T02_01

On the Prospects for Compound-specific Radiocarbon Analysis of Carbohydrates

Dee M¹,  van der Wal K¹, Ghislain T², Jurak E³, Kuitems M¹

¹Centre for Isotope Research, University of Groningen, Groningen, Netherlands, ²Biomass Technology laboratory, University of Sherbrooke, Sherbrooke, Canada, ³Bioproduct Engineering, University of Groningen, Groningen, Netherlands

Compound-specific analysis of proteins and lipids lies at the forefront of current radiocarbon research. At the same time, interest has also been growing in radiocarbon measurements on carbohydrates, especially cellulose extracted from wood. Cellulose provides the most reliable record of fluctuations in the atmospheric concentration of ¹⁴CO₂ prior to the Modern Era. As well as information on the carbon cycle, such analyses have become increasingly important to palaeosolar investigations. Hydrolysing cellulose to glucose may appear redundant, given the fact the former is comprised wholly of the latter, but there are several potential advantages. Firstly, raw cellulosic extracts are more likely to retain chemically or physically bound exogenous carbon than a spectroscopically characterised monomer. Secondly, glucose is the primary product of photosynthesis – the most immediate manifestation of local ¹⁴CO₂ values. Thirdly, for cosmic-ray and carbon cycle analysis, radioisotope measurement need not be curtailed for calibration purposes. Such studies are only limited the purity of the extract obtained and the reproducibility of the associated measurements. Thus, compound-specific carbohydrate analysis may allow new levels of detail to be obtained on the past concentration of radiocarbon in the atmosphere. Despite all this potential, previous attempts at glucose preparation for radiocarbon analysis have proven unsuccessful. Here, we discuss some recent investigations into this matter we have been conducting at the University of Groningen.