An apparatus for detecting analytes in a liquid sample may include an elongated primary channel through which an ionic species flows, the primary channel extending through a primary channel member, a first regenerant channel through which a regenerant flows, the first regenerant channel extending adjacent to the primary channel and being formed in a first block, a first charged barrier having exchangeable ions capable of passing ions of only one charge, positive or negative, and of blocking bulk liquid flow, the first charged barrier disposed between the primary channel member and the first block for separating the primary channel from the first regenerant channel, and a first sealing member disposed between the first charged barrier and the first block defining the first regenerant channel.

Systems and methods for inhibiting translocation of ions across ion exchange barriers include an eluent generator having an ion source reservoir with a first electrode, an eluent generation chamber with a second electrode, an ion exchange barrier disposed therebetween, and means for reversing the polarity of a voltage or current applied across the first and second electrodes. A first polarity voltage or current applied across the electrodes generates an electric field that promotes translocation of eluent counter ions from the reservoir across the barrier, where the counter ions combine with eluent ions electrolytically generated in the chamber. By reversing the polarity of the voltage or current across the electrodes, the resulting electric field inhibits translocation of counter ions across the barrier from the reservoir into the chamber. Reverse voltage or current bias reduces counter ion concentration in the resting chamber to prevent exhaustion of ion suppressor capacity during start up.

Open tubular capillary columns for liquid and ion chromatography, based upon an ionically impermeable polyolefin capillary having a bore with a sulfonate-group- or amine-group-functionalized internal surface. The capillary columns may include a coating of ion exchanging nanoparticles electrostatically bound to the functionalized internal surface. The capillary columns may be made by exposing the interior surface to a sulfonating reagent comprising chlorosulfonic acid (ClSO.sub.3H), preferably from 85 wt % to 95 wt % chlorosulfonic acid at a process temperature of 20 to 25 C. The interior surface may be subsequently exposed to an asymmetrical diamine to form a sulfonic mid-linkage to the diamine, i.e., to form a sulfonamide-linked, amine-group-functionalized internal surface. The coating may be provided by subsequently exposing the interior surface to an aqueous suspension of ion exchanging nanoparticles to electrostatically bond the ion exchanging nanoparticles to the functionalized internal surface.

An electrolytic device comprising a housing includes at least first and second adjacent liquid flow-through channels. A barrier impermeable to ion flow and to bulk liquid flow is disposed between the first and second channels. A first electrode assembly is disposed adjacent to one end of the channels and a second electrode assembly is disposed adjacent the other end of the channels. Also, a contaminant removal method using the above electrolytic device. A first aqueous stream including contaminants flows through the first channel while passing a current between the first and second electrode assemblies to remove contaminants. Effluent from the first channel flows, with or without further treatment, through the second channel while passing current between said first and second electrode assemblies to remove further contaminants.

A permeative amine/acid introduction device (PAID) is placed after a conventional KOH eluent suppressed conductometric anion chromatography (SCAC) system. The PAID converts the suppressed eluites from the acid form to the corresponding salt. For example, when the analytes are acids, they are converted to the corresponding ammonium salt (NR.sub.2H+HX.fwdarw.NR.sub.2H.sub.2.sup.++X.sup.) and allows very weak acids HX (pK.sub.a7.0) that cannot normally be detected by SCAC to be measured by a second conductivity detector following the PAID. Permeative reagent introduction is dilutionless, can be operated without pumps and provides good mixing with low band dispersion (as small as 30 L). An exemplary amine is diethylamine (DEA), which was chosen as the amine source due to its low pK.sub.b value (pK.sub.b 3.0), high vapor pressure, and low toxicity and low odor.

An electrolytic device comprising: a central sample flow channel, first and second regenerant flow channels, first and second charged barriers disposed between said sample flow channel and first and second regenerant flow channels, and pairs of oppositely charged, spaced electrodes disposed in the regenerant flow channels. Also, electrolytic devices with a different electrode configuration are described. Also, methods of using the devices, e.g., for suppression in an ion chromatography system are described.

Disclosed herein are scientific instrument support systems, as well as related methods, computing devices, and computer-readable media. For example, in some embodiments, a scientific instrument support apparatus includes chromatogram logic to calculate the square of a retention time and a peak width variance for each of a plurality of peaks in a chromatogram; plate calculation logic to calculate an expected plate number and an observed plate number; and suppressor status logic to determine a suppressor status based on a ratio of the observed plate number to the expected plate number (O/E ratio) and to display the status.

An analytical system comprises a chromatography column configured to separate a sample into one or more analytes; an ion removal device configured to remove at least ions of one charge from the mobile phase, the ion removal device fluidly coupled to an output of the chromatography column; an ion selective sensor configured to measure a signal corresponding to an activity of the ions of one charge in the mobile phase, the ion selective sensor fluidly coupled to an output of the ion removal device; an optional diverter valve that can interrupt the flow of the mobile phase; and a microprocessor configured to monitor the signal of the ion selective sensor and to either switch the optional diverter valve to interrupt the flow of the mobile phase or turn off the pump when the signal is greater than a predetermined threshold.