HNO 3. ICP-AES showed a wide variety of elements to be present with a particular build-up of cobalt,
nickel and zinc (50–100 ppm). The presence of lead, cadmium and mercury at dangerously high levels
was not indicated. Additional qualitative studies were made by electron probe analysis and ICP-MS.
The levels proved to be too low for effective use of the former method whilst the second confirmed the
ICP-AES results. Facilities for X-ray fluorescence were not available and flame photometry was not
considered suitable for the elements of interest.
Systematic quantitative analysis was subsequently carried out utilizing the sensitivity, precision and
simplicity provided by ICP-AES. Pb and Hg were monitored using the superior sensitivities of AAS for
these elements. All measurements were made on the solutions derived from the wet oxidation or
extraction of the samples. A limited series of ICP-MS analyses were made to provide a check on the
results being obtained by atomic absorption and ICP-AES. Figure 12.3 summarizes the various stages in
the solution of this analytical problem.
The Analysis of Hydrocarbon Products in a Catalytic Reforming Study
Example 12.2.4
In hydrocarbon reforming processes the vapour of an alkane is passed over a supported metal catalyst
such as platinum on silica or alumina. Dehydrocyclization, isomerization and cracking reactions all take
place to
Figure 12.3
Outline analysis of shellfish for heavy metal pollutants.