Evaluating the Use of Differential Scanning Calorimetry for the Analysis of Illicit Substances and Their Adulterants

Chemical profiling of seized material is a powerful tool used by law enforcement agencies to determine the presence of illicit drugs and their adulterants within a suspect material. This study presents a proof-of-concept for the use of Differential Scanning Calorimetry (DSC) for the analysis of illicit drugs. Mixtures of methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), heroin and cocaine with their common adulterants, including paracetamol, caffeine, tetramisole HCl and sugars were submitted for DSC analysis. A range of temperature programs were examined to determine the best conditions for analysis. It was determined that the mixtures showed three distinct levels of differentiation. Level 1 contained mixtures which revealed peaks that did not correlate to any pure substances present, making differentiation difficult. In some cases, however, the combination of peaks was unique, allowing for possible identification of a particular combination of components. Level 2 mixtures revealed peaks which were characteristic of one or more substances present or other distinguishing features, such as decomposition patterns, which may indicate the presence of a substance or group of substances. Level 3 revealed very good differentiation facilitating clear identification of the substances present. Level 2 differentiation was the most common across the analysed mixtures. This screening technique may provide useful information to investigators regarding the analysis of drug seizures, guiding further confirmatory analysis.