A suppressor for use in reducing a background signal while detecting analytes in a liquid sample for ion chromatography is described. The suppressor includes a central channel and two flanking regenerant channels. The central channel is formed with an eluent channel plate including a central cutout portion having a peripheral boundary portion. The peripheral boundary portion includes a recessed eluent plate height that is less than the eluent plate height. The peripheral boundary portion includes two or more notches or protrusions. An eluent screen is disposed in the central cutout portion, in which a peripheral border of the eluent screen has two or more corresponding notches or corresponding protrusions to the eluent channel plate.

An ion chromatography (IC) suppressor includes a first clamping plate, an intermediate plate, a second clamping plate, a first ion exchange membrane, a second ion exchange membrane, a first electrode and a second electrode. The first clamping plate, the intermediate plate and the second clamping plate are tightly buckled in sequence to compact the first ion exchange membrane between the first clamping plate and the intermediate plate and compact the second ion exchange membrane between the intermediate plate and the second clamping plate. Resin particles are filled between the two ion exchange membranes. An eluent inlet and an eluent outlet are provided respectively at two ends of the intermediate plate, and an accommodating groove is formed at each of a tail end of the eluent inlet and a head end of the eluent outlet. The first clamping plate and the second clamping plate are provided with a sealing lip, respectively.

First and second electrode liquid seal members are arranged between a first electrode and a second electrode. First and second ion exchange membranes are arranged between the first electrode liquid seal member and the second electrode liquid seal member. An eluent seal member is arranged between the first ion exchange membrane and the second ion exchange membrane. A plurality of first mesh members having different charge amounts are stacked in a first electrode liquid flow path of the first electrode liquid seal member. Each of the plurality of first mesh members is constituted by a first wire group composed of a plurality of first wires and a second wire group composed of a plurality of second wires crossing the first wire group. The plurality of first wire groups of the plurality of first mesh members respectively extend in different directions, and the plurality of second wire groups of the plurality of first mesh members respectively extend in different directions and extend in directions different from those of the plurality of first wire groups.

In an ion chromatograph, a sample that is included in an eluent and is to be measured is separated into ion species components by a separation column. An electrode liquid to be introduced into an input port is branched by a three-way valve and is discharged from each of a first output port and a second output port. An eluent from the separation column passes through an eluent flow path of an ion suppressor. An electrode liquid from the first and second output ports passes through each of an anode-side flow path and a cathode-side flow path of the ion suppressor. Ion exchange is performed by electrolysis between an eluent that passes through the eluent flow path and an electrode liquid that passes through the anode-side flow path and the cathode-side flow path, and a sample that passes through the eluent flow path and is separated by the separation column is detected by a detector. A backward flow of an electrode liquid in the cathode-side flow path is suppressed by a backward flow suppression mechanism.

First and second flow-path portions are opposite to each other, and communicate with each other such that a direction in which an eluent flows through the first flow-path portion and a direction in which an eluent flows through the second flow-path portion are opposite to each other. First and second electrode liquid flow paths are respectively opposite to the first and second flow-path portions. First and second electrode liquids are respectively supplied to the first and second electrode liquid flow paths, such that a direction in which the first electrode liquid flows through the first electrode liquid flow path is same as a direction in which an eluent flows through the first flow-path portion and a direction in which the second electrode liquid flows through the second electrode liquid flow path is same as a direction in which an eluent flows through the second flow-path portion.

First and second electrode liquid seal members are arranged between a first electrode and a second electrode. First and second ion exchange membranes are arranged between a first electrode liquid seal member and a second electrode liquid seal member. An eluent seal member is arranged between a first ion exchange membrane and a second ion exchange membrane. Ion exchange is performed between an eluent that passes through an eluent flow path of the eluent seal member from a separation column and an electrode liquid that passes through each of electrode liquid flow paths of the first and second electrode liquid seal members. In a first surface of the eluent seal member that comes into contact with the first ion exchange membrane, a first projection that surrounds the entire circumference of the eluent flow path to extend along the edge of the eluent flow path and projects toward the first ion exchange membrane is formed.

A chromatography system includes an electrolytic eluent generator; a first valve configured to switch between an operating position which directs an output of the electrolytic eluent generator to a continuously generated trap column and a waste position which directs the output of the electrolytic eluent generator to waste; the continuously regenerated trap column; a degasser; a sample injector including a sample injector valve assembly, the sample injector valve assembly configured to switch between an operation mode which directs an output of the degasser to a separation column, a load mode which loads a sample onto the separation column, and a regenerant mode which directs the output of the degasser to a regenerant line; the separation column; a suppressor; and a detector.

An ion chromatography (IC) suppressor includes a first clamping plate, an intermediate plate, a second clamping plate, a first ion exchange membrane, a second ion exchange membrane, a first electrode and a second electrode. The first clamping plate, the intermediate plate and the second clamping plate are tightly buckled in sequence to compact the first ion exchange membrane between the first clamping plate and the intermediate plate and compact the second ion exchange membrane between the intermediate plate and the second clamping plate. Resin particles are filled between the two ion exchange membranes. An eluent inlet and an eluent outlet are provided respectively at two ends of the intermediate plate, and an accommodating groove is formed at each of a tail end of the eluent inlet and a head end of the eluent outlet. The first clamping plate and the second clamping plate are provided with a sealing lip, respectively.

The eluent used in IC separation contains non-volatile salt which is not compatible with electrospray ionization-mass spectrometry (ESI-MS). A suppressor is required to convert the non-volatile salt into water or the volatile acid form (i.e. acetic acid). When the suppressor fails, the non-volatile salts will enter the MS and cause extensive shutdown and maintenance of the mass spectrometer. The suppressor voltage derivative is used to evaluate the most common suppressor failure modes, including disruption of regenerant flow and excessive backpressure on the suppressor due to clogging in the downstream, and to trigger the eluent pump to stop the eluent flow or to trigger the auxiliary valve to switch the flow to the mass spectrometer from eluent to water.

A suppressor comprising one or more channels, a flow path for each of the channels, and one or more measurement probes positioned in the flow path is described. Each channel includes an inlet and an outlet. Each flow path includes an upstream path to the inlet, a channel stream path through the channel and connecting the inlet to the outlet, and a downstream path from the outlet. A system including the suppressor as well as methods implementing the suppressor are also described.