Wei HuangColumbia UniversityDue to the specific chemical structure of cellulose (C6H10O5)n, people could analyze dual isotopes d13C and d18O of cellulose by TCEA, instead of analyzing them separately. This could save lots of labor to extract cellulose and minimize sample sizes. We did some comparison experiments to test if this method could be applied on other sugars, starches or whole wood tree-ring samples.