Error analysis of the determination of carbon stable isotope ratios in lignin and cellulose from plant samples

Abstract

To determine the accuracy and precision limits associated with carbon stable isotope ratio (δ¹³C) measurements of cellulose and lignin from plant samples, experiments were performed using differing extents of treatment for separating these two components. Laboratory reagent lignin and cellulose were used, together with model mixtures of both components. The resulting data were fitted to empirical functions. It was found that the δ¹³C of cellulose could be determined with higher accuracy (<0.1‰) than that of lignin (<0.25‰). The corresponding precision values were better than 0.04‰ and 0.08‰, respectively. Longer treatment times do not always result in better accuracy of the isotope data for either component.