JPH0477662A - Automatic sample introduction method and its apparatus - Google Patents

Abstract

PURPOSE:To enable introduction of a sample in a short time with a simple construction by a method wherein an introduction pipe for sample dilution is provided and a dilution liquid is supplied from behind a sample to introduce a sample part in a specified zone having a gradient of concentration of the sample associated with a flow into an analysis section. CONSTITUTION:An introduction pipe 23 for sample dilution is provided which forms a field of diluting samples with a specified length and capacity between an injection port 6 and a sample introduction valve 18. The introduction pipe 23 is filled with a dilution liquid beforehand. When a sample is injected at the injection port 6 and subsequently the dilution liquid is injected, the sample is dispersed in the dilution liquid while the sample flows through the introduction pipe 23 and distributed with a concentration gradient formed in a flow thereof. A specified zone having this concentration gradient is measured with a measuring tube 20 of the same introduction valve 18 and introduced into the analysis section to perform a microscopic sampling at a desired dilution ratio. This eliminates the need for arranging an exclusive dilution tank thereby enabling the introduction of the sample in a short time with a simple construction.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an automatic sample introduction method and an automatic sample introduction device, and in particular, when two-stage dilution is required in a liquid chromatograph, etc. The present invention relates to an automatic sample introduction method and an automatic sample introduction device that can be carried out automatically without using a special dilution tank.

[Conventional technology]

For example, in an automatic sample introduction device for a liquid chromatograph, when the amount of sample used for analysis is extremely small, it is difficult to directly sample the small amount of sample. In such cases, as a preliminary step, it was necessary to prepare a solution in which the sample was diluted in advance and sample this solution. For example, the amount of sample required for glycated hemoglobin analysis performed in clinical tests is approximately 0.05 to 0.1 μl, whereas the amount of sample that can be accurately dispensed with a dispenser is 3 μm to 5 μl. Since this is the limit, a two-stage dilution method is adopted in which the sample is diluted 100 to 200 times before sampling.

Conventionally, predilution of samples in such liquid chromatographs has been performed manually. Recently, computer-controlled automatic sample introduction devices with automatic pretreatment functions have been put into practical use, and automatic methods have become popular.

A typical example of a conventional automatic sample introduction device with an automatic pretreatment function will be explained with reference to FIG. In Figure 8,
The automatic sample introduction device 1 includes a sample stage 2, a cleaning layer 3,
A drain port 4, a dilution tank 5, and an injection port 6 are provided. Liquid samples to be measured are stored in each of a plurality of sample containers 7, arranged in a sample rack 8, and mounted on the sample stage 2. The nozzle 9 is configured to be connected to either a syringe pump 12 or a diluent tank 13 via a thin tube 10 and a switching valve 11, and is further connected to each sample container by a drive mechanism 14 in the X-axis direction and the Y-axis direction. or move to the location of each processing port and perform the necessary work.

In the analysis section 15, a reagent tank 17a is supplied by a pump 16.

The reagent 17b is passed through the sample introduction valve 18 to the separation column 19.
It is structured in such a way that it flows smoothly. The sample introduction valve 18 is provided with a metering tube 20, and the sample injected from the injection port 6 is held in the metering tube 20 and introduced into the flow path of the analysis section 15.

The sample separated by the separation column 19 is sent to a detector 21, where sample components are identified.

Sampling of a sample in the automatic sample introduction device having the above configuration is performed as follows. First, a predetermined amount of diluent is sucked into the syringe pump 12 from the diluent tank 13 in advance, and then the nozzle 9 is moved to the position of the sample container 7 to be analyzed, and a predetermined amount of sample is sucked into the tip of the nozzle 9. After that, move the nozzle 9 to the position of the dilution tank 5 and discharge the sample,
A predetermined amount of diluent is discharged from behind to create a sample solution with a predetermined dilution ratio. Next, apply this diluted sample to the nozzle 9.
The nozzle 9 is moved to the position of the injection port 6 and discharged to send it to the sample introduction valve 18. A predetermined amount of sample is measured with the measuring tube 20, and the sample introduction valve 18 is switched to adjust the flow of the analysis section. introduced into the road.

In the conventional sampling method described above, injection port 6
The volume of the tube that forms the flow path from to the sample introduction valve 18 is made as small as possible, and the amount of sample to be injected is sufficiently large relative to the volume of the tube. The principle method for obtaining good sampling accuracy is to discard the sample and cut out a sample area with a stable concentration using a measuring tube.

[Problem to be solved by the invention]

The diluted sampling method using the automatic sample introduction device mentioned above is an automated version of the pre-dilution method that was previously performed manually, and has high dilution accuracy and is widely used for automated flow-type analysis other than liquid chromatographs. This is a common method that can be used. However, this sampling method (1) requires a special dilution tank, (2) pre-dilution takes time, which increases the time required for analysis, and (3) the time required for analysis between consecutive samples. In order to eliminate carryover, the dilution tank must be thoroughly cleaned every time a sample is processed, and a large amount of washing water is required. There are problems such as the need to clean and replace the dilution tank.

In addition, as a known document describing a conventional automatic sample introduction device for liquid chromatograph, there is
There is a publication No. 0. This prior art also has the above-mentioned problems because it has a configuration that requires a special mixing container that functions as a dilution tank.

Furthermore, recently, the usefulness of liquid chromatography analysis in clinical tests has been recognized, and specialized machines for diagnostic purposes have been put into practical use. There are many analyzes that do not require sampling precision.

For example, in the analysis of glycated hemoglobin, measurements are made based on the ratio of separated components. Although the amount of sample required for analysis is extremely small, strict sampling accuracy is not necessarily required. Furthermore, in liquid chromatographs, due to issues such as the recovery efficiency of separation columns, an internal standard solution is often added and measurements are performed using this as a standard.

The purpose of the present invention is to realize an automatic dilution sampling means that is particularly useful for specialized machines for analyzing specific items such as those mentioned above, and has a simple configuration without using a special dilution tank. Another object of the present invention is to provide an automatic sample introduction method and an automatic sample introduction device that can introduce a sample in a short time and with simple operations.

[Means to solve the problem]

In order to achieve the above object, the automatic sample introduction method according to the present invention feeds a certain amount of sample from the inlet to a sample dilution introduction tube having a capacity sufficiently larger than the amount of sample to be introduced, Thereafter, a diluent is delivered to disperse the sample in the diluent while the sample flows through the inlet tube, thereby controlling a specific area of the sample concentration gradient formed in the flow in the inlet tube. Take out the sample part using the flow path switching valve,
It consists of the procedure of feeding a carrier solution into a channel for analysis.

In order to achieve the above object, a first automatic sample introduction device according to the present invention includes an injection port, a dispensing nozzle that sucks a sample in a sample container and injects it into the injection port, and a dispensing nozzle that is connected to the dispensing nozzle. and a sample introduction valve that measures the sample injected from the injection port with a measuring tube and introduces the sample into an analysis section. , a sample dilution introduction pipe having a capacity sufficiently larger than the amount of the sample to be injected is provided between the injection port and the sample introduction valve, and a diluent is fed from behind the injected sample to A part of the sample in the stationary area of the sample concentration gradient formed by dispersing the sample in the diluted liquid with the flow in the pipe is taken out by the sample introduction valve and introduced into the analysis section. .

In order to achieve the above object, a second automatic sample introduction device according to the present invention includes a sample suction nozzle, a sample introduction valve that measures the sucked sample with a measuring tube and introduces the sample into the analysis section, and a sample suction nozzle. In an automatic sample introduction device comprising a suction pump that aspirates a sample from a sample container and supplies it to the sample introduction valve, the amount of the sample is sufficiently larger than the amount of sample to be aspirated between the sample intake nozzle and the sample introduction valve. A sample dilution inlet tube with a capacity is provided, and a diluent tank into which the sample suction nozzle can be inserted is provided, and the diluent is sucked in and fed from behind the sucked sample, and the diluent is fed along with the flow within the introduction interval. A sample portion in a specific area of a sample concentration gradient formed by dispersing the sample in the diluent is taken out by the sample introduction valve and introduced into the analysis section.

[Effect]

The automatic sample introduction method according to the present invention is configured as an automatic dilution sampling method that does not use a specific dilution tank. The introduction tube also has the function of diluting the sample. For example, if this sample introduction tube is filled with a diluent in advance and the sample is injected from the injection port, and then the diluent is injected and delivered,
The sample is dispersed in the diluent while flowing through the inlet tube, and is distributed in the flow in the form of a concentration gradient. Therefore, a specific area of this concentration gradient is metered using the metering tube of the sample introduction switching valve and introduced into the analysis section to perform trace sampling at a desired dilution ratio. In this way, the sample is diluted in the flow of the thin tube that is the sample flow path, and a very small amount of the sample is sampled.

In the first automatic sample introduction device according to the present invention, an injection port similar to that described in the conventional device, a sample introduction valve, and a sample container that can be freely moved between the sample container and the injection port of the automatic sample introduction device are used. A dispensing nozzle that supplies and discharges diluted liquid and a control system that controls sampling, and a unique configuration of this device that exerts the diluting effect on the sample provided between the injection port and the sample introduction valve. and an introduction tube for sample dilution. The inner diameter and length of this sample dilution introduction tube are determined in advance based on the m of the sample to be injected and the dilution ratio to be diluted in the introduction tube according to the purpose of analysis, and then incorporated into the automatic sample introduction device according to the present invention. It will be done.

A second automatic sample introduction device according to the present invention eliminates the injection port and is configured to change the position of the pump to flow the sample and diluent into the introduction tube by suction.

Note that sampling with the automatic sample introduction device according to the present invention is performed in the following procedure.

(1) First, a certain amount of sample is aspirated from the sample container using the dispensing nozzle.

(2) Next, insert the dispensing nozzle into the injection port, inject a certain amount of sample into the sample dilution introduction tube using the syringe pump,
Furthermore, when a diluent is fed from behind, the sample is dispersed in the diluent while flowing inside the introduction tube.

(3) When a specific area of the concentration distribution of the sample flowing while being dispersed reaches the sample introduction valve, the sample introduction valve is switched and introduced into the measuring tube of the sample introduction valve.

(4) Once a given sample area is held in the metering tube,
Switch the sample introduction valve again and introduce the sample into the analysis section.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

A first embodiment of an automatic sample introduction device according to the present invention will be described with reference to FIG. This example shows an example in which an automatic sample introduction device is applied to a liquid chromatograph.

First, the configuration of the device will be explained. In FIG. 1, the same elements as explained in FIG. 8 are given the same reference numerals.

In FIG. 1, an automatic sample introduction device 1 is provided with a sample stage 2, a cleaning tank 3, a drain port 4, and an injection port 6. Multiple samples to be measured are stored in multiple sample containers 7.
The sample containers 7 are arranged in a sample rack 8 and installed on the sample stage 2. The nozzle 9 is connected to a pump 12 via a thin tube 10 and a switching valve 11, and the pump 12 can be selectively connected to either the diluent tank 13 or the nozzle 9 by switching the switching valve 11. It is composed of

The nozzle 9 is moved to the position of each sample container or processing port by the drive mechanism 14 in the X-axis direction and the Y-axis direction, and performs necessary operations such as suction and discharge by the action of the pump.

In the analysis section 15, the reagent tanks 1 and 7 are pumped by the pump 16.
The configuration is such that any of the reagents a, 17b, and 17c selectively flows into the separation column 19 via the sample introduction valve 18. Solenoid valve 22a.

22b and 22c are provided to select reagents to be flowed into the separation column 19 as the analysis progresses. A sample dilution introduction pipe 23 that produces a dilution effect is provided between the injection port 6 and the sample introduction valve 18, and the sample diluted while passing through this pipe can be removed by switching the connection at the sample introduction valve 18. The sample is sent to the measuring tube 20, and by switching the sample introduction valve 18 again, the flow path 24 of the analysis section 15 is
, sent to the separation column 19 , and discharged to the drain tank 25 via the detector 21 . The introduction pipe 23 also serves as a diluter. The sample components separated by the separation column 19 are
It is measured while passing through the detector 21, and the measurement result is sent to the A/D
It is sent to the control unit 27 via the converter 26, processed by the control unit 27, displayed on the display device 28, and displayed on the printer 2.
9 is output.

As is clear from the above description, in the configuration of the automatic sample introduction device of the present invention, a sample dilution field having a predetermined length and capacity is provided between the injection port 6 and the sample introduction valve 18 without using a special dilution tank. An inlet tube 23 for diluting the sample is provided. For example, if this introduction tube 23 is filled with a diluent in advance and a sample is injected from the injection port 6, and then the dilution solution is continuously injected and delivered, the sample is diluted while flowing through the introduction tube 23. It is dispersed in the liquid and distributed by forming a concentration gradient in the flow. By metering a specific area of this concentration gradient using the metering tube 20 of the sample introduction valve 18 and introducing it into the analysis section, a trace amount of sampling at a desired dilution ratio is performed.

Next, before explaining the sampling procedure by the automatic sample introduction device 1 in detail, the principle of the automatic dilution sampling method according to the present invention will be explained with reference to FIGS. 2A to 2C.

As shown in FIG. 2A, when a sample liquid 42 (position A) is injected into a long and thin tube 41 in which a carrier liquid 40 is flowing as shown by the arrow, the sample liquid spreads in the tube 41 as a laminar flow while flowing into the carrier liquid 40. dispersed into If this state of dispersion is expressed as the length of the tube (or the volume of the sample liquid in the tube) on the horizontal axis and the concentration of the dispersed sample on the vertical axis, it will become a curve as shown in FIG. 2B or 2C. In FIGS. 2A to 2C, point A indicates the injection position, and point B indicates the center of dispersion of the sample 42' when it flows through the tube 41 for a length l. In an ideal channel system without dead space, the dispersion becomes a normal distribution as shown in FIG. 2B. The following equation is known as a theoretical equation expressing this dispersed state (JORNAL OF CII
ROMATOGRAPHIC5CIENCE VOL,
9).

Here, r is the inner radius of the tube, l is the length of the tube, each unit is cm, and Q is the flow rate of the liquid (sample liquid, etc.), the unit is 0.
m3/sec, DM is the diffusion coefficient of the sample liquid in cm
2/see, σ1 and σT' are constants generally defined as the standard error and variance of a normal distribution, and their units are Cl113 and Cm6, respectively.

The above formula is a theoretical formula derived based on several assumptions and limiting conditions, and does not necessarily match the actual value in the flow path system handled by the present invention.

However, in liquid chromatography, flow injection analysis methods, etc., the dispersion changes by changing the inner radius r1 length 11 of the tube and the flow rate Q of the sample liquid. Therefore, by appropriately controlling these values, the desired dispersion can be achieved. It is widely known that it can be obtained and reproduced with high precision.

In FIG. 2B, with peak position B of the dispersion curve as the origin, the amount of sample liquid dispersed in the section X1 to x2 (hatched area in the figure) from the origin is expressed by the following formula.

Here, ■ o is the amount of sample injected, and X is the coordinate of the dispersion curve in the flow direction of the tube. The function obtained by the indefinite integral in the above equation represents the volume of the sample liquid in the area from the origin to the distance X. Therefore, the dilution ratio R of the sample to the carrier liquid in the areas X1 to x2 is expressed by the following equation.

R=VO/ (X2-XI) (3) In an actual flow path system, the distribution of dispersion is not necessarily an accurate normal distribution, and for example, the influence of dead spaces in the flow cell where the measurement is performed and other flow path systems, etc. In this case, a tailing phenomenon as shown in Fig. 2C is often exhibited. Even in such a case, σ and σ7 can be obtained by calculation, but since it is complicated, the explanation here will be omitted.

The theoretical formula for dispersion in a capillary has been explained above, but in actual equipment, there are differences in the assumptions and limiting conditions in formula (1) above, it is difficult to obtain accurate values for the diffusion coefficients of sample liquid and carrier liquid, and it is difficult to Due to equipment-specific problems such as dead space in the road system, the actual value often does not necessarily match the calculated value from the theoretical formula. Therefore, when dispersing and diluting a sample liquid by flowing it in an actual device, conduct an experiment by assembling the device based on the conditions estimated from theoretical formulas etc., and then calculate the actual distribution curve of the device and σ1゜X,,X2.
It is desirable to determine a value such as

Next, the sampling procedure in the automatic sample introduction method according to the present invention will be explained in steps.

This sampling is the same as the conditions described above, with length e
Inject the sample liquid from the injection port 6 using the sample dilution introduction tube 23 with an internal volume of Vp. A case will be described in which the carrier liquid for dilution is injected at a flow rate Q and the analysis section 15 samples portions X and X2 in the concentration distribution of the sample dispersed in the state shown in FIG. 2B or FIG. 2C. Further, the explanation will be made using the flow state of the sample at the time of switching the sample introduction valve shown in FIGS. 3A to 3C.

(1) First, the sample introduction valve 18 is connected as shown in FIG. 3A, the nozzle 9 is moved to the position of the injection port 6, and the nozzle 9 is
Insert the tip of the syringe pump 12 into the injection port 6.
is operated to thoroughly clean the inside of the sample dilution introduction tube 23 so that no carryover of the sample previously passed remains, and then the introduction tube 23 is filled with a diluent.

(2) Next, move the nozzle 9 to the position of the sample container 7 to be analyzed, and apply a predetermined amount of V to the tip of the nozzle 9.

Aspirate the sample solution.

(3) Move the nozzle 9 again to the position of the injection port 6, insert it into the injection port 6, operate the syringe pump 12 to inject the sample, and pour the diluted liquid from behind at a flow rate of ff.
Only 1Vp+X is supplied.

(4) While the sample is flowing through the introduction tube 23, it is
Disperse in the state shown in Figure B or Figure 2C. Since the internal volume of the introduction pipe 23 is Vp, at the time when the diluent is flowed at a flow rate Vp,
The center of the dispersed sample reaches the connection point 33 between the sample dilution introduction pipe 23 and the sample introduction valve 18, and the portion Xl reaches the connection point 33 when Vp+X is flowing. The state is shown in FIG. 3A. The filled areas in FIG. 3A are the areas of the distribution curves X, to X2, and the preceding sample portion flows from the connection passage 34 to the discharge passage 35.

(5) In this state, when the sample introduction valve 18 is switched in the direction of the arrow in Fig. 3A and further the carrier liquid is fed by X2X, the areas X and -X of the distribution curve are connected as shown in Fig. 3B. It is sent from the passage 36 to the metering tube 20. As described above, the sample amount VD necessary for analysis is held in this area in a diluted state.

(6) When the sample introduction valve 18 is switched again to the state shown in FIG. 3C, the sample liquid held in the measuring tube 20 and the connecting passage 36 is introduced into the flow path 24 of the analysis section. During this time, the nozzle 9 moves to the wash port 3 to wash its outer wall, and the syringe pump 12 aspirates new diluent from the diluent reservoir 13, thereby waiting for sampling of the next sample.

Through the above steps (1) to (6), the sample injected from the injection port 6 can be diluted to a desired concentration, and a desired amount of sample can be sampled into the analysis section.

Figure 4 is an example of a program for the above-mentioned sampling procedure, Figure 4 (A) is a bar graph showing the work process over time, and Figure 4 (B) is a sample that moves as the work process progresses. It shows the operation timing of each function of the introduction valve 18, nozzle 9, and syringe pump 12.

The features of the apparatus and method of the present invention are that a sample dilution introduction pipe 23 is provided in the sample liquid injection flow path, and that the sample liquid is dispersed in the diluent in the flow. sampling a portion of the sample in a specific area of the concentration gradient.

In other words, as mentioned above, in conventional sample introduction devices, the volume of the flow path from the sample injection port to the sample introduction valve is made as small as possible, and a sufficient amount of sample is injected to replace the cleaning liquid remaining in the flow path. The basic method was to introduce it into the measuring tube. In contrast, the present invention is characterized in that it provides a sample dilution introduction tube 23 whose capacity is sufficiently larger than the amount of sample to be injected, and actively dilutes the sample.

The inner diameter and length of the sample dilution introduction tube 23 are determined in advance from the amount of sample to be injected into the injection port 6 and the desired dilution ratio.
incorporated into the device. Since the value does not necessarily match the above calculation formula, it is desirable to determine the actual value after confirming it by experiment. In order to increase the dilution ratio, it is more effective to increase the inner diameter and length of the introduction tube, but as the internal volume of the introduction tube increases, it takes time to clean the tube and the amount of cleaning liquid used increases. The tail part of the dispersion curve (second B
(See X1 to X2 in the figure and FIG. 2C) will increase the dilution factor, but the sampling accuracy will be lower than when sampling the peak portion of the dispersion curve.

Conversely, sampling at the peak portion of the dispersion curve improves sampling accuracy, but the dilution ratio decreases, and a large-capacity introduction tube is required to increase the ratio.

It is necessary to take these relationships into account to determine a channel system suitable for the purpose. From the experiment in this example, the inner diameter of the sample dilution introduction tube 23 was 0.5 to 1ff+n+, and the length was 0.5
~2n+, pump flow rate 1-3ml/min,
The appropriate amount of sample to be injected is 3 to 10 μl, and by determining the channel conditions within this range and appropriately selecting the sampling area of the dispersion curve, it is possible to sample at a dilution factor of several tens to hundreds of times. .

Next, modified embodiments of the present invention will be described.

FIG. 5 shows a second embodiment of the present invention, showing only the main parts.

Other configurations are the same as in the first embodiment.

In this embodiment, the sample is injected from the injection port 6 with the metering tube 20 of the sample introduction valve 18 connected to the sample dilution introducing tube 23, and the sample flows directly into the metering tube 20, so that a specific area of the sample is measured. This is a method in which feeding is stopped when the sample enters the tube 20, the sample introduction valve 18 is switched, and the sample is introduced into the analysis section 15. Although the area to be cut out is limited by the volume of the metering tube 20, there is an advantage that the sampling time can be shortened.

FIG. 6 shows a third embodiment of the present invention, showing only the main parts.

The other configurations are the same as the first embodiment.

In this embodiment, a small-volume stirrer 30 with a built-in magnetic stirrer rotor is installed in the sample dilution introduction tube 23, and although it takes time to clean the flow path, it is possible to obtain a high dilution ratio. has advantages.

FIG. 7 shows a fourth embodiment of the invention. In this example,
There is no injection port 6 required in the first embodiment, and the syringe pump 12 is also disposed at a position opposite to the sample introduction valve 18, and is configured to perform sampling by suction. The diluent port 31 is supplied with the diluent from the diluent tank 13 by the straining pump 32, and is always filled with the diluent. The sample is aspirated with the tip of the nozzle 9, and then the nozzle 9 is inserted into the diluent port 31. Following the sample, the diluent is aspirated with the syringe pump 12 and flows into the sample dilution inlet tube 23, thereby dispersing the dispersed sample. When the area of the desired concentration gradient reaches the measuring tube 20, the sample introduction valve 18 is switched to introduce the sample into the analysis section.

In this method as well, the same effects as the method of injecting from the injection port as in the above embodiment can be obtained.

All of the above-mentioned modified embodiments are included within the scope of the present invention.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, dilution is performed in the sample introduction channel, there is no need to provide a special dilution tank like in the conventional method, and the structure is simple and maintenance is easy.
The simple pre-dilution function allows sampling of extremely small amounts of samples, making it suitable not only as a sample introduction device for liquid chromatographs used for specific tasks in routine work such as clinical testing, but also as an option for general-purpose liquid chromatographs. Versatile.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of the first embodiment of the automatic sample introduction device according to the present invention, FIGS. 2A to 2C are diagrams for explaining the dilution method in the present invention in principle, and FIGS. Fig. 3C is a diagram for explaining the operation of the sample introduction valve, Fig. 4 is a time chart showing the sampling procedure, Fig. 5 is a main part configuration diagram showing the second embodiment of the present invention, and Fig. 6 is a diagram for explaining the operation of the sample introduction valve. Third invention
FIG. 7 is an overall configuration diagram showing a fourth embodiment of the present invention, and FIG. 8 is a configuration diagram of a conventional automatic sample introduction device. [Explanation of symbols] 1... Automatic sample introduction device 6 ・ ・ 7 ・ ・ 9 ・ ・ 12 ・ 13 ・ 16 ・ 18 ・ 19 ・ 20 ・ 21 ・ 23 φ 42' ・Injection port・Sample container・Nozzle, syringe pump, diluent tank, pump, sample introduction valve, separation column, measuring tube, detector, sample dilution introduction tube, injected sample, sample in specific area

Claims (3)

[Claims] (1) A certain amount of sample is fed from the inlet to a sample dilution introduction tube having a capacity sufficiently larger than the amount of sample to be introduced, and then a diluent is fed, and the sample is transferred to the introduction tube. dispersing the sample in the diluent while flowing through the inlet tube, and taking out a sample portion in a specific area of the sample concentration gradient formed in the flow in the introduction tube using a flow path switching valve;
An automatic sample introduction method characterized by feeding a carrier solution into a channel for analysis. (2) An injection port, a dispensing nozzle that aspirates the sample in the sample container and injects it into the injection port, and a pump that is connected to this dispensing nozzle and supplies diluent to the dispensing nozzle from the rear. , an automatic sample introduction device comprising a sample introduction valve that measures the sample injected from the injection port with a measuring tube and introduces the sample into the analysis section, the sample being injected between the injection port and the sample introduction valve; A sample dilution inlet tube with a capacity sufficiently larger than the amount of sample dilution is provided, the diluent is fed from behind the injected sample, and the sample is dispersed in the diluent as the flow inside the inlet tube. An automatic sample introduction device characterized in that a sample portion in a specific area of a sample concentration gradient is taken out by the sample introduction valve and introduced into an analysis section. (3) A sample suction nozzle, a sample introduction valve that measures the inhaled sample with a measuring tube and introduces it into the analysis section, and the sample suction nozzle sucks in the sample from the sample container and sends it to the sample introduction valve. In an automatic sample introduction device equipped with a suction pump,
A sample dilution introduction tube having a capacity sufficiently larger than the amount of sample to be aspirated is provided between the sample suction nozzle and the sample introduction valve, and a diluent tank into which the sample suction nozzle can be inserted is provided, and the sample is inhaled. A diluted liquid is sucked in and fed from behind the sample, and a sample portion in a specific area of a sample concentration gradient formed by the sample being dispersed in the diluted liquid with the flow within the introduction interval is introduced into the sample. An automatic sample introduction device characterized by taking out a sample using a valve and introducing it into an analysis section.