JP6609108B2 - Liquid sample injection method - Google Patents

Description

  The present invention relates to a liquid sample injection method for injecting a liquid sample into a combustion reaction part in liquid component analysis such as a water quality analyzer. Specifically, the present invention relates to a liquid sample injection method for injecting a certain amount of liquid sample from a sample injection pipe.

  Combustion reaction of liquid sample, convert carbon component or nitrogen component in liquid sample to carbon dioxide gas or nitrogen oxide, measure the concentration or total amount with a gas analyzer, carbon component amount or nitrogen component amount Water quality analyzers that measure water are well known.

  In such a water quality analyzer, as shown in FIG. 4 (a), after collecting a liquid sample LS measured to a predetermined amount, the sample is moved through the sample injection pipe 11 (FIG. 4 (b)), and the tip of the pipe It is dripped from the part 11T into the sample combustion part 12 (FIG. 4C).

  In FIG. 4, the liquid sample LS in the sample injection pipe 11 moves to the pipe tip 11T side by the liquid sample injection carrier gas set at a constant flow rate by the liquid sample injection carrier gas flow rate setting valve 6, and the liquid sample LS. The moving speed of the liquid sample is controlled by the flow rate of the carrier gas for liquid sample injection set by the carrier gas flow rate setting valve 6 for liquid sample injection.

  Here, the liquid sample LS is several tens μl (several tens mg), and the inner diameter of the sample injection pipe 11 is several mm. If the moving speed of the liquid sample LS is increased under such conditions, the liquid sample LS A part of the liquid sample LS may remain on the inner wall of the sample injection pipe 11 due to the influence of dynamic friction with the inner wall of the sample injection pipe 11, which adversely affects the analysis accuracy. For this reason, the moving speed of the liquid sample LS needs to be slow so that a part of the liquid sample LS does not remain on the inner wall of the sample injection pipe 11.

  While it is necessary to slow down the speed of the liquid sample LS moving in the sample injection pipe 11, there may be a problem when the liquid sample LS is dropped from the pipe tip 11T in a slow state. That is, when the liquid sample LS is detached and dropped from the pipe tip portion 11T, the liquid breakage becomes worse, and a part of the liquid sample LS remains in the pipe tip portion 11T, which may adversely affect the analysis accuracy.

  The present invention has been made in view of the above problems, and in a liquid sample injection method in which a liquid sample weighed to a predetermined amount is injected using a sample injection pipe, the liquid sample is formed on the inner surface of the sample injection pipe and the sample injection pipe. A liquid sample injection method that does not remain in any of the tip portions is provided.

In order to solve the above problems, the invention of claim 1
A liquid sample injection method for injecting a liquid sample having a volume of 10 μl to 150 μl with a carrier gas using a sample injection pipe having an inner diameter of 1 to 4 mm , wherein the first portion of the liquid sample and the liquid sample in the sample injection pipe The liquid transfer process for moving the liquid sample to the vicinity of the tip of the sample injection pipe so that the interval between the tips of the sample injection pipe is within 5 mm, and the movement of the liquid sample in the vicinity of the tip of the sample injection pipe It has a liquid stopping process to stop and a dropping process for dropping the liquid sample from the tip of the sample injection pipe.

The invention described in claim 2
2. The liquid sample injection method according to claim 1, wherein a rate at which the liquid sample is dropped in the dropping process is increased as compared with a speed at which the liquid sample moves in the transferring process.

The invention according to claim 3
3. The liquid sample injection method according to claim 2, wherein the liquid sample is moved by pressurized injection of gas into the sample injection pipe, and the liquid sample is moved to the vicinity of the tip of the sample injection pipe. The pressure injection is stopped, and then the pressure is increased to perform pressure injection.

The invention according to claim 4
The liquid sample injection method according to claim 3, wherein in the liquid stopping process, a valve communicating with the pipe is closed, a pressurized state is formed on the upstream side of the valve, and the valve is opened in the dropping step. Thereby, the speed at which the liquid sample is dropped in the dropping process is made larger than the speed at which the liquid sample moves in the transferring process.

  According to the present invention, it is possible to suppress the liquid sample from remaining at the sample injection pipe and the tip of the sample injection pipe, thereby improving the analysis accuracy.

It is a figure which shows the structure of the apparatus which performs droplet injection based on one Embodiment of this invention. It is a figure which shows the state which extract | collected the predetermined amount liquid sample in the apparatus which performs the droplet injection which concerns on one Embodiment of this invention. (A) It is a figure which shows the state which extract | collected the predetermined amount liquid sample in one Embodiment of this invention. (B) It is a figure which shows the state which the liquid sample is moving in the sample injection pipe in the same embodiment. c) A diagram showing a state in which the liquid sample is stopped near the tip of the sample injection pipe in the embodiment. (d) A diagram showing a state in which the liquid sample is dropped from the tip of the sample injection pipe in the embodiment. is there. (A) It is a figure which shows the state which sampled the liquid sample measured to the predetermined amount, (b) It is a figure which shows the state which the liquid sample is moving in the sample injection pipe, (d) The liquid sample is sample injection It is a figure which shows the state dripped from the front-end | tip part of a pipe.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a configuration of a liquid sample injection device 1 according to an embodiment of the present invention. In FIG. 1, a liquid sample injection device 1 includes a liquid sample inlet 2, a liquid sample outlet 3, a cleaning liquid inlet 4, a cleaning liquid outlet 5, a liquid gas injection carrier gas flow rate setting valve 6, a liquid sample injection carrier gas stop valve 7, The liquid sample metering valve drive unit 8, the driving gas switching valve 9, the liquid sample metering slide unit 10, and the sample injection pipe 11 are used as components, and the liquid sample LS weighed to a predetermined amount is supplied from the pipe tip 11T of the sample injection pipe 11. , And has a function of dropping on the sample combustion section 12.

  A liquid sample L flows between the liquid sample inlet 2 and the liquid sample outlet 3, and a cleaning liquid flows between the cleaning liquid inlet 4 and the cleaning liquid outlet 5. The liquid sample injection carrier gas flow rate setting valve 6 sets the flow rate of the liquid injection carrier gas, and the liquid sample injection carrier gas stop valve 7 switches the supply / non-supply of the liquid sample injection carrier gas.

  The liquid sample metering valve drive unit 8 is operated by moving the drive gas switching valve 9 (moving in the left-right direction in FIG. 1), and the liquid sample slide unit 10 is slid by this operation. For this reason, among the liquid sample L flowing between the liquid sample inlet 2 and the liquid sample outlet 3, a predetermined amount of the liquid sample LS existing in the slide part 10 is slid to the left side of the figure. By doing so, it can be moved to the flow path that continues to the sample injection pipe 11. The sample injection pipe 11 moves and drops a predetermined amount of liquid, and has an inner diameter of about 1 to 4 mm.

  Hereinafter, a procedure for dropping the liquid sample L to the sample combustion unit 12 as the liquid sample LS measured to a predetermined amount using the liquid sample injection device 1 of FIG. 1 will be described.

  First, from the state in which the liquid sample L flows between the liquid sample inlet 2 and the liquid sample outlet 3 as shown in FIG. 1, the driving gas switching valve 9 is driven, and the liquid sample metering slide portion 10 is moved to the left side. When the predetermined amount is moved, as shown in FIG. 2, the liquid sample LS weighed to the predetermined amount moves to the flow path connected to the sample injection pipe 11. Note that the volume of the liquid sample LS measured by the liquid sample measuring slide unit 10 is about 10 to 150 μl.

  The state of the liquid sample LS in the flow path including the sample injection pipe 11 will be described with reference to FIG. The pressure of the carrier gas for liquid sample injection acts on the liquid sample LS that has moved to the flow path connected to the sample injection pipe 11 from the opposite side of the pipe tip 11T of the sample injection pipe 11. By this liquid sample injection carrier gas, the liquid sample LS moves toward the pipe tip portion 11T (FIG. 3 (a) to FIG. 3 (b)). Here, the speed at which the liquid sample LS moves in the sample injection pipe 11 as shown in FIG. 3B is the flow rate of the liquid sample injection carrier gas set by the liquid sample injection carrier gas flow rate setting valve 6. However, the liquid sample LS needs to be set at a low speed that does not remain on the inner wall of the sample injection pipe 11.

  The speed at which the liquid sample LS moves in the sample injection pipe 11 can be set. If the distance between the liquid sample slide portion 10 and the pipe tip portion 11T of the sample injection pipe 11 is known, the liquid sample LS is transferred to the sample injection pipe. The time to reach the vicinity of the eleven pipe tip portions 11T can be obtained. For this reason, if the liquid sample injection carrier gas stop valve 7 is closed when the liquid sample LS reaches the vicinity of the pipe tip 11T of the sample injection pipe 11, the liquid sample LS will be the pipe tip 11T of the sample injection pipe 11. (Fig. 3 (c)). In the state of FIG. 3C, gravity is applied to the liquid sample LS, but the liquid sample LS stops without dripping due to friction with the inner surface of the sample injection pipe 11 or the like. By the way, the vicinity of the pipe tip portion 11T of the sample injection pipe 11 is a state in which the tip portion of the liquid sample LS (on the pipe tip 11T side) is close to a distance of about 5 mm or less from the tip portion 11T of the sample injection pipe 11.

  As shown in FIG. 3C, when the liquid sample LS stopped at the pipe tip 11T of the sample injection pipe 11 is pressurized again by the liquid sample injection carrier gas stop valve 7, one droplet is dropped at the pipe tip 11T. It becomes easy to drop and become (FIG.3 (d)). As for the moving speed of the liquid sample LS after stopping at the pipe tip portion 11T of the sample injection pipe 11, as a result of various attempts, the liquid sample LS moves within the sample injection pipe 11 although there are some differences depending on the liquid sample LS. It has been found that the liquid sample LS tends to be less likely to remain at the pipe tip portion 11T when it is larger than the speed at which it is performed.

  In order to increase the speed at which the liquid sample LS is moved (dropped) from the pipe tip portion 11T of the sample injection pipe 11 to be higher than the movement speed within the sample injection pipe 11, the carrier gas stop valve 7 for liquid sample injection is set. It is necessary to make the speed of the carrier gas for liquid sample injection after opening higher than before closing the carrier gas stop valve 7 for liquid sample injection. To this end, the liquid sample injection carrier gas stop valve 7 can be opened after the liquid sample injection carrier gas flow rate setting valve 6 has raised the set flow rate while the liquid sample injection carrier gas stop valve 7 is closed. However, the set flow rate by the carrier gas flow rate setting valve 6 for liquid sample injection may not be changed. That is, since the upstream side of the liquid sample injection carrier gas stop valve 7 is in a pressurized state compared to before the liquid sample injection carrier gas stop valve 7 is closed, the liquid sample injection carrier gas stop valve 7 is opened. The speed of the carrier gas for liquid sample injection immediately after this is transient (instantaneous), but becomes faster than before the liquid gas carrier gas stop valve 7 is closed, and the liquid sample LS is dropped instantaneously. It will be.

  After the liquid sample LS is dropped on the sample combustion unit 12 and the analysis is performed, the liquid sample injection device 1 drives the driving gas switching valve 9 from the state of FIG. 1 is moved to a state shown in FIG. By changing from the state of FIG. 2 to the state of FIG. 1, the cleaning liquid between the cleaning liquid inlet 4 and the cleaning liquid outlet 5 moves to the flow path connected to the sample injection pipe 11 and the inside of the sample injection pipe 11 is cleaned. For this reason, even if there is a residue in the sample injection pipe, it is removed by the cleaning liquid, so that the influence on the next liquid sample injection is reduced.

As described above, according to the present invention, it is difficult for the liquid sample to remain on the inner surface of the sample injection pipe by slowing the liquid sample moving in the sample injection pipe, and the liquid sample is temporarily stopped near the tip of the sample injection pipe. Then, it is possible to prevent the sample injection pipe from remaining at the tip of the sample injection pipe by dropping it at a faster speed than moving through the sample injection pipe. As a result, the liquid sample weighed to a predetermined amount can be injected into the sample burning part without reducing the volume, so that it is possible to prevent a decrease in measurement accuracy due to variation in the amount of liquid sample injected into the sample burning part in water quality analysis or the like. .

DESCRIPTION OF SYMBOLS 1 Liquid sample injection device 2 Liquid sample inlet 3 Liquid sample outlet 4 Washing liquid inlet 5 Washing liquid outlet 6 Carrier gas flow rate setting valve for liquid sample injection 7 Carrier gas stop valve for liquid sample injection 8 Liquid sample metering valve drive unit 9 Drive gas switching valve DESCRIPTION OF SYMBOLS 10 Liquid sample measurement slide part 11 Sample injection pipe 11T (sample injection) Pipe tip part 12 Sample combustion part L Liquid sample LS Liquid sample measured to predetermined amount

Claims (4)

A liquid sample injection method for injecting a liquid sample having a volume of 10 μl to 150 μl by carrier gas using a sample injection pipe having an inner diameter of 1 to 4 mm ,
A liquid transfer process in which the liquid sample is moved to the vicinity of the tip of the sample injection pipe so that a distance between the leading portion of the liquid sample and the tip of the sample injection pipe is within 5 mm in the sample injection pipe;
A liquid stopping process for stopping the movement of the liquid sample in the vicinity of the tip of the sample injection pipe,
A liquid sample injection method comprising: a dropping process of dropping the liquid sample from a tip portion of the sample injection pipe. The liquid sample injection method according to claim 1,
A liquid sample injection method, wherein the liquid sample is dropped at a rate of dropping in the dropping process as compared with a speed at which the liquid sample moves in the transferring process. A liquid sample injection method according to claim 2,
The liquid sample is moved by pressurized injection of gas into the sample injection pipe,
When the liquid sample has moved to the vicinity of the tip of the sample injection pipe, the pressure injection is stopped,
A liquid sample injection method characterized by performing pressure injection after increasing the pressure. A liquid sample injection method according to claim 3,
In the liquid stopping process, the valve communicating with the pipe is closed, and a pressurized state is formed on the upstream side of the valve,
By opening the valve in the dropping step,
A liquid sample injection method, wherein the liquid sample is dropped at a rate of dropping in the dropping process as compared with a speed at which the liquid sample moves in the transferring process.

Images