Hepatic fatty acid conjugation of 2-chloroethanol and 2-bromoethanol in rats.

To study the formation of fatty acid conjugates of 2-chloroethanol (2-CE) and 2-bromoethanol (2-BE), rats were administered (by gavage) 50 mg/kg of 2-CE and 2-BE in mineral oil and sacrificed on fifth day of the treatment. Hepatic microsomal lipids were extracted, and the fatty acid esters were separated by preparative thin-layer chromotography. The ester fraction was further purified by reverse-phase, high-performance liquid chromatography and analyzed by ammonia chemical ionization mass spectrometry. Pseudomolecular ions (M + NH4+, base peak) at m/z 336/338, 362/364, and 364/366 in a ratio of 3:1 and 380/382 and 408/410 in a ratio of 1:1 confirmed the in vivo formation of 2-chloroethyl palmitate, 2-chloroethyl oleate, 2-chloroethyl stearate, 2-bromoethyl palmitate, and 2-bromoethyl stearate, respectively. These results demonstrate the formation of fatty acid conjugates of 2-CE and 2-BE in vivo. These fatty acid conjugates may be retained in the body for a longer time and cause toxic manifestations.