JPH04256859A - Chemical-distribution controlling method - Google Patents

Abstract

PURPOSE:To prevent the formation of liquid droplets at the end part of a nozzle at the time of distribution operation. CONSTITUTION:A valve 14 is provided between a container filled with reagent and a syringe 13. The syringe 13 is driven with a direct operating device 17. The reagent in the container 11 is sent into a distributing nozzle 15 by the driving of the syringe 13 and added into the receiving part of a test tube and the like through the valve 14. After the addition of the reagent, the reagent at the tip part of the distributing nozzle 15 is sucked into the inside of the nozzle by a certain amount with the syringe 13.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method for controlling the dispensing of reagents used for measuring sludge activity.

0002

2. Description of the Related Art Various measuring instruments are currently used for measuring sludge activity. Traditionally, the above measurements were performed by manual analysis, but in recent years, automatic measuring devices with dispensing mechanisms have been developed to faithfully reproduce the measurement process of manual analysis. It's here. It has also become known that adjustment capabilities such as an automatic reagent dispensing function are important in realizing this automatic measuring device. As the dispensing mechanism, a method using a pump such as a straining pump or a plunger pump, a function using a syringe and a valve, etc. are adopted.

0003

[Problem to be Solved by the Invention] When adding a reagent solution related to measurement to a batch-type measurement object, it is necessary to send a certain amount of the reagent solution with a syringe or the like, and then add it from a nozzle to a receiving part of a test tube or the like. The method is adopted. In this method, a phenomenon occurs in which the droplet A stops at the end of the nozzle as shown in FIG. 6, and the following problem occurs.

[0004] a. Decrease in reagent solution quantitative performance, b. Contamination of equipment and human bodies by reagent liquid, c. The reagent solution may be contaminated by foreign matter from the outside, and depending on the type of reagent solution, it may be easily changed or oxidized by light or heat.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a reagent dispensing control method that prevents droplets from forming at the end of a nozzle.

[0006]

[Means and Effects for Solving the Problems] In order to achieve the above object, the present invention provides a batch-type measurement method in which a reagent solution is automatically added from a dispensing nozzle to a receiving part such as a test tube. After discharging the reagent liquid from the dispensing nozzle with a smaller inner diameter into the receiving part from the upstream part of the dispensing nozzle, immediately after discharging the reagent solution, the reagent solution is slightly injected into the interior from the dispensing nozzle tip. It is designed to suck a large amount.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. In FIG. 1, 11 is a container filled with a reagent solution, and the reagent solution in this container 11 enters a syringe 13 via a pipe 12. The syringe 13 is controlled by a linear motion device whose details are shown in FIGS. 2 to 4. 14 is a valve, and this valve 14 is for supplying the reagent liquid in the container 11 to the dispensing nozzle 15 through the syringe 13. The dispensing nozzle 15 has a tip portion having a smaller inner diameter than an upstream portion of the dispensing nozzle. Therefore, the flow rate of the reagent liquid supplied to the dispensing nozzle 15 is set relatively high, and immediately after the liquid is fed and discharged, the syringe 13 is moved inside from the tip of the nozzle, as shown in FIG. Aspirate like this.

FIG. 2 is a detailed explanatory diagram of the configuration shown in FIG. added. The movable part 13a of the syringe 13 is shown in FIG.
, 4 is driven by a linear motion device 17 shown in FIG. Linear motion device 1
Reference numeral 7 includes a stepping motor 19 provided within a frame 18, and a rotation-linear conversion device 20 that converts the rotational motion of the motor 19 into linear motion. Syringe 13
The movable part 13a is the movable piece 21 of the rotation-linear conversion device 20.
can be attached to. In addition, in FIGS. 3 and 4, 22a
, 22b are rails that serve as guides for the movable piece 21. The stepping motor 19 is driven by a pulse generator (not shown).

The operation of dispensing the reagent solution in the container 11 will be described using the above embodiment. After filling the container 11 with the reagent liquid, the linear motion device 17 is driven to move the movable part 13a of the syringe 13 to send the reagent liquid to the dispensing nozzle 15. Experiments have shown that the faster the reagent liquid is fed at this time, the better the reagent liquid runs out at the nozzle tip. At that time, when the flow rate was 60 ml/min or more, there was almost no difference and good results were obtained.

[0010] As a result of examining variations in liquid shortage due to differences in the properties of the reagent liquid, it was found that droplets were least likely to arrive at the end of the nozzle when the liquid feeding rate was 80 ml/min. Further, the smaller the nozzle inner diameter, the better, and the best result was 0.5 mm in consideration of another factor, the resistance of the flowing liquid. Regarding the outer diameter of the nozzle, it is preferable to make it thin so that droplets of the reagent solution do not easily adhere thereto. Considering the strength, an outer diameter of 0.1 mm was good.

From the above experimental results, the dispensing nozzle 15
By making the inner diameter smaller and the outer diameter thinner, and increasing the flow rate, it becomes difficult for droplets to adhere to the nozzle tip, and immediately after sending the liquid to the dispensing nozzle 15 at the above flow rate. A small amount of liquid is sucked into the interior from the tip of the dispensing nozzle 15 as shown in FIG. In addition, the suction amount is 3
0 microliter, and minimize contact with the outside at the nozzle end.

0012

[Effects of the Invention] As described above, according to the present invention,
There is an advantage in that immediately after the reagent liquid is discharged from the nozzle tip, a small amount of the reagent liquid can be sucked into the nozzle to completely eliminate droplets at the nozzle tip.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a detailed configuration of an embodiment of the invention.

FIG. 3 is a front view of the linear motion device.

FIG. 4 is a sectional view of the linear motion device.

FIG. 5 is an explanatory diagram when a reagent is sucked into the nozzle end.

FIG. 6 is an explanatory diagram when droplets are generated at the end of the nozzle.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11... Container, 12... Pipe, 13... Syringe, 14... Valve, 15... Dispensing nozzle, 17... Direct-acting device.

Claims (1)

[Claims] Claim 1: In a batch measurement method in which a reagent solution is automatically added from a dispensing nozzle to a receiving part of a test tube, etc., the inner diameter of the tip of the dispensing nozzle is smaller than that of the upstream part of the dispensing nozzle. A chemical solution dispensing control method characterized in that, after discharging the reagent solution from the dispensing nozzle into the receiving part, a small amount of the reagent solution is sucked into the interior from the tip of the dispensing nozzle immediately after the dispensing.