JP2629539B2 - Sample liquid supply device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus (sampler) for supplying a predetermined amount of a liquid sample to a measuring apparatus such as a liquid chromatograph.

[0002]

2. Description of the Related Art A procedure for supplying a predetermined amount (hereinafter referred to as M) of a sample liquid to a liquid chromatograph by a conventional automatic sample liquid supply device (auto sampler) will be described with reference to FIG. The present autosampler is disposed between a pump and a column of a liquid chromatograph apparatus, and an inlet (IN) 22 is connected to a pump and an outlet (OUT) 21 is connected to a column. The following operations are all automatically performed by a control device (not shown) such as a microcomputer.

[0003] First, a washing liquid 18 is sucked by a syringe 17, and the sucked washing liquid is then discharged toward a needle 15 to fill a flow path to the tip of the needle 15 with the washing liquid. Then, after inhaling a small amount of air from the tip of the needle 15, the needle 15 is inserted into the sample container 14,
The sample liquid is inhaled by the amount of [M + α]. The amount of [+ α] can be arbitrarily set in advance. After inhaling the amount of the sample liquid of [M + α], a small amount of air is again inhaled, and further the washing liquid is inhaled. The air sucked before and after the sample liquid is
It functions as a separation layer for preventing the sample solution and the washing solution before and after the sample solution from mixing. The needle 15 having sucked the sample liquid in this manner is moved to the injection port 12 and inserted therein.

The six-way valve 20 is initially in a state shown by a solid line in FIG. 4, and a port P1 connected to the injection port 12 is connected to a port P6 connected to the drain 24.
In this state, the sample liquid previously sucked is pushed out to the injection port 12 by the syringe 17, and the piston of the syringe 17 is stopped when the tip of the sample liquid has just come out of the port P 6 of the six-way valve 20. Then, the six-way valve 20 is rotated 60 degrees counterclockwise in FIG. 4 to set the flow path to the position indicated by the dotted line, and the sample liquid is further pushed out by the syringe 17. As a result, a predetermined amount of the sample liquid (including the part of the sample liquid in the flow path in the part between the port P1 and the port P6 of the six-way valve 20) is supplied to the port P1,
It enters the sample loop 19 via the port P2. Thereafter, the six-way valve 20 is rotated 60 degrees in the reverse direction (clockwise) to return the flow path to the position indicated by the solid line.

When a pump (not shown) of the liquid chromatograph is operated in this state, a mobile phase is injected into the autosampler from the inlet 22, and the sample liquid in the sample loop 19 is transferred through the ports P2 and P3. Exit 21
Push out to the side. Thereby, a predetermined amount M of the sample liquid is supplied to the column.

In FIG. 4, reference numeral 11 denotes a needle 15
Is a washing port for washing the outside of the sample, 13 is a reagent container for storing a reagent to be added to the sample for derivatizing the sample, etc., and 23 is a bypass channel.

[0007]

When the needle 15 is inserted into the injection port 12, the needle 15 is held in a water-tight manner at the injection port 12, so that the amount of movement of the piston of the syringe 17 (this is directly controlled by the autosampler). Is proportional to the amount of liquid (washing liquid and sample liquid) injected from the needle 15 into the injection port 12. However, because there are error factors such as the inner diameter of the flow path in the middle is not always strictly constant, the proportional constant is not strictly constant,
There is some error in the relationship between the amount of movement of the piston of the syringe 17 and the amount of liquid injected from the injection port 12. For this reason, as described above, a large amount of the sample liquid is previously suctioned from the sample container 14 (by [M + α]) into the needle 15, and the sample liquid is supplied from the port P1 to the port P6 while the flow path of the six-way valve 20 is a solid line. As shown in FIG. 5 (a), the sample liquid was pushed out to the port P6 (toward the drain 24) in an extra amount (for α ′) in anticipation of safety. Also, when the sample solution is pushed toward the sample loop 19, as shown in FIG. 5 (b), a small amount of the sample solution is left at the last portion (by an amount α ″) in anticipation of safety (see FIG. 5B). That is, α in the initial inhalation amount [M + α] is α ′ + α ″
Is). The amount of [+ α] may be substantially the same as the predetermined amount M required for the analysis. If the amount of the sample solution is very small, the amount of the sample solution that can be used for the analysis is further reduced, and the analysis accuracy is reduced. However, there was a problem that was reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a sample liquid supply apparatus which can use a sample liquid without waste.

[0009]

A sample liquid supply apparatus according to the present invention, which has been made to solve the above-mentioned problems, sucks a sample liquid from a sample container into a needle using a syringe and measures the sucked sample liquid. A sample liquid supply device for injecting into the middle of a flow path of a device or the like, a) a needle receiver having a seal for keeping a needle watertight, and b) a needle not inserted into the needle receiver. First
In the state i) Syringe and needle ii) Needle receiver and drain iii) In the second state in which the upstream connection port and the downstream connection port of the flow path are connected and the needle is inserted into the needle receiver iv) The above An upstream connection port of the flow path and a needle v) a switching valve for connecting the needle receiver to the downstream connection port of the flow path;

[0010]

First, the switching valve is set to the first state. In this state, when the needle is inserted into the sample container and the piston of the syringe is pulled, the sample liquid is sucked into the needle (and the flow path connected thereto) by the connection in i). Thereafter, the switching valve is set to the second state, and the needle is inserted into the needle receiver. At this time, the needle is held water-tight in the needle receiver by the seal. In this state, when pressure is applied from the upstream side of the flow path of the measuring device or the like (for example, when the pump is driven in the liquid chromatograph device), the pressure is connected to the sample liquid supply device by the connection of iv). The sample liquid is transmitted to the needle via the connection port with the upstream side of the flow path, and pushes the sample liquid inside the needle into the needle receiver. This sample liquid is further pushed out to the downstream side of the measuring device or the like through the downstream connection port by the connection of the above v). Thus, the pressure on the upstream side of the measuring device or the like pushes all the sample liquid in the needle to the downstream side of the measuring device. Therefore, it is not necessary to previously inject the sample liquid into the needle more than the amount required by the measuring device.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An automatic sample liquid supply apparatus (auto sampler) according to an embodiment of the present invention will be described with reference to FIGS. The autosampler of this embodiment has the same components as the conventional autosampler shown in FIG. 4 except that a three-way valve 25 is added. However, in the autosampler of this embodiment, the six-way valve 20 is not used.
The connection state to is different from the conventional one, and is as follows. Port P1: Drain 24 Port P2: Injection port 12 (the above needle receiver) Port P3: Outlet (OUT) 21 (the above downstream connection port) Port P4: Inlet (IN) 22 (the above upstream connection port) Port P5: Needle 15 Port P6: Three-way valve 25

The three ports Q1 to Q3 of the three-way valve 25
3 is connected as follows. Port Q1: Port P6 of the six-way valve 20 Port Q2: Syringe 17 Port Q3: Cleaning liquid 18

When the autosampler of this embodiment is connected to a liquid chromatograph, and the sample liquid is injected into the flow channel,
Perform as follows. First, the six-way valve 20 is set to the position as shown in FIG. 1, and [port P1 and port P2], [port P3 and port P4], [port P5 and port P6]
Respectively. The three-way valve 25 is in a state where the ports Q1 and Q2 are connected. Needle 1 in this state
5 is inserted into the sample container 14, and the piston of the syringe 17 is pulled. In this embodiment, the rotation of the six-way valve 20 and
Operations such as raising and lowering the needle 15 and moving the piston of the syringe 17 are automatically performed by the microcomputer. The negative pressure caused by pulling the piston of the syringe 17 is applied to the needle 15 via the port Q2, the port Q1, the port P5, and the port P6.
The sample liquid in the sample container 14 is sucked into the needle 15.

Next, the six-way valve 20 is rotated 60 degrees, and FIG.
[Port P2 and Port P
3], [port P4 and port P5], and [port P6 and port P1]. And the needle 15
To the injection port 12 and inserted there. At this time, as shown in FIG.
2 are sealed watertight by a high-pressure seal 26 provided inside. When a pump (not shown) of the liquid chromatograph is driven in this state, the mobile phase enters the autosampler from the inlet 22, and pushes the sample liquid sucked into the needle 15 via the ports P4 and P5. . The pressed sample liquid is sent from the injection port 12 to the column from the outlet 21 via the ports P2 and P3. Thus, in the autosampler of the present embodiment, the needle 15
All the sample liquid sucked into the column is sent to the column as it is.

[0015]

In the sampler according to the present invention, since all the sample liquid sucked into the needle enters the flow path of the measuring device or the like, it is not necessary to suck wasteful sample liquid not used for the measurement, and a small number of samples can be obtained. It can be used effectively and the accuracy of measurement can be increased.

[Brief description of the drawings]

FIG. 1 is a flow chart of a first state of an autosampler according to an embodiment of the present invention.

FIG. 2 is a flow chart of a second state of the autosampler of the embodiment.

FIG. 3 is a sectional view showing a state where a needle is inserted into an injection port (needle receiver).

FIG. 4 is a flow diagram of a conventional autosampler.

FIG. 5 is an enlarged view around a six-way valve of a conventional autosampler.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Washing port 12 ... Injection port (needle receiver) 14 ... Sample container 15 ... Needle 17 ... Syringe 18 ... Washing liquid 19 ... Sample loop 20 ... Hex valve 21 ... Outlet (downstream connection port) 22 ... Inlet (upstream connection) Mouth) 24 ... Drain 25 ... Three-way valve 26 ... High pressure seal

Claims (1)

(57) [Claims] 1. A sample liquid supply device for sucking a sample liquid from a sample container into a needle using a syringe and injecting the sucked sample liquid into a flow path of a measuring device or the like, comprising: A needle receiver having a seal to keep it watertight; b) a first needle not inserted into the needle receiver;
In the state i) Syringe and needle ii) Needle receiver and drain iii) In the second state in which the upstream connection port and the downstream connection port of the flow path are connected and the needle is inserted into the needle receiver iv) The above A sample liquid supply device, comprising: an upstream connection port of a flow channel and a needle v) a switching valve connecting a needle receiver and a downstream connection port of the flow channel.