Automatic sampler provided with dilution tank and dilution pipeline

Abstract

To provide an automatic sampler for a liquid chromatography provided with a dilution tank and a dilution pipeline which enhance haemolysis / dilution efficiency in a compact and inexpensive manner.SOLUTION: An automatic sampler for a liquid chromatography is provided with an automatic sampler part which contains an aspirator and an ejector for a biological specimen of an analysis object and cleaning fluid, and a dilution unit. The dilution unit is provided with a dilution block containing a dilution tank, a pump which sucks and discharges a blend of the biological specimen of the analysis object and the cleaning fluid, and a dilution device which fluidly connects the dilution tank and the pump.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an autosampler for liquid chromatography. [Background technology]

[0002] Liquid chromatography is widely used for clinical testing of biological samples, such as hemoglobin, lipoproteins, catecholamines, vitamins, and amino acids. In hospitals and testing centers, there is a demand to subject biological samples, such as blood and urine samples, to liquid chromatography without the pretreatment process required for manual methods in order to improve work efficiency and shorten the total measurement time. However, it is known that some proteins, lipids, and blood cell components in blood interfere with the analysis results, and the injection of impurities other than the measurement target causes a shortened service life of the analytical column and line filter. To reduce the influence of impurities, the blood may be diluted or hemolyzed with a diluent or hemolyzing solution in the autosampler before analysis.

[0003] As mentioned above, there is a high demand for shortening the total analysis time, and there is a demand for a high degree of shortening of the measurement time per sample. Therefore, there is also a demand for shortening the time spent on dilution and hemolysis. As a result, this can lead to insufficient hemolysis and unstable dilution, which can affect the stability of the analysis results. Furthermore, the high load on line filters and columns leads to a shortened lifespan of these. For example, Patent Document 1 reports a technology for hemolyzing blood samples using ultrasound. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special table 2011-528105 Summary of the Invention [Problem to be solved by the invention]

[0005] In medical facilities, there is a demand for shorter analysis times, as well as smaller and less expensive analytical devices. In the hemolysis technique described in Patent Document 1, an ultrasonic mechanism must be installed inside the device, which leads to an increase in the size and cost of the device. [Means for solving the problem]

[0006] Therefore, an object of the present invention is to provide an autosampler for liquid chromatography that is small, low-cost, and equipped with a dilution tank and dilution piping that have improved hemolysis and dilution efficiency. In order to solve the above problems, an autosampler for liquid chromatography according to one aspect of the present invention is provided that includes an autosampler section including an aspirator and a discharger for a biological sample to be analyzed and a cleaning solution, and further includes a dilution unit.An autosampler for liquid chromatography according to another aspect is provided that includes in its dilution unit a dilution block including a dilution tank, a pump for aspirating or discharging a mixture of the biological sample to be analyzed and a cleaning solution, and a dilution device for fluidly connecting the dilution tank and the pump.

[0007] According to these configurations, turbulent flow can be efficiently generated in the flow path, and effective hemolysis and dilution operations can be performed without the need for a complex mechanism.

[0008] Furthermore, the liquid chromatography autosampler can be provided with a hemolysis dilution unit, characterized in that the first dilution pipe is connected perpendicular to the central axis of the dilution tank at a position radially away from the bisective position of the radius of the connection surface. This generates a spiral vortex in the dilution tank, enabling a more effective hemolysis and dilution operation to be carried out. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram for liquid chromatography according to the present invention. [Diagram 2]1 is an enlarged view of a main portion of an autosampler for liquid chromatography according to the present invention. [Diagram 3] 1A and 1B are a top view and a vertical sectional view showing a main part of a dilution block according to a first embodiment of the present invention. [Figure 4] 11A and 11B are a top view and a vertical sectional view showing a main part of a dilution block according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an autosampler for liquid chromatography according to an embodiment will be described with reference to the drawings. In this application, the X, Y, and Z directions are defined as follows. The Y direction (Y axis) is the driving direction of the sampling arm. The X (X axis) direction is a direction perpendicular to the Y direction. The Z (Z axis) direction is the driving direction of the sampling needle.

[0011] FIG. 1 is a schematic diagram of a liquid chromatography apparatus according to the present invention. A biological sample to be analyzed is aspirated in a predetermined amount by a sampling needle 110 and a syringe pump (1) 111 configured in an autosampler section 100. A washing solution 107 is led to a dilution tank 112 in a dilution block 109 through a dilution device 114 by a syringe pump (2) 108. The dilution device 114 is configured with a pipe or an adapter. Washing solution that exceeds the capacity of the dilution tank is discharged through a waste liquid port 113, and the dilution tank and dilution device are filled with a specified amount of washing solution. The sampling needle that has aspirated the sample to be analyzed moves into the dilution tank and discharges a specified amount of the sample. The syringe pump (2) reciprocates to perform a pretreatment operation for hemolysis and dilution and a dilution operation. The autosampler switches various flow paths in synchronization with the operation of a rotary valve 115 to perform operations such as sampling and dilution. Examples of washing solutions include purified water and hemolysis washing solution. The diluted sample is introduced into a sample loop 104 by a syringe pump (1) and a sampling needle, or by a syringe pump (2), etc. An eluent 101 is supplied as a mobile phase by a liquid delivery pump 104, and is introduced into an analytical column 105 together with the sample held in the sample loop 104 by the operation of an injection valve 103, and the substances separated in the analytical column 105 are detected by a detector 106.

[0012] FIG. 2 is an enlarged view of a main portion of an autosampler 100 for liquid chromatography according to the present invention.

[0013] FIG. 3 is a top view and a vertical cross-sectional view showing the main part of the dilution block 1, which is a first embodiment of the dilution block 109. The waste liquid block includes a waste liquid port 113, a dilution tank 112, a dilution device connection part 201, and a waste liquid piping connection part 202. The dilution tank is used for hemolysis or dilution of a sample, but may also be used, for example, for cleaning the surface of a sampling needle. For this reason, it is desirable to have an approximately cylindrical, approximately truncated cone, or approximately conical shape with an inner diameter equal to or larger than the outer diameter of the sampling needle. It is desirable to design the total capacity of the dilution tank according to the dilution ratio of the sampled sample. A tapered structure can be provided at the sampling needle introduction part so that the sampling needle can smoothly descend. The material of the dilution block is not particularly specified, and examples thereof include polytetrafluoroethylene, ethylene-tetrafluoroethylene, and polyether ketone. A first dilution device 114 is fluidly connected to the dilution tank 112 via the dilution device connection part 201. The dilution device connection part 201 is positioned perpendicular to the rotation axis of the dilution tank and near the side surface of the dilution tank in order to generate a swirling flow in the dilution tank. Specifically, it is connected perpendicular to the central axis of the dilution tank at a position radially away from the half-centre position of the radius of the connection surface. It is more preferable to connect along the tangential direction of the circumferential surface of the dilution tank. It can also be connected at an angle from the lower or upper side with an inclination to the height (Z axis). It is also preferable to install it as close to the bottom surface of the dilution tank as possible to prevent impurities from accumulating at the bottom of the dilution tank. Dilution is performed by flow in the dilution tank, but it is also preferable to perform dilution in the dilution device. As a result of the study, it was found that dilution is efficient when the dilution device 114 is composed of three pipes (116, 117, 118), one of which, the pipe 117, has an inner diameter 1.5 to 20 times the diameter of the two pipes (diameter) and the pipe length is 1 to 10 times the inner diameter of the pipe. It was also found that dilution is efficient when the dilution device 114 is composed of two pipes (121, 122) connected via an adapter (123), the adapter flow path diameter is 1.5 to 20 times the diameter of the two pipes (diameter) and the flow path length is 1 to 10 times the inner diameter of the flow path. The material of the pipes and adapter of the dilution device is not particularly specified, and examples thereof include polytetrafluoroethylene, ethylene-tetrafluoroethylene, polyether ketone, stainless steel, and glass. The change in the inner diameter of the piping or the adapter in the dilution device 114 is included in the area of ​​the piping capacity for the amount of liquid sucked and discharged by the stroke of the syringe pump during the dilution operation with respect to the dilution tank side. In other words, during the dilution operation, the mixture of the measurement sample and the cleaning liquid is diluted through the change in inner diameter or the adapter in the dilution device. The dilution block and the dilution device are combined to form a dilution unit. FIG. 4 is a top view and a vertical sectional view showing a main part of a dilution block 2 which is a second embodiment of the dilution block 109 according to the present invention. The dilution block 109 includes a waste liquid port 114 , a dilution tank 113 , two dilution device connectors 201 and 203 , and a waste liquid pipe connector 202 .

[0014] The dilution device connectors 201 and 203 are positioned perpendicular to the axis of rotation of the dilution tank and near the side of the dilution tank in order to generate a vortex in the dilution tank. Specifically, they are connected perpendicular to the central axis of the dilution tank at a position radially away from the half-centre position of the radius of the connection surface. More preferably, they are connected along the tangential direction of the circumferential surface of the dilution tank. In addition, it is preferable that the two connectors are positioned on the side surfaces facing each other with respect to the central axis. They can also be connected at an angle from the lower or upper side with an inclination with respect to the height (Z axis). In addition, it is preferable that at least one dilution device connector is provided as close to the bottom surface of the dilution tank as possible to prevent impurities from accumulating at the bottom of the dilution tank.

[0015] Next, the operation and effects of the present invention will be described. The dilution block Z, which is a comparative example, is connected so that the dilution device connection part is perpendicular to the center of the rotation axis of the dilution tank, and has a shape that does not cause eddy current in the dilution tank. The dilution device Y is composed of two pipes (inner diameter 0.5 mm, length 100 mm, inner diameter 1.0 mm, length 500 mm), and both pipes are connected with an adapter (inner diameter 0.8 mm, length 2 mm). The dilution device Z is composed of three pipes (inner diameter 0.15 mm, length 100 mm, inner diameter 2 mm, length 150 mm, inner diameter 1.0 mm, length 500 mm), and each pipe is connected with an adapter (inner diameter 0.8 mm, length 2 mm). As an embodiment, the above-mentioned dilution block 1 and dilution block 2 were adopted. The dilution device 1 is composed of three pipes (inner diameter 0.15 mm, length 100 mm, inner diameter 2 mm, length 100 mm, inner diameter 1.0 mm, length 500 mm), each of which is composed of an adapter (inner diameter 0.8 mm, length 2 mm). The dilution device 2 is composed of three pipes (inner diameter 0.15 mm, length 100 mm, inner diameter 2 mm, length 30 mm, inner diameter 1.0 mm, length 500 mm), each of which is composed of an adapter (inner diameter 0.8 mm, length 2 mm). The dilution device 3 is composed of two pipes (inner diameter 0.5 mm, length 100 mm, inner diameter 1.0 mm, length 500 mm), each of which is connected by an adapter (inner diameter 2 mm, length 8 mm). The dilution device 4 has two sets of two pipes (inner diameter 0.5 mm, length 100 mm, inner diameter 1.0 mm, length 100 mm) and an adapter (inner diameter 2 mm, length 8 mm) connected with one three-way adapter PEEK Tee F-300 (IDEX Health and Sciences), which is connected to one pipe (inner diameter 1.0 mm, length 100 mm). Each dilution tank was designed to dilute the sample to about 1 / 200.

[0016] The dilution unit of the autosampler for liquid chromatography according to the present invention improves dilution efficiency, improving injection reproducibility. In addition, the sample in the blood can be effectively hemolyzed, suppressing adsorption of impurities to the analytical column, column filter, and line filter, thereby suppressing an increase in system pressure. Furthermore, the cleaning of the dilution tank is improved, making it possible to reduce carryover.

[0017] (evaluation) The dilution unit was replaced with an automatic glycohemoglobin analyzer HLC-723G11 (manufactured by Tosoh Corporation) that uses the principle of cation exchange chromatography, and the evaluation was carried out. The same sample (Yellow No. 4 aqueous solution) was measured 20 times in succession (diluted within the device) to confirm the reproducibility of the total area value of the chromatogram. Carry-over was evaluated by measuring the Yellow No. 4 aqueous solution, followed by measuring purified water (both diluted within the device). The ratio of the peak area value seen in the measurement results for purified water to the peak area value of the Yellow No. 4 aqueous solution was evaluated. Pressure rise was evaluated by measuring the pressure rise across the system after measuring 500 whole blood samples compared to before measurement. An example of the dilution unit configuration and the results are shown in Table 1 below.

[0018] Table 1 TIFF2025068291000002.tif66169

[0019] By changing the dilution block, the reproducibility was improved in all of Examples 1 to 6. This is thought to be due to the improvement in the stability of the dilution operation. In addition, by changing the dilution device, the carryover was improved in all of Examples 3 to 6. Furthermore, it was confirmed that the pressure rise was suppressed by combining the dilution block and the dilution device. [Explanation of symbols]

[0020] 100 Autosampler 101 Eluent 102 Liquid delivery pump 103 Injection valve 104 Sample Loop 105 Analytical Column 106 Detector 107 Cleaning fluid 108 Syringe Pump(2) 109 Dilution Block 110 Sampling needle 111 Syringe Pump(1) 112 Dilution tank 113 Waste liquid port 114 Dilution device 115 Rotary Valve 201, 203 Dilution device connection part 202 Waste liquid piping connection

Claims

1. An autosampler for liquid chromatography comprising an autosampler unit including an aspirator and a discharger for a biological sample to be analyzed and a cleaning solution, Further, a dilution unit is provided, The dilution unit comprises: a dilution block including a dilution tank; a pump for aspirating or discharging a mixture of the biological sample to be analyzed and a cleaning solution; a dilution device fluidly connecting the dilution tank and the pump; Autosampler for liquid chromatography.

2. The dilution unit further comprises: A first dilution device is connected to the dilution tank at a position radially away from the radial bin of the connection surface so as to be perpendicular to the central axis of the dilution tank.

2. The autosampler for liquid chromatography according to claim 1.

3. The suction device for the biological sample to be analyzed and the cleaning solution includes a sampling needle and a syringe pump; 2. The autosampler for liquid chromatography according to claim 1.

4. The dilution tank is substantially cylindrical, substantially truncated cone, or substantially conical, with an inner diameter equal to or larger than the outer diameter of the sampling needle.

4. The autosampler for liquid chromatography according to claim 3.

5. The cleaning solution is introduced into a dilution tank in the dilution block through a dilution device by the syringe pump, and the dilution tank and the dilution device are filled with a specified amount of the cleaning solution.

4. The autosampler for liquid chromatography according to claim 3.

6. The washing solution is one or a combination of two or more selected from the group consisting of purified water and a hemolysis washing solution.

2. The autosampler for liquid chromatography according to claim 1.

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