Analysis and Air Quality Division, Environmental Technology Centre, Environment Canada, 3439 River Road, Ottawa, Ontario, Canada K1A OH3;
Due to the limited number of environmental matrix certified reference materia..1s (CRMs) with assigned values for natural levels of polychlorinated dibenzo-p-diox- ins and dibenzofurans (PCDDFs), an interlaboratory study was undertaken by the National Institute of Standards and Technology (NIST) and Environment Canada to establish reference concentration values for selected PCDDFs in two well-characterized NIST Standard Reference Materi- a.ls (SRMs): SRM 1649a (Urban Dust) and SRM 1944 (New York/New Jersey Waterway Sediment). Results from .14 laboratories were used to provide reference values for the seventeen 2, 3, 7, 8-substituted PCDDF congeners, the totals for individual tetra- through hepta-substituted PCDD!F homologues, and the total amount of tetra- through hepta-substituted PCDD!Fs. The mass fractions for the individua12, 3,7, 8-substituted congeners range from approximately 0.0 1 #mu#g/kg to 7 #mu#g/kg dry mass.
Chung H.Chiu; Analysis and Air Quality Division, Environmental Technology Centre, Environment Canada, 3439 River Road, Ottawa, Ontario, Canada K1A OH3; Fresenius'Journal of Analytical Chemistry; V.369 N.3/4 2001; 356-363