There has been considerable interest in the determination of anions at trace levels by IC. For example, the Electric Power Research Institute (EPRI) has established IC as the analytical technique for determining sodium, chloride, and sulfate down to 0.25 mg/L (ppb) in power plant waters. For high-purity water used in semiconductor processing, the Semiconductor Equipment and Materials International (SEMI) recommends the use of IC for tracking trace ionic contaminants from 0.025 to 0.5 mg/L.