Ion chromatography is a form of liquid chromatography that uses ion-exchange resins or gel matrix consisting of agarose or cellulose beads in a column to separate atomic or molecular ions based on their interaction with the resin (stationary phase). A sample, with a minimum volume of 10mL, is introduced either manually or with an auto sampler, into a loop of known volume. A buffered aqueous solution known as the mobile phase carries the sample from the loop on to the column that contains the stationary phase. This target analytes (anions or cations) are retained on the stationary phase, but can be eluted by increasing the concentration of a similarly charged species that will displace the analyte ions from the stationary phase. In Ion chromatography ions in the aqueous sample are detected by measuring the conductivity of the solution. The mobile phase contains ions that create background conductivity, making it difficult to measure the conductivity due only to the analyte ions, as they exit the column. This problem can be greatly reduced by selectively removing the mobile phase ions after the analytical column and before the detector. This is done by converting the mobile phase ions to a neutral form or removing them with an eluent suppressor, which consists of an ion-exchange column or membrane. For cation analysis, the mobile phase is often HCl or HNO3 which can be neutralized by an eluent suppressor that supplies OH (-ve). For anion analysis, the mobile phase is NaOH or NaHCO3 and the eluent suppressor supplies H (+ve) to neutralize the anion.