Theoretical and practical limits in atomic spectroscopy. Plenary lecture

Abstract

Theoretical expressions are given for the efficiency of detection and the efficiency of measurement for several atomic methods, including atomic absorption, atomic emission, atomic ionization, atomic fluorescence, and mass spectrometry, where flames, plasmas and furnaces are used to produce atoms or ions and in some cases excited atoms and ions. These unique expressions are then used with noise expressions to develop detection limit expressions. Assuming reasonable values of instrumental and spectroscopic parameters, efficiencies of detection and measurement and detection limit of atoms in the sample are estimated to within an order of magnitude. Several methods have the capability of being single atom measurement approaches, and therefore potentially useful for atom counting. Considerable discussion of noise sources and a comparison of atomic methods with respect to a variety of analytical figures of merit are given. The present fundamental approach is used to predict the future potential of various atomic methods.