JPH0690216B2 - Liquid dispensing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention performs a chemical analysis of a desired item by reacting a sample with a reagent and measuring the concentration of a specific component in the reaction solution. At this time, the present invention relates to a liquid dispensing method applied when the sample is dispensed into a reaction container.

(Prior Art) For example, serum collected from a human body is used as a sample (sample), and a desired reagent is reacted with the sample, and the concentration of a specific component in the reaction solution is measured by, for example, a colorimetric method to obtain desired items. An automatic chemical analyzer that analyzes total protein (TP), uric acid (UA), neutral fat (TG), etc. is known.

FIG. 8 is a schematic plan view showing an example of the configuration of such an analyzer, in which a plurality of reaction vessels 2 are arranged in a circular thermostat 1, and these reaction vessels 2 are moved in the direction of the arrow by a drive source (not shown). It is moved intermittently in a certain cycle. Constant temperature bath 1
A sample dispensing nozzle 3 is arranged at a position A around the
The reagent dispensing nozzle 4 is arranged at the position, and the stirring bar 5 is arranged at the position C. While the reaction container 2 is stopped, a desired sample to be analyzed is dispensed by the sample dispensing nozzle 3 into the reaction container 2 in the A position, and a sample dispensing nozzle in the reaction container 2 in the B position. A desired reagent that reacts with the sample is dispensed by 4, and a stirring bar 5 stirs the reaction liquid consisting of the sample and the reagent in the reaction container 2 at the C position. Further, a photometric system 6 including a light source 7 and a photodetector 8 arranged via the reaction container 2 is provided at an intermediate position on the moving path of the reaction container 2, and the concentration of a specific component in the reaction liquid in the reaction container 2 is provided. Is measured by a colorimetric method so that a chemical analysis of a desired item is performed.

When performing the chemical analysis in this way, the sample is drawn into the reaction container 2 from the sample container 10 in which the desired sample 9 to be analyzed in advance is stored by the sample dispensing nozzle 3 as shown in FIG. Dispensing and so-called sampling are usually performed, but in most cases analysis of multiple items is performed for one sample.In this case, multiple reaction vessels are used.
The required amount of sample is sampled in each of 2a, 2b, 2c ... 2n.

As described above, in the case of dispensing a sample corresponding to many items, two methods have been conventionally used. As an example, A
The dispensing method for the case of analyzing 16 items from P to P will be described. In the first method, as shown in FIG. 6 (a), the total amount of the samples 9A to 9P necessary for analyzing 16 items A to P is sucked at once by the nozzle 3, and then the container corresponding to each item is drawn. This is a method of sequentially dispensing each sample into 2a to 2p as shown in FIG. 6 (b). When the sample is sucked in this way, the nozzle 3 is filled with water 11 in advance, and the sample 9 is sucked by the negative pressure when the water 11 is sucked. In order to prevent the sample 9 from being contacted and diluted, an air tank 12 is interposed between the two. However, since the sample 9 is diluted by the water 11 traveling on the inner wall surface of the nozzle 3 even in this case, a sample not used for analysis between the sample 9 and the air tank 12, a so-called dummy sample 13, is commensurate with the amount of the sample to be analyzed. It is practiced to suck and intervene by a certain amount in advance. The dummy sample 13 is discharged at a predetermined position after all the samples have been dispensed.

The second method is as shown in Fig. 7 (a), in which each sample 9A to 9P required for analysis of 16 items A to P is sucked and dispensed by the nozzle 3 each time, and the sample 9A to 9P is repeated. It is a method of dispensing into each container. In this case, dummy samples 13A to 1
The operation of sucking and discharging 3P is repeated each time.

(Problems to be Solved by the Invention) However, each of the conventional sample dispensing methods has a problem that a large amount of dummy sample is required and the sample to be analyzed is still diluted in the nozzle. Since the dummy sample is collected from the patient in the same manner as the sample to be analyzed, it is desirable that the dummy sample is small in consideration of the burden and the cost on the patient. However, the actual dispensing requires about half the amount of the analytical sample. For example, each of the 16 items requires a sample volume of 10μ (total volume 10μ ×
16 = 160μ), the dummy sample needs to be about 80μ, which is half of the total amount. Regarding the degree of dilution of the sample, in the case of the dispensing method of FIGS. 6 (a) and 6 (b), the sample amount of 160 μ and the dummy sample amount of 80 μ are used, the distance L from the tip of the nozzle 3 and the dilution The relationship with the rate D is as shown in FIG. In both the sample 9 and the dummy sample 13, the closer to the water 11, the higher the dilution rate due to the influence of water. Such dilution of the sample 9 occurs as a result of water 11 penetrating the dummy sample 13 and the sample 9 along the inner wall surface of the nozzle 3 and diffusing into the sample.

The present invention has been made in response to the above circumstances,
An object of the present invention is to provide a liquid dispensing method capable of reducing the dilution rate of a sample with a small number of dummy samples.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention has a second and subsequent suction and separation of a desired liquid while leaving at least a part of the first sucked dummy liquid. The injection operation is repeated.

(Operation) Even when performing chemical analysis on multiple items of this liquid by dispensing the liquid into multiple containers, it is possible to improve the analysis accuracy without decreasing the dilution rate of this liquid. In addition, even if the number of measurement items is large, it is possible to dispense with a large number of items with a small amount of dummy liquid, so that it is possible to eliminate unnecessary waste of the sample.

(Example) The principle of the present invention will be described prior to the description of the examples of the present invention.

The following facts were confirmed as a result of experiments conducted with reference to two conventional dispensing methods. First of all, as in the first method, by previously sucking the dummy sample 13 by an amount corresponding to the amount of the analysis sample at one time, the contact area between the dummy sample 13 and the inner wall surface of the nozzle 3 becomes large, and as a result, the infiltration of the water 11 is allowed. It is to make it easier. In this respect, sucking the dummy sample 13 by the required amount each time as in the second method has an advantage that it is difficult to allow water to enter because the contact area becomes small. On the other hand, the fact that the amount of the dummy sample 13 is always small as in the second method has a drawback that water easily diffuses.

However, when viewed comprehensively, it can be judged that the second method is superior in terms of dilution rate as shown in the following table.

In addition, in Fig. 4, a sample of 10μ is sucked and a dummy sample of 10μ is drawn.
It shows the relationship between the dummy sample amount V and the dilution rate D when it is varied within the range. It is shown that D decreases as V decreases. Therefore, the dilution ratio D can be reduced by selecting the dummy sample amount V in an appropriate amount in relation to the sample amount.

The present invention is based on the above principle,
Embodiments of the present invention will be described below with reference to the drawings.

1 (a) and 1 (b) are explanatory views showing a first embodiment of the liquid dispensing method of the present invention. As shown in FIG. 1 (a), the nozzle 3 is filled with water 11 in advance and the air layer 12 is formed. With dummy sample 13
First, sample 9A necessary for the analysis of item A in the state of sucking
After sucking, the sample 9A is dispensed into the corresponding container 2a as shown in FIG. 1 (b). Next, after the sample 9B necessary for the analysis of the item B is sucked with the dummy sample 13 as it is, the sample 9B is dispensed into the corresponding container 2b as shown in FIG. 1 (b). Subsequently, while the dummy sample 13 is left as it is, the sample 9C necessary for the analysis of the item C is sucked, and then the sample 9C is dispensed into the corresponding container 2c as shown in FIG. 1 (b). Thereafter, the dummy sample 13 is left as it is, and the same suction and dispensing operations are repeated until the item P is reached. As an example, a sample amount of 10 μ was selected for each of the 16 items A to P, and a dummy sample amount of 40 μ was selected.

According to this embodiment, the total amount of samples to be analyzed as the dummy sample 13 (10 μ × 16 = 160 μ in this example)
)), A relatively small amount (40μ) is selected, and while holding this amount in the nozzle 3, the suction and dispensing operations of 16 items of samples 9A to 9P are repeated, so that the infiltration and diffusion of water can be suppressed. it can. Therefore, the dilution rate of the sample can be reduced, and the dilution rate of 0.1 to 1% was obtained.

FIGS. 2 (a) and 2 (b) show a second embodiment of the present invention. When 160 .mu. Is selected as the total amount of the sample, a dummy as shown in FIG. Aspirate sample 13 by 5μ + 32μ (160μ × 0.2), then sample 9A
After aspirating 10μ, sample 9A was placed in container 2a as shown in Fig. 2 (b).
To dispense. Thereafter, similar suction and dispensing operations are repeated until the item P is reached with the dummy sample 13 held at 37 μ in this way. Note that 32μ is an example of 20μ of the total sample 160μ.
It was selected as a measure of%. Also in this embodiment, by selecting a relatively small amount (37μ) of dummy sample,
Since the suction and dispensing operations of the samples 9A to 9P are repeated, it is possible to obtain the same effect as that of the above embodiment.

FIGS. 3 (a) and 3 (b) show a third embodiment of the present invention. When 160 .mu. Is selected as the total amount of the sample, a dummy sample as shown in FIG. After sucking 13 (5 μ + 2 μ) and then sucking 10 μ of the sample 9A, the sample 9A is dispensed into the container 2a as shown in FIG. 3 (b).
Then, 2μ was sucked as a dummy sample 13 (total 9μ)
After that, aspirate 10μ of the sample 9B and place it in a container as shown in Fig. 3 (b).
Dispense sample 9B into 2b. Further, subsequently, 2 μm is sucked as the dummy sample 13 (11 μm in total), 10 μm of the sample 9C is sucked, and the sample 9C is dispensed into the container 2c as shown in FIG. 3 (b).
Thereafter, the dummy sample 13 is added by 2 .mu.m in this way, and then the sample suction and dispensing operations are repeated until the item P is reached. Also in this embodiment, a relatively small amount (37μ = 5μ + 2μ × 16)
Since the dummy sample 13 is selected, it is possible to obtain the same effect as that of the above embodiment.

As the fourth embodiment of the present invention, when the total amount of the samples 9A to 9P is selected to be half (160 μ × 1/2 = 80 μ) of the second embodiment, the dummy sample 13 is selected to be 4 μ + 16 μ (80 μ × 0.2) and the second execution is performed. By repeating suction and dispensing operations similar to the example,
A similar effect can be obtained by using a smaller amount of dummy sample (20μ).

The following table shows each data obtained in each of the above examples in comparison with the conventional example.

The numerical values shown in each of the above embodiments are merely examples, and can be arbitrarily changed according to the use, purpose, and the like. Further, although an example in which a sample is used as an object to be dispensed is shown in the examples, the present invention is not limited to this and is similarly applicable to other liquids such as reagents.

As described above, according to the present embodiment, the sample dilution rate can be lowered, so that the items to be measured can be freely selected and the accuracy of the measurement data can be stabilized. Moreover, since the object can be achieved by using a small amount of dummy liquid, the burden on the patient can be reduced, and the cost of the sample can be further reduced. Furthermore, when performing multi-item dispensing, the sample is suctioned and dispensed for each item, so the sampling speed can be increased, and the sampling efficiency is improved by adopting a dispensing method using multiple nozzles. You can also do it.

[Effects of the Invention] As described in detail above, according to the present invention, even when performing chemical analysis on a plurality of items of this liquid by dispensing the liquid into a plurality of containers, the dilution rate of this liquid can be adjusted. Analytical accuracy can be improved without lowering, and even if there are multiple measurement items, it is possible to dispense with a small number of dummy liquids corresponding to multiple items, so no wasted sample is wasted It has an excellent effect of being able to provide a liquid dispensing method.

[Brief description of drawings]

1 (a), (b) to 3 (a), (b) are explanatory views showing a different embodiment of the liquid dispensing method of the present invention, and FIG.
5 and 5 are characteristic diagrams for explaining the principle of the present invention, FIGS. 6 (a) and 6 (b) and FIGS. 7 (a) and 7 (b) are explanatory diagrams of a conventional example, and FIG. 8 is an automatic chemical analysis. FIG. 9 is a schematic plan view showing an example of the configuration of the apparatus, and FIG. 9 is an explanatory diagram of sample dispensing. 2 ... Reaction container, 3 ... Sample dispensing nozzle, 9 ... Sample (sample), 11 ... Water, 12 ... Air layer, 13 ... Dummy sample.

Claims (4)

[Claims] 1. A liquid dispensing method for performing a chemical analysis of a desired liquid by suctioning a desired liquid through a dummy liquid with a nozzle and dispensing the liquid into a predetermined container. When performing chemical analysis on a plurality of items of the liquid by dispensing, the second and subsequent suction and dispensing operations of the liquid are repeated while leaving at least a part of the initially sucked dummy liquid. Liquid dispensing method. 2. The liquid dispensing method according to claim 1, wherein the second and subsequent suction and dispensing operations of the desired liquid are repeated while leaving the whole of the initially sucked dummy liquid. 3. The liquid dispensing method according to claim 1, wherein a desired amount of dummy liquid is added to each of the first sucked dummy liquids before the second and subsequent desired liquids are sucked. 4. The fixed amount and 2 at which the dummy liquid is first sucked.
4. The liquid dispensing method according to claim 3, comprising a variable amount which is determined according to the suction amount of the desired liquid before the subsequent suction of the desired liquid.