Coca paste: chemical analysis and smoking experiments.

Several samples of Colombian and a sample of Peruvian coca paste were subjected to chemical analysis to ascertain the complexity of these products. A neutral and acid fraction and a basic fraction were analyzed by gas chromatography/flame ionization detection (GC/FID) and gas chromatography/mass spectrometry (GC/MS). The basic fraction was also analyzed as its trimethylsilyl (TMS) derivative. Several gasoline residue components were identified in the neutral fraction. In addition to cocaine (greater than 60% in all cases), other alkaloids were identified. Lead and manganese analyses were carried out on these samples. While all the samples contained no lead (less than 45 ppm), most of the Colombian samples contained significant amounts of manganese (greater than 5%). Preliminary smoking experiments with a Colombian coca paste sample indicated that it behaves more like free cocaine than like a cocaine sulfate salt.