To ultrafilter or to not: Is further purification necessary for reliable radiocarbon dating of collagen from ancient aboriginal Canary Island bones?

Abstract The use of ultrafiltration remains a subject of ongoing debate among pretreatment methods employed in radiocarbon dating of mammalian archaeological bone. However, such discourse had not previously extended to the archaeology of the Canary Islands (Spain), where detailed descriptions of laboratory processing methods for collagen purification often remain absent. Our study presents a case study involving a new set of radiocarbon dates obtained from the remains of ancient natives of Tenerife Island. For the first time in this region, we compared the results of ultrafiltered with non-ultrafiltered collagen from the same individuals, focusing on the method’s implications for dating accuracy in the Canaries. Through an examination of the cleaning protocols of ultrafilters and an assessment of the reliability of radiocarbon dating outcomes, we have found that ultrafiltration may influence the accuracy of results. However, given the additional handling required and the potential risk of contaminating the samples, its application should be carefully considered. In the context of the Canary Islands, ultrafiltration may be most relevant for samples associated with early human occupation, though further research is needed to assess its necessity across different biogeographical contexts. This communication further contributes to a broader understanding of preparation methods for radiocarbon dating bone from various environmental contexts, emphasizing the uniqueness of each case. Furthermore, we discuss the implications of our findings for archaeological research in the Canary Islands, highlighting the methodological gaps that persist in the region and underscoring the importance of ensuring the accuracy and reliability of chronological interpretations in archaeological investigations.