Environmental Isotope Analysis

Compound-specific isotope analysis (CSIA) is a powerful tool for identifying chemical origins radiocarbon dating and unravelling intricate environmental processes, therefore providing insights into the origins, transformations, and fate of specific compounds in the environment. For example, 14C can be used in radiocarbon dating to determine the age of biologically-derived carbon containing materials and artefacts. Stable isotope ratio measurements can also be used to track the origin and transfer of compound thorough environmental systems and ecological processes e.g. using carbon, hydrogen, oxygen and nitrogen stable isotopes in food-web studies, nutritional research, palaeodietary reconstruction, archaeological residue analysis, forensics, environmental management and  conservation efforts.  

Compound-Specific Radiocarbon Dating

McCullagh's D.Phil. (Oxford) involved the development of a compound-specific radiocarbon dating method using preparative mixed-mode chromatography to separate individual amino acids derived from archaeological bone protein (mainly Type 1 collagen) which were then converted to carbon and then 14C content measured using accelerator mass spectrometry. This has become a gold-standard method for dating in archaeology as it provide collagen-specific dates with less interference from contamination associated that can be associated with other methods.

Compound-specific isotope analysis (13C/12C)

By examining the stable isotopic compositions of individual molecules, CSIA provides a unique lens to trace the sources, transformations, and fates of crucial elements within organic compounds. CSIA enables precise identification of the origins of carbon and nitrogen-containing substances for example, offering insights into biogeochemical processes and paleodiets where evidence is often missing from the archaeological record. McCullagh and co-workers developed online CSIA methods for 13C/12C analysis in 2006 and examined the role of amino acids in biochemical systems in particular in a series of publications.

 
egu poster amino acid method development lc irmsconferencefinal
Selected publications
radiocarbon
carbon isotope analysis of bulk keratin and single amino acids from british and north american hair
pnas 1116328109b page
mccullagh et al