Pretreatment of the Tree-Ring Samples for Stable Isotope Analysis

The study of stable isotopes in tree rings,including δ13C,δ18O and δD,as a potential tool for studying dendrochronology,has rapidly developed and widely applied in the past 30 years.To extract α-cellulose from wood is a necessary pretreatment for palaeoclimate and palaeoenvironment studies by using tree-ring stable isotopes.However,it is time-consuming and labor-intensive.With the purpose of drawing forth more attention to the experimental flow for obtaining isotopic samples in tree rings and eliminating differences resulted from divergent experimental processes,the extraction procedures of cellulose and cellulose nitrate both at home and abroad in the recent years are summarized in this paper.The extraction method used in our research group is also provided.Their feasibility is also discussed.It is expected that more attentions will be paid to the influences of samples pretreatment on the stable isotopic values and to eliminate them in the studies of palaeoclimate,palaeoenvironment and ecology.