Analyzing device and method for controlling same

An analyzing device includes a feeder connected to a container in which a sample is contained for sucking the sample from the container and feeding the sample, and a controller for performing control for feeding from the feeder to a measurer. In measuring the sample, the controller performs control so that results of a plurality of times of measurement are obtained with respect to the single container in which the sample is contained, without changing the container. This arrangement allows quick accuracy check.

INCORPORATION BY REFERENCE

This application is a 371 of International Application No. PCT/JP2009/067217 filed Oct. 2, 2009, which claims priority to Japanese Patent Application No. 2008-258703 filed Oct. 3, 2008, the entire contents of which being hereby incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to an analyzing device used as an analysis means in the field of biochemistry, medicine and the like. The invention also relates to a control method for checking the accuracy of such a device. The invention is particularly related to liquid chromatography.

BACKGROUND ART

In recent years, liquid chromatography devices are often used for sample analysis in the field of organic chemistry, biochemistry, medicine or the like. An example of a liquid chromatography device is disclosed in e.g. Patent Document 1.FIG. 5shows the structure of a typical liquid chromatography device. The illustrated liquid chromatography device X includes a column91, a detector92, a liquid feed pump93, an injection valve94, a sample suction nozzle95and a suction unit96. The liquid feed pump93is attached to a mobile phase container B containing a mobile phase such as an eluant and can feed the eluant to the column91via the injection valve94. The sample suction nozzle95is attached to a sample container C containing a sample. The suction unit96is used to draw the sample into the injection valve94.

The liquid chromatography device X is controlled by a controller, not shown. The controller controls the device so that the eluant is fed by the liquid feed pump93into the column91after the sample drawn into the injection valve94is adsorbed to the filler in the column91and then measurement is performed by the detector92. The sample adsorbed to the filler is desorbed by the eluant and separated into components within the column91. The detector92detects each separated component by e.g. measuring the absorbance.

With respect to such a liquid chromatography device X, the measurement accuracy of the device needs to be regularly checked for stable working of the device. For instance, to check the accuracy, two sample containers C one of which contains a sample of a known higher concentration and the other one of which contains a sample of a known lower concentration are prepared, and concentration measurement is performed with respect to each sample container under the above-described control by the controller, to check if correct measurement result corresponding with the known concentration is obtained with respect to each container. In a clinical site, for example, such accuracy check needs to be performed in the morning, during which a lot of other works need to be done. Thus, it is desirable that the accuracy check can be completed quickly. However, with the conventional liquid chromatography device X, the measurement for accuracy check takes much time, because the nozzle or the like needs to be cleaned every time the sample is changed.

Moreover, to check the accuracy of the device more precisely, the measurement of a sample of a known concentration for such accuracy check is usually performed a plurality of times, e.g. three times, with respect to each concentration. To perform measurement a plurality of times with the liquid chromatography device X, a large number of sample containers need to be prepared, which requires much time for sample preparation and much cost.Patent Document 1: JP-A-H10-96715

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

The present invention has been proposed under the circumstances described above. It is therefore an object of the present invention to provide an analyzing device which allows quick accuracy check and reduction in cost for accuracy check, and to provide a controlling method for the device. The invention particularly relates to a problem with a liquid chromatography device, among various analyzing devices.

Means for Solving the Problem

According to a first aspect of the present invention, there is provided an analyzing device comprising: a feeder connected to a container in which a sample is contained, where the feeder is configured to suck the sample from the container and feeding the sample; and a controller for performing control for feeding the sample from the feeder to a measurer. In measuring the sample, the controller performs control so that results of a plurality of times of measurement are obtained with respect to the single container in which the sample is contained, without changing the container.

In a preferred embodiment of the present invention, the feeder includes a tubular portion capable of retaining in it the sample of an amount necessary for two or more times of measurement. The controller first performs control so that part of the sample retained by the feeder is fed to the measurer, and then, after a single time of measurement, the controller performs control so that at least part of the remaining sample retained by the feeder is fed to the measurer.

In a preferred embodiment of the present invention, the analyzing device comprises a liquid chromatography device in which: the measurer includes a column containing a filler, and an injection valve capable of introducing a predetermined amount of sample into the column and also capable of feeding a mobile phase into the column, the measurer being configured so that the sample adsorbed to the filler is desorbed by the mobile phase and an effluent thereby produced is subjected to measurement for obtaining measurement results; the feeder is configured to feed the sample to the injection valve; and in checking accuracy by using a sample of a known concentration as the sample, the controller performs control so that results of a plurality of times of measurement are obtained with respect to the single container in which the sample of the known concentration is contained, without changing the container.

In a preferred embodiment of the present invention, the feeder includes a tubular portion capable of retaining in it the sample of an amount necessary for two or more times of measurement as a result of a single time of suction of the sample from the container. The controller first performs control so that part of the sample retained by the feeder is fed to the column via the injection valve, and then, after a single time of measurement, the controller performs control so that at least part of the remaining sample retained by the feeder is fed to the column via the injection valve.

According to a second aspect of the present invention, there is provided a method of controlling an analyzing device comprising a feeder connected to a container in which a sample is contained for sucking the sample from the container and feeding the sample, and a measurer to which the sample is fed from the feeder. The method comprises performing control, in measuring the sample, so that results of a plurality of times of measurement are obtained with respect to the single container in which the sample is contained, without changing the container.

In a preferred embodiment of the present invention, the feeder includes a tubular portion capable of retaining in it the sample of an amount necessary for two or more times of measurement. The method comprises first performing control so that part of the sample retained by the feeder is fed to the measurer, and then, after a single time of measurement, performing control so that at least part of the remaining sample retained by the feeder is fed to the measurer.

In a preferred embodiment of the present invention, the analyzing device comprises a liquid chromatography device in which: the measurer includes a column containing a filler, and an injection valve capable of introducing a predetermined amount of sample into the column and also capable of feeding a mobile phase into the column, the measurer being configured so that the sample adsorbed to the filler is desorbed by the mobile phase and an effluent thereby produced is subjected to measurement for obtaining measurement results; and the feeder is configured to feed the sample to the injection valve. The method comprises performing control, in checking accuracy by using a sample of a known concentration as the sample, so that results of a plurality of times of measurement are obtained with respect to the single container in which the sample of the known concentration is contained, without changing the container.

In a preferred embodiment of the present invention, the feeder includes a tubular portion capable of retaining in it the sample of an amount necessary for two or more times of measurement. The method comprises first performing control so that part of the sample retained by the feeder is fed to the column via the injection valve, and then, after a single time of measurement, performing control so that at least part of the remaining sample retained by the feeder is fed to the column via the injection valve.

Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1is a structural view showing an example of liquid chromatography device according to the present invention. The liquid chromatography device A shown inFIG. 1includes a column1, a detector2, a liquid feed pump3, an injection valve4, a feeder5and a controller6. The liquid chromatography device A separates a sample into components for analysis by using an eluant8, which is a mobile phase.

The column1contains filler for adsorbing a sample7introduced into the column. After the sample7is adsorbed to the filler, the eluant8is introduced into the column1, whereby the adsorbed sample7is desorbed by the eluant8. The desorbed sample7and the eluant8flow through the column1as an effluent and are then discharged.

The detector2performs e.g. measurement of absorbance with respect to the effluent flowing in the column1to analyze the components of the sample7.

The liquid feed pump3is attachable to a mobile phase container B and feeds the eluant8from the mobile phase container B to the column1under control by the controller6. The liquid feed pump3is also used to feed the sample7within the injection valve4to the column1.

The injection valve74comprises e.g. a six-way valve and includes ports4a,4b,4c,4d,4f,4gand an injection loop4e. The valve further includes individual fluid paths between the ports4aand4b, between the ports4cand4f, and between the ports4dand4g. Portions of the injection valve4except the injection loop4eare rotatable under control by the controller6so that connection target of the ports4a,4b,4c,4d,4f,4gcan be changed. In order for the liquid feed pump3to feed the eluant8to the column1, the port4ais connected to the liquid feed pump3, whereas the port4bis connected to the column1. In this state, the eluant8flows into the column1through the fluid path between the ports4aand4b. The injection loop4eis configured to connect the ports4fand4dor the ports4aand4d. The injection loop4eis capable of storing a sample7of a predetermined amount necessary for a single time of measurement. For instance, the amount of the sample7necessary for a single time of measurement is 5 μm.

The feeder5is provided to feed the sample7from the sample container C to the injection valve4under control by the controller6and includes a sample suction nozzle Sa, a tubular portion5band a suction unit Sc. For instance, 400 μL of sample7is stored in the sample container C. The sample suction nozzle5ais attached to the sample container C to draw the sample7into the tubular portion5b. In the state shown inFIG. 1, the port4cis connected to the tubular portion5b, whereas the port4dis connected to the suction unit5c. The tubular portion5bis capable of storing the sample7of an amount necessary for at least three times of measurement, and has a volume of e.g. about 400 μL. The suction unit5cdraws the sample7through the sample suction nozzle5ainto the tubular portion5bunder control by the controller6. The suction unit5cfurther draws the sample7stored in the tubular portion5binto the injection loop4econnected to the ports4fand4gof the injection valve4.

Apart from the control during normal measurement, the controller6is capable of performing special control for checking the accuracy of the liquid chromatography device A. The accuracy check is performed by measuring the concentration of a sample7of a known concentration three times and checking whether the measurement results correspond with the known concentration. The control method for this accuracy check is described below with reference toFIGS. 2-4.

First, as shown inFIG. 2, the controller6causes the suction unit5cto draw the sample7of an amount necessary for three times of measurement from the sample container C into the tubular portion5bthrough the sample suction nozzle5a. Then, the controller6causes the suction unit5cto draw part of the sample7from the tubular portion5binto the injection loop4e. By this, the sample of an amount necessary for two times of measurement is left in the tubular portion5b.

Then, as shown inFIG. 3, the controller6causes the injection valve4to rotate through60degrees so that the port4gis connected to the column1, the port4bis connected to the feed pump3, the port4cis connected to the suction unit5c, the port4fis connected to the tubular portion5b, and the ports4aand4dare connected to the injection loop4e. This connection establishes a flow path for the eluant8to flow into the column1through the feed pump3and the injection loop4e. Then, the controller6causes the feed pump3to dispense the eluant8drawn from the mobile phase container B, thereby causing the sample7in the injection loop4eto be sent into the column1. Then, after the sample7is adsorbed to the filler in the column1, the controller6causes the injection valve4to rotate through60degrees so that the port4bis connected to the column1, the port4ais connected to the liquid feed pump3, the port4dis connected to the suction unit5c, the port4cis connected to the tubular portion5b, the ports4fand4gare connected to the injection loop4e. Then, the controller6causes the feed pump3to send the eluant8from the mobile phase container B into the column1. The eluant8sent into the column1desorbs the sample7from the filler, whereby effluent is obtained. The effluent is subjected to measurement by the detector2, whereby the result of the first time of measurement is obtained.

Then, as shown inFIG. 4, the controller6causes the suction unit5cto draw part of the sample7remaining in the tubular portion5binto the injection loop4e. By this, the sample of an amount necessary for a single time of measurement is left in the tubular portion5b. At this time, since the sample7is not a newly drawn sample, cleaning of the injection loop4eis not necessary. Thereafter, measurement is performed under the same control as that for the first time of measurement, whereby the result of the second time of measurement is obtained.

Thereafter, similarly to the above, the third time of measurement is performed using the sample7remaining in the tubular portion5b.

The advantages of the liquid chromatography device A are described below.

According to the present embodiment, measurement for accuracy check can be performed three times using a single sample container C. Thus, it is not necessary to prepare a lot of sample containers C for accuracy check. Thus, the liquid chromatography device A considerably saves the effort for the accuracy check and also reduces the cost for the accuracy check.

According to the present embodiment, cleaning work, which usually takes a lot of effort and time, does not need to be performed even a single time before the three times of measurement is completed. Thus, the effort and time taken for the accuracy check is considerably saved. Thus, the liquid chromatography device A allows quick accuracy check.

According to the present embodiment, once the sample7is sucked, three times of measurement can be performed, without the need for sucking the sample again. Thus, the accuracy check can be performed efficiently, and the time taken for the accuracy check is considerably reduced. This also contributes to the quick accuracy check of the liquid chromatography device A with reduced cost.

According to the present embodiment, the tubular portion5bis commonly used as the feeding path for the sample7and as the sample storage portion during the accuracy check. Thus, the liquid chromatography device A does not require any special structural member used exclusively for the accuracy check.

The analyzing device according to the present invention is not limited to the foregoing embodiment. The specific structure of each part of the analyzing device according to the present invention may be varied in design in many ways. For instance, although the tubular portion5bis configured to store the sample7of the amount necessary for three times of measurement in the foregoing embodiment, the tubular portion may be configured to store the sample necessary for the measurement of any number of times greater than two. The portion for storing the sample between the sample suction nozzle5aand the injection valve4is not limited to a tubular one, and e.g. a storage tank may be provided instead.