ICP-OES (Inductively Coupled Plasma Optical Emission Spectrometry) is a fast multi-element technique with a dynamic linear range and moderate detection limits (~0.2-100 ppb). The instrument uses an ICP source, made by ionizing argon gas, to dissociate the sample into its constituent atoms or ions, exciting them to a level where they emit light of a characteristic wavelength. Up to 60 elements can be screened per single sample run of less than one minute.
ICP-MS (Inductively Coupled Plasma Mass Spectrometry) is a multi-element technique for trace analysis where low detection limits (0.0005-1.0 ppb) are required and for high-precision isotope ratio studies. The plasma source is an excellent ion source and most elements from 0-240 amu are ionised into singly charged positive ions (M+ ). Sample preparation is more crucial than in ICP-OES with samples ideally dissolved in 2% HNO3 v/v, a total dissolved solids content < 0.2 %.