The1 application of voltammetric methods to the
determination of some compounds of environmental1 importance is described. In addition, a comparison of
electrochemical (EC) detection and ultraviolet (UV)
detection for the quantification of phenolic compounds in
beers following separation by high performance liquid
chromatography is also illustrated.
A field study is described in which differential
pulse anodicj stripping voltammetry (DPASV) at a mercury
I film electrode (MFE) was used to measure the levels of
dissolved cadmium, lead and copper in the Irish Sea.
Difficulties encountered with DPASV measurements in rough
weather suggest that the method is not suitable for field
analyses. In contrast, cold vapour atomic absorption
spectroscopyl is Ideally suited to the quantification of
mercury In field analyses.
A speciation scheme was developed to separately
measure inorganic, dimethyl- and trimethyl-lead species in
mixtures. Quantification was carried out using DPASV. By
using a plating potential of -1.2V the three lead species
are simultaneously measured. When the plating potential is decreased to -0.6V only inorganic and dimethyl-lead are
measured. On addition of a complexing agent and using the
latter plating potential, dimethyllead can be measured in
the presence of inorganic lead.
The HPLC method used for the separation of
phenolic compounds is a modification of a previously
described method. A comparison was made between a UV
detector and an EC detector in series. In general, the EC
detector offered lower limits of detection for most of the
phenolic compounds studied. Analysis of beers indicated
that EC detection was more suitable than UV detection with
respect to sensitivity and selectivity.