A new R6-million ultraclean isotope geoscience laboratory has been launched at the School of Geosciences at the University of the Witwatersrand (Wits).
The Wits Isotope Geoscience Laboratory (WIGL), working closely with the University of Johannesburg’s (UJ’s) Department, aims to deliver a platform for local isotope analysis, eliminating the need to ship samples to Europe and saving time, costs and resources.
The laboratory, which was funded by Wits and took over a year to build, provides an opportunity for Southern African ecology, palaeontology, medicinal and geoscience scientists to perform ultraclean, contamination-free experiments that separate isotopes from Earth materials.
The elements and isotopes that the laboratory aimed to separate were normally present in extremely low abundance in rocks, meteorites, fossils and water, explains WIGL director Dr Grant Bybee.
“Elements like lead, strontium, copper and zinc are normally only present at the part per million or part per billion level in these materials and so it is crucial that we process these samples in an extremely clean and contamination-free environment,” says Bybee.
Normal air contains over one-million particles per cubic foot, but the complex air filtration system in WIGL reduces this by about a million times to one to ten particles per cubic foot.
“Along with a completely metal-free environment – everything in the lab is constructed of durable, acid-resistant plastic – this air quality ensures that any sensitive samples processed in the WIGL remain contamination-free,” he added.
The WIGL is made up of four separately sealed rooms, where the air quality and flow is carefully controlled.
“A working sample, like a crushed rock, would enter through the first room, where it would be weighed on an incredibly precise scale. It would then pass through a secure air-controlled hatch, where, in the second room, it would be dissolved in strong acid, like hydrochloric acid, and prepared for analysis in the third and fourth rooms,” Bybee further explains.
Special resins and chemical techniques allow the researchers to separate the elements of interest, after which samples will be sent to an ultraprecise mass spectrometer at UJ’s Department of Geology Department, where the exact amount of each isotope will be measured.
“The two labs at Wits and UJ have developed an incredibly strong collaboration aimed at advancing our understanding of Earth processes using high-quality isotope measurements,” Bybee adds.