Chemical speciation study of platinum group elements in geological samples by stepwise dissolution and inductively coupled plasma mass spectrometry Original Research Article

A chemical speciation study method for platinum group elements in geological samples was developed, including stepwise dissolution, nickel sulphide fire assay preconcentration and inductively coupled plasma mass spectrometry (ICP-MS) determination. Samples were firstly separated into eight components (water-soluble phase, exchangeable phase, carbonate phase, Fe/Ni metal phase, sulfide phase, oxide phase, silicate phase and HF-insoluble residue) by a newly-revised selective chemical dissolution procedure. The separated components were pretreated and subjected to nickel sulphide fire assay to preconcentrate platinuim group elements, which were determined by ICP-MS. The chemical speciation of platinum group elements in a Danish Cretaceous/Tertiary (K/T) boundary sample was studied as a demonstration.