The effect on woods of a sterilisation process based on gamma rays

Gamma ray sterilization is applied to very different products as medical material and gear - including more generally pharmaceuticals and cosmetics - and wooden craft products, e.g. musical instruments. The purpose of irradiating wood is to improve shelf-life, destroying the living causes of decay: bacteria, fungi, worms and insects with their eggs and larvae. In general, gamma sterilization does not induce large changes in the chemical components of wood, or at least, no larger than other sterilization processes. In this work, preliminary results are shown on chemical and structural effects of a sterilization experimental campaign in which increasing doses of gamma rays were delivered to four different types of wood: fir, maple, poplar and oak. The effects were evaluated comparing the results obtained with cyclic voltammetry, linear square voltammetry, and infrared spectroscopy techniques. Furthermore, the surface products of wood degradation, and in particular of the degradation of cellulose and hemicelluloses, were investigated with a non-invasive method in which they were removed with gel of gellan. After that, electrochemical measurements were performed of glucose - one of the degradation products of polysaccharides - extracted by the application of the gel. Results were compared to those attained from spectroscopic analysis, to reveal structural characteristics and possible presence of heavy metals.