ANALYSIS OF THE HOMOGENEITY OF POWDERS BY GAS CHROMATOGRAPHY-MASS SPECTROMETRY

In forensic drug chemistry, most street drugs are formulated by the combination of powders, one or more of which is an illicit drug. Because the amount of controlled substances contained in the mixture determines sentencing, laboratory practices must ensure that portions combined for analysis are representative of the entire seizure. Often it is difficult to ascertain whether or not the mixture is truly uniform, especially when all powders combined are white. The analyst may rely on visual cues that have not been evaluated. In this study, caffeine and mannitol were chosen as surrogates for illicit drug and cutting agent. Caffeine and mannitol were chosen for this project due to their accessibility as a non-controlled substance and abundance in real world forensic exhibits. Mixtures of caffeine and mannitol were combined at several different known purities and then analyzed via gas chromatography-mass spectrometry (GC-MS). Experiments were conducted to evaluate the homogeneity of mixtures prepared by changing time mixed, amount mixed and color of substance.