A material derived from non-living sources, inorganic carbon (IC) exists in pharmaceutical waters as carbonate, bicarbonate and dissolved carbon dioxide (CO2). Whether your instrument quantifies IC as part of a differential calculation or removes it as part of a “non-purgeable” method of TOC determination, your instruments ability to remove and/or measure IC must be validated. Below are the most commonly requested IC concentrations for calibration and validation of TOC instrumentation.