Safy Khalifa

Toxaphene Insecticide: A Complex Biodegradable Mixture

Adsorption and gas-liquid chromatography separate toxaphene into at least 175 polychlorinated 10-carbon compounds including Cl6, Cl7, Cl8, Cl9, and Cl10 derivatives. One toxic component is 2,2,5-endo,6-exo,8,9,10-heptachlorobornane. Rats metabolically dechlorinate toxaphene, removing about half of the chlorine from the technical insecticide and from each of seven subfractions of varying composition and toxicity.

Alkyl phosphate metabolite levels in the urine of field workers giving blood for cholinesterase test in California

During the Summer of 1975, a blood cholinesterase (thE) monitoring study was conducted at farm worker health clinics in Californta*s Central Valley. Blood samples were collected at the clinic during the months of January, May, July and September and tested for ChE activity (KNAAK et al. 1978). During the grape harvest season, in September, 154 urine specimens (110 from males and 44 from f~=les) were collected from field workers in addition to blood samples. This study reports the level of (1) alkyl phosphates in the urine, using a modification of the test procedure publtshed by SEAFXK el: al. (1973) and (2) the Xevel of ChE activity in the blood of these individuals.

Characterization of the photoisomers from cis- and trans-chlordanes, trans-nonachlor and heptachlor epoxide

Abstract Irradiation of acetone solutions of trans-chlordane (4a) and trans-nonachlor (4b) with UV light produces new half-cage photoisomers (5a or 6a and 5b or 6b, respectively) with bridging that differs from that of the photoisomers (2 and 8a) obtained from cis-chlordane (1b) and heptachlor epoxide (7). A new photoisomer (10) obtained from heptachlor epoxide is transformed into photoisomer 8a on further irradiation. Detailed PMR and 13C-NMR studies establish the structures of the new photoisomers and permit a decision between alternative formulations for the structures of the half-cage photoisomers of heptachlor epoxide and cis-chlordane,