JP2005265807A - Sample cooler unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sample cooler unit hardly generating temperature unevenness in a sample container. <P>SOLUTION: A rack 1 cooled via a metal block 23 by a cooler (Peltier element 21) is constituted of a heat transferring casing 3, an upper support member 7 and a bottom part support member 8, and the sample container 2 stored in an inside thereof is supported by the two support members not to contact directly with the heat transferring casing 3. The cooling is moderate since the sample container 2 is cooled substantially via air, by this constitution, and the temperature unevenness is hardly generated because quick cooling is not occurred locally. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an analyzer that automatically analyzes a liquid sample, and more particularly to a sample cooling device that cools a sample before analysis in a liquid chromatograph.

  In automatic analysis in a liquid chromatograph, a sample container filled with a small amount of sample in advance is mounted on a rack, this rack is set in an automatic sample injection device, and the automatic sample injection device starts from the sample container on this rack according to a predetermined program. This is performed by sequentially sucking up the sample and injecting it into the liquid chromatograph. Samples on the rack that are waiting for analysis are often placed at room temperature, but some samples may need to be kept at a low temperature to prevent alteration. In such a case, an apparatus used for the purpose of cooling the sample is a sample cooling apparatus.

FIG. 2 shows an example of a conventional sample cooling apparatus set in an automatic sample injection apparatus.
The analyst first places the liquid sample 4 in the sample container 2 (usually a glass vial) and mounts it on the rack 5. The rack 5 is made of aluminum having excellent heat conductivity, and has about 100 holes 5a into which the sample containers 2 are inserted. Heat is transmitted to the sample container 2 through the bottom and the inner wall of the hole 5a (hereinafter, simply referred to as heat includes cold heat).

The rack 5 loaded with the liquid sample 4 is placed on the metal block 23 in the apparatus. The metal block 23 is cooled by a cooler (Peltier element 21) attached to the lower surface, and the upper surface is in close contact with the bottom of the rack 5 to maintain good heat conduction.
The Peltier element 21 is controlled by a temperature control device (not shown) to cool the metal block 23 to a predetermined temperature on its heat absorption surface, and on its back surface (heat radiation surface), the heat radiation fins 22 face the inside of the ventilation duct 27. It is attached and has a structure in which the heat absorbed from the metal block 23 is radiated by the air blown by the fan 28 through the radiating fins 22.
With such a configuration, the rack 5, the sample container 2 mounted on the rack 5, and the liquid sample 4 therein are kept at a predetermined low temperature. The rack 5 is covered with a heat-insulating cover 6 for cold insulation, but the head of the sample container 2 is exposed from the cover 6 and exposed to room temperature air so that the liquid sample 4 can be taken out by the needle 11. Has been.

  The needle 11 of the automatic sample injection device 10 can be moved back and forth, right and left and up and down by a mechanism (not shown). According to the program, the needle 11 sucks the liquid sample 4 and moves to the sample inlet 12 of the liquid chromatograph. Automatic analysis is performed by injecting a liquid sample 4. Since the liquid chromatograph needs to be analyzed once enough, the liquid sample 4 on the rack 5 is long and is waiting for analysis for several tens of hours. During this time, the liquid sample 4 is kept at a low temperature to avoid alteration of the liquid sample 4. It is done.

  In the sample cooling apparatus configured as described above, since the sample container 2 is mainly cooled from the bottom, temperature irregularity may occur in the internal liquid sample 4, and in order to eliminate this, the sample container There is also an example in which a heat insulating member is interposed between the bottom of 2 and the rack 5 to suppress heat transfer from the bottom of the sample container 2 (see, for example, Patent Document 1).

JP 2000-137031 A

  As described above, since the head of the sample container 2 is exposed to air at room temperature, and the rack 5 is structurally cooled mainly from below, the sample container 2 is said to have a cold bottom and a warm upper part. State, that is, temperature unevenness is likely to occur. In addition, since convection does not occur because the lower temperature is low, the temperature unevenness does not disappear even when time passes and tends to persist. If the sample container 2 has temperature unevenness, the liquid sample 4 in the sample container 2 may have concentration unevenness. If sampling is performed in such a state, the analysis result may vary.

As described in Patent Document 1, if a structure that suppresses heat transfer from the bottom of the sample container is used, there is a certain effect in solving this problem, but it is still difficult to say that it is perfect.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a sample cooling apparatus that hardly causes temperature unevenness as described above.

In order to solve the above-mentioned problems, the present invention has a structure in which a sample container is housed in a cooled heat conductive casing and is supported so that the sample container does not directly contact the heat conductive casing. That is, the apparatus of the present invention is a sample cooling apparatus including a rack configured to arrange and store sample containers in a heat conductive casing cooled by a cooler from the bottom, wherein the sample container is the heat conductive casing. A sample cooling apparatus comprising a support member that supports the sample container at a predetermined position without contacting the inner surface of the sample container.
With this configuration, the temperature unevenness of the liquid sample due to the local cooling of the sample container is eliminated.

  As described above, the apparatus of the present invention is configured to support the sample container so that it does not directly contact the heat-conducting housing and to cool mainly through air, so that the bottom of the sample container is strongly cooled. And temperature unevenness hardly occurs in the sample liquid inside. As a result, density unevenness based on the temperature difference is also suppressed, so that the reproducibility of the analysis is improved.

One embodiment of the present invention is shown in FIG. In the figure, the same components as those in FIG.
This embodiment is different from the conventional one in the structure of the rack 1. That is, the rack 1 includes a box-shaped heat conductive housing 3 having an open top, an upper support member 7 that covers the upper portion, and a bottom support member 8 that is placed on the inner bottom surface of the rack 1. .

The heat transfer housing 3 is placed in close contact with the metal block 23, cooled from the bottom by heat transfer from the metal block 23, and the internal air that touches this is cooled.
The upper support member 7 is made of hard plastic or the like, and a large number of holes 7a for inserting the sample container 2 are arranged at predetermined positions, and the horizontal position of the sample container 2 inserted therein is regulated. . Even if the hole 7a is located at the end, the sample container 2 inserted therein is arranged so as not to contact the wall surface of the heat conductive casing 3.
The bottom support member 8 supports the sample container 2 from below and prevents the bottom of the sample container 2 from coming into contact with the bottom of the heat transfer casing 3. The bottom support member 8 is made of hard plastic or a metal with poor heat transfer (for example, , Stainless steel).

The cooling of the sample according to the present embodiment configured as described above is performed as follows.
The heat transfer case 3 is first cooled by heat transfer from the metal block 23 cooled by the Peltier element 21, and the sample container 2 and further the liquid sample 4 inside thereof are cooled through the air thus cooled. The The sample container 2 is supported by the upper support member 7 and the bottom support member 8 which are not good in heat transfer so as not to come into direct contact with the heat transfer case 3, and thus is almost completely cooled only by air. It will be. Therefore, the cooling is slow and rapid local cooling does not occur, so that temperature unevenness hardly occurs.

  Since the bottom support member 8 needs to circulate air in the upper and lower spaces sandwiching the bottom support member 8, it may be configured by using a punching metal or a wire net having air permeability. In addition to the structure rising from the bottom as shown in FIG. 1, a structure laid in contact with the bottom or a structure suspended from the upper support member 7 through an appropriate spacer (not shown) is also possible.

  Since the upper support member 7 also has a role of confining cold air inside the rack 1, the upper support member 7 is made of a heat insulating material, and if necessary, a heat insulating cover (not shown) is put on the heat insulating material to provide a cooling effect. You may make it raise. Further, as another means for enhancing the cooling effect, the hole 7a in which the sample container 2 is not inserted may be closed with a heat insulating plug (not shown).

In the present embodiment, which is cooled from below, convection is unlikely to occur, and there is a concern that the cold air is stagnating near the bottom of the rack 1. As a countermeasure, it is easily considered as a design matter to stir the internal air of the rack 1 with a blower (not shown) to make the temperature uniform.
The above shows the basic configuration of the present invention and some modifications, and the present invention is not limited to this.

It is a figure which shows one Embodiment of this invention. It is a figure which shows the conventional structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rack 2 Sample container 3 Heat conductive housing 4 Liquid sample 5 Rack 5a Hole 6 Cover 7 Upper support member 7a Hole 8 Bottom support member 10 Automatic sample injection device 11 Needle 12 Sample injection port 21 Peltier element 22 Radiation fin 23 Metal block 27 Ventilation duct 28 Fan

Claims (1)

A sample cooling apparatus for cooling a liquid sample in a sample container mounted on a rack to room temperature or lower, wherein the rack arranges and stores the sample containers in a heat conductive casing cooled by a cooler from the bottom. What is comprised in this way, The sample cooling device provided with the supporting member which supports the said sample container in a predetermined position, without contacting the said sample container with the inner surface of the said heat conductive housing | casing.

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