The present invention relates to a sample rack supporting sample holding containers.
Some liquid chromatographic apparatuses have an automatic sample introduction device (an automated sampler). In the apparatus, sample liquid contained in a sample holding container (sample bottle) arranged in a sample rack mounted to a rack holder is sucked with a needle and automatically injected into a mobile-phase passage of the apparatus. The sample rack of the liquid chromatographic apparatus is configured to be removable from the rack holder in some cases. With such a configuration, the sample rack is removed from the rack holder and attachment and detachment work for the sample holding container can be performed at another place. Thus, user's operability can be enhanced. If a plurality of the sample racks are prepared and installation work for the sample holding containers is previously done, sample liquid can be replaced quickly.
To obtain assay results with high reproducibility through liquid chromatography, it is required that the concentration of sample liquid to be analyzed be stable. In other words, it is important to keep the temperature of the sample liquid constant during the analysis. In general, when sample liquid to be analyzed through liquid chromatography is prepared, organic solvent (or liquid partially containing organic solvent) is frequently used as liquid dissolving a sample to be analyzed. However, as the boiling point of an organic solvent is lower, the saturated vapor pressure thereof at a certain temperature and a vapor rate therefor become higher. Therefore, the concentration of the sample liquid tends to vary. Because of this, the liquid chromatography generally performs analysis in a state where a sample liquid is cooled to approximately 4 to 15° C. and its temperature is kept constant. Therefore, a sample cooling device is sometimes used to cool the sample liquid in the sample holding container.
Sample cooling devices are such that while sample liquid is cooled, dew condensation occurs on a sample holding container or a sample rack depending on conditions: environmental conditions such as ambient temperature, ambient moisture and the like; a target temperature setting condition; or configuration conditions such as a sample rack, a rack holder and the like. Dew condensation may occur on the upper portion (e.g. a septum) of the sample holding container. In such a case, dew condensation water, along with a needle, enters the inside of the sample holding container to vary sample concentration, which causes an erroneous assay result in some cases.
With this point in mind, a sample rack (sample holders) has a sample cooling device installed below a sample rack main body whose bottom portion is made of metal. This sample cooling device is mainly intended to cool the bottom portion of the sample holding container, thereby suppressing the occurrence of dew condensation on the upper portion of the sample holding container. (See JP-UM-3-17542-A) Another sample rack is configured as follows. A drain discharge hole is provided on a bottom portion of a containing section for a sample holding container in a sample rack main body. The sample rack main body is made of synthetic resin with lower thermal conduction efficiency than metal. Dew condensation water held between the discharge hole and the bottom surface of the sample holding container is used to mainly cool the bottom portion of the sample holding container. In this way, it is contemplated to suppress the occurrence of dew condensation on the upper portion of the sample holding container. (See JP-UM-4-88843-A)
However, the two above documents described about a sample rack do not describe the specific configuration for discharging dew condensation water from the drain hole formed in the bottom portion of the containing section. Therefore, dew condensation water that has been formed may probably accumulate inside the sample rack or the rack holder. (Considering the point where dew condensation water held between the drain hole and the bottom surface of the containing section of the sample holding container is used to try the cooling promotion for sample liquid, it is speculated that dew condensation water is not forcibly discharged to the outside.) If the dew condensation water accumulates, when the sample rack is removed from the rack holder, the dew condensation water may probably be scattered on a user or the vicinity thereof. This may degrade workability encountered during removal of the sample rack. If the dew condensation water accumulates as described above, the sample liquid in the sample holding container will be cooled via the dew condensation water. However, cooling capacity ΔT (a difference between reachable temperature and ambient temperature) lowers compared with the case where the sample liquid is cooled via a material with high efficiency of thermal conduction such as metal or the like. Therefore, it is probable that target temperature is not reached.
It is an object of the present invention to provide a sample rack having improved workability encountered during removal and high sample cooling capacity.
(1) To achieve the above object, the present invention provides a sample rack in which a sample holding container containing sample liquid is loaded, the sample rack comprising: a containing section in which the sample holding container is contained; and a groove portion disposed with inclination below the containing section; wherein a bottom surface of the containing section communicates with the groove portion.
(2) In the above (1), preferably, the containing section is configured to be able to come into contact with a bottom surface and a side surface of the sample holding container when the sample holding container is contained in the containing section.
(3) In the above (1), preferably, the groove portion is disposed with inclination below the bottom surface of the containing section, communicates with an outside at an end where the inclination is steepest, and further communicates with a side surface of the containing section.
(4) In the above (1), preferably, the containing section has, as a part of the containing section, a containing-section lower portion adapted to receive a bottom surface and a side surface of the sample holding container, and as a part of the containing section, a containing-section upper portion located above the containing-section lower portion and adapted to receive the side surface of the sample holding container; and the containing-section lower portion is formed of a material with relatively higher efficiency of thermal conduction as compared with that of the containing-section upper portion.
(5) In the above (4), preferably, the height of the containing-section lower portion is equal to or lower than that of a barrel portion of the sample holding container when the sample container is contained in the containing section.
(6) In the above (1), a sample cooling device comprises: the sample rack according to the above (1); a rack holder removably supporting the sample rack; a cooling device adapted to cool the rack holder; and water storing means for storing water discharged from the groove portion.
(7) In the above (6), preferably, the rack holder is formed of a material with relatively higher efficiency of thermal conduction as compared with that of the containing-section upper portion.
(8) In the above (6), preferably, the rack holder has other groove portion disposed with inclination below the groove portion and adopted to receive water discharged from the groove portion, and the water storing means stores water that has been discharged from the groove portion and passed through the other groove portion.
According to the present invention, dew condensation water is forcibly discharged; therefore, workability encountered during removal of the sample rack and sample cooling capacity can be improved.
Embodiments of the present invention will hereinafter be described with reference to the drawings.
In the figure, the sample rack 1 includes a lower member 10 in contact with the rack holder 5 in the sample introduction device 100; an upper member 20 mounted on the upper portion of the lower member 10; and a cover member 30 mounted on the upper portion of the upper member 20. A plurality of containing sections 40 in which the sample holding containers 6 are contained are arranged in a lattice pattern in the sample rack 1 assembled from the lower member 10, the upper member 20 and the cover member 30. Although details are described later, the containing sections 40 are each formed of a containing-section lower portion 41 of the lower member 10, a containing-section upper portion 42 of the upper member 20, and a hole 43 of the cover member 30.
As shown in
It is preferred that the height of the containing-section lower portion 41 (the depth of the recessed portion) be made to correspond to the height of the liquid level of the sample liquid contained in the liquid holding container 6. This is because cooling only the sample liquid without cooling an unnecessary portion is effective in view of suppressing the formation of dew condensation water as much as possible. In other words, it is preferred that the height of the containing-section lower portion 41 be made equal to or lower than the height of the barrel portion 63a of the sample holding container 63. Preferably, the height of the containing-section lower portion 41 is made approximately equal to the height of the barrel portion 63a at a maximum. If the containing-section lower portion 41 is formed as described above, cooling the vicinity of the septum 62 can be suppressed. Therefore, the formation of dew condensation water on the septum 62 can be suppressed, which can prevent the dew condensation water from entering the inside of the sample holding container along with a needle.
A groove portion 11 is located below the corresponding containing-section lower portions 41, which is a flow passage through which the dew condensation water formed in the sample rack 1 flows. In addition, the groove portion 11 is disposed with inclination with respect to a horizontal plane. The groove portion 11 of the present embodiment extends in the transverse direction of the sample rack 1. In addition, a plurality of the groove portions 11 are rowed in the longitudinal direction of the sample rack 1. The number of rows of the groove portions 11 corresponds to that of the containing sections 40 in the longitudinal direction of the sample rack 1. The groove portions 11 are each formed to decline from the central portion toward both the left and right ends in the transverse direction of the sample rack 1. In addition, the end at which the inclination is steepest is exposed as an opening portion 12 to the outside at both the left and right side surfaces of the lower member 10. The dew condensation water formed in the containing sections 40 passes through the groove portion 11 and then is discharged to the outside of the sample rack 1 via the opening portions 12.
The containing-section lower portion 41 of the present embodiment communicates with another containing-section lower portion 41 adjacent thereto in the transverse direction of the sample rack 1 via a communicating portion 13 installed on the side surface thereof. The communicating portion 13 communicates with the groove portion 11 disposed below the bottom surface of the containing-section lower portion 41. The bottom end of the communicating portion 13 conforms to the bottom surface of the groove portion 11. In other words, the groove portion 11 of the present embodiment communicates with the side surface of the containing-section lower portion 41. The dew condensation water can be discharged also from the side surface of the containing-section lower portion 41 to the groove portion 11. As described above, with such a configuration in which the discharge can be made also from the side surface of the containing-section lower portion 41, the dew condensation water can be permitted to flow down to the groove portion 11 via a portion of the side surface of the sample holding container 6, the portion facing the communicating portion 13. Thus, the dew condensation water can be discharged more forcibly compared with a case where discharge of the dew condensation water is made possible only from the bottom surface of the receiving-portion lower portion 41.
Incidentally, in the present embodiment, a plurality of the groove portions 11 formed with inclination in the transverse direction of the sample rack 1 are arranged in the longitudinal direction of the sample rack 1. However, a plurality of the groove portions 11 formed with inclination in the longitudinal direction of the sample rack 1 may be arranged in the transverse direction of the sample rack 1.
As shown in
Incidentally, in view of suppressing the formation of dew condensation water in the vicinity of the septum 62 of the sample holding container 6, it is preferred that the upper member 20 (the containing-section upper portion 42) be formed of a material having relatively lower efficiency of thermal conduction as compared with that of the lower member 10 (the containing-section lower portion 41). (In other words, it is preferred that the lower member 10 (the containing-section lower portion 41) be formed of a material having relatively higher efficiency of thermal conduction as compared with that of the upper member 20 (the containing-section upper portion 42). Specifically, it is preferred that a foam material (polypropylene (PP), polystyrene (PS), etc.), rubber sponge (ethylene-propylene-diene rubber (EPDM), silicone rubber (Si), etc.), or resin (PP, polyphenylene-sulfide (PPS), polyphenylene ether (PPE), denatured polyphenylene ether (m-PPE) etc.) be used for the upper member 20.
The cover member 30 has a hole 43 adapted to receive the sample holding container 6 inserted thereinto, the hole being a part of the containing section 40. Similarly to the containing-section lower portion 41, the hole 43 of the present embodiment is formed into approximately cylindrical shape to conform to the shape of the sample holding container 6. In view of ensuring the strength of the sample rack 1, it is preferred that metal materials (stainless steel, aluminum or the like) or resin (PP, PPE, m-PPE) be used as a material of the cover member 30.
The rack holder 5 is a portion on which the sample rack 1 is placed in the sample introduction device 100. The rack holder 5 removably supports the sample rack 1; therefore, the sample holding container 6 can be loaded into and removed from the sample rack 1 at any place. Since the rack holder 5 is configured as above, attachment and detachment work for the sample holding containers can be done at another place with the sample rack 1 is removed from the rack holder 5. Thus, user's operability can be enhanced. If a plurality of the sample racks 1 are prepared and installation work for the sample holding containers 6 is previously done, sample liquid can be replaced quickly.
Incidentally, although the present embodiment is configured such that the groove portion 53 is disposed in the rack holder 5 and water passed through the groove portion 11 of the sample rack 1 and through the groove portion 53 of the rack holder 5 is stored in the water storage tray 7, another configuration may be adoptable in which other passage is installed to directly introduce, to the water storage tray 7, water discharged from the opening portion 12 of the sample rack 1.
The rack holder 5 of the present embodiment is formed of a plate-like first member 51 and a second member 52 surrounding the first member 51 from the left, right and back sides and provided with the groove portions 53. A cooling device 8 configured by using a Peltier element or the like is installed below the first member 51. The cooling device 8 cools the sample holding container 6 via the rack holder 5 and via the sample rack 1 and keeps the sample liquid in the sample holding container 6 at a predetermined temperature. Therefore, in view of efficiently cooling the sample liquid, it is preferred to ensure a contact area large as much as possible between the first member 51 and the lower member 10 of the sample rack 1. In addition, in view of the same, it is preferred that the first member 51 be formed of metal (aluminum, copper, bronze or the like) with high thermal conduction efficiency similarly to the lower member 10 of the sample rack 1. On the other hand, in view of suppressing the lowering of a cooling effect due to the formation of dew condensation water around the first member 51, it is preferred that the second member 52 be formed of a material with lower efficiency of thermal conduction as compared with that of the first member 51.
In the sample introduction device 100 configured as described above, when the cooling device 8 is actuated to keep the sample liquid in the sample holding container 6 at a fixed temperature (a target temperature), the rack holder 5 is cooled by the cooling device 8. The rack holder 5 thus cooled cools the sample liquid in the sample holding container 6 via the lower member 10 of the sample rack 1. In this case, the lower member 10 of the sample rack 1 is in contact with the bottom surface and side surface of the sample holding container 6 at the containing-section lower portion 41. Accordingly, the contact area in this case is larger than that in a case where only the bottom surface of the sample holding container 6 is cooled. Thus, the sample liquid in the sample holding container 6 is cooled efficiently. In particular, if only the bottom surface of the sample holding container 6 is cooled, upper sample liquid is hard to be cooled. Thus, a temperature difference in the height direction of the sample liquid is likely to occur. In the present embodiment, however, the sample liquid is cooled by heat not only from the bottom surface of the sample holding container 6 but also from the side surface thereof. Therefore, it is possible to suppress the occurrence of the temperature difference in the height direction of the sample liquid.
While the sample liquid is cooled as described above, dew condensation may occur on the sample holding container 6 or the sample rack 1 depending on environmental conditions such as ambient temperature, ambient moisture and the like or setting conditions such as target temperature. However, the sample rack 1 according to the present embodiment has the groove portion 11 disposed below the containing section 40 with inclination and communicating with the bottom surface of the containing section 40. Therefore, dew condensation water formed does not accumulate on the containing section 40 and is forcibly discharged to the outside of the sample rack 1 via the groove portion 11. In other words, if the sample rack 1 is formed as described above, problems can be solved which will arise in lowering of cooling capacity due to the accumulation of dew condensation water and in scattering of dew condensation water on the user and the vicinity of the device when the sample rack 1 is removed. Thus, according to the present embodiment, as dew condensation water is forcibly discharged, it is possible to improve workability encountered during the removal of the sample rack 1 and sample cooling capacity.
Incidentally, the rack holder 5 according to the present embodiment is provided with the groove portion 53 with inclination so as to be located below the opening portion 12. Therefore, the dew condensation water formed at the periphery of the sample holding container 6 passes through the groove portion 11 of the sample rack 1 and is forcibly discharged from the opening portion 12. The dew condensation water thus discharged passes through the groove portion 53 and is recovered by the water storage tray installed in front of the sample introduction device 100. In this way, since also processing of the dew condensation water is facilitated, the workability encountered during removal of the sample rack 1 is further improved.
A second embodiment is next described. In comparison with the previous embodiment, the present embodiment is mainly different therefrom in the shape of a lower member 10A of a sample rack 1A and in the shape of a first member 51A of a rack holder 5A.
Among the containing-section lower portions 41 of the lower portion 10A shown in the figures, those located at both left and right ends of the sample rack 1A have respective opening portions 12A each opening to the bottom surface of the lower member 10A. The opening portions 12A communicate with a groove portion 11. The dew condensation water formed in the containing section 40 passes through the groove portion 11 and then is discharged to the outside of the sample rack 1A via the opening portions 12A.
The first member 51A shown in the figures has two groove portions 53A each disposed with inclination. The groove portions 53A are each disposed so as to be located below the opening portion 12A of the lower member 10A when the sample rack 1A is placed on the rack holder 5A. In addition, each of the groove portions extends in the longitudinal direction so as to correspond to the position of the associated opening portion 12A. The groove portions 53A of the present embodiment are formed to decline toward the back from the front in
Although the automatic sample introduction device is configured described above, the dew condensation water formed during the cooling of sample liquid can be discharged to the outside via the groove portions 11 and opening portions 12A of the sample rack 1A. Further, the discharged water can be recovered by the water storage tray 7A via the groove portions 53A and opening portions 54 of the rack holder 5A. Thus, also the present embodiment can produce the same effect as that of the previous embodiment.
Incidentally, the above description is given taking as an example the sample introduction device equipped with the cooling device 8. However, needless to say, the present invention can be applied also to a sample cooling device in which a sample introduction function is omitted in the sample introduction device.
1 Sample rack
5 Rack holder
6 Sample holding container
7 Water storage tray
8 Cooling device
10 Lower member
11 Groove portion
12 Opening portion
13 Communicating portion
20 Upper member
30 Cover member
40 Containing section
41 Containing-section lower portion
42 Containing-section upper portion
43 Hole
53 Groove portion
54 Opening portion
61 Cap
62 Septum
63
a Barrel portion
63
b Neck portion
100 Sample introduction device
Number | Date | Country | Kind |
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2009-253199 | Nov 2009 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2010/069315 | 10/29/2010 | WO | 00 | 4/25/2012 |