title: Three trace-element geological materials certified as a result of a co-operative investigation.
abstract: The results of a Nordic analytical trace-element study of three geological samples are given. Recommended concentration values for 27 trace elements and 14 main elements have been arrived at by the analysts in the course of several round-table conferences. The samples are now available as reference materials, for other analytical laboratories.
authors.affiliation: University of Oslo, Laboratory of Mass Spectrometry, P.b. 1048 Blindern, Oslo 3, Norway.
authors.forename: O H
authors.initials: OH
authors.lastname: Christie