These tracers are formed from a core of a strongly acidic cation exchange resin radiolabelled with 68Ga supplied by a SnO268Ge/68Ga generator. 68Ga has a half-life of 68 minutes, and we aim to radiolabel the tracer particle with sufficient activity for experiments for duration of 2-3 hours. The radiolabelled ion exchange resin is then coated or embedded within another particle to obtain the desired physical and chemical properties. The size of the core resin is dependent on the target application, with higher speed or dense systems tending to require higher levels of labelled activity and thus a bigger core size. If the material of interest is absorbent or porous, it is possible to coat and seal a particle to maintain its physical characteristics. We can also control the surface hydrophobicity or density of the final tracer with specialised coatings.
Our current range of routinely available tracer particles are below:
Types of tracers
0.05 - 1.2
1.0 - 1.2
0.6 - 1.5
Hydrophillic - hydrophobic
1.4 - 2.9
As base material
0.9 - 6.0
A selection of PEPT Cape Town tracer particles from left to right: moulded density modified, mineral coating, silica coating, coal particles, glass bead.The first tracer on the left is approximately 300 microns in width.
Radiochemistry laboratory upgrade
Renovations in 2017 now allow for tracer production and research to be performed within the centre. This new area is dedicated to producing tracer particles for our current projects as well as development of new tracer methods for future projects. We developed a novel method for improving production control and reliability by removing contaminants from the radionuclide supply (van Heerden et al., 2020).
The best tracer particles for PEPT are physically representative of the particles in the system of interest. With each new application for PEPT, we work closely with the equipment and materials involved to develop appropriate tracer labelling techniques. Please contact us to discuss your bespoke tracer requirements.
Coming soon: tracer particles radiolabelled with 18F by ion exchange and direct activation. 18F has different ionic behaviour to 68Ga and a longer half-life of 110 minutes.
Department of Physics
RW James Building, University Avenue
University of Cape Town
+27 (0) 21 650 3339 / 3326 Andy Buffler