Applications of PIXE in the life sciences

Abstract

During the last decade, particle-induced X-ray emission spectrometry (PIXE) has been accepted by the analytical chemistry community as a standard method. Instead of routine bulk analysis of biomedical samples where several competing analytical techniques are available, the full strength of PIXE could be exploited in special applications where also location of the detected ions is desirable. In this article, two different approaches for this purpose are discussed and illustrated: (1) nuclear microscopy, where micro-PIXE utilizing a proton beam spot of approx 1 micron 2 or less promises unique perspectives to obtain elemental maps at the cellular level, and (2) in situ PIXE analysis of the minute metalloprotein volumes concentrated in thin-layer electrophoretograms.

Quantitative imaging of metals in tissues

“…The energy of the emitted X-rays is element specific and can be used to determine the elemental composition of a biological sample with an energy dispersive detector. However, electrons generate a significant amount of Bremsstrahlung (radiation caused by decelerations of charged particles when passing through the field of nuclei), which lowers the sensitivity for trace elements (Sparks 1980). Current sensitivity of EM in thin sections is between 100 and 1,000 lg/g.…”

Overview of the methodology of nuclear analytical techniques for speciation studies of trace elements in the biological and environmental sciences

“…different types of chromatography, are adopted for this purpose. Although nuclear analytical techniques (NAT) are thought to be unsuitable for speciation analysis, because they, in principle, are based on nuclear characteristics, rather than on atomic or electronic behavior, in recent years more and more nuclear analysts are endeavoring to use NAT for speciation studies [3,4,5,6,7,8,9,10,11,12,13,14,15]. The main techniques include molecular activation analysis (MAA), proton-induced X-ray emission spectrometry (PIXE), and synchronous radiation-based analytical methods, etc.…”