JPH01217257A - Background remover - Google Patents

Abstract

PURPOSE:To obtain a background remover for analysis of anions with a simple construction, by laminating cation exchange films and sheets having grooves each filled with a spherical substance on both sides of a sheet having a groove filled with a spherical substance. CONSTITUTION:A first sheet 2 made of, for example, rubber provided with a groove 2a at the center thereof, a second sheet 3 comprising a cation exchange film, a third sheet 4 made of, for example, rubber provided with a groove 4a at the center thereof, a fourth sheet 5 comprising a cation exchange film and a fifth sheet made of, for example, rubber provided with a groove 6a at the center thereof are laminated sequentially. Here, the grooves 2a, 4a and 6a are filled with a spherical filler, for example, a cation exchange resin. The laminated body thus obtained is sandwiched, for example, by acrylic substrates 1 and 7 on both sides thereof. The background remover thus obtained runs an eluate from a separation column of an anion analyzer to the groove 4a and a removing liquid of H2SO4 or the like to the grooves 2a and 6a, thereby enabling efficient removal of cations in an eluate.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is installed in an anion analyzer for analyzing anions in a liquid to be measured, and detects the conductivity background of the eluate from the separation column or the sample solution itself. The present invention relates to a background removal device that reduces background noise.

<Prior art> Generally, in order to analyze anions in a sample liquid, a dilute basic solution (for example, sodium carbonate or hydroxide) is added to a separation column packed with an anion exchange resin with a low ion exchange capacity. A fixed amount of the liquid to be measured is transported using a mobile phase consisting of sodium, etc.), and anions in the liquid to be measured are chromatographically separated for analysis. Anions in the sample solution can be detected by directly detecting the eluate from the separation column with a detector (for example, a conductivity detector) to obtain the above analysis result of taromad crumb. A suppressor column packed with an acid-type cation exchange resin is placed in between, and the mobile phase (e.g., sodium hydroxide, sodium carbonate, etc.) is made conductive by passing the mobile phase (eluate from the column) through the suppressor column. By using a liquid with a low ratio (such as water or carbonic acid) and changing the counter ions of the anions in the sample liquid to hydrogen ions, the conductivity of the mobile phase can be lowered and the S/N ratio can be improved. Anions in the measurement solution are measured. In this case, if a suppressor column using a cation exchange membrane can be used instead of a suppressor column filled with an acid-type cation exchange resin, water can be continuously converted through the cation exchange membrane. This is extremely convenient when using analytical equipment.

<Problems to be Solved by the Invention> However, as a conventional example of a suppressor using a cation exchange membrane, there is a suppressor made of a cation exchange tube with a double tube structure. This has a double tube structure in which a hollow cation exchange tube with an outer diameter smaller than the inner diameter of these tubes is placed inside a stainless steel or Teflon tube.

The eluate from the column flows through a hollow cation exchange tube, and the removal solution flows around the outside of the tube under its own current relative to the flow of the mobile phase, allowing for continuous background removal. ing.

However, since the above suppressor uses a hollow cation exchange tube, the ion exchange efficiency is not very high and it is difficult to reduce background with high efficiency.

Therefore, in order to obtain a sufficient subrest effect, a considerable length is required, resulting in an increase in internal volume, resulting in extra analysis time and the problem of spreading out the components separated by the separation column. . As a solution to these problems, it is possible to use an ion exchange tube with a small inner diameter or an ion exchange tube with high ion exchange efficiency, but such tubes are extremely difficult to obtain. Another problem is that it is not very easy to manufacture and process.

The present invention has been made in view of the drawbacks of the conventional examples, and its purpose is to use easily available sheet-like cation exchange membranes and spherical packings (e.g., cation exchange resins, polymer pieces, glass spheres). , metal balls, etc.).
An object of the present invention is to provide a background removal device (structure).

<Means for Solving the Problems> A feature of the present invention that solves the above-mentioned problems is that, in a background removal device, a first sheet having a long groove filled with a spherical substance and a cation exchange membrane are used. A second sheet consisting of a spherical substance, a third sheet having long grooves filled with a spherical substance, a fourth sheet consisting of a cation exchange membrane, and a fifth sheet having a long groove filled with a spherical substance are laminated. The upper and lower sides thereof are sandwiched between first and second substrates, and the mobile phase is caused to flow through the gap flow path of the third sheet sandwiched between the second and fourth sheets (cation exchange membranes). The mobile phase and the removal liquid flow in the gap flow path of the first and fifth sheets (sandwiched between the second sheet and the first substrate and the fourth sheet and the second substrate) formed on the outside of the fourth sheet. It is to flow.

<Example> Hereinafter, the present invention will be described in detail using the drawings. 1st
The figure shows conductivity background reduction (removal) according to the present invention.
FIG. 2 is a conceptual diagram showing the principle in detail.

In Fig. 1, three chambers C1, C2, and C3 partitioned by two cation exchange membranes M are filled with a spherical filler R such as a cation exchange resin, and the wasted volume is reduced. ing. In addition, the eluent eluted from the separation column containing the sample to be measured (for example, C1- ion) and the solution to be measured (for example, NaOH containing NaCl) flow into the room C2, and the eluent and the solution to be measured (for example, NaOH containing NaCl) flow into the chambers C1 and C3. A removal liquid (for example, H2S04) is flowing in the flow direction. In this state, the Na+ ions contained in the eluent from the separation column in room C2 and the solution to be measured (e.g. Na leaf containing NaC1) are removed from the removal solution (e.g. H2S04) in rooms C1 and C3. The cation exchange membrane M exchanges ions with the H+ ions contained in the cation exchange membrane M. At this time, the eluent from the separation column and the component to be measured (for example, CI-) in the solution to be measured have the same charge as the ion exchange membrane M that partitions each chamber, so they remain in the chamber C2 without being ion-exchanged.

Therefore, the liquid eluted from the chamber C2 contains the component to be measured (for example, MC
The liquid (e.g., H2O) from which the conductivity background containing I removal solution (e.g. H2304
) and excess removal liquid (eg, H2SO).

On the other hand, FIG. 2 is an exploded perspective view of an embodiment of the present invention.

In this figure, 1 is a first substrate made of an acrylic plate, 1a1 to 1a10 are through holes provided in the first substrate, and I
b is a bolt inserted into the through hole 1al, 1c is an inlet for the eluent, 1d is the first inlet for the removal liquid, 1e is the outlet for the solution M, and 1 is the first inlet for the removal liquid. At the outlet, 2 is a first sheet made of rubber, for example, with a groove 2a in the center, 3 is a second sheet made of a sheet-like cation exchange membrane, 4 is a sheet of rubber, for example, with a groove 4a in the center. 3rd sheet made of
6 is a fourth sheet made of a sheet-like cation exchange membrane; 6 is a fifth sheet made of rubber, for example, with a groove 6a provided in the center;
7 is a second substrate made of an acrylic plate, 7a, 1-
7a10 is a through hole provided in the second substrate, 7c is a second inlet for removing liquid, 7d is a second outlet for removing liquid, 8a1
8b1 is a washer, and 8b1 is a nut that fits with the threaded portion of the bolt 1b1. Note that the groove 2a of the first sheet and the groove 4 of the third sheet
a and the fifth sheet 6a are both embedded (filled with) a spherical filler, such as a cation exchange resin.
There is.

The embodiment of the present invention having the above-mentioned exploded configuration is the first
~ After the fifth sheets 2 to 6 are laminated, the sheets 2 to 6
The bolts 1b1 (and bolts 1b2 to 1b10, not shown) are inserted between the through holes 1a1 (and 1a2 to 1a10) and the through holes 7a.
1 (and 7a2 to 7a10), washer 8a1 (and washer 8a2 to 8alO (not shown)
) are inserted, and finally pol1~1b1 (and 1b2~
By screwing the nut 8b1 (and nuts 8b2 to 8b10, not shown) into the threaded portion of the bolt 1b10), the assembly of the background removing device according to the embodiment of the present invention is completed. The background removing device assembled in this manner is used by being attached to an anion analyzer as shown in FIG. That is, FIG. 3 is an explanatory diagram of the configuration of an example of use of the embodiment of the present invention, in which the separation column 12, suppressor 13, and detector 14 are housed in a constant temperature bath 15 and kept at a constant temperature (for example, 45°C). is maintained. Also,
When the pump 10a is driven, the eluent in the tank 9a is discharged at a flow rate of, for example, 111+/Fin. Inlet port 1c of chamber 13b→Inner chamber 13b of background removal device 13→
Outlet port 1e of inner chamber 13b of background removal device 13
→Flows through the detector 14 to the waste liquid tank 9c, and the pump 10b
When driven, the removal liquid in the tank 9b is reduced to 1 ml/In, for example.
At the same flow rate, bonder 10b → background removal device 1
3, the first introduction hole 1d of the outer chamber 13c → the outer chamber 13cm of the background removing device 13 + the background removing device 13
1f of the outer chamber 13C → second introduction lower cm of the outer chamber 13c of the hack ground removal device 13 + outer chamber 13c of the background removal device 13 → second extraction lower of the outer chamber 13c of the background removal device 13 d and flows to the waste liquid tank 9d. Therefore, the cations contained in the liquid flowing in the inner chamber 13b (grooves 4a, in FIG. 2) of the background removal device 13 are removed from the cation exchange membrane 13a (the second sheet 3 and the grooves 4a in FIG. 2). 4 sheet 5) to exchange the cations contained in the liquid flowing in the outer chamber 13c (grooves 2a and 6a in FIG. 2) of the background removing device 13, and ultimately eliminate the conductivity background. It will be possible to lower it.

<Effects of the Invention> According to the embodiments of the present invention as described in detail above, easily available sheet-like cation exchange membranes and spherical packings (for example, cation exchange resins, polymer beads, glass spheres,
A background removal device with a simple configuration (structure) with a small dead volume that does not impair the peak shape in a talomadogram is realized by using metal balls (metal balls, etc.). Also,
Cation exchange membrane and spacer (first to fifth sheets 2 to 6)
) (specifically, the long grooves 2a, 4a,
6a) is filled with a filler such as a cation exchange resin, which has the advantage that the cation exchange resin backs up the cation exchange membrane and increases the pressure resistance of the flow system through which the solution H flows. be.

Furthermore, the same effect can be obtained even if the space formed by the cation exchange membrane and the spacer (specifically, the long grooves 2a, 4a, 6a) is filled with a filler, polymer beads, glass balls, or metal balls. It is valid.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram showing the principle of conductivity background removal in detail, FIG. 2 is an exploded perspective view of an embodiment of the present invention, and FIG.
The figure is an explanatory diagram of the configuration of an example of use of the embodiment of the present invention.

Claims (3)

[Claims] (1) A background removal device that is attached to an anion analyzer that analyzes anions in a liquid to be measured and that reduces the conductivity background of a liquid eluted from a separation column, which has a long groove filled with a spherical substance. a first sheet, a second sheet made of a cation exchange membrane, a third sheet having a long groove filled with a spherical substance, a fourth sheet made of a cation exchange membrane, and a long groove filled with a spherical substance. A fifth sheet having the following properties is laminated and its upper and lower sides are sandwiched between the first and second substrates, and the mobile phase is caused to flow through the gap flow path of the third sheet sandwiched between the second and fourth sheets. 2nd and 4th
A background removal device characterized by flowing a removal liquid into a gap flow path between a first sheet and a fifth sheet formed on the outside of the sheet. (2) The background removing device according to claim 1, wherein the first sheet and the fifth sheet are filled with cation exchange resin, polymer beads, glass spheres, and metal spheres. (3) The background removing device according to claim 1, wherein the third sheet is filled with a cation exchange resin, polymer beads, glass spheres, or metal spheres.