ICS-1000 Ion Chromatography System Operator's Manual

F • Glossaryof relatively clean sample. This allows large volumes of sample to be injected,lowering concentration detection limits.ConductivityA measure of the ease with which electrical current flows through a liquidcontained between two opposite charged electrodes. Conductivity is acharacteristic of ions in solution. Units are siemens.CounterionIons carrying a charge opposite that of the sample ions (e.g., Na + ) may be thecounterion of a Cl - analyte. These ions preserve electrical neutrality in solution.% CrosslinkDivinylbenzene content in a polystyrene/divinylbenzene (PS-DVB) resin; thiscontributes to the mechanical strength of the resin and determineschromatographic properties.Equivalent Conductivity (λ)The contribution of an ionic species to the total conductivity of a solution asmeasured in a standard cell having electrodes 1 cm 2 in area and exactly 1 cmapart.Guard ColumnA small column that prevents poisoning of the separator column by sorbingorganic contaminants and removing particulates. It is filled with the same packingas the separator column. Synonymous with Pre-Column.HETP (H)Height Equivalent to a Theoretical Plate. A measure of column efficiency whichallows comparison between columns of different lengths.HETP = H = L/NWhere: L = the column length (in mm)N = the number of theoretical platesIon-Exchange CapacityThe number of active ion exchange sites in a given weight or volume of resin; thisis usually expressed in meq/g or meq/mL.Ion-Exchange ResinAn insoluble polymer matrix containing fixed-charge exchange sites (anionic orcationic). IC resins are formed into small spherical particles (beads).Doc. 031879-01 3/03 F-3