A comparative study by infrared spectroscopy and optical oxygen sensing to identify and quantify oxidation of Baltic amber in different ageing conditions

The aim of this study was to provide evidence about the interaction between Baltic amber and oxygen, essential to understanding the mechanisms by which the material degrades and to propose techniques for preventive conservation based on the control of environmental parameters where amber objects are stored or displayed. To investigate the oxidation of Baltic amber, the methodology consisted of artificial ageing, in order to initiate degradation of model amber samples, and non-destructive analytical techniques, in order to identify and quantify changes in chemical properties and oxygen consumption. Pellet-shaped samples, obtained from pressed amber powder, were exposed to different microclimatic conditions, subjected to accelerated thermal ageing and analysed by infrared spectroscopy together with optical oxygen sensing. The experiments provided comparable results about the oxidation state of the molecular structure and the consumption of atmospheric oxygen in similar conditions, confirming the degrading role of oxygen.