Analytical Details
Analytical Routines
About 70 % of the analyses performed in our lab are mineral analyses of
common silicates like garnet, olivine, pyroxene etc. For this kind of analyses
we usually use the phi-rho-z matrix correction of Armstrong. We use well
characterised (mostly natural) minerals with end-member composition as
calibration standards. See below for details of the standards. In most cases
analytical conditions are 15 kV accelerating potential and 15 or 20 nA probe
current. Typical counting times for major elements are 10 to 15 seconds on
the peak.
For the analyses of special materials (e.g. volcanic glass, REE minerals,
alloys) we have special analytical routines which can differ significantly from
those of silicate mineral analyses.
Standards
We have access to a wide range of standards, which enables us to cover
various analytical purposes. Amoung the standards in use are Smithsonian
mineral and REE orthophosphate standards as well as element and minerals
standards supplied by MAC. Additionally we have a set of Boron an Beryllium
mineral standards supplied by Harvard Museum and special glass standards
for Rb, U, Th, K from Hopkins and a number of special standards for special
purposes.
Follow this link to obtain an almost full
list of primary and secondary standards used in our lab.