An approximate model for the liberation and ionization of atoms from individual solute particles in flame spectrometry

Abstract

A model is described which incorporates the generation and ionization of atoms during the vaporization of individual solute particles in flames. Particles initially larger than a critical radius have two vaporization rate constants because of a change in the vaporization mechanism related to size. Consequently, the mathematical formulation of the model consists of a series of three equations which are used to curve-fit different portions of emission intensity-time profiles in an air-acetylene flame. Values for the vaporization rate constants for three alkali chlorides found for this fitting process are: Na (244 μm2/s, 127 μm/s), K (650 μm2/s, 299 μm/s), and Cs (385 μm2/s, 847 μm/s). First-order ionization rates are 58 s-1 for Na, 268 s-1 for K, and 1128 s-1 for Cs. © 1981.