Tropane ethyl esters in illicit cocaine: isolation, detection, and determination of new manufacturing by-products from the clandestine purification of crude cocaine base with ethanol.

Seven ethyl homologues of known tropane esters have recently been detected as impurities in the gas chromatographic signature profiles of authentic Peruvian illicit cocaine base and hydrochloride exhibits. Peruvian cocaine base processors are now known to use ethanol for the purification of crude cocaine base. This process is referred to as the "base lavada" or "washed base" process and is a recent substitute method for the potassium permanganate oxidation purification methodology.