JP2006317307A - Sample separation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sample separation device capable of shortening a pretreatment time, while keeping liquid circulation speed wherein a metal can be captured sufficiently into a solid-phase extraction column. <P>SOLUTION: A storage vessel storing conditioning solution 1 is connected to six-way valves 2, 3 through a pump 10 by a liquid sending pipe. The six-way valves 2, 3 are connected mutually in parallel with respect to the pump 10. A storage container storing a measuring sample 7 is connected to the six-way valves 2, 3 through a pump 12 by the liquid sending pipe. The six-way valves 2, 3 are connected mutually in parallel with respect to the pump 12. A storage container storing nitric acid 8 is connected to the six-way valve 2 through a pump 11 by the liquid sending pipe. When supplying the conditioning solution and measuring sample solution to a separation column, the pretreatment time can be shortened, while keeping the liquid circulation speed at the speed wherein the metal can be captured sufficiently, because supply is performed by connecting a plurality of separation columns in parallel. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sample separation apparatus using a solid phase extraction method.

  An example in which a trace metal in river water is pretreated by a solid phase extraction method in a sample separation apparatus used in a liquid chromatograph apparatus or the like will be described.

  Ammonium acetate is added to the river water sample to be pretreated, and the pH is adjusted to an optimum pH so that the target metal can be captured by the solid phase extractant with nitric acid or ammonia. The solid phase extraction column is then conditioned and washed in the order of an organic solvent (acetone, acetonitrile, etc.), ultrapure water, nitric acid, and ultrapure water.

  Here, the previously prepared sample solution is flowed at a constant flow rate, and the target metal is captured by the solid phase extraction agent. After passing through the sample, washing is performed by passing a cleaning solution such as ultrapure water, and finally, nitric acid is passed through to elute the captured metal to obtain a pretreated sample solution.

  In the technique described in Patent Document 1, two separation columns are connected in series to separate and analyze a small amount of sample in a large amount of specimen.

  In the technique described in Patent Document 2, a low pressure column and a high pressure column are connected in series with each other in order to separate a large amount of a high concentration target component at high speed.

JP-A-2-141659 Japanese Patent Laid-Open No. 62-191760

  In the sample separation device used in the liquid chromatograph, when pre-processing the sample by the solid phase extraction method, the liquid properties (pH, etc.) of the sample are adjusted so as to be optimal for the solid phase extraction. Then, it is passed through the solid phase extraction column at a constant speed. This liquid passing speed needs to be a speed at which the metal is sufficiently captured by the solid phase extraction column.

  Therefore, when the sample has a large capacity, the pretreatment time becomes long, and as a result, the sample analysis processing time becomes long.

  In addition, when the pretreatment time becomes long, there is a high possibility that dust existing in the pretreatment chamber or the like is mixed into the sample and metal contamination occurs. In this case, the reliability of the analysis value of the measurement sample after the pretreatment is lowered.

  In addition, when a large volume of sample is passed through the column, there are metals (Al, Mo, etc.) that cause the trapped metal to elute by the sample itself that passes through, reducing the recovery rate of the target metal and analyzing it. The result might be lower than the true value.

  An object of the present invention is to realize a sample separation apparatus capable of shortening the pretreatment time while maintaining a liquid passing speed at which the metal is sufficiently captured by the solid phase extraction column.

  In the present invention, a plurality of separation columns (solid phase extraction columns) are supplied with a conditioning solution and a measurement sample in order to shorten the pretreatment time when the sample is large in volume or to suppress the elution of captured metal by the sample itself. At this time, they are connected in parallel.

  As a result, the amount of sample passed through one separation column is 1/2 if there are two columns, and 1/3 if it is 3, so that the amount of sample per one can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the sample separation apparatus which can shorten pre-processing time can be implement | achieved, maintaining the liquid flow rate by which the metal is fully capture | acquired by the separation column.

  In addition, the phenomenon in which the captured metal is eluted by the sample itself can be suppressed, and the recovery rate can be further improved.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
1 to 3 are schematic configuration diagrams of a sample separation apparatus according to the first embodiment of the present invention.

  In the first embodiment, the two separation columns (solid phase extraction columns) 5 and 6 are connected in parallel to each other for supplying the measurement sample and the conditioning solution, and for supplying the metal eluent. On the other hand, they are connected in series with each other.

  FIG. 1 shows a state in which the solid phase extraction column is conditioned. In FIG. 1, the storage container in which the conditioning solution 1 is stored is connected to the six-way valves 2 and 3 through a pump 10 by a liquid supply pipe. These six-way valves 2 and 3 are connected to the pump 10 in parallel with each other.

  In addition, the storage container in which the measurement sample 7 is stored is connected to the hexagonal valves 2 and 3 by a liquid feeding pipe via the pump 12. These six-way valves 2 and 3 are connected to the pump 12 in parallel.

  Further, the storage container in which nitric acid 8 is stored as an eluent is connected to the hexagonal valve 2 through a pump 11 by a liquid supply pipe.

  The six-way valve 2 is connected to the six-way valve 4 via a separation column 5, a six-way valve 3, and a separation column 6.

  In the above configuration, first, the operation of a control device (not shown) rotates the six-way valves 2, 3, 4 so that the conditioning solution 1 can be passed through the columns 5, 6 using the pump 10. The pump 10 is connected to the separation columns 5 and 6 so that the liquid is discharged from the column 5 and is also discharged from the column 6.

  As described above, since the six-way valves 2 and 3 are connected to the pump 10 in parallel with each other, the conditioning of the columns 5 and 6 can be performed independently and simultaneously.

  Here, conditioning means that an organic solvent (acetone, acetonitrile, etc.), ultrapure water, nitric acid, and ultrapure water are passed through the solid phase extraction columns 5 and 6 to prepare for capture of the target metal.

  After the conditioning shown in FIG. 1 is performed, sample loading is performed. FIG. 2 shows a state in which sample loading is performed.

  In FIG. 2, a hexagonal valve 2, 3, 2, 3, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 4 is rotated, the pump 12 and the separation columns 5 and 6 are connected, and the waste liquid is set from each of the columns 5 and 6.

  As described above, since the six-way valves 2 and 3 are connected to the pump 12 in parallel with each other, the supply of the measurement sample (sample load) of the columns 5 and 6 can be performed independently and simultaneously. it can.

  In addition, when analyzing the component which is not capture | acquired by the columns 5 and 6, the sample solution eluted in the container etc. is ensured, or it introduce | transduces into the apparatus which can analyze the component, and performs analysis.

  In the illustrated example, the number of columns is two, but the preprocessing time can be changed depending on the number of columns connected in parallel.

  In this case, since the amount of sample passed through one column can be reduced, the phenomenon that the captured metal elutes by the sample solution itself can be suppressed.

  Also, if two or more columns connected in series are connected in parallel, the second and subsequent columns can be used as a backup for metal with a low capture rate.

  After the sample loading shown in FIG. 2 is performed, metal elution is performed. FIG. 3 shows a state where metal elution is performed.

  In FIG. 3, a hexagonal valve 2, 3 so that a solution (nitric acid) 8 for eluting the metal trapped in the columns 5, 6 is passed through the columns 5, 6 by the operation of a control device (not shown). 4, the pump 11 is connected to the separation columns 5 and 6, and the post-treatment sample 9 is discharged from each of the columns 5 and 6 and collected in a container such as a vial. Alternatively, the processed sample 9 is directly introduced into an apparatus capable of detecting and measuring the component and analyzed.

  In this metal elution method, since the columns 5 and 6 are connected in series with each other, the captured metal can be eluted with the amount of nitric acid for one column.

  However, since the concentration of nitric acid decreases each time the column is passed through, it is necessary to increase the concentration of nitric acid when the number of columns increases.

  4 to 5 are tables showing recovery rates when elements are recovered by applying the present invention. Table 1 shown in FIG. 4 shows three results obtained by connecting two solid-phase extraction columns, passing 3 mol / L nitric acid, eluting the captured metal, and obtaining the recovery rate.

  In the case of a solid phase extraction method for capturing a metal, generally, the acceptable range of the recovery rate is considered to be 100 ± 10%, but the recovery rate was 88 to 94% for any element, which was a good result.

  Table 2 shown in FIG. 5 shows three results obtained by connecting three solid-phase extraction columns, passing 3 mol / L nitric acid, eluting the captured metal, and obtaining the recovery rate.

  Considering an allowable range of 100 ± 10% for recovery, the recovery rate was 52% to 77%, which was lower than the allowable range. This is presumably because nitric acid was diluted with water remaining in the column and elution was not sufficiently performed.

  Therefore, Table 3 in FIG. 6 shows the results of obtaining the recovery rate using 12 mol / L nitric acid (concentrated nitric acid) in the same manner using three solid-phase extraction columns.

  By using 12 mol / L nitric acid (concentrated nitric acid), the recovery rate, which was low with 3 mol / L nitric acid, was 89 to 113%, which was almost within the allowable range of the recovery rate.

  It is important that the concentration of nitric acid used for cleaning is equal to or higher than the concentration of nitric acid used as an eluent. In order to suppress the loss of recovery rate due to dilute nitric acid concentration when multiple columns are connected, it is considered that the concentration of nitric acid flowing into the last column should be 3 mol / L or more.

  Next, the approximate number of columns that can be connected in a serial system when supplying the eluent will be described.

  However, the concentration of nitric acid for eluent is C (mol / L), the flow rate of nitric acid for elution is V (mL), the amount of nitric acid remaining in the column x stage is Yx (mL), and the 1st to x stages Let Vx be the total amount of nitric acid remaining.

  Yx is a function of x, and indicates the amount when converted into the concentration of nitric acid for elution because nitric acid is diluted with water contained in the column and the concentration changes each time the number of stages is increased.

  Vx can be expressed by the following formula (1). However, as a condition, the amount of water remaining in the column does not change before and after the passage of nitric acid.

Further, the concentration C _{x + 1} of nitric acid flowing into the x + 1 stage column can be expressed by the following equation (2).

If C _{x + 1} C is 3 mol / L or more, it is considered that the captured metal can be sufficiently eluted, so that it is considered that the columns can be connected in series by the number of stages satisfying the following formula (3).

  As described above, according to the first embodiment of the present invention, when the conditioning solution and the measurement sample solution are supplied to the separation column, the plurality of separation columns are connected in parallel and supplied. The pretreatment time can be shortened while maintaining the flow rate of the conditioning solution and the measurement sample solution through the separation column at a rate at which the metal is sufficiently captured.

  In addition, a liquid chromatograph apparatus using this sample separation apparatus can be realized.

  Next, a second embodiment of the present invention will be described with reference to FIGS.

  7-9 is a schematic block diagram of the sample separation apparatus which is the 2nd Embodiment of this invention.

  In this second embodiment, the three separation columns (solid phase extraction columns) 16, 17, and 18 are connected in parallel to each other for supplying the measurement sample, supplying the conditioning solution, and supplying the eluent. Is done.

  FIG. 7 shows a state in which the solid phase extraction column is conditioned. In FIG. 7, the storage container in which the conditioning solution 13 is stored is connected to the six-way valve 14 through a pump 22 by a liquid supply pipe.

  In addition, the storage container in which the measurement sample 19 is stored is connected to the hexagonal valve 14 via a pump 23 by a liquid feeding pipe.

  In addition, the storage container in which nitric acid 20 is stored as an eluent is connected to the six-way valve 14 via a pump 24 by a liquid supply pipe.

  The six-way valve 14 is connected in parallel to the six-way valve 15 via separation columns 16, 17, and 18. An adapter that can branch as many as the number of columns connected in parallel is installed between the hexagonal valve 14 and the columns 16, 17, and 18.

  In the above configuration, first, the operation of a control device (not shown) rotates the hexagonal valve 14 so that the solution can be passed through the columns 16, 17, and 18 using the conditioning solution 13 pump 22, and the pump 22 The separation columns 16, 17, and 18 are connected and set to be drained through the six-way valve 15.

  As described above, since the columns 16, 17, and 18 are connected to the pump 22 in parallel with each other, the conditioning can be performed independently and simultaneously.

  After the conditioning shown in FIG. 7 is performed, sample loading is performed. FIG. 8 shows a state in which sample loading is performed.

  In FIG. 8, the hexagonal valve 14 is set so that the measurement sample 19 whose pH is optimally adjusted in advance can be passed through the columns 16, 17, and 18 using the pump 23 by the operation of the control device (not shown). Rotate, connect the pump 23 and the separation columns 16, 17, 18, and set the six-way valve 15 so that the liquid is discharged from the columns 16, 17, 18.

  As described above, since the columns 16, 17, and 18 are connected to the pump 23 in parallel with each other, the supply of the measurement samples (sample loads) of the columns 16, 17, and 18 can be performed independently of each other at the same time. It can be carried out.

  When analyzing components that are not captured by the columns 16, 17, and 18, the sample solution eluted in a container or the like is ensured, or introduced into an apparatus that can analyze the components and analyzed.

  In addition, the preprocessing time can be changed by changing the number of parallel columns. Further, if the columns are arranged in parallel or the number of figures is increased, the amount of the sample that passes through one column decreases, so that the phenomenon that the captured metal elutes by the sample solution itself can be suppressed.

  Further, if two or more columns connected in series are used for each of the columns 16, 17 and 18, that is, if they are in a series-parallel state, the second and subsequent columns can be used as a backup for metals with a low capture rate. You can also

  After the sample loading shown in FIG. 8 is performed, metal elution is performed. FIG. 9 shows a state where metal elution is performed.

  In FIG. 9, a solution (nitric acid) 20 for eluting the metal trapped in the columns 16, 17, 18 is passed through the columns 16, 17, 18 by the operation of a control device (not shown). The valve 14 is rotated, the pump 24 is connected to the separation columns 16, 17, and 18, and the valve 15 is set so as to be collected in a container such as a vial as the processed sample 21. Alternatively, the processed sample 21 is directly introduced into an apparatus capable of detecting and measuring the component and analyzed.

  As described above, also in the second embodiment of the present invention, the same effect as that of the first embodiment can be obtained.

  If the parallel method is used, the metal elution nitric acid 20 flows to the columns 16, 17, and 18, so that the metal can be eluted at a nitric acid concentration of 3 mol / L regardless of the number of columns.

  However, since nitric acid passes through any column, the final sample amount varies depending on the number of columns, and the concentration rate is lower than that in the serial system.

Thus, the proper use of the serial method and the parallel method of the present invention in metal elution will be described.
In the serial system, the number of columns that can be connected is limited, but regardless of the number of columns used, finally the captured metal can be eluted with the amount of nitric acid eluted for one column.

  Therefore, it is optimal for samples that want to be collected at a high concentration rate.

  On the other hand, in the parallel system, since the eluted nitric acid is simultaneously passed through each of the connected columns, the amount of sample finally obtained increases in proportion to the number of connected columns.

  Therefore, although the concentration rate cannot be as high as that of the in-line method, it is optimal for a sample having a large amount of sample and a high concentration rate.

  By using these properly, it can be applied to all samples.

  Therefore, for supplying the conditioning solution and the measurement sample, it is connected in parallel to a plurality of columns. For supplying the eluent, whether the plurality of columns are connected in parallel or in series. Can be configured to be switchable.

  For example, a series / parallel switching valve is disposed in the flow path between the pump 11 and the hexagonal valve 2 in FIG. 1, and the columns 5 and 6 are connected in parallel to the series / parallel switching valve. And when supplying the eluent to the columns 5 and 6, the flow path is switched by the series-parallel switching valve so that the plurality of columns can be switched between parallel connection and series connection. Can do.

It is a figure which shows the state of the conditioning in the 1st Embodiment of this invention. It is a figure which shows the state of the sample load in the 1st Embodiment of this invention. It is a figure which shows the state of the metal elution in the 1st Embodiment of this invention. It is a table | surface which shows an example of the elution execution result in the 1st Embodiment of this invention. It is a table | surface which shows the other example of the elution execution result in the 1st Embodiment of this invention. It is a table | surface which shows the further another example of the elution execution result in the 1st Embodiment of this invention. It is a figure which shows the state of the conditioning in the 2nd Embodiment of this invention. It is a figure which shows the state of the sample load in the 2nd Embodiment of this invention. It is a figure which shows the state of the metal elution in the 2nd Embodiment of this invention.

Explanation of symbols

1,13 Conditioning solution 2,3,4 Hexagonal valve 5,6 Solid phase extraction column 7,19 Measurement sample solution 8,20 Nitric acid for metal elution 9,21 Sample after pretreatment 10,11,12 Pump 14,15 Hexagonal valve 16, 17, 18 Solid phase extraction column 22, 23, 24 Pump

Claims (15)

A liquid sample mixed with the target substance is passed through the separation column by the sample feeding means, the target substance is trapped in the separation column, and the eluent is passed through the separation column by the eluent feeding means, and captured. In a sample separation device for eluting the target substance released from the separation column,
A sample separation apparatus, wherein a plurality of separation columns are connected in parallel to the sample liquid feeding means.   2. The sample separation apparatus according to claim 1, further comprising conditioning solution feeding means for passing a conditioning solution through the separation column, wherein the plurality of separation columns are connected in parallel to the conditioning solution feeding means. A sample separation device.   3. The sample separation apparatus according to claim 2, wherein the plurality of separation columns are connected in parallel to the sample liquid feeding means and the conditioning solution liquid feeding means, and are connected in series to the eluent liquid feeding means. A sample separation device comprising first connection switching means for connection.   3. The sample separation device according to claim 2, wherein the plurality of separation columns are connected in parallel to the sample liquid feeding means, the conditioning solution liquid feeding means, and the eluent liquid feeding means. Sample separation device.   3. The sample separation apparatus according to claim 2, further comprising a second connection switching unit that switches whether the plurality of separation columns are connected in series or in parallel to the eluent liquid feeding unit. A sample separation device.   3. The sample separation apparatus according to claim 2, wherein a plurality of series sets each including a plurality of separation columns connected in series with each other are provided, and the plurality of series sets are connected in parallel to the sample liquid feeding means. A sample separation device.   7. The sample separation apparatus according to claim 6, wherein the plurality of series sets are connected in parallel to the sample liquid feeding means and the conditioning solution liquid feeding means, and are connected in series to the eluent liquid feeding means. A sample separation device comprising first connection switching means for connection.   7. The sample separation apparatus according to claim 6, wherein the plurality of series groups are connected in parallel to the sample liquid feeding means, the conditioning solution liquid feeding means, and the eluent liquid feeding means. Sample separation device.   7. The sample separation apparatus according to claim 6, further comprising a second connection switching unit that switches whether the plurality of series sets are connected in series or in parallel to the eluent liquid feeding unit. A sample separation device. A liquid sample mixed with the target substance is passed through the separation column by the sample feeding means, the target substance is trapped in the separation column, and the eluent is passed through the separation column by the eluent feeding means, and captured. In a liquid chromatograph that elutes the target substance separated from the separation column and analyzes the eluted multi-purpose substance,
A liquid chromatograph apparatus, wherein a plurality of separation columns are connected in parallel to the sample liquid feeding means. A liquid sample mixed with the target substance is passed through the separation column by the sample feeding means, the target substance is trapped in the separation column, and the eluent is passed through the separation column by the eluent feeding means, and captured. In a sample separation method for eluting the target substance released from the separation column,
A sample separation method, wherein a plurality of separation columns are connected to each other in parallel to the sample liquid feeding means, and the supply of the sample is started almost simultaneously to the plurality of separation columns.   12. The sample separation method according to claim 11, wherein the plurality of separation columns are connected in parallel to a conditioning solution feeding means for passing a conditioning solution through the separation column, and the conditioning solution is supplied to the plurality of separation solutions. A method for separating a sample, which is started almost simultaneously with a separation column.   12. The sample separation method according to claim 11, wherein the plurality of separation columns are connected in parallel to the sample liquid feeding means and the conditioning solution liquid feeding means, and are connected in series to the eluent liquid feeding means. A sample separation method comprising: connecting and supplying the sample, the conditioning solution, and the eluent to the plurality of separation columns.   12. The sample separation method according to claim 11, wherein the plurality of separation columns are connected in parallel to the sample feeding means, the conditioning solution feeding means, and the eluent feeding means, so that the sample and the conditioning solution are mixed. And a sample separation method, wherein an eluent is supplied to the plurality of separation columns.   12. The sample separation apparatus according to claim 11, wherein the plurality of separation columns are switched to be connected in series or in parallel to the eluent liquid feeding means, and the eluent is separated into the plurality of separation liquids. A sample separation method comprising supplying to a column.

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