A comparison of analytical methods for the certification of biobased products

Abstract

ABSTRACT. The U.S. Federal Biobased Products Preferred Procurement Program (FB4P) requires all federal agencies to give preference to eligible biobased products as defined by the U.S. Department of Agriculture. In the development of FB4P, Iowa State University has employed a number of laboratories nationwide to measure the percentage levels of modern carbon present in the biobased products. The measurements are made in accordance with ASTM Method D6866-05, which specifies 3 different radioanalytical procedures that can be used. Two of the analytical methods involve radioisotope measurement by liquid scintillation counting (LSC) of samples prepared as 14C carbamate or 14C benzene. A third method uses accelerator mass spectrometry (AMS) with graphite sample preparation. The Center for Applied Isotope Studies (CAIS) at the University of Georgia is unique in its analytical capabilities to perform onsite analyses of biobased products using all 3 methods. This paper compares the sensitivity of the 3 methods and reports results of biobased product samples of industrial origin as mea-sured at the CAIS.