Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES)
ICP-OES is another technique for measuring trace metals in liquid solutions. Similar to HR-ICP-MS, the liquid sample is sprayed into an argon plasma where the dissolved metals are excited to emit their characteristic ultraviolet and visible radiation. The radiation is dispersed by a grating monochrometer and detected with photomultiplier tubes. Radiation wavelength is used to identify the element and radiation intensity is used to determine its concentration. ICP-OES measures elements in the concentration range of 1ppb (part-per-billion) to 1000ppm (parts-per-million) or more. It is a particularly useful technique for measuring samples with high dissolved solids (e.g., slurries and etchants) and samples containing both high and low concentration elements in the same solution (e.g., waste streams, raw water, RO concentrates, etc).
• Varian Liberty Series II