Raman analysis of illicit drug precursors

Ephedrine and pseudoephedrine have long been available in cold remedies as a decongestant. They are also common precursor materials from which illicit methamphetamine may be synthesized.

On a global scale, methamphetamine is one of the worlds most consumed synthetic stimulant drugs and its prevalence owes itself, in part, to the relative ease in which it can be manufactured. For this reason legislation has been implemented to help monitor and control the global trade of ephedrine and pseudoephedrine. Since ephedrine and pseudoephedrine have become implicated in criminal activity the correct identification of these materials can be crucial for intelligence and in criminal investigations.

An in-house study carried out by Foster + Freeman applications expert Justin Gould, a specialist in the field of Drugs of Abuse who has previously produced drugs intelligence reports for the UK Home Office and National Crime Agency, sought to quickly and accurately discriminate between ephedrine and pseudoephedrine using the new Foram3 785nm Raman spectrometer.


The Raman advantage

Currently the most commonly used drug analysis technique employed by forensic laboratories is Gas Chromatography/Mass Spectrometry (GC/MS). However, in the case of Ephedrine and Pseudoephedrine, diasteraomers that have the same molecular formula, GC/MS requires the additional undesirable process of derivatization. In contrast to GC/MS, Raman spectroscopy provides rapid, sensitive, non-destructive analysis with little or no sample preparation required.

Using the Foram3 integral video microscope for precise targeting, samples in this study were scanned with results displayed on screen in less than 3 seconds. The resulting spectra allowed the two stimulants to be easily distinguished with the accuracy of the results being such that the technique may also facilitate in the interpretation of mixtures.

An essential technique for forensic laboratories wishing to analyse, discriminate and identify materials of forensic interest, high power 785nm Raman spectroscopy using the Foram3 is suitable for the analysis of trace evidence including explosives, cosmetics, fibres, paints, inks and other unknowns.


Download the complete study:  Discrimination of methamphetamine precursors using Raman spectroscopy