CN116124941A - Double-filler foam electrode inhibitor for ion chromatograph - Google Patents

Abstract

The invention discloses a dual-filler foam electrode suppressor for ion chromatography. The electrode suppressor comprises an anode fixing plate, a foam anode, ion-exchange membrane I, a reaction layer plate, ion-exchange membrane II, foam The cathode and the cathode fixed plate; the foam electrode includes a foam anode and a foam cathode; the middle part of the fixed plate is provided with an electrolytic cell; the foam electrode is fixed on the position of the electrolytic cell on the fixed plate, and the depth of the electrolytic cell on the fixed plate is greater than the thickness of the foam electrode , the extra space of the electrolytic cell is filled with ion-exchange resin with larger particle size; the center of the reaction layer plate is provided with a reaction tank and filled with ion-exchange resin with small particle size; The platinum porous titanium alloy foam electrode effectively improves the current efficiency and reduces the system pressure. By changing the shape of the electrode, the current efficiency is improved, the suppression ability of the suppressor is improved, the flow resistance of the electrolytic layer is reduced, and the system pressure is effectively reduced.

Description

A dual-filler foam electrode suppressor for ion chromatography

technical field

The invention relates to an electrode suppressor for ion chromatography.

Background technique

The suppressor is the core component of the ion chromatography system. It is connected after the chromatographic column and before the conductivity detector. Its main function is to reduce the background conductivity of the eluent and increase the signal value of the target component to be detected. The working principle of the suppressor is shown in Figure 1, taking the anion suppressor as an example. The interior of the suppressor is divided into three parts: the anode electrolytic layer, the cathodic electrolytic layer and the reaction layer. The reaction layer and the two electrolytic layers are separated by a selectively permeable ion-exchange membrane, with inert electrodes at both ends, and a constant current is applied between the electrodes. When the eluent and sample solution flow through the reaction layer, the salt solution Under the action of an electric field, the cations are discharged through the ion exchange membrane and replaced by H+ from the anode, thus converting the eluent into water with low conductivity, hydroxide system or CO2 and water, carbonate system, and the sample The analyte ions are converted into the corresponding acids. The background conductivity value of the eluent is effectively reduced, and the signal-to-noise ratio is improved.

A traditional suppressor uses a flat plate electrode, which is a solid flat plate. The gas generated by electrolysis flows through the electrolytic layer together with the solution, resulting in an increase in the resistance of the electrolytic layer, a decrease in the efficiency of the current applied between the two electrodes, and a decrease in the inhibitory effect under the same current. At the same time, the flow resistance of the liquid increases, resulting in an increase in the system pressure. risk of leakage.

Fill the electrolytic layer and the reaction layer with certain materials to play a supporting role and provide channels for the flow of the solution. The filling materials are divided into two types: (1) fill the screen in the electrolytic layer and the reaction layer. The advantage of filling the screen is that the solution flow resistance is small, but because the screen is not dense enough, the dead volume of the reaction layer is large, which causes the sample to diffuse when it flows through, and the chromatographic peak extension phenomenon occurs after reaching the conductivity detector. (2) An ion exchange resin with a small particle size is filled in the electrolytic layer and the reaction layer. The advantage of filling the resin is that the dead volume of the reaction layer is small and the chromatographic peaks are sharp, but it will cause the system pressure to increase.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art, and to provide a dual-filler foam electrode suppressor for an ion chromatograph.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A dual-filler foam electrode suppressor for an ion chromatograph, the electrode suppressor includes an anode fixing plate, a foam anode, an ion exchange membrane one, a reaction layer plate, an ion exchange membrane two, a foam cathode and a cathode fixing plate; the foam electrode includes a foam anode and a foam cathode; the middle part of the fixed plate is provided with an electrolytic cell; The thickness of the foam electrode, and the extra space of the electrolytic cell is filled with ion-exchange resins with larger particle sizes; the center of the reaction layer plate is provided with a reaction tank and filled with ion-exchange resins with small particle sizes; the ion-exchange resin An electrolytic layer is formed; both sides of the reaction layer plate are separated from the anode and cathode fixed plates by the ion exchange membrane one and two.

Further, the foam electrode is a porous titanium alloy composite electrode coated with platinum on the surface.

The platinum coated on the surface of the foam electrode increases the inertia of the electrode, and at the same time reduces the electrolysis voltage because water electrolysis occurs more easily on the platinum electrode. The porous structure increases the specific surface area of the electrode, effectively reduces the current density and improves the current efficiency. The porous structure can allow aqueous solution to pass through, effectively reducing the flow resistance of the electrolytic layer and reducing the system pressure. The gas generated by electrolysis is generated from the living pores on the electrode surface and can be exported through the electrode pores, which further reduces the resistance of the solution flow and the system pressure.

The electrolytic layer is filled with ion-exchange resin with a larger particle size, the resin particle size is larger, and the gaps between the resin balls are larger, so that the liquid passage resistance is smaller, and the solution flow resistance is reduced, that is, the system pressure is reduced. The reaction layer is filled with ion-exchange resin with small particle size, and the gaps between resin balls are small, which reduces the dead volume of the entire reaction layer and effectively reduces the extension of chromatographic peaks. Although the pressure of the reaction layer increased slightly, the overall pressure of the system was reduced due to the substantial reduction of the pressure of the two electrolytic layers.

The beneficial effects of the invention are: the invention effectively improves the current efficiency and reduces the system pressure by replacing the traditional plate electrode with a platinum-coated porous titanium alloy foam electrode. By changing the shape of the electrode, the current efficiency can be improved, the inhibitory ability of the suppressor can be improved, the flow resistance of the electrolytic layer can be reduced, and the system pressure can be effectively reduced; The peak extension caused by the dead volume of the device reduces the flow resistance of the electrolytic layer, improves the passage of liquid, and reduces the overall pressure. By changing the filling of the electrolytic layer and the reaction layer from the traditional screen or single filler to two kinds of resin fillers with different particle sizes in the electrolytic layer and the reaction layer, the system pressure is effectively reduced and the dead volume of the suppressor is reduced. The peak extension caused by the large dead volume of the chromatographic peak is eliminated.

Description of drawings

Figure 1 is a schematic diagram of the working principle of an anion suppressor;

Fig. 2 is an exploded schematic view of the components of the double filler foam electrode suppressor of the present invention;

Label names in the figure: 1-foam anode, 2-foam cathode, 3-reaction layer plate, 4-ion exchange membrane 1, 5-ion exchange membrane 2, 6-anode fixed plate, 7-cathode fixed plate, 8-anode Electrolyzer, 9-reaction tank, 10-cathode electrolyzer, 11-installation hole.

Detailed ways

Below in conjunction with the embodiment the present invention is described in further detail, as shown in Figure 2, a kind of dual packing foam electrode suppressor for ion chromatograph, this electrode suppressor comprises anode fixed plate 6, foam anode 1 successively according to spatial arrangement , ion-exchange membrane one 4, reaction layer plate 3, ion-exchange membrane two 5, foam cathode 2 and cathode fixed plate 7; The foam electrode comprises a foam anode 1 and a foam cathode 2; the middle part of the fixed plate is provided with an electrolyzer; The foam electrode is fixed on the position of the electrolytic cell on the fixed plate, the depth of the electrolytic cell on the fixed plate is greater than the thickness of the foam electrode, and the extra space of the electrolytic cell is filled with ion exchange resin with a larger particle size The center of the reaction layer plate 3 is provided with a reaction tank 9 and filled with an ion exchange resin with a small particle size; the ion exchange resin constitutes an electrolytic layer; 5 is separated from the anode fixing plate 6 and the cathode fixing plate 7. The foam electrode is a porous titanium alloy composite material electrode coated with platinum on the surface.

The above content is only used to illustrate the technical solution of the present invention. Simple modifications or equivalent replacements to the technical solution of the present invention by those skilled in the art will not depart from the essence and scope of the technical solution of the present invention.

Claims (2)

1. A dual-packing foam electrode suppressor for an ion chromatograph, characterized by: the electrode inhibitor sequentially comprises an anode fixing plate, a foam anode, an ion exchange membrane I, a reaction laminate, an ion exchange membrane II, a foam cathode and a cathode fixing plate according to space arrangement; the foam electrode comprises a foam anode and a foam cathode; an electrolytic tank is arranged in the middle of the fixed plate; the foam electrode is fixed at the position of the electrolytic cell on the fixed plate, the depth of the electrolytic cell on the fixed plate is larger than the thickness of the foam electrode, and the space which is more than the electrolytic cell is filled with ion exchange resin with larger particle size; the center of the reaction laminate is provided with a reaction tank and is filled with ion exchange resin with small particle size; the ion exchange resin forms an electrolyte layer; the two sides of the reaction laminate are separated from the anode and cathode fixing plates by the first ion exchange membrane and the second ion exchange membrane.

2. The dual packing foam electrode suppressor for ion chromatography of claim 1, wherein: the foam electrode is a porous titanium alloy composite electrode with the surface coated with platinum.

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