Investigation of Transient Molecular Absorption in a Graphite Furnace by Laser-Induced Plasmas

The transient molecular species that are produced in electrothermal atomizers are probed by backlighting the furnace with continuum emission from laser-induced plasmas. Laser plasmas provide a stable and strong continuum spectrum in the UV region for molecular absorption studies. These plasma sources exhibit a substantial improvement in UV absorption measurement over the more conventional sources, permitting good time resolution. The molecular absorption spectrum from 190 to 320 nm for NaI, NaCl, and KH 2 PO 4 are illustrated. The temporal and spectral resolution of this instrument are 100 ms and 0.2 nm, respectively.