Molecule flight speed for detecting drugs

The presence of cannabinoids in textile and pharmacological goods and the need to distinguish them from those found in drugs and psychotropics has led to the development of analytical techniques to differentiate them. A University of Cordoba research group headed by Analytical Chemistry Professor Lourdes Arce, along with institutional collaborators, participated in the development of a new methodology using ion mobility spectrometry. The new method has been shown to be effective and uses a simple way to distinguish between certain cannabinoid types in a short period of time.

The secret of this new methodology, published in the journal Sensors and Actuators B: Chemical, is rooted in focusing attention on the molecule volatility of hemp. It uses a chemical sensor known as ion mobility spectrometry, capable of detecting the presence of volatile or semivolatile substances even in very small samples. The sample can be a plant extract (approximately 100 mgs) or a plate with a fingerprint from a hand that has handled plant waste. It is heated to 240 degrees Celsius to extract volatile compounds, which are then separated according to their shape, size and chemical composition. This is used to classify the kinds of molecules. These chemical compounds travel through a tube at different speeds, depending on the characteristics of their molecules. Travel time of the compounds before arriving at the detector is determined and compared to the behavior of chemical patterns of different kinds of cannabinoids and to the concentrations characterized by their different uses.

This research group has designed a methodology to extract compounds from plants and carry out the mathematical treatment of the data that allows for classifying plants in terms of the content in psychoactive substances. According to Lourdes Arce, the final aim is that state law enforcement could use this portable detection system for cases when seizing drugs and for road checkpoints, to quickly discern if the variety of cannabis contains psychotropic substances or not.