Inclusion of C-13(12)-labelled mono-, di-, and tri-chlorinated dibenzo-p-dioxin and dibenzofuran standards in US EPA methods 0023A/8290

C-13(12)-Labelled mono-, di-, and tri-chlorinated dibenzo-p-dioxin (CDD) an d chlorinated dibenzofuran (CDF) standards have been tested for their appli cability to standard EPA sampling and analytical Methods 0023A/8290. These methods target for analysis only the tetra- through octa-CDD/CDF homologues . Extension of the isotope dilution method to include those lower chlorinat ed homologues is important toward obtaining reliable species concentration data on the complete, mono- to octa-chlorinated homologue profile. These da ta will improve our ability to model poly CDD/CDF concentrations through un derstanding mechanisms of poly-CDD/CDF formation, chlorination, and dechlor ination. (C) 2001 Elsevier Science Ltd. All rights reserved.