JPH08194003A - Sampling device - Google Patents

Abstract

PURPOSE: To simplify the constitution of a sampling device for performing the positional detection of a liquid surface and the suction and the point contact of liquid by using a pressure supplying means for supplying a positive pressure or a negative pressure into a nozzle line and at the same time to accurately perform the point contact and the positional detection of liquid surface. CONSTITUTION: A pressure source for supplying air to a draft tube 209 at the time of performing the positional detection of a liquid surface and a pressure source for supplying air to the draft tube 209 at the time of performing the point contact are constituted of the same syringe 210. A piston 215 fitted into the syringe 210 is moved up and down by driving a third motor 211, thereby supplying or sucking air to/from the draft tube 209. The driving of the third motor 211 is controlled by a control part 214, and the control part 214 is constituted to control the driving of the third motor 211 so that the velocity of air supplied into the draft tube 209 at the time of performing the point contact is higher than that of air supplied into the draft tube 209 at the time of performing the positional detection of a liquid surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sampling device mainly used in a biochemical analysis device for performing biochemical analysis using a dry analysis element.

[0002]

2. Description of the Related Art In recent years, quantitative analysis of the content or activity value of a specific chemical component contained in a sample, or the content of a tangible component, by simply spotting and supplying small droplets of a liquid sample. A dry-type integrated multi-layer analytical element (also referred to as multi-layer analytical element or multi-layer analytical film), or
A dry-type electrolyte analysis element having at least one pair of ion-selective electrodes having an ion-selective layer as an outermost layer that selectively responds to specific ions has been developed and put into practical use.

In a biochemical analyzer for performing biochemical analysis and the like using such a dry analytical element, a container containing a predetermined liquid such as a sample or reference liquid used for biochemical analysis or a diluting liquid. There is used a sampling device which sucks and holds these liquids from the above, and discharges the held liquids to the dry analysis element for spotting.

This sampling device uses a nozzle conduit having a suction and discharge port at its tip and a pressure source such as a syringe for sending air into the nozzle conduit or sucking air in the nozzle conduit. A pressure supply means for supplying a positive pressure or a negative pressure to the inside, and a moving means for vertically moving the tip end portion of the nozzle conduit relative to the liquid surface of the liquid, and the nozzle conduit is Generally the nozzle body,
A nozzle tip attached to the tip of this nozzle body,
It is composed of a vent pipe connected between the nozzle body and the pressure source, and the pressure supply means sucks and holds the liquid from the tip of the nozzle tip into the nozzle tip and discharges the held liquid. It is configured to apply spots.

By the way, in such a sampling device, when sucking a liquid such as a sample, it is necessary to partially infiltrate the tip portion of the nozzle conduit (generally, the tip portion of the nozzle tip) into the liquid. If the amount to be applied is increased, the liquid tends to adhere to the outer surface of the tip of the nozzle conduit. If a large amount of liquid adheres to the outer surface of the tip of the nozzle conduit, the liquid that has adhered during spotting may drop and the amount of spotting may change, which may adversely affect the accuracy of biochemical analysis. There is

For this reason, the sampling device is provided with a liquid level detecting mechanism for detecting the liquid level position of the liquid in order to properly maintain the amount of penetration of the tip of the nozzle conduit into the liquid. Although various liquid level detection mechanisms are conventionally known,
It is known that one of them is provided with a pressure detecting means for detecting the pressure in the nozzle conduit, and is configured to detect the position of the liquid surface based on the pressure detection result of the pressure detecting means.

The position of the liquid surface is detected by this liquid surface detecting mechanism as follows. That is, the tip of the nozzle conduit is brought closer to the liquid level while the air is sent or sucked into the nozzle conduit by the pressure supply means to make the inside of the nozzle conduit positive or negative. When the tip portion of the nozzle conduit comes into contact with the liquid surface, the nozzle conduit is closed, and the pressure in the nozzle conduit increases or decreases. By detecting the pressure change in the nozzle conduit with the pressure detecting means, it is possible to detect that the tip of the nozzle conduit has reached the liquid surface, that is, the liquid surface position.

[0008]

By the way, in the sampling device equipped with such a liquid level detecting means, the velocity of the air sucked or discharged from the tip of the nozzle conduit when the position of the liquid level is detected, At the time of spotting, it is necessary to make the speed of the liquid such as the sample discharged from the tip of the nozzle conduit considerably different. That is, the velocity of the air sucked or discharged from the tip of the nozzle pipe when detecting the position of the liquid surface is about the same as the appropriate velocity of the liquid discharged from the tip of the nozzle pipe when spotting. If it becomes faster, the liquid surface will be disturbed when the tip of the nozzle conduit approaches the liquid surface, or the nozzle conduit tip inside the nozzle conduit before and after contact with the liquid surface Since it becomes difficult to detect the pressure change, there is a possibility that the position of the liquid surface cannot be accurately detected. On the other hand, the speed of the liquid discharged from the tip of the nozzle pipe line when performing spotting is about the same as the appropriate speed of the air sucked or discharged from the tip of the nozzle pipe line when detecting the position of the liquid surface. If it becomes late, the speed at which the liquid is sucked into the dry analysis element will be faster than the discharge speed of the liquid, and the spotting will not be done at once and so-called liquid shortage will occur in the middle, There is a risk that it cannot be performed with high accuracy.

As described above, since it is necessary to make the air suction or discharge speed at the time of detecting the position of the liquid surface and the liquid discharge speed at the time of spotting considerably different, the conventional sampling device The structure of the pressure source for supplying the pressure into the nozzle conduit when detecting the position of the liquid level and the structure of the pressure source for supplying the pressure into the nozzle conduit during the spotting are completely different. However, it is necessary to provide those having the same or similar structures but having greatly different pressure supply capacities, and to separately control the driving of these different pressure sources.

Therefore, there is a problem that the device structure is complicated and the cost is increased.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a sampling device which is simple in construction, can reduce cost, and can detect a liquid surface position and spotting with high accuracy. To do.

[0012]

To achieve the above object, the sampling device of the present invention supplies a nozzle pipe having a suction and discharge port at its tip and a positive or negative pressure to the nozzle pipe. Pressure supply means, pressure detection means for detecting the pressure in the nozzle pipeline, and moving means for moving the tip of the nozzle pipeline up and down relative to the liquid surface of a predetermined liquid are provided. The tip of the nozzle conduit is brought into contact with the liquid surface by the moving means while discharging or sucking air from the suction / discharge port by means, and the position of the liquid surface is detected based on the pressure change in the nozzle conduit at that time. In addition, the sampling device for sucking the liquid from the suction / discharge port into the nozzle conduit by the pressure supply means, discharging the sucked liquid from the suction / discharge port, and spotting the liquid. hand Is the same as the pressure source for sending or sucking air to the nozzle conduit when detecting the position of the liquid surface and the pressure source for sending air to the nozzle conduit when performing spotting. It is used as a pressure source, and the air to the nozzle pipe line at the time of spotting is faster than the speed of air feeding or suction to the nozzle pipe line at the time of controlling the drive of this same pressure source to detect the position of the liquid surface. It is characterized in that it is provided with a control means for increasing the feeding speed of.

The pressure source is composed of an air chamber forming portion for forming a variable volume air chamber and a drive portion for changing the volume of the air chamber. The air in the air chamber is changed to a nozzle tube by the volume change of the air chamber. An air pump having a bellows-shaped air chamber configured to send air into the duct and suck the air in the duct into the air chamber, or a syringe can be used.

Further, the nozzle conduit is composed of the nozzle main body only, the nozzle main body and the ventilation pipe connected to the nozzle main body, and these are mounted on the tip portion of the nozzle main body. And a nozzle tip that includes a nozzle tip.

[0015]

As described above, in the sampling device of the present invention, the pressure source for supplying the pressure into the nozzle conduit when detecting the position of the liquid surface and the inside of the nozzle conduit when performing the spotting. Since the pressure source that supplies pressure to is the same pressure source,
The device configuration becomes simple and low cost can be achieved. In addition, the drive of the same pressure source is controlled, and the air is sent to the nozzle pipeline when performing spotting, rather than the speed of the air that is sent to the nozzle pipeline when performing liquid level position detection or the suction speed. Since the control means for increasing the speed of the nozzle pipe is provided, the speed of the air sucked or discharged from the tip of the nozzle pipe is low when the position of the liquid surface is detected, and the speed of the nozzle pipe is small when the spotting is performed. The velocity of the air discharged from the tip portion can be increased, which makes it possible to perform both the position detection of the liquid surface and the spotting with high accuracy.

[0016]

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

First, a biochemical analyzer incorporating a sampling device according to an embodiment of the present invention will be described. FIG. 1 is a perspective view showing a schematic configuration of a biochemical analyzer.

The biochemical analysis apparatus 10 includes, as a colorimetric measurement system (general measurement system), a main storage 11 for storing a cartridge 3 in which a dry analysis element 1 made of a dry analysis film piece is stored,
An incubator 12 arranged beside the main storage 11 for keeping the dry analytical element 1 at a constant temperature for a predetermined time, and the main storage 11
An element transporting means 13 for taking out and transporting the dry analytical element 1 from the incubator 12 and a sample holding means 14 for holding a sample container 77 containing a plurality of samples such as serum and urine,
A first spotting means 15 for spotting the sample of the sample holding means 14 on the dry analytical element 1 until the dry analytical element 1 is transported to the incubator 12 by the element transporting means 13, and arranged below the incubator 12. The measuring means 16 is provided.

Further, as a potential difference measuring system, an electrolyte storage cabinet 21 for storing an electrolyte cartridge 4 in which a dry analysis element 2 by an electrolyte slide is also stored, and an electrolyte dry analysis element 2 from the electrolyte cartridge 4 in the electrolyte storage cabinet 21. To a spotting position, a second spotting means 23 for spotting a sample from the sample holding means 14 onto the electrolyte dry analysis element 2, and a reference solution from a reference solution container 97 to the electrolyte dry system. A third spotting means 24 for spotting on the analytical element 2 and a potential difference measuring means 25 installed in front of the electrolyte spotting position for keeping the electrolyte dry analytical element 2 at a constant temperature for a predetermined time and measuring the potential difference. There is. On the other hand, the first and second
In the vicinity of the spotting means 15 and 23, a tip supply means 26 for holding a tip rack 79 in which nozzle tips 78 to be attached to the tips of the spotting nozzles 83 and 93 are arranged and stored is installed.

The sample holding means 14 is provided with a sample table 76 which is rotated, and a plurality of sample containers 77 containing samples are set on the inner and outer peripheral portions of the sample table 76, and the sample containers 77 are rotated by the rotation. It is sequentially moved to the supply position. The sample container 77 set on the inner side of the sample table 76
Is for emergency measurement.

The tip supply means 26 on the back of the first and second spotting means 15 and 23 has a tip rack 79 in which nozzle tips 78 mounted on the tips of the spotting nozzles 83 and 93 are arranged and housed. In addition, the diluting container 80 in which cup-shaped recesses are arranged in parallel is slid in the lateral direction, and the position of the nozzle tip 78 or the diluting container 80 is sequentially rotated below the spotting nozzles 83, 93. The tip rack that has been spared and supplied with the movement controlled to be located at
It has a standby position for holding 79 and a discharge position.

Further, the first spotting means 15 for spotting the sample from the sample container 77 onto the dry analysis element 1 sucks and discharges the sample to the tip of the sampling arm 82 which is rotatable and vertically movable. A dot wearing nozzle 83 having the dot wearing nozzle
The pipette-shaped nozzle tip 78 is attached to the tip of 83, and the dry analysis is performed by sucking and moving the sample from the sample container 77 of the sample table 76 and holding it on the transfer member 73 of the element moving means 13. It is spotted on the element 1. The sample table 76
A diluent holder 84 is disposed adjacent to the sample holder, and the sample is diluted with the dilution container 80 and then spotted on the dry analytical element 1 depending on the measurement item. The specific structure of the sampling arm 82 will be described later.

The nozzle tip 78 after spotting is discarded every time the sample changes, and the nozzle tip 78 is attached to the upper end.
A tip waste tube 69 that hooks the upper end of the tip waste nozzle 83 to remove it from the tip of the spotting nozzle 83 is disposed, and the nozzle tip 78 that falls from the tip waste tube 69 is discarded in a waste box 74.

Sampling arm 91 of second spotting means 23
Like the first sampling arm 82, is provided with a spotting nozzle 93 that is rotatable and vertically movable, and that suctions and discharges a sample at the tip, and the tip of the spotting nozzle 93 has a pipette-like shape. Nozzle tip 78 is attached and sample table 76
The sample is sucked from the sample container 77, moved, and spotted on the electrolyte dry analysis element 2 which is transported to the spotting position. The nozzle tip 78 after the spotting is to be discarded, and the tip waste tube 75 for hooking the upper end of the nozzle tip 78 to the upper end to remove it from the tip of the spotting nozzle 93 is disposed. The nozzle tip 78 falling from 75 is discarded in the waste box 98.

Similarly, the reference liquid arm 94 of the third spotting means 24 is also rotatably and vertically movable, has a spotting nozzle 96 at its tip, and sucks the reference liquid from the reference liquid container 97 to remove the electrolyte. It is spotted on the dry analytical element 2 and the potential difference is measured by the measuring means 25. In this reference liquid arm 94,
Although a nozzle tip (not shown) is attached, it does not need to be replaced for each spotting, and is provided in a structure for suppressing evaporation by covering the reference liquid container 97 at the time other than spotting. The used electrolyte dry analysis element 2 is discarded in the disposal box 98.

Next, the structure of the sampling apparatus according to this embodiment will be described.

This sampling device, as shown in FIG.
Reference numeral 100 denotes a colorimetric measurement sampling unit 101 for performing colorimetric measurement, and a potentiometric measuring sampling unit 102 for performing potentiometric measurement, and each of these sampling units includes the following constituent elements of the biochemical analyzer 10. It consists of components. That is, the sampling unit 101 for colorimetric measurement is a sample holding unit including the sample table 76.
14 and the first spotting means 15 including the sampling arm 82
And a chip supply means 26 including a tip rack 79, a diluent holder 84, and a dilution container 80. The sampling unit 102 for measuring the potential difference is the sample holding means.
14 and the second spotting means 23 including the sampling arm 91
The tip supply means 26, the diluent holder 84,
It is composed of the dilution container 80.

The spotting means 15 will be described in detail with reference to FIG.
The configuration is as shown in. That is, this spotting means
Reference numeral 15 denotes a sampling arm 82 that supports a spotting nozzle 83 at one end thereof so as to be vertically movable, and a sampling arm 82.
At the other end of 82, a vertically extending spline shaft 202 that holds the sampling arm 82 horizontally and a claw portion that engages with a groove portion 202a that is formed axially in the side wall of the spline shaft 202 are provided. , A belt wheel 203 having a small diameter portion and a large diameter portion, which is relatively fixed in the rotational direction and movable in the axial direction with respect to the spline shaft 202, the belt 205, and the belt 205. Direction (arrow A direction) to rotate the belt wheel 203 in a predetermined direction by a predetermined amount, a first motor 204, a collar portion 206 fixed to the bottom of the spline shaft 202, and a collar portion 206. And a second motor 208 for moving the belt 207 in a predetermined direction (direction of arrow B) to vertically move the spline shaft 202 by a predetermined amount. Eteiru.

In addition, in this spotting means 15, one end 209a is connected to the other end 83a of the spotting nozzle 83 penetrating into the sampling arm 82, and the following portion 209b extends inside the sampling arm 82 and further the sampling arm 82. Vent pipe 209 extending from the portion close to the other end to the outside of sampling arm 82, syringe 210 as a pressure source connected to the other end 209c of this vent pipe 209, and it can move up and down inside this syringe 210 The piston 215 fitted in the
The belt 212 fixed to one end of the valve 5 and the belt 212 are moved in a predetermined direction (direction of arrow E) to move the piston 215 up and down by a predetermined amount, thereby changing the volume in the syringe 210 and changing the volume of the vent tube 209. The piston 215 and the belt 212 together with the piston 215 and the belt 212 that feeds or sucks air from the other end 209c into the ventilation pipe 209 and supplies pressure into the nozzle pipe line constituted by the nozzle tip 78, the spotting nozzle 83 and the ventilation pipe 209. As a pressure detecting means which is attached to a portion of the sampling arm 82 near the one end portion 209a of the ventilation pipe 209 and the third motor 211 which constitutes the driving portion of the pressure source, and which detects the pressure in the pipeline at the attachment position. Pressure sensor 216
It has and.

Further, control as a control means for receiving a detection signal from the pressure sensor 216 and outputting a predetermined motor drive signal for controlling the rotation of each of the motors 204, 208 and 211 described above according to a predetermined sequence program. And section 214. The syringe 210 is configured such that the maximum stroke of the piston 215 is set to a predetermined value, for example, 55 mm, and air can be continuously discharged or sucked only while the piston 215 moves within the range of the maximum stroke. . Further, in this embodiment, the control unit 21
4, the syringe 210, the piston 215, the belt 212 and the third motor 211 constitute pressure supply means.

The spotting means 15 constructed as described above operates as follows based on the sequence program of the control unit 214. That is, first, the control unit 214 causes the first motor
A predetermined motor drive signal is output to 204, and the sampling arm 82 is swung (in the direction of arrow C) by the driving force of the first motor 204 that rotates according to this motor drive signal, and the spotting nozzle 83 and nozzle tip 78 are sampled. It is located on the sample container 77 containing 220. The maximum distance from the tip of the nozzle tip 78 to the liquid surface of the sample 220 in the sample container 77, that is, the maximum stroke of the vertical movement of the sampling arm 82 is set to a predetermined value, for example, 124 mm.

Next, a predetermined motor drive signal is output from the control unit 214 to the third motor 211, and the piston 215 is moved upward by a predetermined speed, for example, 8 mm by the drive force of the third motor 211 which rotates in accordance with this motor drive signal. The air inside the syringe 210 moves at a predetermined speed, for example, 8 mm / s and the ventilation pipe 209
Sent in. As a result, the inside of the nozzle conduit is in a positive pressure state. Immediately after the air is sent into the ventilation pipe 209, the pressure fluctuation in the nozzle conduit is large, and therefore the sampling arm 82 is stopped for, for example, 2 seconds until the pressure fluctuation in the nozzle conduit becomes small. Kept and then control
A predetermined motor drive signal is output from 214 to the second motor 208, and the sampling arm 82 descends at a predetermined speed, for example, 200 mm / s by the driving force of the second motor 208 that rotates according to this motor drive signal. .

On the other hand, from the pressure sensor 216, a detection signal indicating the pressure in the nozzle conduit at the position near the one end 209a of the ventilation pipe 209 is output momentarily. Pressure sensor 216
Is provided with a piezoelectric element that generates a voltage according to the pressure in the nozzle conduit, and is configured to output the voltage generated from this piezoelectric element as a detection signal. Specifically, the control unit 214 compares the output value of the detection signal from the pressure sensor 216 every moment and differentiates it and outputs the differentiated value, and compares the differentiated value output from the differentiator with a predetermined threshold value. Comparison circuit and each motor described above based on the comparison result in the comparison circuit
A motor drive signal generation circuit for generating motor drive signals 204, 208 and 211 is provided, and the comparison judgment is performed in the comparison circuit while the spotting nozzle 83 and the nozzle tip 78 are descending.

When the tip of the nozzle tip 78 comes into contact with the liquid surface of the sample in the sample container 77 to close its mouth by continuing the descending movement of the sampling arm 82, the pressure in the nozzle conduit increases rapidly. . Then, when the differential value of the output value from the pressure sensor 216 exceeds a predetermined threshold value, the control unit 214 outputs a motor stop signal to the second motor 208 to stop the driving of the second motor 208. Then, this stops the descending of the sampling arm 82. At the same time, a motor stop signal is output from the control unit 214 to the third motor 211 and the driving of the third motor is stopped, whereby the upward movement of the cylinder 215 is stopped and the syringe 210 to the inside of the vent pipe 209. The pumping of air to is stopped.

FIG. 3 shows a timing chart showing the relationship between the descending speed of the sampling arm 82 and the ascending speed of the piston 215 (the speed of feeding air from the syringe 210 into the ventilation pipe 209) at the time of detecting the liquid surface position. . In the example shown in FIG. 3, the descending speed of the sampling arm 82 is 200 mm / s,
The rising speed of the piston 215 is set to 8 mm / s,
The sampling arm 82 starts descending 2 seconds after the 215 ascends. Also nozzle tip
The maximum distance from the tip of 78 to the liquid level of specimen 220 is 124 mm, and the time required from the start of descending of sampling arm 82 to the tip of nozzle tip 78 reaching the liquid level of specimen 220 is 0.62 seconds. During that time, the maximum movement amount of the sampling arm 82 is 124 mm, and the movement amount of the piston 215 is 21 mm in 2.62 seconds from when the piston 215 starts rising to when it stops.

The descending speed of the sampling arm 82 and the ascending speed of the piston 215 are not limited to the above specific examples, and may be set appropriately. However, the following points should be noted in the setting. That is, the liquid level of the specimen 220 is not disturbed by the air discharged from the tip of the nozzle tip 78, and
From the syringe 210 to the vent pipe 209 so that the inside of the nozzle pipe is maintained at a pressure at which the pressure sensor 216 can quickly detect the pressure change before and after the tip of the 78 contacts the liquid surface.
It is necessary to set the inflow rate of air into the inside, that is, the rising speed of the piston 215, the time when the tip of the nozzle tip 78 actually reaches the liquid level, and the pressure change in the nozzle pipeline by the pressure sensor 216. Since there is inevitably a time lag between the detection and the time when the tip of the nozzle tip 78 reaches the liquid surface, the descending speed of the sampling arm 82 is set so that a large error does not occur in the liquid surface position detection. What you must do and consider the maximum stroke length of piston 215 to allow for continuous pumping of air from syringe 210 into vent 209 while the sampling arm 82 moves at a set descent rate. It should be noted that it is necessary to satisfy all the conditions that the rising speed must be set. The example described above is one example that satisfies these conditions in this embodiment.

After the sampling arm 82 is stopped, the control unit 214 outputs a predetermined motor drive signal to the third motor 211, and the piston 215 is moved downward by the drive force of the third motor 211 that rotates according to this motor drive signal. And a predetermined amount of the specimen 220 is sucked and held in the nozzle tip 78. Thereafter, the control unit 214 outputs a predetermined motor drive signal to the second motor 208, and the driving force of the second motor 208 that rotates in accordance with this motor drive signal causes the sampling arm 82 to rise at a predetermined speed. After the sampling arm 82 moves up by a predetermined distance, a motor stop signal is output from the control unit 214 to the second motor 208 to stop the driving of the second motor 208, which stops the rising of the sampling arm 82.

Next, the control unit 214 causes the first motor 204 to
A predetermined motor drive signal is output to the sampling motor 82 by the driving force of the first motor 204 that rotates according to this motor drive signal, and the sampling arm 82 is directed to the position where the nozzle tip 78 is located directly above the dry analysis element 1. To move. When the nozzle tip 78 is located right above the dry analysis element 1, a motor stop signal is output from the control unit 214 to the first motor 204, and the driving of the first motor 204 is stopped. The rotation movement of stops. Further, a predetermined motor drive signal is output from the control unit 214 to the second motor 208, and the sampling arm 82 is lowered by the rotation of the second motor 208 that rotates according to this motor drive signal. When the sampling arm 82 descends and the tip of the nozzle tip 78 contacts the surface of the dry analytical element 1, the control unit
A motor stop signal is output from 214 to the second motor 208 to stop the driving of the second motor 208, which stops the descending of the sampling arm 82.

Next, a predetermined motor drive signal is output from the control unit 214 to the third motor 211, and the piston 215 detects the liquid surface position by the drive force of the third motor 211 which rotates in accordance with this motor drive signal. At a speed faster than the rising speed of the piston 215, for example, 32 mm / s, the air in the syringe 210 moves upward at a speed faster than the air feed speed at the time of detecting the liquid surface position, for example, at 32.5 mm / s. It is sent into the ventilation pipe 209. As a result, the inside of the nozzle conduit is brought into a positive pressure state, and the sample 220 held in the nozzle tip 78 is ejected onto the dry analysis element 1 from the tip of the nozzle tip 78. In synchronization with this, a predetermined motor drive signal is output from the control unit 214 to the second motor 208, and the driving force of the second motor 208 that rotates in accordance with this motor drive signal causes the sampling arm 82 to move at a predetermined speed, for example, 0.63 mm. It rises at / s. That is, the spotting of the specimen 220 on the dry analysis element 1 is performed while the tip of the nozzle tip 78 is separated from the dry analysis element 1.

Sampling arm 82 at the time of spotting
4 is a timing chart showing the relationship between the rising speed of the piston 215 and the rising speed of the piston 215 (the speed of feeding air from the syringe 210 into the ventilation pipe 209). In the example shown in FIG.
Sampling arm 82 rising speed is 0.63 mm / s, piston
The ascending speed of 215 is set to 32.5 mm / s, and the ascending of the piston 215 and the assembling of the sampling arm 82 are started at the same time. It takes 0.37 seconds from the start of
The amount of movement is 12 mm, and the sampling arm 82 between them is also
The moving amount is 0.23mm.

The ascending speed of the piston 215 at the time of spotting, that is, the sample discharge spotting speed is not limited to the above specific example, and may be set appropriately. However, when setting it, it is necessary to be careful not to cause so-called liquid shortage during spotting. In the present embodiment, the sampling arm 82 is raised during the spotting and the sampling arm 82 is 0.3 mm so that the spotting can be performed particularly accurately.
The ascending speed of the sampling arm 82 and the ascending speed of the piston 215 are set in consideration of completion of spotting before the ascent.

The second spotting means has the same structure as the above-mentioned first spotting means. Also, the third spotting means
The present invention may be applied to 24.

Although the embodiments of the present invention have been described above, the sampling device of the present invention is not limited to the specific modes of the embodiments, and various modifications can be made. For example, although a syringe is used as a pressure source in the above embodiment, an air pump that expands and contracts a bellows-shaped air chamber to take in and out air therein, a compressed air pump that can continuously take in and out air, and the like are used. It may be used as a source.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a biochemical analyzer in which a sampling device according to an embodiment of the present invention is incorporated.

FIG. 2 is a perspective view showing the configuration of the first spotting means of the embodiment.

FIG. 3 is a timing chart showing the relationship between the descending speed of the sampling arm and the ascending speed of the cylinder when the liquid surface position is detected in the embodiment.

FIG. 4 is a timing chart showing the relationship between the ascending speed of the sampling arm and the ascending speed of the cylinder during spot application in the embodiment.

[Explanation of symbols]

 1, 2 Dry analytical element 3, 4 Cartridge 10 Biochemical analyzer 11 Main storage 12 Incubator 14 Sample holding means 15, 23, 24 Spotting means 21 Electrolyte storage 26 Tip supply means 76 Specimen table 77 Specimen container 78 Nozzle tip 79 Tip rack 80 Diluting container 82, 91, 94 Sampling arm 83, 93, 96-point wearing nozzle 84 Diluting liquid holder 85 Diluting liquid container 100 Sampling device 101 Sampling unit for general measurement 102 Sampling unit for measuring potential difference 202 Spline shaft 204 1st Motor 208 Second motor 209 Vent pipe 210 Syringe 211 Third motor 214 Controller 216 Pressure sensor 220 Sample

Claims (2)

[Claims] 1. A nozzle conduit having a suction and discharge port at its tip, pressure supply means for supplying a positive or negative pressure to the nozzle conduit, and a pressure for detecting the pressure in the nozzle conduit. A detection means; and a movement means for vertically moving the tip end portion of the nozzle conduit relative to the liquid surface of a predetermined liquid,
Based on a pressure change in the nozzle pipeline at that time, the tip of the nozzle pipeline is brought into contact with the liquid surface by the moving means while discharging or sucking air from the suction discharge port by the pressure supply means. A sampling device that detects the position of the liquid surface, sucks the liquid from the suction / discharge port into the nozzle conduit by the pressure supply unit, and discharges the sucked liquid from the suction / discharge port for spotting. The pressure supply means is a pressure source for feeding or sucking air to the nozzle pipeline when performing the position detection of the liquid surface, and a pressure source for the nozzle pipeline when performing the spotting. The pressure source for feeding air is the same pressure source, and the speed of feeding or suctioning air to the nozzle conduit when the drive of the same pressure source is controlled to detect the position of the liquid surface. Than the above, the sampling device further comprises control means for increasing the speed of feeding air into the nozzle conduit when performing the spotting. 2. The pressure source includes an air chamber forming portion that forms a variable volume air chamber and a drive portion that changes the volume of the air chamber, and the air in the air chamber is changed by the volume change of the air chamber. 2. The sampling apparatus according to claim 1, wherein the sampling device is configured to send the air into the nozzle conduit and suck the air in the conduit into the air chamber.