JPS62140044A - Method for weighing and mixing liquid specimen - Google Patents

Abstract

PURPOSE:To perform certain feeding and mixing regardless of the length of a feed distance and to prevent the generation of liquid dripping or contamination and deterioration, by supplying a predetermined amount of a liquid to a receiver by a quantitative pump before performing the liquid drainage in a feed pipe by jet gas. CONSTITUTION:Gas feed pipes 12, 12A are opened to the outlet sides of the fine tubes 11, 11A provided to a part of feed pieces 10, 10A each having such an inner diameter that an internal liquid steadily forms a gas-liquid interface with the min. area in a horizontal direction. Quantitative pumps 13, 13A are provided to the liquid feed sides of the feed pipes 10, 10A and a change-over cock 15 is provided in the liquid sending sides thereof. For example, a predetermined amount of a liquid 19 pumped up by one quantitative pump 13 is fed to he feed pipe 10 and gas is injected to the outlet of the fine tube 11 when the supply of the liquid is stopped to perform liquid drainage and the liquid in the downstream side is injected in a receiver 17 through the change-over cock 15 and a discharge tube 16. If the quantitative supply by one pump 13 is finished, the change-over cock 15 is changed over to perform the quantitative supply of the liquid from the other quantitative pump 13A. Hereupon, a desire liquid mixture of liquids 19, 19A is obtained in the receiver 17.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method for measuring and mixing liquid samples such as waste water and various solutions and suspensions.

(B) Conventional technology In automatic testing equipment that handles multiple liquid samples or reagent solutions, operations such as adding a reagent solution to a liquid sample or mixing the sample liquid and a diluent or reagent solution in various ratios can be performed in 2 minutes. This is referred to as dilution, dilution, or mixing operation, and common means for performing these operations include 1, for example, fixed-quantity supply means using a tube pump, and means for variable-metered supply of arbitrary amounts using means such as an electric burette or syringe. JP-A-49-39490, JP-A-52-69383
As shown in Japanese Patent Laid-Open No. 53-22492, a liquid sample such as a sample liquid or a reagent solution is measured and mixed into a container such as a mixing or reaction tank using the above-mentioned metering and supplying means. The means for measuring, supplying, and mixing these liquid samples basically uses dedicated supply pipes for each type of liquid sample, and is set so that all of the liquid discharged from the discharge port can be supplied to the container. A mixing operation is taking place.

In addition, in liquid inspection equipment, from several μl to several tens of ohms
This is because a relatively small amount of liquid, 1 liter, is handled.

The inner diameter of the liquid supply pipe is approximately 3 to 5 m/m or less.

The discharge port is narrowed down further.

Therefore, when a supply pipe is filled with liquid and left to stand with one end closed, the liquid forms an interface with air at the other end, that is, a tip surface, and every corner of the supply pipe is filled with liquid. JP-A-57-4485
As seen in Japanese Patent Publication No. 7 or Japanese Unexamined Patent Publication No. 144464/1983, means for quantitatively supplying a small amount of liquid almost always utilizes this phenomenon to maintain meterability. A specific example of this will be explained based on the schematic diagram of an electric burette shown in FIG.
The tip outlet (3A) of the cock part (2) and the conveyor pipe (3)
The tip of the liquid is always defined at the discharge port (3A) position, and then the piston (4) is
Press twice as desired to push out the liquid from the cylinder part (1), and discharge the desired amount of liquid from the discharge port (3A). When the piston (12) is stopped, the tip of the liquid stays at the discharge port (3A), and liquid delivery is stopped. When the piston (4) is pushed again, the desired amount of liquid is delivered from the discharge port (3A). The liquid is what makes it drain.

(c) Problems that the invention attempts to solve In the conventional liquid quantitative supply means described above.

The flow path from the supply section to the discharge port of the transport tube is filled with liquid not only during transport but also when transport is interrupted, and a dripping phenomenon occurs in which liquid drips from the discharge port of the transport pipe when transport is interrupted. If some kind of vibration is transmitted to the conveying pipe, there will be a problem that the liquid will drip from the discharge port.

Furthermore, if the specified supply amount of liquid is extremely small and the liquid is discharged as droplets from the discharge port, even if the liquid is supplied from the supply section with high precision and at a constant flow rate, only a single droplet may be delivered to the supply destination. Due to the intermittent stepwise supply of an integral multiple of the number of droplets, the phenomenon that the last droplet is too large to drop by itself and remains unsupplied often occurs, and the amount of liquid in the supply section must be mixed at the supply destination. This causes the inconvenience that accuracy cannot be maintained. In order to avoid this inconvenient drop in liquid volume accuracy due to intermittent stepwise supply, the irregular amount remaining around the discharge port is
As in Japanese Patent No. 127853, the supply is carried out by blowing air out, or the discharge port is brought into contact with the wall of the receiver to be supplied, and the outlet is supplied along the wall of the receiver, or the outlet is connected to the inside of the receiver to be supplied. Conventionally, a method of supplying the material by immersing it in liquid has been used.

However, if such a liquid draining means is adopted in a field where highly accurate mixing of small amounts of liquid is required, the secondary liquid may be transferred to a single receiver in order to supply multiple types of liquid. If the tubes are concentrated, problems such as contamination of the liquid inside the receiver may occur due to diffusion of liquid that is not intended to be supplied.

The present invention provides a method for weighing and mixing two or more liquid samples, which is free from the fear of dripping and is particularly suitable for a liquid sample testing device.

(2) Means for Solving Problems As shown in FIG. 1, the liquid metering and mixing method according to the present invention is such that the internal liquid constantly forms a gas-liquid interface with a minimum area in the horizontal direction. A thin tube (11) having a smaller diameter than the conveying tube (10) is provided in a part of the conveying tube (10) having an inner diameter of
2) is opened, and at least two sets of liquid metering and supplying devices (14) each equipped with a supply liquid amount control unit 5, for example, a metering pump (13) are used on the liquid supply side of the conveying pipe (10). Transfer pipe (IOXI) on the liquid sending side of the device (14XI4A)
OA) to the switching cock (15).

A metered liquid sample is fed by a metering pump (13) to the conveying tube (10), and when the liquid supply is stopped, a conveying gas is force fed to the outlet of the capillary tube, and this gas drains the liquid at the outlet of the capillary tube. At the same time, the liquid in the conveying pipe (10) extending from the thin tube outlet in the liquid feeding direction is transferred to the switching cock (1
5) from the discharge pipe (16) to the designated receiver (17), switch the switching cock (15), and similarly supply the fixed amount of liquid supplied from the other liquid metering and supplying device (+4A). is supplied from the discharge pipe (16) to the receiver (17) via the switching cock (15), thus mixing at least two types of weighed 1α body samples.

The liquid supply means applied to the liquid metering and mixing method of the present invention include a metering pump and an electric burette, and the liquid volume is controlled by numerical factors such as the number of reciprocating movements, operating time, or variable position. It is desirable that the thin tube section is provided at a position close to the liquid supply section.

In addition, the wetted parts, conveyance pipes, thin tubes, and air supply pipes of the liquid supply device are made of materials that are not corroded or altered by liquids, such as glass, stainless steel, and plastics such as fluororesin, polyethylene resin, and acrylic resin. Even if you fill the inside with liquid, close the opening at one end, and open the opening at the other end to the atmosphere.

For example, in a glass tube, the inner diameter is approximately 5 mmφ or less so that the internal liquid does not flow out from the open opening due to the action of surface tension between the liquid and the inner circumferential wall and between the liquid and gas such as air. internal diameter, preferably 1.5
A tube with a small inner diameter of about 4 mmφ is applied, and the thin tube has an inner diameter smaller than at least the above-mentioned conveying tube,
Preferably an inner diameter of 1/2 or less of the inner diameter of the conveying pipe 1 Usually number 10
A thin inner diameter of approximately μm to 1 mm is applicable. Further, the air supply pipe has an inner diameter smaller than the above-mentioned conveyance pipe, and preferably has an inner diameter of about 100 μm.

Instead, the volume does not change by operating a reverse valve using a stainless steel pole with a small diameter of about 3 to 5 mm, a 9-turn cock, or a slide valve that slides the conduction hole in a direction other than the conduction direction. In the case of using a blocking device, the object of the present invention can be achieved even if the diameters of the thin tube and the air supply tube are made slightly larger.

A metering pump or an electric syringe is used for the supply section, but in cases where digital supply is permitted, such as for mixing, a type operated by digital signals, such as a pulse motor, is convenient for simplifying control.

Example of discharging a small constant volume of liquid every pulse ij
i;7μノ/Puts or o, sm7/Pu
It is particularly advantageous to use a pulsed metering pump of Is, controlled by the cumulative number of pulses. In analog supply such as dispensing, a metering pump such as a tube pump or an electric syringe that supplies liquid at a constant flow rate is used as the supply unit, and the operation time and piston displacement are controlled.
Alternatively, a liquid pump with a liquid volume meter attached may be used to grasp and control the amount of liquid passing through the liquid volume meter, or a metering pump such as a diaphragm pump that alternates suction and discharge operations may be used to discharge the liquid. The two methods of the present invention can be performed automatically by controlling the operating time by integrating only the time.

(v) Function The operation of the liquid measuring and mixing method according to the present invention will be summarized based on FIGS. 1 and 2. As shown in FIG. 1, the liquid container (18 ) in the liquid (19) through the suction pipe (2o) and the metered supply pump (
When pumped up by the liquid (19), the liquid (19) passes through the conveying pipe (10) and is transferred to the destination position, and is discharged through the discharge pipe (10).
16) into the receiver (17). Then, in synchronization with the stoppage of the metering pump (13), an arbitrary air supply source (21) is placed at the outlet position of the thin tube (11) provided in a part of the conveying tube (0).
When gas is jetted out through the air supply pipe (12), the liquid after the thin tube outlet (22) is blown out by itself and flows into the discharge pipe (12).
6) is actively discharged toward the side, and at the same time the tubule exit (
22), the liquid is drained by the supply device (
+4A). Therefore, all subsequent liquid feeding starts from this state, and since liquid feeding is stopped in this state, the lα form (
The conveyance amount of 19) is determined numerically and accurately based on the operating time and displacement amount of the metering pulp (13), and since the liquid is drained at the capillary part, the flow rate between the pump (13) and the capillary outlet (22) is For liquid remaining in the open position, use the switching cock (15)
Remains without flowing to the side.

As described above, the weighability of the present invention is based on the thin tube outlet (22) provided near the liquid pump. That is, as shown in FIG. 4, before the start of metering and after the end of metering, the tip (23) of the liquid is held at the narrow tube outlet (22) position. The amount of gas now ejected from the air supply pipe (12) is G, and the volume of the conveyance path from the thin tube outlet (23) to the discharge pipe (16) is V.
Then, the liquid metered and discharged using the above-mentioned ejected gas where V
), and while liquid measurement is stopped, there is no liquid in the transport pipe path from the capillary outlet (23) to the discharge pipe 16). Next, when the right supply device (14A) with the switching cock (15) switched is operated in the same manner as above to supply a fixed amount of the different type of liquid (19A) in the container (18A), the liquid (+9A) is Discharge pipe (16)
The two liquids (19) (19A) are mixed in the receiver (17).

(F) Example Below, the embodiment of the present invention will be explained based on the drawings. Figures 1 and 2 show two types of liquid metering and supplying devices (14XI4A) having the same function. This shows a mode of measuring and mixing liquid, and the two-car supply device (14) (14A) includes a liquid container (18) (1
8A), metering pump (13) (13A), pumping pipe connected to the suction side of the metering pump (13) (+3A) (
20) (2OA), the metering pump (13) (+3A)
A liquid transport pipe (10) (IOA) extending from the discharge side, a capillary (II) (IIA) provided in a part of the route of the transport pipe (10) (IOA), and an outlet of the capillary (IIXIIA) 22 ) (22A) (+2) (+2
A), and an air supply source (2+) (2+A). The ends of the conveying pipes (10) (IOA) of both the supply devices (14) (14A) are connected to one switching cock (1
5), and one or the other of the conveying pipes (10) or (10A) is selectively directed to the receiving tank by operating the movable Bragg (25) of the switching cock (15). (16). In this embodiment, the conveying pipe (10) (IOA) has an inner diameter of 4 m.
/m, consisting of a glass tube with a total length of about 100 marks,
Tube <11) (IIA) has an inner diameter of 0.3 m/m and a length of 30 m.
/m, and the inner diameter of the discharge portion of the air pipe (12) (12A) is 1 m/m. Both liquids (19X1
9A), first mix both supply devices (+4) (
+4A) alternately, and metering pump (+3) (+3A
) into the conveying pipe (10) (IOA), and then the pump (+3
) (+3A), and feed 5 oJ' of air from the air supply pipe (+2) (12A) into the conveyance pipe (10) (IOA) to exit the narrow tube (11) (ILA) (22) ( 22A)
At the same time, the liquid from the outlet (22) (22A) is discharged to the receiver (17) via the switching cock (15) and the discharge pipe (16), and the transport channel is cleaned with the sample liquid. Do this. FIG. 4 shows a state in which the liquid runs out at the outlet of the thin tube, and the tip of the liquid maintains a slightly concave vertical surface. Measuring and mixing of both liquids (+9) (19A) is started from this state. That is, based on a preset automatic program, first the metering pump (
13) is activated to dispense the desired amount of liquid (+9), e.g. 5ml.
of liquid (19) is fed into the conveying pipe (10), and at the same time as the pump (13) is stopped, the air supply source (21) is activated and, for example, 50 rnl of air is pumped from the air supply pipe (12) into the conveying pipe (10). 1o), the above-mentioned liquid is drained by this air, and 5 ml of liquid (19) existing after the capillary outlet (22) passes through the switching cock (15) and the discharge pipe (16). It is injected into the receiver (17).

Next, switch the switching cock (15) to the other supply device (14).
A) and then remove the liquid container (
When a predetermined amount of the liquid (+9A) in 18A) is injected into, for example, the +oJ receiver (17), both liquids (+9) (+9A) are mixed at a predetermined mixing ratio in the receiver (17).

FIG. 3 shows an embodiment in which a large number of liquid samples are diluted and mixed using a culture solution, and a large number of liquid sample containers (18B) (18
C) (+8D) and each container (18B) (18c
) (180) suction pipes (20B) (20C
) (20D) and the suction side conduit (26) of the metering pump (13), a multi-branch cock (27) is interposed, and a stirrer equipped with a magnetic stirrer below the discharge pipe (16). (29) A mixing receiver (17) equipped with a drainage conduit (3I) equipped with an on-off valve (30) is arranged.

According to this embodiment, each liquid sample (19B) (19C) (+9D) is made into a component by operating the multi-branch cock (27) and operating the device (14) in the same manner as described above;
It is possible to obtain various liquid mixtures with desired mixing ratios, in which liquid (+9A) is mixed as necessary.

FIG. 6 shows an inspection apparatus 1 for liquid samples with a number of 'a', for example, BOD.
This diagram schematically shows an example in which the present invention is applied to a device that makes a test liquid for a measuring device. That is, as described above, a plurality of sets of liquid metering and supplying devices (14) each equipped with a transport pipe (10) having a narrow tube portion, an air supply pipe (12), a metering pump (13), etc., each transport pipe (10). Multi-branch switching cock (15)
are connected and each conveying pipe (1) is connected by operating the cock (15).
0) is connected to the discharge pipe (16).

Further, the discharge pipe (16) is connected to a multi-branch switching cock (30), and the discharge pipe (16) is switched by operating the cock (30).
1 of branch pipe (31A) (318) (31CX31D)
Each branch pipe (31A)
(318) (31C) A mixing container (32A) (32B) (32C) (32D) equipped with a stirring function is arranged on the discharge side of (31C), and each mixing container (32A) (32B032C) (32
D) Conduit (33A) (33B>(33C) (33D)
The structure is such that each can be introduced into a test container (not shown). When the present invention is applied to a liquid sample testing device in this way, each metering and feeding device (14) (+4) is selectively operated based on a predetermined program. Suction pipe (20
) (20) The predetermined amount of liquid in the containers (+8) (+8) is sequentially mixed in the mixing containers (32A) (32B) (32C) (32
A predetermined mixture of two or more liquids (34A) (34B>(34C)(
34D) can be created efficiently.

Furthermore, if a check valve (35) is provided on the discharge side of the metering pump (13) of the metering supply device (14) and on the air supply pipe (12) as shown in Fig. 5, the inner diameter of the thin tube can be increased. can.

(g) Effects of the Invention As described above, the method for measuring and mixing liquids according to the present invention provides a method for measuring and mixing liquids in a portion of a conveying pipe (10) having an inner diameter such that the internal liquid constantly forms a gas-liquid interface with a minimum area in the horizontal direction. A thin tube (11) having a smaller diameter than the conveying tube (10) is provided, and an air supply tube (12) is opened at the outlet position of the thin tube (11), and the supply liquid is connected to the liquid supply side of the conveying tube (10). At least two sets of liquid metering and supplying devices (14) equipped with a quantity control unit are used, and a conveying pipe (10) on the liquid feeding side of each supplying device (14) is used.
is connected to the switching cock (15), and the liquid sample measured by the supply liquid control unit is fed to the transport pipe (10), and when the liquid supply is stopped, the transport gas is force-fed to the outlet of the thin tube. , This gas drains the liquid at the outlet of the capillary tube, and a conveying tube (10) extends from the outlet of the capillary tube in the liquid feeding direction.
The liquid inside is injected into any receiver (17) via the switching cock (+5) and the discharge pipe (16), and the fixed amount of liquid from the plurality of liquid metering and supplying devices (14) is fed into the receiver (17). Since it mixes at There is no residual liquid, so there is no dripping or contamination.Furthermore, the measured liquid sample is quickly conveyed by air, so the mixing operation is achieved smoothly and quickly.

[Brief explanation of drawings]

1 and 2 are explanatory diagrams illustrating the basic mixing method of the present invention, FIG. 3 is an explanatory diagram illustrating another embodiment, and FIG.
The figure is an enlarged view showing the drained state. Fig. 5 is a diagram showing an example of a check valve, Fig. 6 is an explanatory drawing of the present invention applied to a two-part inspection device, and Fig. 7 is a schematic diagram of a conventional electric burette. be. (10) is a conveying pipe, (11) is a thin tube, (+2) is an air supply pipe, (13) is a metering pump, (+4) is a liquid metering and supplying device, (+5) is a switching cock, (+6) is a discharge pipe, (IT) is a mixed receiver.

Claims (1)

[Claims] A part of the conveying pipe (10) has an inner diameter such that the internal liquid constantly forms a gas-liquid interface with a minimum area in the horizontal direction,
A thin tube (11) having a smaller diameter than the conveying tube (10) is provided, and an air supply tube (12) is opened at the outlet position of the thin tube (11) to control the amount of liquid to be supplied on the liquid supply side of the conveying tube (10). At least two sets of liquid metering and supplying devices (14) each equipped with a control unit are used, and a conveying pipe (
10) is connected to the switching cock (15), and the liquid sample measured by the supply liquid amount control unit is fed to the transport pipe (10), and when the liquid supply is stopped, the transport gas is supplied to the outlet of the thin tube. The gas is used to drain the liquid at the outlet of the capillary tube, and a conveying tube (
10) through the switching cock (15) and the discharge pipe (1).
6) into any receiver (17) to receive the fixed amount of liquid from the plurality of liquid metering and supplying devices (14).
) A method for measuring and mixing a liquid sample, characterized by mixing the sample at