| Summary: | Motivation: The health effects of platinum on the human body are a great concern. It affects
the respiratory system as well as the skin. The demands for platinum have seemingly
increased over the last few years due to its use in automobile exhaust gas catalysts. Thus
there will be an increase in the production and processing of platinum and therefore a greater
possibility of exposure to platinum compounds. This is why it is of great importance to evaluate
the surface sampling methods, to ensure that they are effective for platinum use. Objectives:
1) To evaluate and compare a few different surface sampling methods for removal of platinum
salts from contaminated surfaces in order to determine which one of these methods has the
best retention and recovery efficiency. 2) To use the most effective method to monitor surface
contamination on porous and non–porous surfaces in a platinum refinery. Methods: Two types
of filters (mixed cellulose ester and polyvinyl chloride) and GhostwipesTM were evaluated and
compared in this study. Platinum solution (hexachloroplatinic acid) concentrations of 50, 150
and 300 ug Pt/ml solution were used. The retention efficiency of the different sampling
mediums was tested by releasing 1 ml of each concentration directly onto the sampling
medium. Efficiencies were tested on a non–porous (glass) and porous surface (semi–face
bricks). This was done to see how the collection efficiency of the medium will differ on these
two surfaces. A total of three wipes were used per surface, however were analyzed individually.
All the samples were analyzed using the Inductively Coupled Plasma Atomic Emission
Spectroscopy (ICP–AES) analytical method by an accredited laboratory. Results: The results
obtained indicated the retention and recovery efficiencies of the three sampling mediums at the
three platinum concentrations of 50, 150 and 300 ug Pt/ml solutions. The retention efficiency of
the GhostwipesTM was 93.2% at 50 ug Pt/ml solution, 95.3% at 150 ug Pt/ml solution and 93.6%
at 300 ug Pt/ml solution, whilst the mixed cellulose ester (MCE) filters and polyvinyl chloride
(PVC) filters were lower than 30% at all three concentrations. The overall recovery efficiencies
of all three concentrations of the GhostwipesTM and MCE filter were the highest: the
GhostwipesTM with levels of 73.9 %, 84.4% and 63.5% and the MCE filters with levels of 71.4%,
84.4% and 80.2%, whilst the PVC filters did not achieve levels above 60%. The wipe materials
were also evaluated in terms of the ASTM E1792 standard requirements for wipe materials.
Conclusion: GhostwipesTM were found to be the most suitable sampling medium based on
retention and recovery efficiencies. The GhostwipesTM also complies with all the requirements
listed in the ASTM E1792 standard for wipe materials, which makes it the most suitable wipe
sampling material. The MCE and PVC filters however do not comply with all the ASTM E1792
requirements. === Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011.
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