Analysis of Compounds of Biological Interest by Electron Spectroscopy

Abstract

Abstract Electron spectroscopy involves measuring the energies of electrons ejected when matter is irradiated with photons. One of the more powerful applications of electron spectroscopy is the determination of the binding energies of the inner shells of atoms with soft X-rays. The binding energies of the inner shells are characteristic of the element; thus, a means of qualitative analysis is provided. Quantitative analysis can be done also. In addition, use of high-resolution spectroscopy enables one to determine the oxidation state of each atom, because the binding energies will shift with chemical environment. For example, the K shell binding energy in nitrogen is about 10 V lower for an amine group than for a nitro group. This analysis can be used for all elements with atomic numbers higher than lithium. The advantages of electron spectroscopy for biological research, both for fundamental and in chemical applications, are discussed in general. Recent studies on t-RNA and its bases are given as specific examples of the applicability of the method.