Precious metals are usually determined by using either a lead or nickel sulphide fire assay preconcentration step prior to analysis. This is required to separate the precious metals from the matrix and what could be interfering elements. The lead collection method (using Ag as a collector) is used routinely for gold, platinum and paladium or with no collector for silver or with gold as a collector for Rh. Various types of analytical finishs can be used including INAA, atomic absorption, Gravimetric, ICP and ICP/MS.
In order to do the full platinum group element suite a nickel sulphide fire assay is required with either an INAA or ICP/MS finish.