JPH04204154A - Background removing apparatus - Google Patents

Abstract

PURPOSE:To make it possible to decrease a background characterized by high efficiency and high conductivity by using readily obtainable sheet-shaped cation exchange films and woven nets. CONSTITUTION:In this apparatus, a first sheet 200, a third sheet 300 and a second sheet 400, which comprise cation exchange films, are laminated. Thereafter, the first-third sheets 200, 400 and 300 are held with first and second substrates 100 and 500. Then, bolts are penetrated into through holes 106a-106l and 506a-506l through washers. Thereafter, the washers are placed. Finally, nuts are mounted on the bolts. Eluate is made to flow through the gap flow path formed of the cut out of the third sheet 300. Removing liquid is made to flow through the gap flow path formed of the first sheet 200 and the first substrate 100 and the gap flow path formed of the second sheet 400 and the second substrate 500. Thus, the background characterized by high efficiency and high conductivity can be decreased.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a background removal device, and more specifically, it is attached to an anion analyzer that analyzes anions in a liquid to be measured. The present invention relates to a background removal device that reduces the conductivity background of a liquid or a sample solution itself.

<Prior art> Generally, in order to analyze anions in a liquid to be measured, a separation column packed with an ion exchange resin with a low exchange capacity is charged with a constant eluent using a dilute salt or alkali (e.g. Na0H). transporting a certain amount of a liquid to be measured and performing analysis by chromatographically separating anions in the liquid to be measured;
Detection of anions in the liquid to be measured is performed by directly detecting the eluate from the separation column with a detector (for example, a conductivity detector) to obtain a chromatogram as the above analysis result. However, by placing a suppressor column filled with an acid-type cation exchange resin between the separation column and the detector, and passing the eluent (eluate from the column) through the suppressor, the salt is converted to water and the By changing the counter ion of the anion in the measurement liquid to a hydrogen ion, the conductivity of the eluent is reduced and the conductivity of the component to be measured is increased, improving the S/N ratio while reducing the anion in the measurement liquid. Measuring ions is performed. 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 to water through the cation exchange membrane. This is extremely convenient when using an ion analyzer.

However, as a conventional example of a suppressor using a cation exchange membrane, a suppressor made of a cation exchange tube with a double tube structure is known. This has a double tube structure in which a hollow cation exchange tube having an outer diameter smaller than the inner diameter of these tubes is placed inside a stainless steel or Teflon tube. For this reason, the eluate from the separation column flows through the hollow anion exchange tube, and the removal liquid flows outside in the direction of the eluate and its own flow, making it possible to continuously remove the background.

<Problems to be solved by the invention> However, the double pipe structure suppressor as described above has the following problems:
Since a hollow cation exchange tube is used, the ion exchange efficiency is not very high, and it is difficult to reduce background with high efficiency.

In order to obtain a sufficient subrest effect, a considerable length is required, resulting in an increase in internal volume, which requires extra analysis time, and has the disadvantage that the components separated in the separation column may spread out. Ta.

For this reason, it has been considered to use an ion exchange tube with a small inner diameter or an ion exchange tube with high ion exchange efficiency, but such ion exchange tubes are generally difficult to obtain and are not easy to manufacture or process. There was a drawback.

The present invention has been made in view of the drawbacks of the conventional examples, and its purpose is to provide a background removal device with a simple configuration using an easily available sheet-like ion exchange membrane and a woven net. It is in.

Means for Solving the Problems> A feature of the present invention that solves the above-mentioned problems is that it is installed in an ion analyzer that analyzes anions in a liquid to be measured, and is used to eliminate the conductivity background of the liquid to be measured. In the background removal device for reducing background, the first sheet and the second sheet are made of a cation exchange membrane, and the third sheet has a long notch in the center.
A sheet is sandwiched between a first substrate and a second substrate having a long groove in the center, and elution is performed in a gap flow path formed by the notch of a third sheet sandwiched between the first and second sheets. In addition to flowing the liquid, the removal liquid is also caused to flow into the gap flow path formed by the first sheet and the first substrate and the gap flow path formed by the second sheet and the second substrate.

Effect〉 A detailed explanation of the present invention is as follows.

FIG. 1 is an explanatory diagram of the principle of the present invention for explaining the present invention in detail. In this figure, two ion exchange membranes Ml
, three rooms C1, C2, C3 partitioned by M2
is filled with a woven mesh made of polypropylene, for example, to reduce wasted volume.

Also, with these fillings, each room C,, C2, C
The volume of No. 3 is small and the flow path resistance is not too large, and the ion exchange efficiency through the ion exchange membranes M, M2 is improved and good.

On the other hand, 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, Na0H containing NaC1) flow into the room C1,
In C3, a removal solution (for example, H2SO
4) is flowing. In this state, the eluent from the separation column in room C2 and the solution to be measured (for example, N containing NaCl) are
For example, Na+ ions contained in room C
For example, H+ ions contained in the removal liquid (for example, H2SO) in I and C3 are ion-exchanged via ion exchange membranes M1 and M2. At this time, the component to be measured (for example, Cl-'' ion) in the solution to be measured from the separation column has the same charge as the ion exchange membranes M, M2 that partition each chamber, so it is not ion-exchanged and flows into chamber C2. For this reason, the liquid eluted from chamber C2 is a liquid with conductivity background removed (e.g. H2O >, and the liquid eluted from chambers C1 and C3 is a removal liquid (e.g. Na
2S Oa) and excess removal liquid (e.g. H2S0a)
It becomes a highly conductive liquid containing .

Examples> The present invention will be described in detail below with reference to the drawings. Second
The figure is an exploded perspective view of the embodiment of the present invention, and in the figure, 10
0 is a first substrate made of, for example, a polypropylene plate; 10
1 is an eluent inlet, 102 is an eluent outlet, 1
03 is the first inlet for the removal liquid, and 104 is the first inlet for the removal liquid.
Derivation date, 105 is a groove provided in the center, 106a to 10
61 is a through hole provided in the first substrate, 200 is a first sheet made of a sheet-like ion exchange membrane, and 300 is a sheet having a thickness of about 10 to 100 μm (preferably 50 μm) and having a notch 301 in the center. A third sheet made of a polyester sheet, 400 a second sheet made of a sheet-like ion exchange membrane, 500 a second substrate made of a polypropylene plate, 503 a second inlet for the removal liquid, 504 a second sheet made of a sheet made of polyester; A second outlet port 105 for the removal liquid is provided in the center,
506a to 5061 are through holes provided in the second substrate 500. Note that the cutout 301 of the third sheet is filled with a woven net made of polypropylene, for example.

In addition, the groove 105 of the first substrate and the edge 505 of the second substrate are often filled with, for example, a woven polypropylene net, polymer beads, glass beads, metal balls, etc., but they are not filled with anything. At least, a sufficient background removal effect may be obtained due to the ion exchange efficiency of the cation exchange membrane.

In an embodiment of the present invention having such an exploded configuration, the first sheet 200. 3rd seat 300. and second sheet 400
are laminated, and then the sheets are used as the first and second substrates 100.
, 500, and then bolts (not shown) are inserted through the through holes 106a-1061 and 506a-
5061, then a washer (not shown) is inserted, and finally a nut (not shown) is attached to the bolt, completing the assembly of the background removing device according to the present invention.

FIG. 3 is a structural explanatory diagram showing an example of the use of the background removing apparatus according to the present invention assembled in this manner. In this figure, a sample injector 3, a separation column 4, a suppressor 5, and a detector 6 are housed in a constant temperature bath 7 and maintained at a constant temperature (for example, 45° C.). Also, pump 2
When a is driven, the eluent in the tank la is, for example, 1 ml/l.
With a flow rate of in, the pump 2a-+sample injector 3-separation force ram 4-inlet 5 of the internal chamber 5b of the background removal device 5
f → Background removal equipment! 5 → the outlet 5g of the interior chamber 5b of the background removal device 5 → flows through the detector 6 to a waste liquid tank (not shown), and when the pump 2b is driven, the removed liquid in the tank 1b is reduced to 11/lin, for example. At the flow rate of pump 2b→inlet 5d, 5d'' of outer chamber 5c of background removing device 5→outer chamber 5c of background removing device 5
→ Outlet 5e of the outer chamber 5c of the background removal device 5,
5e- and flows to a waste liquid tank (not shown). For this reason,
Inner chamber 5b of background removing device 5 (notch 3 in Fig. 2)
01) The cations contained in the liquid flowing inside are ion exchanged! 15a (first sheet 200 and second sheet 400 in FIG. 2) to the outer chamber 5 of the background removing device 5.
By exchanging cations contained in the liquid flowing in the grooves 205 and 505 in FIG. 1, it becomes possible to ultimately reduce the background of conductivity.

<Effects of the Invention> According to the embodiments of the present invention as described in detail above, an easily available sheet-like ion exchange membrane and a woven mesh are used to create a membrane with a small dead volume that does not impair the peak shape in the chromatogram. A background removal device with a simple configuration is realized. In addition, since the packing packed in the eluent flow path is simply a woven mesh, there is a problem with the use of spherical packings, such as an increase in channel pressure due to the movement of the filler in the flow path, and the formation of voids. Another advantage is that it can be used stably for a long period of time without problems such as generation.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the principle of the present invention, FIG. 2 is an exploded perspective view of an embodiment of the present invention, and FIG. 3 is a diagram illustrating a configuration of an example of use of the embodiment of the present invention. la, lb... oak, 2a, 2b... pump, 3... sample injector, 4... separation column, 5... Suppressor, 6...Detector, 7...Thermostat, 100,500...
...Substrate, 101...Inlet for eluent, 10
2... Eluent outlet, 103.503...
...Inlet for removal liquid, 104.504...
・Outlet for removal liquid, 105.505...Groove,

Claims (3)

[Claims] (1) In a background removal device that is attached to an ion analyzer that analyzes anions in a liquid to be measured and reduces the conductivity background of the liquid to be measured, a first sheet and a second sheet made of a cation exchange membrane; A third sheet having a long notch in the center is sandwiched between a first substrate and a second substrate having a long groove in the center, and the third sheet is sandwiched between the first and second sheets. The eluent is caused to flow through the gap flow path formed by the notch, and the gap flow path is formed by the first sheet and the first substrate and the gap flow path is formed by the second sheet and the second substrate. A background removal device characterized by flowing a removal liquid into. (2) The channel formed by the first sheet and the long groove of the first substrate and the channel formed by the second sheet and the long groove of the second substrate are filled with woven nets, polymer beads, glass, etc. The background removing device according to claim 1, which comprises a sphere or a metal sphere. (3) The method according to claim (1), wherein the gap flow path formed by the long grooves of the third sheet sandwiched between the first and second sheets is filled with a woven net having the same shape as the long grooves. Background removal device.