Quantitative microanalysis by proton-induced x-ray emission spectrometry

Abstract

A system for routine quantitative x-ray analysis of trace elements optimized in the Z range 25 to 35, using proton excitation and a Si(Li) x-ray detector, is described. Consistent methods for making targets of samples of blood serum, organic tissue, and water are outlined. The method is sensitive to .8yU.g/ml in the Z range 25 to 35 for blood serum drop targets of 4 mg/cm2 thickness on aluminized formvar backings, using 1 microcoulombs of 3 MeV protons. The minimum analysis time per sample is presently limited to 1 seconds, due to volatilization of the target by higher beam intensities.