A Gel-Permeation/Column Chromatography Cleanup Method for the Determination of CDDs in Animal Tissue

Abstract

A method which can be implemented in a routine organochlorine analysis laboratory equipped with a quadrupole GC/MS is presented for determination of tetrachloro-(T_4-) to octachloro- (O_8-) dibenzodioxins (CDDs) in animal tissues. Long chain-length biogenic compounds such as lipids are removed by gel-permeation chromatography (GPC), and the CDDs are separated from most interfering organochlorine compounds by a combination of alumina and Florisil chromatography. Recoveries from spiked samples were in the 87–97% range for T₄CDDs-H₇CDDs at the 5–100 ng/kg level except for 1,3,6,8- and 1,3,7,9,-T₄CDD, which had variable losses in the alumina chromatography step (recoveries of 73–97%). O₈CDD recoveries depended on level, 80% at 200 ng/kg, 52–59% at 30–40 ng/kg. Precision of replicate analysis was generally in the 2–7% range. Positive interferences not completely removed by the method were identified as methoxychloro-biphenyls and methoxychloro-diphenylethers. Examples of the application of the method are given.