Sotirios E. Raptis

X-ray fluorescence determination of trace selenium in organic and biological matrices

W. Wegscheider, G. Knapp, G. Tölg, 1980 .

Selenium Content of Geochemical Reference Samples Determined by a Simple Method at ng/g Level

H. Kolmer, S. Raptis, Sotirios E. Raptis, 1983 .

A partially mechanized system for the combustion of organic samples in a stream of oxygen with quantitative recovery of the trace elements

P. Schramel, G. Knapp, B. Schreiber, 1981 .