JPH09184846A - Liquid sample dispensing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent drops of a liquid adhering to a nozzle from dropping into a container storing the other liquid and causing contamination, etc., in a liquid sample dispensing apparatus wherein the nozzle is moved up/down and the liquid in the container is sucked through a front end of the nozzle. SOLUTION: The apparatus is provided with a discharging means for discharging a minute amount of a sample and a speed selection means 6 for changing a moving speed of a nozzle in a Z-axis direction. After the sample is sucked, a minute amount of a liquid is discharged to a front end of the nozzle 2 from the discharging means 5, and subsequently the nozzle 2 is moved up and down. At this time, the nozzle 2 is accelerated suddenly and stopped suddenly. Accordingly, liquid drops adhering to the nozzle 2 are dropped and removed together with the minute amount of the fresh discharged liquid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for sucking a sample from a liquid container and dispensing the sample liquid to an analyzing device such as an ultraviolet / visible spectrophotometer, and more particularly to a device for sucking a sample liquid suction nozzle. The present invention relates to a liquid sample dispensing device having a function of removing accumulated droplets.

[0002]

2. Description of the Related Art In a liquid sample dispensing apparatus that sucks a liquid in a liquid container through a nozzle and discharges the liquid into another container such as a cuvette, the nozzle is usually mounted with its longitudinal direction vertically. Therefore, the droplets are likely to adhere. The conventional liquid sample dispenser does not have any function to remove the liquid droplets adhering to the nozzle, or the liquid container is covered with a rubber-like thin plate, and the liquid adhering to the nozzle while the nozzle moves through the thin plate. It is known that drops are squeezed.

[0003]

In the liquid sample dispensing apparatus which does not have the droplet removing function described above, the droplets adhering to the nozzle drop into a container containing another liquid to cause contamination. It may occur. In addition, a device that uses a rubber-like thin plate needs to be designed to withstand the force when the nozzle penetrates, and if it is used many times, the hole in the thin plate becomes large and the force to squeeze the outer circumference of the nozzle is reduced. become weak.

Therefore, there has been a demand for a liquid sample dispensing apparatus having a mechanism for effectively removing the liquid droplets attached to the nozzle.

[0005]

In order to solve such a problem, the present invention has a liquid container, a nozzle, and a nozzle moving mechanism, and sucks the liquid in the liquid container through the nozzle to remove the liquid. In a liquid sample dispensing device that discharges to another container or transfers to another flow path that is in communication with the nozzle, it has a minute discharge means for discharging a small amount of liquid from the tip of the nozzle, and the nozzle moving mechanism is There are two kinds of vertical movement speeds, a slow speed used during a normal sample dispensing operation and a fast speed faster than this, and the two kinds of speeds can be switched by a speed selection means. In order to remove the liquid droplets adhering to the nozzle, a minute amount of liquid is discharged to the tip of the nozzle by the minute amount discharging means, and then a high speed is selected by the speed selecting means, and the nozzle is moved vertically. Providing a liquid sample dispensing apparatus that features that dropping the droplets adhering to the nozzle integrally with a liquid that is discharged by the trace discharge means.

In the present invention, the liquid sample dispensing device is
Like an automatic sample dispenser that dispenses a fixed amount of sample into the cuvette part of an ultraviolet / visible spectrophotometer, a sample or reagent dispenser of an automatic biochemical analyzer, and a sample injection device of a high-performance liquid chromatograph. It also includes any of the automatic sample introduction devices of the type in which the sample liquid sucked from the nozzle is guided to the holding loop, and the holding loop is incorporated into the analysis flow path connected to the column by the flow path switching valve.

In the present invention, the nozzle moving mechanism has two kinds of vertical moving speeds of the nozzle. This is because the motor shaft has two pulleys and the pulley has two effective rotation diameters. This is achieved by means such as changing the diameter of the gear that connects the nozzle moving mechanism or changing the rotation speed of the motor itself.

In the present invention, the minute amount discharging means for discharging a minute amount of liquid may be used together with a microsyringe for sucking and discharging the liquid.
In addition, in the holding channel that holds the sucked liquid until discharge,
It can also be achieved by connecting another microsyringe or pressure supply pipe. Further, the small amount is an amount necessary for the liquid droplets attached to the nozzle tip to drop, for example, 1
Refers to an amount of 0 μl to 50 μl.

Further, in the present invention, the nozzle means a tip portion of a hollow pipe, the nozzle is put in a liquid and the other end is depressurized by a microsyringe or the like, and the liquid is sucked and held in the hollow portion. The material is stainless steel,
Made of metal such as copper and synthetic resin such as tetrafluoroethylene.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partial schematic view of a liquid sample dispensing apparatus which is an embodiment of the present invention.

In FIG. 1, 1a, 1b and 1c are liquid containers,
Reference numeral 2 is a nozzle, 3 is a nozzle moving mechanism in the X-axis direction, 4 is a nozzle moving mechanism in the Y-axis and Z-axis directions, 5 is a microsyringe, and 6 is a speed selecting means for moving the nozzle.

Next, the operation of this liquid sample dispensing apparatus will be described.

The nozzle 2 is positioned by the nozzle moving mechanism 3 in the X-axis direction and the nozzle moving mechanism 4 in the Y-axis direction so that the nozzle 2 is positioned above the preset liquid container containing the liquid. Next, the nozzle 2 is moved downward by the nozzle moving mechanism in the Z-axis direction, and the tip of the nozzle 2 is positioned in the preset liquid. At this time, the speed selection means selects the slower speed, and the nozzle 2
Downward movement progresses relatively slowly.

After this, the syringe of the microsyringe 5 moves upward and the liquid in the liquid container is held in the nozzle or in the barrel of the syringe 5. The sample amount held at this time is the total value of the sample amount to be dispensed thereafter by the trace amount sample discharging means and the sample amount to be dispensed. For example, 10 μl discharged by the trace amount sample discharging means and 50 μl required for spectroscopic analysis, that is, 60 μl in total are held in a syringe or the like.

Next, the nozzle 2 is pulled up by the nozzle moving mechanism 4 in the Z-axis direction. At this time, the speed selecting means keeps selecting the slower speed, and the upward movement is performed relatively slowly.

Subsequently, the dispensing device performs a droplet removing operation. This operation will be described with reference to FIGS. 2, 3, and 4.

FIG. 2 is a schematic view of the liquid attached to the tip of the nozzle. In FIG. 2, 7 is the tip of the nozzle,
Reference numeral 8 indicates a droplet, a indicates a case where the droplet adheres to the inside of the nozzle, and b indicates a case where the droplet adheres to the outside of the nozzle.

Here, in the first step, the amount of droplets is increased in order to promote the dropping of the droplets. That is, the syringe of the microsyringe 5 is moved downward by an amount corresponding to 10 μl, and 10 μl of the liquid is discharged from the tip of the nozzle.

FIG. 3 is a schematic diagram of the liquid attached to the tip of the nozzle after the trace amount of liquid has been discharged to the nozzle tip by the trace amount discharging means. FIG. 3c shows the case where the liquid was initially attached inside the nozzle (FIG. 2a), and FIG. 3d shows the case where the liquid droplet was originally attached outside the nozzle (FIG. 2b).

Next, as the second step, the nozzle is moved up and down to remove the droplets adhering to the tip of the nozzle. FIG. 4 is a schematic view showing the vertical movement operation of the nozzle. FIG. 4P shows the nozzle position immediately after the trace amount of liquid is discharged by the trace amount discharging means. At this point, the speed selection means is switched to one that provides a high operation speed.

Subsequently, the nozzle is rapidly accelerated downward and moved vertically, and suddenly stops at a position where the distance advances by x (FIG. 4).
Q). Further, it is suddenly accelerated upward and moved vertically, and suddenly stops at a position where the distance advances by y (FIG. 4R). Further, the tip of the needle is moved upward to return to the original position.

Here, when the nozzle is moved up and down,
It is considered that the droplets divided into two parts as shown in FIG. 3d are merged into one droplet due to the effect of the vertical movement, resulting in the same state as in FIG. 3c and dropping.

After this, the speed selecting means is switched to a slower operating speed, the nozzle moving means is driven to position the nozzle directly above the measurement cuvette, and the required amount of liquid sample is discharged into the cuvette.

In the present invention, the removal of the liquid adhering to the nozzle depends on the acceleration given to the nozzle, and it is important to perform rapid acceleration and sudden stop when the nozzle moves up and down. Although the above-described specific example is the apparatus for performing the vertical movement operation in FIG. 1, the droplets can be more reliably removed by performing the vertical movement operations a plurality of times.

Further, it is suitable to move the nozzle in the vertical direction due to the use of the earth's gravity and the ease of the process of collecting the dropped liquid droplets, but it is possible to remove the liquid droplets even by moving in the horizontal direction or the licking direction. is there.

[0027]

The liquid sample dispensing apparatus of the present invention can prevent contamination due to the drop of liquid droplets from the nozzle.

Further, the droplet removing mechanism of the liquid sample dispensing apparatus of the present invention is realized at a relatively low cost because most of them share the mechanism which such an apparatus has to achieve its original purpose. it can.

[Brief description of the drawings]

FIG. 1 is a partial schematic view of a liquid sample dispensing apparatus which is an embodiment of the present invention.

FIG. 2 is a schematic diagram of a liquid attached to a tip portion of a nozzle.

FIG. 3 is a schematic diagram of the liquid that has adhered to the tip of the nozzle after the trace amount of liquid has been discharged to the tip of the nozzle by the trace amount discharging means.

FIG. 4 is a schematic diagram showing a vertical movement operation of a nozzle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid container 2 Nozzle 3 Nozzle moving mechanism in X-axis direction 4 Nozzle moving mechanism in Y-axis and Z-axis direction 5 Microsyringe 6 Speed selecting means 7 Tip part of nozzle 8 Droplet

Claims (1)

[Claims] 1. A liquid container, a nozzle, and a nozzle moving mechanism, which sucks the liquid in the liquid container through the nozzle and discharges the liquid to another container or transfers it to another flow path communicating with the nozzle. The liquid sample dispensing device has a small amount discharging means for discharging a small amount of liquid from the tip of the nozzle, and the nozzle moving mechanism uses the vertical moving speed of the nozzle as the slow speed used during normal sample dispensing operation. There are two kinds of speeds which operate faster than this, and the two kinds of speeds can be switched by speed selecting means, and in order to remove droplets adhering to the nozzle, the tip of the nozzle is discharged by a minute amount discharging means. A small amount of liquid is discharged onto the nozzle, then a high speed is selected by the speed selecting means, and the nozzle is moved up and down to discharge the droplets adhering to the nozzle by the small amount discharging means. Liquid sample dispensing device characterized by dropping as a unit with liquid.