JPH0438289Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to an automatic sample introduction device for a headspace gas chromatograph, and in particular, to detect when the sample components in the sample container and their headspace components reach equilibrium. This invention relates to an automatic sample introduction device that shortens the time.

(b) Prior art In headspace gas chromatographs, a certain amount of volatile components evaporated into the equilibrium gas phase from the sample liquid or solid filled in the sample container is introduced into the sample vaporization chamber, so there is no possibility of contamination of the gas chromatograph. This has the advantage that no interfering components are introduced, and therefore no errors are caused in the analysis results of the sample gas.

In this type of device, the needle of the gas-tight syringe is inserted into the head space inside the sample container, and in order to cause the gas-tight syringe to suck the sample, the following steps are required:
Usually, a sample container placed in a thermostatic chamber is heated to a predetermined temperature, a specific sample gas is evaporated from the sample liquid, and the sample gas in the head space and the sample components in the sample liquid are brought into equilibrium. Pre-processing work is being carried out.

Since it takes a certain amount of time to reach this equilibrium state, a magnetic stirrer is used to shorten this time. In operation using a magnetic stirrer, it is necessary to insert a stirrer into the sample container one by one, which complicates the sample filling operation, and also requires a structure for rotating the stirrer, making it complicated.

(c) Purpose The present invention solves the drawbacks of the prior art described above, and is aimed at displacing the head space components by positioning the needle of a gas-tight syringe in the gas phase of the head space of a sample container in a constant temperature bath. Provides an automatic sample introduction device that sucks the sample into a tight syringe, then immerses the needle in the sample liquid, discharges the sucked head space components in the form of bubbles, and agitates the sample liquid to shorten the equilibration time. The purpose is to

(D) Structure The present invention uses a first drive mechanism to position the needle of a gas tight syringe at a first position in a sample container, and a second drive mechanism to tighten the gas phase in the head space within the sample container. The needle of the gas-tight syringe is moved to the second position in the sample container by the first drive mechanism.
By driving the second drive mechanism, the aspirated head space gas phase is discharged into the sample liquid, thereby stirring the sample liquid.

(E) Embodiment An embodiment of the automatic sample introduction device of the present invention will be described below with reference to FIG.

FIG. 1 shows a side cross section of an embodiment of the device of the present invention,
Figure A shows the initial state before inserting the needle of the gas tight syringe into the sample container, Figure B shows the state with the needle inserted into the gas phase of the head space of the sample container, and Figure C shows the sample liquid in the sample container. The needle is inserted into the gas-tight syringe, and the headspace gas phase drawn into the gas-tight syringe is discharged.

In FIG. 1A, 1 is a support block, 2a and 2b are arms fixed to the support block 1, and a first air cylinder 3 functioning as a first drive mechanism is supported on this arm. . Compressed air inlet holes 4a and 4b are provided on the upper and lower end sides of the air cylinder 3, and a piston 6 that slides along the side surface is provided inside the air cylinder 3. One end of the rod 5 is fixed to the upper and lower surfaces, and the other end of the rod 5 is fixed to the frame 7.

The frame 7 is driven upward and downward by the upward and downward movement of the piston 6 of the air cylinder 3, and the frame 7 has a second drive for causing the gas tight syringe 13 to suck in and discharge. Arms 7a and 7b that support the second air cylinder 8, which is a mechanism, are provided, and arms 7c and 7d that support the gas-tight syringe 13 are further provided.

Compressed air inlet holes 8a and 8b are provided on the upper and lower end sides of the air cylinder 8. The illustrated piston is provided in the air cylinder 8, and the upward and downward movement of this piston causes the rod 9 to move upward and downward. The lower end of the rod 9 is fixed to the upper arm of a U-shaped holding member 10.

The gas-tight syringe 13 is equipped with a needle 14, and its rod 9 is slidably inserted into the lower arm of the U-shaped holding member 10, and the upper end surface of the rod 9 has a gas-tight syringe head to prevent it from coming off. A portion 11 is fixedly installed.

Reference numeral 15 denotes a constant temperature bath, only a portion of which is shown cut away in the figure, filled with a sample liquid 18, in which a sample container 16 having a cap 17 is disposed, and is heated or kept warm by a heating element (not shown).

Reference numeral 19 denotes a stopper provided on the support block 1. When the stopper 19 is not in operation, it is located within the support block 1 and maintains its initial state, and when it is in operation, it protrudes to the left as shown in FIG. When the cylinder 3 is driven and the frame 7 is lowered, the needle 14 of the gas-tight syringe 13 is stopped in the gas phase of the head space of the sample container 16, which is the first position.

In FIG. 1B, the needle 14 is shown positioned in the gas phase of the head space of the sample container 16.
When the rod 9 is driven upward by the operation of the air cylinder 8, the rod 12 of the gas-tight syringe 13 is driven upward, and the head space gas phase in the sample container 16 is passed through the needle 14 into the gas-tight syringe 13. Let it be sucked into.

The stopper 19 becomes inoperative and the support block 1
After the air cylinder 3 is driven, the frame 7 is further lowered, and the needle 14 of the gas tight syringe 13 is immersed in the sample liquid 18 of the sample container 16 in the second position. In FIG. 1C, which shows a state in which the air cylinder 8 is operated, the rod 9 is driven downward, and the gas sucked into the gas tight syringe 13 passes through the needle 14 and forms bubbles 20 in the sample liquid 18. The sample liquid 18 is then discharged and stirred.

Next, the operation of the device of this embodiment will be explained.

In FIG. 1A, the stopper 19 in the support block 1 is operated and kept in a state where it projects to the left. Then, compressed air is fed through the compressed air inlet 4a of the air cylinder 3, and as the piston 6 is driven downward, the rod 5 is driven downward, and the frame 7 is moved to the stop position as shown in FIG. 1B. The frame 7 is driven downward until it comes into contact with the frame 19. Therefore, the needle 14 of the gas-tight syringe 13 pierces the cap 17 of the sample container 16 and is positioned in the first position in the gas phase of the head space of the sample container 16.

In this state, compressed air is fed from the compressed air inlet 7b of the air cylinder 8, raises the piston (not shown), drives the rod 9 upward, and connects the gas tight syringe head 11 via the holding member 10.
is driven upward, causing the rod 12 to be driven upward and drawing the headspace gas phase into the gas-tight syringe 13 through the needle 14.

Next, the stopper 19 is retracted into the support block 1, the piston 6 is driven downward, and the frame 7
is further lowered, and the needle 14 is immersed in the sample liquid 18 in the sample container 16 at the second position, as shown in FIG. 1C. In this state, compressed air is sent from the compressed air inlet 8a of the air cylinder 8, the piston (not shown) is lowered, the rod 9 is lowered, and the gas tight syringe head 11 is lowered via the holding member 10. Along with this, the rod 12 is lowered, and the head space gas phase sucked into the air cylinder 13 is discharged as bubbles 20 into the sample liquid 18 through the needle 14.
This stirs the sample liquid. By stirring the sample liquid 18 in this way, the temperature distribution of the sample liquid 18 in the sample container 16 is made uniform, and the discharged head space gas phase and the sample liquid are mixed and contacted with each other, so that a specific Evaporation of sample component gas is promoted.

(f) Effects As explained above, according to the present invention, the first drive mechanism positions the needle of the gas tight syringe in the first position, which is the gas phase of the head space of the sample container, and in this state, the needle of the gas tight syringe is moved to the second position. activating the drive mechanism to aspirate the headspace gas phase into the gas-tight syringe; the first drive mechanism then positions the needle in the sample liquid of the sample container in a second position; Since the structure is such that the head space gas phase sucked into the gas tight syringe is discharged into the sample liquid by the mechanism, the temperature distribution of the sample liquid in the sample container is made uniform, and the head space gas phase and the sample liquid are mutually separated. It is possible to promote the evaporation of a specific sample component by contacting the sample component, thereby shortening the time it takes for the sample component gas phase to reach an equilibrium state with the sample component in the sample liquid.

[Brief explanation of the drawing]

Figure 1 shows an embodiment of the automatic sample introduction device of the present invention, where Figure A is a side sectional view showing the initial state before inserting the needle of the gas-tight syringe into the sample container, and Figure B is a side sectional view of the sample container. Figure C is a side sectional view showing the state in which the needle is inserted into the gas phase of the head space of the sample container. 1 is a support block, 2a and 2b are arms, 3 is an air cylinder, 4a and 4b are compressed air inlet holes,
5 is rod, 6 is piston, 7 is frame, 7
a, 7b, 7c, 7d are arms, 8 is an air cylinder, 9 is a rod, 10 is a holding member, 11 is a gastight syringe head, 12 is a rod, 13 is a gastight syringe, 14 is a needle, 15 is a heat insulating tank , 16 is a sample container, 17 is a cap, 18 is a sample liquid, 19 is a stopper, and 20 is a bubble.

Claims (1)

[Scope of utility model registration request] a first drive mechanism that positions the needle of the gas-tight syringe at a headspace gas phase position and a sample liquid position within the sample container; and a second drive mechanism that causes the gastight syringe to aspirate and discharge the headspace gas phase. , a stopper attached to the first drive mechanism that positions the needle of the gas tight syringe in the head space gas phase position when moved by the first drive mechanism; be moved,
the gas-tight syringe, which is caused by the second drive mechanism to aspirate the head space gas phase of the sample container at the head space gas phase position and discharge the aspirated head space gas phase into the sample liquid at the sample liquid position; An automatic sample introduction device having