JPS64606Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a metering tube for supplying a predetermined amount of gas to a gas analyzer such as a gas chromatograph.

FIG. 2 shows a schematic diagram of a gas chromatograph, and FIG. 1 shows a conventional metering tube.

In the figure, 1 is a carrier gas cylinder, 2 is a gas conduit, 3 is a sample introduction pot, and 04 is a conventional measuring tube for measuring a certain amount of sample, and nuts 04b, 0 are connected to the sample introduction pot 3.
4c are arranged at both ends of the measuring tube 04. 5 is a syringe for sending the sample into the measuring tube 04;
Reference numerals 6 and 7 are injectors for introducing a liquid sample, 8 is a measurement column, and 9 is a reference column filled with a packing material for separating analytical components.

Note that 10 is a detector, 11 is a recorder, 12 is an integrator, and 13 is a constant temperature bath that keeps the ambient temperature of the measurement column 8 and the like constant.

To explain the case of analyzing an inorganic gas using this gas chromatograph, first fill the constant temperature chamber 13 with a packing material such as Molecular Seabu 5A according to the analysis component, perform dry baking, and then use the measurement column 8. A carrier gas cylinder 1 is opened, and a carrier gas such as He or Ar is pumped through a gas conduit 2 to a gas chromatograph.

The carrier gas passes through the sample introduction tank 3, flows into the injection columns 6 and 7, and then flows through the measurement column 8 and the reference column 9, reaching the detector 10, and is discharged into the atmosphere, replacing the inside of the system with the carrier gas.

Next, the constant temperature bath 13 is set and regulated to the optimum temperature for analysis. The carrier gas flow rate is the same for both measurement column 8 and reference column 9 (for example, 20~
60 c.c./min), and a current is passed through the detector 10.

A baseline is drawn on the recorder 11 to confirm the stability of the gas chromatograph.

On the other hand, a sample is collected into a syringe, and the sample introduction pot 3 is charged to be force-fed to the measuring tube 04.

Leave it for about 30 seconds to bring the measuring tube 04 to atmospheric pressure, set the sample introduction pot 3 to discharge, and then turn the measuring tube 04 into atmospheric pressure.
The sample inside is introduced into the measuring column 8 together with a flow of carrier gas.

The introduced sample is separated into each component by the filler and reaches the detector 10 .

The detector 10 uses the thermal conductivity of the separated gas components flowing in to generate an electrical signal proportional to the concentration.

This is extracted as a peak by the recorder 11 or the integrator 12, and the peak area and the integral value of the peak are determined.

In addition, an analysis is performed in advance using a standard gas in the same manner as for the sample, and a calibration curve is created in which the concentration of each target component is proportional to the peak area, thereby determining the concentration of the target component in the sample.

Conventional measuring tubes, such as those shown in Figure 1, are prepared in various sizes, from small to large volumes.In case of low concentration or lack of sensitivity, use medium or large volume ones.
On the other hand, if the filler contains a large amount of moisture, which reduces sensitivity due to high concentration or shortens the life of the filler, a smaller volume one is used. Therefore, it is troublesome to prepare and replace various measuring tubes, so there is a drawback that it takes a lot of time and effort to set the gas chromatograph to optimal analysis conditions.

The present invention eliminates these drawbacks by communicating an odd number of tubes connected in a U-shape through an even number of three-way pipes and opposing three-way pipes located on the same U-shape. It is characterized by consisting of a communicating tube and a connecting nut installed on each end of the U-shaped tube, and its purpose is to measure samples from small to large volumes using one measuring tube. It is an object of the present invention to provide a measuring tube that is capable of measuring and dividing a sample into a measuring column in several batches and introducing the sample into a measuring column in one sample collection.

An embodiment of the present invention shown in FIG. 3 will be described below.

4d to 4h are five small-capacity tubes connected in a U-shape via four three-way sockets 4i to 4l.

Also, three-way Kotoku 4i, 4k and 4 facing each other
j and 4l are communicated with each other through communication pipes 4m and 4n, respectively.

Note that 4b and 4c are connection nuts for connecting to the sample introduction pot 3 shown in FIG.

The metering tube 4 of this embodiment constructed in this manner is
Instead of the measuring tube 04 shown in the figure, connect it to the sample introduction pot 3 using connecting nuts 4b and 4c to receive the sample from the syringe barrel 5.

In this operation, 3-way Kotoku 4i or 4l
The tubes 4d to 4h and the communication tubes 4m and 4n are filled with samples with all the tubes opened.

Next, the sample in the metering tube 4 is introduced into the measurement column 8 along with the flow of carrier gas, and the amount introduced can be set in three stages.

That is, when the three-way pots 4i to 4l are all opened, all the sample in the measuring tube 4 is discharged.

In addition, if the three-way pots 4j and 4l are rotated to open the circuit of tube 4e, communication tube 4n, and tube 4h, and close tube 4f, the sample in the area other than tube 4f will be discharged, and the amount will decrease slightly. .

Further rotate the 3-way tips 4i and 4k, and remove the tube 4.
If only the circuits d, communicating tube 4m, and tube 4g are opened, only the sample in that portion will be discharged, and the amount will be the smallest.

The subsequent analysis operation is the same as when using the conventional measuring tube 04.

In this way, according to the measuring tube of one embodiment of the present invention, the measuring stage can be changed into three, so that: (a) there is no need to prepare various measuring tubes as in the conventional one; It is possible to obtain a wide range of volumes, so there is no need to replace them each time.

When sending a sample to a measuring tube using a syringe, etc., calculate the volume of each tube and the pipes in the middle, and divide the sample by switching the three-way switch, so that the measurement for introduction into the measuring column can be performed with one sample collection. Sample collection efficiency is high because it can be done several times at once.

Effects such as this can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram of a conventional metering tube, FIG. 2 is a schematic explanatory diagram of a gas chromatograph, and FIG. 3 is a diagram of a metering tube showing an embodiment of the present invention. 4...Measuring tube, 4b, 4c...Connection nut, 4
d to 4h...pipe, 4i to 4l...three-way pipe, 4m, 4n...communicating pipe.

Claims (1)

[Scope of utility model registration request] An odd number of tubes connected in a U-shape through an even number of three-way tubes, a communication tube that communicates between opposing three-way tubes located on the same U-shape, and tubes at both ends of the U-shape, respectively. A metering tube comprising a connecting nut.