Provenance determination of Ricinus communis by trace elemental analysis

The castor bean plant (Ricinus communis) is an introduced perennial shrub found throughout Australia that contains the toxin ricin within its seeds. Ricin, the toxin popularised by the TV series Breaking Bad, is listed as a Schedule 1 toxin by the Department of Foreign Affairs and Trade and a Category B (second highest in priority) bioterrorism agent by the US Centers for Disease Control and Prevention. This is due to the easy accessibility to the castor bean plant and simple purification of the toxin, which is fatal through multiple modes of contact at extremely low doses. Historically ricin has been implicated as the lethal agent for the assassination of Georgie Markov in 1979. The ability to classify unknown samples of R. communis by comparing the elemental profile to established region-specific trends would be beneficial to law enforcement and forensic agencies.

Following on from preliminary findings, R. communis specimens and their corresponding soil profiles will be collected from VIC, NSW, QLD, WA, SA, and central Australia as part of this research project. Detailed characterisation of the soil profiles from each sampling site across all capital cities, and all other population centres of significance, will be undertaken to establish the variability between these locations. Analysis of the elemental profile of these samples will assist in establishing the similarities and differences between the soil profile and the seeds and, importantly, the identification of trace elements responsible for the interstate and intrastate discrimination of R. communis.