Thesis-1987-Stone.pdf (4.73 MB)
Models for dispersion in flow injection analysis
thesis
posted on 2013-11-20, 12:26 authored by David C. StoneAn extensive study has been made of the factors affecting sample
dispersion in flow injection analysis. This has included the effect
of different manifold parameters on peak height and shape, and the use
of various flow models to describe the physical processes involved.
The factors investigated included sample flow-rate, tube length
and diameter, sample volume, and the diffusion coefficient of the
solute. The role of the detector has also been investigated, and was
found to exert a strong influence on the observed dispersion behaviour
of a flow injection manifold. In the light of this, a low volume flow
cell was constructed which minimised the contribution of the detector
to dispersion. Different modes of sample injection ("time" and "slug"
injection) have been studied, and an automatic valve constructed in
connection with the work.
Both new and existing flow models have been evaluated in terms of
their ease-of-use and ability to predict peak shape. Conditions for
which the different models were valid were derived both experimentally
and from consideration of the assumptions of the models. The
applications of such models to the characterisation and design of flow
manifolds has also been considered, and this approach compared to the
purely theoretical and empirical approaches that have been described
in the literature. The models examined in this thesis are the
convection, diffusion, tanks-in-series, well-stirred tank, two-tanks in-
parallel and two-tanks-in-series models.
Finally, the practical implications of this work for the design
of flow injection manifolds and the derivation of so-called "rules for
dispersion" have been discussed, and suggestions made for further
areas of research.
Funding
Financial support from the Science Education Research Council and Pye Unicam Ltd.
History
School
- Science
Department
- Chemistry
Publisher
© D.C. StonePublication date
1987Notes
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.Language
- en