Currently, accelerator mass spectrometry (AMS) technology provides the radiocarbon researcher with the ability to routinely measure samples of 500 micrograms to one milligram of graphitic carbon. Radiocarbon age determinations using AMS technology reduces the carbon requirement by several orders of magnitude from decay counting methods. This reduction in the required carbon sample size has allowed researchers access to samples previously not practical to measure. This study will focus on two methods to reduce the required amount of carbon for AMS radiocarbon dating in the ultra small sample range. This project has two pivotal objectives. The first objective is to optimize the processing of microgram to nanogram-sized samples of catalytically-reduced graphitic carbon for AMS radiocarbon age determinations. The second goal is to determine the most accurate way to correct 14C/13C ratios for contaminant contribution to the measured ratios of these ultra small samples. The ability to utilize AMS technology that reduces the required amount of a graphitic carbon sample to the levels of ultra small samples on a routine basis would provide the archaeological researcher with the opportunity to seek new areas of scientific inquiry. These include but are not limited to organic residues on potsherds, rock art, pollen, phytoliths, sherd temper, plant amino acids, amino acids from bone, seeds, charcoal smudges, and organic residues on tools. All of these materials are candidates for radiocarbon age determinations but the limiting factor is the extremely small amounts of organic material. Critical data from these sources could provide clues to help answer a variety of questions about human origins and prehistoric cultures. Paleontology, environmental and paleoclimatic studies and oceanography would also benefit from this research. Material that may be used for ultra small samples include amino acids in fossil bone and teeth that fall within the range of radiocarbon, chemical compounds in atmospheric aerosols, marine dissolved organic carbon and foraminifera. Each of these research areas could utilize ultra small sample technology to gather critical data and develop new areas of inquiry. The funding provided by the POWRE program opens up new avenues of research that will allow career enhancement and substantively further professional standing with the research community. Since the investigator is in a non-tenured research associate position, POWRE support may assist in her academic advancement as well. This project could provide the scientific community with a useful new tool and offers the researcher a chance to contribute in an area not ordinarily available through regular research grants.
