About the lab
The Stable Light Isotope Laboratory at UCT is one of only a few labs of its kind in Africa.
It provides an essential research tool for many disciplines within the Earth and Life Sciences, including archaeology, geology, oceanography, plant and animal physiology and ecology and biomedical sciences.
The research group measures naturally occurring variations in the stable light isotopes (mainly carbon, nitrogen, and oxygen) to investigate many processes in the natural world, such as flows of nutrients through foodwebs. We are particularly interested in past diets and climate.
We offer a range of analytical services for researchers, along with training, and scope for collaboration.
Lab history
The Stable Light Isotope Laboratory at UCT was founded in the mid-1970s by Nikolaas van der Merwe when he took up the Chair of Archaeology at UCT. Initially samples were prepared in Cape Town and purified carbon dioxide gas (in glass flasks) flown to Pretoria, where the isotope measurements were made in John Vogel’s lab at the Council for Scientific and Industrial Research (CSIR).
Among the early projects was their joint study of the introduction of maize farming into eastern North America – the very first application of ¹³C/¹²C as a dietary tracer. In 1982 the lab acquired its first light isotope mass spectrometer (a VG 602E), followed in 1994 by a Finnigan 252 with elemental analyser and Kiel device. These enabled automated gas production, purification and introduction into the mass spec, allowing much larger numbers of samples to be analysed.
The success of the lab was critically dependent on John Lanham’s maintenance and supervision of these and subsequent instruments until his retirement in 2018. By that time, the lab was producing more than 20 000 stable isotope analyses per year for users from UCT, institutions elsewhere in South Africa, other African countries and beyond.
Recently, the lab has received a major boost from the Biogeochemistry Research Infrastructure Platform (BIOGRIP), which has supported the acquisition of new IRMS and TILDAS instruments, as well as ancillary smaller items of equipment. A major renovation and upgrade of our lab is planned for 2021-2022.
Nikolaas van der Merwe next to a manual gas separation line in the Stable Light Isotope Laboratory in 1999.