EXPERIMENTAL STUDIES ON SPATIAL DISTRIBUTIONS OF ATOMS SURROUNDING AN INDIVIDUAL SOLUTE PARTICLE VAPORIZING IN AN ANALYTICAL FLAME

An experimental procedure Is described which allows the direct, time-resolved investigation of the spatial distribution of analyte atoms surrounding an individual solute particle vaporizing in a laminar flame. In the procedure, the individual atomic clouds are observed spectrometrically as the flame sweeps them past a fixed horizontal viewing region. The spatial intensity profiles so obtained are treated by a spherically symmetric Abel-type series, to provide the radial analyte distribution in each cloud. These measured radial distributions are used to experimentally verify a theoretical model, previously described, which convolves the processes of analyte vaporization and diffusion. From measured vaporization rates and least-squares fits to experimental data, effective diffusion coefficients for analyte atoms are determined. The lateral diffusion interference of phosphate on calcium In nitrous oxide-acetylene flames is also studied with the new method. It was found that the calcium vaporization rate and not Its diffusion coefficient changes with addition of phosphate, causing the observed alteration in spatial distribution. © 1979, American Chemical Society. All rights reserved.