture type detector, a hydrogen flame thermionic detector, a flame photometric detector, a helium ionization detector, etc. Can be used. The detection signals detected by the detection units 51 and 52 are sent to the reading / recording unit 6 including the amplifiers 61 and 62 and the recorders 63 and 64.

The first GC (gas chromatograph) oven 41 and the second GC oven 43 are temperature-controlled by the first temperature control device 42 and the second temperature control device 44, and the connecting portion of both GC ovens is an intermediate temperature control device. The temperature is controlled by 45.

The operation of the gas chromatograph according to the embodiment of the present invention will be described below. Large diameter column 46
Is connected to the sample injection port and the split line 33 of the vaporization chamber 31, and the small diameter capillary column 47 is connected to the sample injection port and the line 34 of the vaporization chamber 31. Then, the carrier gas flow rate adjusting unit 2 adjusts the flow rate and flow rate of the carrier gas, and supplies the carrier gas having an appropriate flow rate and flow rate to the sample injection port and the vaporization chamber 31.

Since the large-diameter column 46 and the small-diameter capillary column 47 are a kind of resistance tube, when a proper pressure or flow rate is supplied to the inlet, the carrier gas causes the carrier gas to have a resistance ratio of the large-diameter column 46 and the small-diameter capillary column 47. Is branched according to. Here, the sample inlet and the vaporization chamber 31
When the sample is injected into the sample injection port of, the vaporized sample moves to the large diameter column 46 and the small diameter capillary column 47 through the split lines 33 and 34 together with the carrier gas. The sample transferred to each column is separated at a temperature suitable for each column condition and detected by the detectors 51 and 52. Although each column is housed in another GC oven in FIG. 1, it can be installed in a common GC oven when the temperature conditions of the large diameter column and the small diameter capillary column are the same.

The branching ratio between the large diameter column and the small diameter capillary column can be changed by changing the inner diameter and the length of both columns or by providing a split line having a variable resistance at the inlet. . For example, by changing the inner diameter and length of both columns for the same pressure on the vaporization chamber side, a flow rate suitable for the analysis conditions can be set. Note that the configuration shown in FIG. 1 shows a case of a configuration example in which a split sample vaporization chamber for a small diameter column is used as the vaporization chamber, but it may be configured by a packed column sample vaporization chamber for a large diameter column. it can. In this case, a line for connecting a small diameter capillary column is provided in addition to a line for connecting a large diameter column such as a packed column originally provided in the packed column sample vaporization chamber. As a result, it is possible to configure a gas chromatograph capable of performing separation analysis with a large-diameter column and a small-diameter capillary column with a single sample injection.

Next, the structure for connecting a plurality of large diameter columns will be described with reference to FIG. The configuration shown in FIG. 2 is similar to that of FIG.
Since the configuration is substantially the same as that of (1), only different points will be described. In FIG. 2, the sample inlet and the vaporization chamber 31
Of the first split line 33-1 to the third split line 33-3.
The first large diameter column 46, the second large diameter column 48, and the third large diameter column 4 are formed in each split line
9 can be connected. A small-diameter capillary column 47 can be connected to the sample inlet and the line 34 of the vaporization chamber 31. When the carrier gas and the sample are injected, each of the first large diameter column 46 and the second large diameter column 4
8. The flow rates corresponding to the respective resistance ratios are branched and introduced into the third, large diameter column 49 and the small diameter capillary column 47. Each of the first detector 51, the second detector 52, the third detector 53, and the fourth detector 54 detects the sample component separated by each column.

Next, referring to FIG. 3, a structural example using a heat conduction type detector as a detector will be described, and FIGS. 4 and 5 show examples of detection results. It should be noted that FIG. 3 shows a configuration for sending the carrier gas to the reference side of the temperature sensitive element of the heat conduction type detector. In FIG. 3, the first GC oven 41
A packed column (packed column) is used as a large-diameter column, a first packed column 81 is provided on the sample side, and a second packed column 82 made of the same type of column is provided on the reference side. One end of the first packed column 81 is connected to the split line 33 of the vaporization chamber 31, and the other end is connected to the sample side end 51-1 of the first detector 51. On the other hand, one end of the second packed column 82 is connected to the second carrier gas flow rate control unit 2 to receive only the carrier gas, and the other end is connected to the reference side 51-2 of the first detector 51.

On the second GC oven side 43,
A small-diameter capillary column 83 is provided on the sample side, and a second resistance tube 85 is provided on the reference side. Small diameter capillary column 8
The input end of 3 is connected to the line 34 of the vaporization chamber 31, and the output end is connected to the sample side end 52-1 of the second detector 52. Further, the carrier gas is supplied to the output end through the first resistance tube 84 to adjust the flow rate. In addition, the second resistance tube 8
One end of 5 is connected to the carrier gas flow rate control unit 2 to receive only the carrier gas, and the other end is connected to the reference side 52-2 of the second detector 52. The carrier gas for reference and the flow rate adjustment shown in FIG. 3 may be supplied by a separately prepared carrier gas flow rate adjusting unit.

FIG. 4 is an analysis result of oxygen-containing compounds in gasoline having the configuration of FIG. 3, and FIG. 5 is an analysis result of kerosene component of gasoline having the configuration of FIG. As an analysis condition for analyzing the oxygen-containing compound, a packed column of 3 m × 3 mmφ was used, 30 ml / min of helium was used as a carrier gas, and the column temperature was kept at 45 ° C. for 4 minutes, then 6 ° per minute. When the temperature of C rises to 100 ° C, 1
The temperature is controlled to be held at 00 ° C for 20 minutes, the inlet temperature is set to 200 ° C, and the heat conduction type detector of 80 mA is set to 120 ° C as a detector.

As the analytical conditions for analyzing the kerosene component, a small-diameter capillary column of 25 m × 0.32 mmφ and df = 0.5 μm was used, and the column temperature was maintained at 50 ° C. for 1 minute and then 7 per minute. 180 ° at a temperature rise of ° C
As C, perform temperature control of holding at 180 ° C for 8 minutes,
A thermal conductivity type detector of 100mA is used as a detector at 180 ° C.
Helium was used as the carrier gas (make-up gas) to be added, and the temperature of the intermediate heater was 180 ° C. Table 1 below shows the reproducibility of the peak area of gas chromatography, and Table 2 shows the reproducibility of the retention time.

[0027]

[Table 1]

[0028]

[Table 2] In the structure of the present invention, the large diameter column may or may not have a packing material. When using a non-packed column, the total length of the column can be increased, while when using a packed column, the type and amount of the liquid phase applied to the inner surface of the column can be increased and analysis can be performed. This is advantageous in that there are many kinds of substances and the sample concentration can be increased. Whether to use a packed column or a non-packed column can be appropriately selected according to the purpose of use.

According to the embodiment of the present invention, the labor and time conventionally required for separate analyzes can be shortened, and the carrier gas and sample conventionally discharged from the split line and discarded can be effectively used. Can be used for analysis,
The consumption of expensive high-purity carrier gas can be saved.

[0030]

As described above, according to the present invention,
It is possible to provide a gas chromatograph capable of performing separation analysis using a large-diameter column and a small-diameter column with greatly different flow rates with a single sample injection.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration of an embodiment of a gas chromatograph of the present invention.

FIG. 2 is a block diagram illustrating a configuration for connecting a plurality of large diameter columns of the gas chromatograph of the present invention.

FIG. 3 is a block diagram illustrating a configuration in which a calibration column is connected to the gas chromatograph of the present invention.

FIG. 4 is an analysis result of oxygen-containing compounds in gasoline by the gas chromatograph of the present invention.

FIG. 5 is a result of analysis of kerosene components in gasoline by the gas chromatograph of the present invention.

FIG. 6 is a schematic diagram for explaining the configuration of a conventional gas chromatograph.

FIG. 7 is a schematic diagram for explaining the configuration of a conventional gas chromatograph.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Carrier gas part, 2 ... Carrier gas flow control part, 3 ... Sample vaporization part, 4 ... Separation column part, 5 ... Detection part,
6 ... Reading / recording unit, 31 ... Sample injection port and vaporization chamber, 33
… Split line, 34… Line, 41, 42… GC
Oven, 46, 48, 49 ... Large diameter column, 47, 8
3 ... Small-diameter capillary column, 51-5458, 58 ...
Detectors, 81, 82 ... Packed columns, 84, 85 ... Resistance tubes.

Claims (1)

[Claims] 1. A gas chromatograph in which a column is connected to a sample vaporization chamber and a sample that has passed through the column is detected, and the sample vaporization chamber enables connection of a large-diameter column and a small-diameter column with greatly different flow rates. A gas chromatograph characterized in that a vaporized sample obtained from a sample is branched and supplied to each connected column.