Abstract
An improved method, involving potassium tert.-butoxide and tert.-butanol treatment followed by acetylation, is described for the similtaneous confirmation of heptachlor, heptachlor epoxide, and cis- and trans-chlordanes in cleaned-up feed samples. Parent pesticide residues can be identified at levels of 0.01 ppm and above. As a confirmative test for dieldrin, the formation of an acetate and subsequent conversion to a “ketone” by acetic anhydride/ sulfuric acid treatment is used. The concentrated sulfuric acid-catalyzed isomerization of endrin is also reported.