EstablishedThe sample must be dissolved or ablated first, so the analysis is of a prepared solution or an ablated volume rather than of the rock as it stood.
What ICP-MS analyses is a prepared aliquot, not the rock as it stood. In the USGS national soil survey the material was decomposed by a near-total four-acid digestion at 125 to 150 °C before analysis; where a solid is analysed without dissolution it is by ablating a small volume of it with a laser, as in the subduction-fluid experiments this corpus also cites.
- precision note: Narrowed on the Phase 7 second pass. The first version of this restored claim opened "The sample must be taken into solution first", which the cited soil survey does not state and which evidence already in this corpus contradicts: the Kessel subduction-fluid paper reports direct laser-ablation ICP-MS. One survey’s sample preparation had been generalised into a property of the instrument.
Evidence support: Supported by the cited evidence 2 sources, multiple sources, independence unknown
Evidence: Smith 2013 Primary authority; Kessel 2005 Peer-reviewed