The oscillator strength in atomic absorption spectroscopy

The role of the oscillator strength in atomic absorption spectroscopy, and in particular in absolute elemental analysis by atomic absorption, is discussed. A universal method for determining atomic lifetimes, and hence absolute oscillator strengths of atomic resonance lines, for almost any element in the Periodic Table is described. It is shown that for the idealized conditions of a pure natural-broadened absorption line and a monochromatic emission line, the peak atomic absorption coefficient is independent of the oscillator strength and that the oscillator strength enters into an atomic absorption signal only through extraneous broadening processes such as Doppler, collisional, and transit-time broadening. An atomic absorption experiment, based on samples of near-stationary laser-cooled atoms and a near-monochromatic diode-laser light source, that satisfies the requirements for "oscillator-strength-free" atomic absorption is described, (C) 1999 Academic Press.