Samples can be submitted to the network as bulk organic sediment samples, which can be prepped and processed at Yale University, or as the following sample types: plant/wood fragments, charcoal, mollusc, Coral, Foraminifera, Otolith, and/or bulk sediment (carbonate material). Processing of bulk organic sediment samples includes removing organic and inorganic contaminants from the samples. We can also separate out samples (e.g. plant fragments and charcoal) from the bulk sediment through sieving and picking using a brush or tweezers under a microscope. In order to pick out these samples, submitters should not grind their bulk sediment prior to sample submission. Root material should be avoided in sample submissions as modern roots or rootlets could contribute modern contamination. Collaborators interested in compound-specific 14C measurements will currently need to collect the compound fraction as of right now, though this may change in the future. Compounds of interest for such measurements could include fatty acids, lignin phenols, sterols, plant waxes, PAHs, PCBs, and lipids.
Pretreatment of plant/wood, charcoal, and bulk organic sediment at Yale University would involve a series of acid-base-acid leaches to remove mobile phases of organic carbon and inorganic carbon. A general rule-of-thumb is to estimate 40% carbon by weight for plant/wood or charcoal. Some weight is potentially lost due to pre-treatment. Expect to need about 1mg of organic carbon samples following the treatment to achieve 100-300 ug C. Inorganic carbon (carbonate) samples may require 1-3mg to achieve a yield of 100-300 ug C. For bulk sediment, we would need to know the relative amount of organic carbon so if this has previously been measured, please include these measurements with your sample submission. If this data is missing, we can determine it in YASIC.