Compositional Analysis of Archaeological Leather and Simulated Leather and their Degradation Research Based on HRMS

Abstract

Leather, as one of the earliest natural materials, have been extensively utilized not only in daily attire but also in military protection in the ancient times. Combined with simulated degradation experiments, high-resolution mass spectrometry (HRMS) was employed for the rapid and non-targeted detection of components in archaeological leathers, and systematically analyze the chemical composition of leather samples. Comparative amino acid analysis of simulated and archaeological leather samples demonstrated that L-hydroxyproline content and the signal intensity ratio of isoleucine & leucine to valine serve as integrated parameters for evaluating leather aging status. Moreover, the identification of other amino acids and tens of degraded products such as succinic acid, L-carnitine and 4-guanidinobutanoic acid deserve special attention. 4-Guanidinobutanoic acid existed in both simulated leather and archaeological artifacts. This research provided a new analytical tool for the significant insights into ancient leathers and their degradation status. In addition, HRMS enables detection of early degradation signals in cultural relics, allowing conservation professionals to quantify degradation levels among different artifacts. This facilitates prioritization of deteriorated leather by heritage institutions.