Role of aerosol water vapour loading in inductively coupled plasma mass spectrometry

Abstract

The influence of aerosol water loading has been shown to be of great significance in inductively coupled plasma mass spectrometry (ICP-MS). The resultant spectra from both singly charged M⁺, oxide MO⁺ and doubly charged M²⁺ species have a strong dependence on the water loading in the plasma. Similarly the levels of polyatomic species, whether derived directly or indirectly from water components (O⁺, H⁺) are also significantly improved when loadings are lowered. At low water loadings, the mean ion energies are reduced to low but reasonably constant levels (ca. 4 eV) for a wide range of elements facilitating more predictable plasmas and minimising mass dependent ion focusing.