MONITORING THE PRESENCE OF HUMIC SUBSTANCES IN WOOL AND SILK BY THE USE OF NONDESTRUCTIVE FLUORESCENCE SPECTROSCOPY: QUALITY CONTROL FOR C-14 DATING OF WOOL AND SILK

Radiocarbon dating of degraded wool and silk provides C-14 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 C-14 age reliability. This study suggests considering with care wool/silk samples C-14 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 C-14 dates can be provided.