This thesis is divided into two parts. Part A
describes the development o f some biosensors based on
the immobilisation o f enzymes, tissue, microbes and
plant materials in carbon paste. The performance
characteristics o f these biocatalytic devices were
investigated in both batch and flowing systems for the
detection o f neurotransmitters, mono-phenols and
glucose using amperometry. A new immobilisation
procedure involving the use o f spectroscopic graphite
and silicone grease is also described. Anodic
Stripping Voltammetry was employed to illustrate the
detection o f Pb(II) and Cu(II) at lichen-modified
carbon paste electrodes.
Continuing the theme o f metal analysis in Part B,
comparison o f chromatographic and spectrometric
methods is described for the detection o f Fe(III) and
Al(III) in soils and clays. Information regarding
speciation o f these metals within the matrices o f
soils and clays was obtained. Subsequently, a
chromatographic method for the separation o f Fe(II)
and Fe(III) was investigated involving the use o f an
ion-pairing reagent.