The determination of all the platinum group elements and gold in rocks and ore by neutron activation analysis after preconcentration by a nickel sulphide fire-assay technique on large samples

Petrological and geochemical studies of an abyssal periodotite from the Atlantis II fracture zone

“…Nickel ftre assay with sodium tetraborate flux was used for all the solid samples to ensure complete dissolution and sample-spike equilibration. Fusion and Os separation were based on the techniques of Luck (1982), Ravizza (1993), Reisberg et al (1991), and Hoffman et al (1978). Os isotope analysis was conducted on the NIMA-B mass spectrometer.…”

Geochemical and fluid dynamic investigations into the nature of chemical heterogeneity in the Earth's mantle

“…For Os analysis, Os was preconcentrated from the rock matrix by nickel sulfide fire assay (Hoffman et al, 1978). Prior to the fire assay, 30-100 grams ofrock powder were weighed into a Coors glazed ceramic crucible, spiked with I90Qs, and then, after the spike had dried, mixed with a glass rod in order to distribute the spike evenly through the powder.…”

“…During the fusion , the platinum-group elements are concentrated in the immiscible NiS bead which segregates at the bottom of the crucible (Hoffman et a!., 1978). For fusions with high sample/flux ratios, typically the NiS formed several small beads.…”

Siderophile Elements in Tracing Planetary Formation and Evolution

“…To harvest enough Os from the picrites, Al had to apply the exciting Ni-sulphide fire assay technique of Hoffman et al (1978). This method requires mixing 100-200 g of sample powder with huge amounts of NiS and sodium tetraborate, then fusing the mix in a large ceramic crucible at 1100 °C.…”