Monitoring the Presence of Humic Substances in Wool and Silk by the Use of Nondestructive Fluorescence Spectroscopy: Quality Control for 14C Dating of Wool and Silk

Abstract

Radiocarbon dating of degraded wool and silk provides 14C results of questionable reliability. In most cases, degraded wool/silk contains humic substances (HSs). Thus, a nondestructive fluorescence spectroscopy method, using a fiberoptic probe, was developed to monitor the presence of HSs in degraded wool and silk. This method can provide information about the presence of HSs before and after pretreatment and about the 14C age reliability. This study suggests considering with care wool/silk samples 14C dating wherein HSs are detected, because the conventional solvent pretreatment method using a NaOH wash is in most cases not sufficient to remove all humic substance contaminants. As a result, unreliable 14C dates can be provided.