Radiocarbon dating of single compounds isolated from pottery cooking vessel residues.

Abstract

We have developed and demonstrated a practical methodology for dating specific compounds (and octadecanoic or stearic acid--C (sub 18:0) --in particular) from the lipid material surviving in archaeological cooking pots. Such compounds may be extracted from about 10 g of cooking potsherd, and, after derivatization, can be purified by gas chromatography. To obtain sufficient material for precise dating repetitive, accumulating, GC separation is necessary. Throughout the 6000-year period studied, and over a variety of site environments within England, dates on C (sub 18:0) show no apparent systematic error, but do have a greater variability than can be explained by the errors due to the separation chemistry and measurement process alone. This variability is as yet unexplained. Dates on C (sub 16:0) show greater variability and a systematic error of approximately 100-150 years too young, and it is possible that this is due to contamination from the burial environment. Further work should clarify this.