Trace Element Analysis is Possible with the Proton Probes

9 TRACE ELEMENT ANALYSIS IS POSSIBLE WITH THE PROTON PROBES 

In the initial studies of trace elements of human skin cross sections, a Ca profile evolved which was increasing from the basal, germinative level of the epidermis toward the horny layer. The drastic concentration drop of Ca concentration down to threshold values at the border of the stratum germinativum and the stratum corneum was a particularly interesting feature.15-17 Only a few years later this finding could be correlated to the fact that a Ca concentration 0.1 mmol was essential if a fully cornified stratum corneum was to be obtained in cell culture. This relationship between Ca and terminal differentiation of the epidermal cells was verified in a PIXE study of epidermal cell cultures.18 

The skin dependence on appropriate availability of Zn2+ for normal function is a subject that has not been completely resolved.27 28 However, it is conceivable that these problems can at least partially be solved using particle probe analysis. 

---