JPH0752616Y2 - Structure of sample introduction part to analytical column - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is to introduce a sample into an analytical column used when introducing a carrier liquid mixed with a sample liquid into an analytical column of an analytical instrument such as a liquid chromatograph. Regarding structure.

[Conventional technology]

Conventionally, in a liquid chromatograph, a predetermined amount of sample liquid is mixed with a carrier liquid from an injector using a measuring pipe or the like, and this carrier liquid is caused to flow from a carrier liquid introduction pipe to an analytical column. When connecting the carrier liquid introducing pipe and the small-diameter analytical column,
A connecting member having the structure shown in FIG. 7 or FIG. 7 is generally used.

That is, the connecting member a shown in FIG. 6 has a carrier liquid introducing tube insertion port b formed at one end in the lengthwise direction of the cylindrical body and an analysis column insertion port c formed at the other end thereof. c
A small-diameter flow section d is provided between the two, and the end of the carrier liquid introduction pipe e is inserted into the carrier liquid introduction pipe insertion port b, and the end of the analysis column f is inserted into the analysis column insertion port c. Is used to connect the carrier liquid introducing pipe e and the analysis column f. In the figure, g and g are plastic ferrules attached to the introduction tube e and the column f, h and h, respectively.
Are push screws.

Further, the connecting member i of FIG. 7 is formed in a cylindrical shape, and the end face of the introducing pipe e and the end face of the column f are brought into contact with each other in the ferrule j arranged inside, or the column is provided in the introducing pipe e. f
The introduction pipe e and the column f are connected by inserting the end portion of the column. Note that k and k are push screws.

When the carrier liquid introducing pipe and the analytical column are connected by the connecting members shown in FIGS. 6 and 7 described above, since the introducing pipe and the column are connected with almost no dead volume between them, the sample The carrier liquid mixed with the sample liquid in the introduction part immediately flows into the column from the introduction pipe, and further, the carrier liquid reaches the detector after the sample liquid is dissolved in the carrier liquid in the column. If a large amount of sample is introduced into the carrier liquid, the sample will not dissolve sufficiently,
The separation of the sample deteriorates and accurate measurement cannot be performed.

[Problems to be solved by the device]

A conventional connecting member has a structure in which a carrier liquid introduction pipe and an analysis column are connected without dead volume and a sample is dissolved in the carrier liquid in the column. In this case, if the column has a large diameter, a large amount of sample is sampled. Is introduced into the carrier liquid, the sample is sufficiently dissolved in the carrier liquid in the column. However, when a capillary column, micropacked column, etc. with a small inner diameter of 50 to 100 μm is used as the column, the flow rate of the carrier liquid is so small that if a large amount of sample is mixed with the carrier liquid, the carrier liquid in the column will be mixed. The sample does not dissolve sufficiently. Therefore, when a column having a small diameter is used, the amount of the sample that can be introduced into the carrier liquid is limited, and therefore, there is a problem that a large amount of the sample cannot be introduced into the column to perform measurement with high sensitivity. Occurs. Such a problem becomes particularly noticeable when a column having a small diameter such as a capillary column or a micropacked column is used in a system such as a supercritical fluid chromatograph in which it takes time for a sample to dissolve in a carrier liquid.

On the other hand, the inventor of the present invention, as a connecting member of the analytical column capable of surely dissolving the sample in the carrier liquid and performing high-sensitivity measurement even when using a small-diameter column, has one end in the longitudinal direction of the main body The insertion port of the carrier liquid introduction pipe at the part and the insertion port of the analysis column at the other end, and has a volume not less than the volume of the sample liquid introduced into the carrier liquid and not less than the inner diameter of the analysis column. Proposed is a connecting member in which a hollow sample dissolving portion having an inner diameter is provided between the both insertion ports, and the carrier liquid introducing pipe insertion port and the analysis column insertion port are communicated with each other through the sample dissolving part. It was done (Actual application No. 1-1111263).

This connecting member forms a sample dissolving section having the above-mentioned configuration between the carrier liquid introducing tube insertion port and the analysis column inserting port, and the carrier liquid flowing out of the carrier liquid introducing tube passes through the sample dissolving section to the analysis column. Since it is made to flow in, the carrier liquid is agitated in the dissolution portion when passing through the sample dissolution portion, whereby the sample is sufficiently dissolved in the carrier liquid. In this case, in the connection member, the volume of the dissolving portion is set to be equal to or larger than the volume of the sample liquid introduced into the carrier liquid, and the inner diameter of the dissolving portion is set to be equal to or larger than the inner diameter of the analytical column. It is generated, and thereby the sample is surely dissolved in the carrier liquid.

When the sample introducing part to the analytical column is constructed by using the connecting member having the sample dissolving part, the structure is usually as shown in FIG. That is, in the figure, 1 is a connecting member in which a sample dissolving portion is formed, m is a carrier liquid introducing pipe, n is an injector, and o is an analytical column. In this sample introducing structure, the injector n is a carrier liquid introducing pipe. A predetermined amount of the sample liquid is mixed with the carrier liquid in m, the carrier liquid is flown to the connecting member l to dissolve the sample in the carrier liquid at the sample dissolving portion, and then the carrier liquid is introduced into the analytical column o. .

However, in the structure of the sample introducing portion shown in FIG. 5, the flow rate of the carrier liquid that can flow in the carrier liquid introducing pipe m is regulated to the flow rate necessary for the separation in the column o, so that the amount of the sample introduced is also this carrier liquid. Since the flow rate is regulated, the amount of sample introduced into the carrier liquid cannot be increased beyond a certain amount. Therefore, the amount of sample introduced can be increased to improve the analysis accuracy.
It may be disadvantageous in that the amount of sample introduced is adjusted to perform analysis efficiently. That is, the carrier liquid introducing pipe m
The flow rate of the carrier liquid flowing through the column is
In order to determine whether or not good separation of the components is performed, the flow rate is set to a specific value according to the column o. On the other hand, the amount of the sample dissolved in the carrier liquid in the dissolving portion of the connecting member 1 is proportional to the product of the flow rate of the carrier liquid mixed with the sample liquid flowing through the dissolving portion and the time.
However, in the structure of the sample introducing part shown in FIG. 5, when a constant flow rate of the carrier liquid is flown through the carrier liquid introducing pipe m, the product of the flow rate and the time when the carrier liquid flows through the dissolving part of the connecting member is also accompanied. Since the amount is fixed to a constant value, the amount of the sample that can be introduced into the carrier liquid is also fixed to a constant amount, and therefore the amount of the sample introduced cannot be increased beyond this amount.

The present invention has been made in view of the above circumstances, and in the structure of the sample introducing section for connecting the carrier liquid introducing tube and the analytical column by using the connecting member in which the sample dissolving section is formed,
It is an object of the present invention to provide a sample introduction part structure capable of increasing the amount of sample introduced to an arbitrary amount.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a carrier liquid introducing pipe through which a carrier liquid flows, and a carrier liquid flowing through the carrier liquid introducing pipe connected to the carrier liquid introducing pipe. A first flow dividing pipe and a second flow dividing pipe for dividing the flow at a predetermined flow rate ratio;
An injector, which is interposed in the flow dividing pipe, mixes a predetermined amount of the sample liquid with the carrier liquid flowing through the first flow dividing pipe, and a carrier in which the first flow dividing pipe and the second flow dividing pipe are connected to one end of the main body in the length direction. A sample dissolving section having a liquid introduction tube insertion port and an analysis column insertion port at the other end and having an inner diameter larger than the inner diameter of the analysis column at a volume larger than the volume of the sample liquid mixed with the carrier liquid from the injector. Is provided between the both insertion ports, and a connecting member that connects the both insertion ports to each other through the sample dissolving section is provided, and a structure for introducing a sample into an analytical column is provided.

[Action]

In the present invention, since the carrier liquid flowing through the carrier liquid introducing pipe is divided into the flow dividing pipes, the flow rate of the carrier liquid flowing through each dividing pipe is reduced as compared with the flow amount of the carrier liquid flowing through the carrier liquid introducing pipe. . Since the sample liquid is introduced into the carrier liquid from the injector in the first branch pipe where the carrier liquid flow rate is decreased, the time required for introducing the sample liquid (from the front end to the rear end of the sample liquid in the injector is changed to the carrier liquid). The time of introduction) is increased as compared with the case of introducing the sample solution into the carrier solution introduction tube. For example, assuming that the flow rate of the carrier liquid in the first branch pipe is reduced to 1/2 of the flow rate of the carrier liquid in the carrier liquid introduction pipe,
The sample introduction time into the first flow dividing pipe is doubled as compared with the case where the sample is introduced into the carrier liquid introducing pipe. On the other hand, in the present invention, since the outflow end of each flow dividing pipe is continuous with the connecting member, the flow rate of the carrier liquid flowing through the sample dissolving portion of the connecting member is the same as the carrier liquid flow rate of the carrier liquid introducing pipe before the diversion. Is. Then, as described above, the amount of the sample dissolved in the carrier liquid in the dissolving portion is proportional to the product of the flow rate of the carrier liquid mixed with the sample flowing through the dissolving portion and the passage time. By increasing the introduction time of the liquid, the time for which the carrier liquid containing the sample passes through the dissolution portion increases, while the flow rate of the carrier liquid in the dissolution portion does not change, the product of the above flow rate and time increases, Therefore, the introduction amount of the sample can be increased according to this increase, and the introduction amount of the sample can be determined by the ratio of the carrier liquid flow rate of the first diversion pipe and the carrier liquid flow rate of the second diversion pipe. It is possible.

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples.

〔Example〕

FIG. 1 shows a structure for introducing a sample into an analytical column according to an embodiment of the present invention.

In the figure, 1 is a carrier liquid introducing pipe through which the carrier liquid flows,
1a and 1b are respectively connected to the above carrier liquid introducing pipe 1,
A first flow dividing pipe and a second flow dividing pipe for dividing the carrier liquid flowing through the introduction pipe 1 at a predetermined flow rate ratio, 3 is a small-diameter analytical column such as a capillary column or a micropacked column, and 4 is a carrier liquid introduction pipe insertion port at one end Is connected to the outflow ends of both of the flow dividing pipes 1a and 1b, and the inflow end of the analysis column 3 is connected to the analysis column insertion port at the other end, which is a connecting member having a sample dissolving portion inside.

Here, the connecting member 4 has the structure shown in FIG. 2 or FIG. That is, the connecting member 4 of FIG.
Circular carrier liquid introduction tube insertion port 6 at one end in the length direction of
A circular analysis column insertion port 7 is formed at the other end, and a sample dissolution section 8 is formed between the insertion ports 6 and 7. In addition, the connecting member 4 in FIG.
The member of FIG. 2 is provided with a narrowed portion 10 having a circular passage 9 at the center on the other end side of the melting portion 5, and the diameter of the passage 9 is formed to be substantially equal to the inner diameter of the column 3. The dissolving section 8 has a volume equal to or larger than the volume of the sample liquid introduced from the injector 2 into the carrier liquid, and has an inner diameter equal to or larger than the inner diameter of the analysis column 3. In this case, the volume of the sample dissolving portion is preferably about 1 to 100 times, especially about 1 to 10 times the volume of the sample liquid mixed with the carrier liquid. In addition, the inner diameter of the sample dissolving section is 1 to 100 times the inner diameter of the analytical column, especially 2 to 5 times.
It is preferably about 0 times.

Further, the connecting portion of the both flow dividing pipes 1a and 1b to the connecting member 4 has the structure shown in FIG. That is, the tip ends of the flow dividing pipes 1a and 1b are respectively inserted into the insertion member 10 made of rubber or the like having two insertion holes.

And, as shown in FIGS. 2 and 3, the connection between the flow dividing pipes 1a, 1b and the column 3 by the connecting member 4 is performed by attaching ferrules 11 and 11 to the ends of the inserting member 10 and the column 3, respectively. These ferrules 11 and 11 are inserted into the insertion ports 6 and 7, and further push screws 12 and 12 are screwed into the peripheral wall portions of the insertion ports 6 and 7 to fix both ferrules 11 and 11 in the insertion ports 6 and 7. In this way, both of the flow dividing pipes 1a, 1b and the column 3 are communicated with each other via the dissolving section 8.

When the sample solution is introduced into the analytical column 3 by the sample introduction section of the present embodiment, the carrier solution is introduced into the carrier solution introduction tube 1 at a predetermined flow rate, and the carrier solution is divided into the flow dividing tubes 1a and 1b. In this case, the means for adjusting the flow rate ratio of the carrier liquid to be flown in the both flow dividing pipes 1a and 1b is not limited, but
Means for adjusting the length of a, 1b, inserting a capillary tube in one or both of the flow dividing tubes 1a, 1b, or using a throttle valve can be appropriately adopted. In this case, the flow rate of the carrier liquid flowing through the first flow dividing pipe 1a in which the injector 2 is interposed is set to the minimum flow amount required to push the sample, and most of the carrier liquid flows through the second flow dividing pipe 1b. So that
Although desirable in terms of increasing the amount of sample introduced, the effect of the present invention can be obtained by flowing a small amount of carrier liquid into the second flow dividing pipe 1b. Therefore, it is preferable that the flow ratio between the first flow dividing pipe 1a and the second flow dividing pipe 1b be 1: 0.1 or more.

Then, a predetermined amount of sample liquid is introduced from the injector 2 into the carrier liquid of the first flow dividing pipe 1a, but in the present embodiment, both flow dividing pipes 1a, 1b and the column 3 are connected via the sample dissolving section 8. Therefore, the carrier liquid in which a predetermined amount of the sample liquid is mixed by the injector 2 flows into the dissolving portion 8, where the carrier liquid is agitated and the sample is dissolved in the carrier liquid. Is what flows into.

Therefore, according to the present embodiment, since the carrier liquid is agitated by the dissolving portion 8 of the connecting member 4 to dissolve the sample, it is possible to dissolve a large amount of the sample in the carrier liquid even when the column 3 having a small diameter is used. In addition, the carrier liquid can be divided into both flow dividing pipes 1a and 1b.
Since the sample is introduced into the carrier liquid in the first flow dividing pipe 1a, the product of the flow rate and the passage time of the carrier liquid mixed with the sample in the dissolving portion 8 is arbitrarily controlled as described above. As compared with the structure of the introduction part shown in FIG. 5, a large amount of sample can be introduced to improve the sensitivity, and the introduction amount of the sample can be adjusted to the first branch pipe.
Since it can be determined by the ratio of the carrier liquid flow rate of 1a and the carrier liquid flow rate of the second flow dividing pipe 1b, the sample introduction conditions can be freely selected and the analysis can be performed efficiently. In this case, even if the introduction time of the sample is lengthened, the component to be measured is once held in the column and then reaches the detector, so that broadening of the peak of the chromatogram does not occur.

Although the number of the flow dividing pipes is two in the above embodiment, three or more flow dividing pipes may be provided. Further, although both the diversion pipes are connected to the connecting member, respectively, the both diversion pipes may be connected and merged, and then connected to the connecting member. Further, in the above embodiment, the flow dividing pipes 1a, 1b and the column 3 are attached to both the insertion ports 6, 7 by using the ferrules 11, 11 and the push screws 12, 12, but the flow dividing pipes 1a, 1b, and the column 3 are attached. The mounting structure is not limited to this. Further, other configurations may be variously modified without departing from the scope of the present invention.

[Effect of device]

As explained above, according to the structure of the sample introduction part of the present invention, a large amount of sample can be introduced into the carrier liquid, and the amount of sample introduced can be arbitrarily controlled. Therefore, according to the present invention, even when a small-diameter column such as a capillary column or a micropacked column is used, it is possible to introduce a large amount of sample into the carrier liquid and perform measurement with high sensitivity. The amount can be arbitrarily controlled to enable efficient analysis. Therefore, the sample introduction structure of the present invention is particularly effective when using a small diameter column in an analytical instrument such as a liquid chromatograph, particularly in a system where it takes time to dissolve the sample in a carrier liquid such as a supercritical chromatograph. used.

[Brief description of drawings]

FIG. 1 is a flow chart showing an embodiment of the sample introduction structure of the present invention, and FIGS. 2 and 3 are sectional views showing an example of a connecting member used in the present invention, and FIGS. 4 (A) and 4 (B). ) Is an enlarged cross-sectional view showing the outflow ends of both branch pipes, and Fig. 5 shows the second and
FIG. 3 is a flow chart showing an example of the structure of the sample introducing part using the connecting member shown in FIG. 3, and FIGS. 6 and 7 are sectional views showing the conventional connecting member. DESCRIPTION OF SYMBOLS 1 ... Carrier liquid introduction pipe, 1a ... 1st distribution pipe, 1b ... 2nd distribution pipe, 2 ... Injector, 3 ... Analysis column, 4 ... Connection member, 5 ... Cylindrical main body, 6 ... Carrier liquid introduction pipe insertion port, 7
… Analysis column insertion port, 8… Sample dissolving part.

Claims (1)

[Scope of utility model registration request] 1. A carrier liquid introducing pipe in which a carrier liquid flows, and a first flow dividing pipe and a second flow dividing pipe connected to the carrier liquid introducing pipe and dividing the carrier liquid flowing in the carrier liquid introducing pipe at a predetermined flow rate ratio. And is installed in the first flow dividing pipe,
An injector for mixing a predetermined amount of sample liquid with a carrier liquid flowing through the flow dividing pipe, and a carrier liquid introducing pipe insertion port to which the first flow dividing pipe and the second flow dividing pipe are connected at one end in the length direction of the main body, In addition, it has an analysis column insertion port at the other end, and a sample dissolution part having an inner diameter larger than the inner diameter of the analysis column is formed between the both insertion ports with a volume larger than the volume of the sample liquid mixed with the carrier liquid from the injector. And a connecting member in which both insertion ports communicate with each other through the sample dissolving section, the structure for introducing a sample into an analytical column.