Hello! First of all, I know that this post will rehash some points / topics already discussed in previous posts by other users. My intentions are not to repeat the conversation but seek additional elaboration and exploration. Second, I am not a chemist. I work in clinical pathology, but I have a minors in chemistry which included a year of analytical chem. With the preamble out of the way, let's get into it.

I have, in my years, acquired a handful of friends who enjoy the rave scene. Something that has been a continuous boogeyman, an increasingly frightening one in recent years, is adulterants present in standard "party drugs" such as MDMA. I am aware of the presence of testing kits which claim to be able to detect adulterants but these fall short in the (very limited) available data¹. I am also aware of first responders making use of handheld spectroscopy instruments (such as the ThermoFisher First Defender RM) to identify unknown substances; usually narcotics or explosives.

In previous posts, commenters have seemed overall skeptical (or outright negative) about the ability of non-mobile phase spectroscopy to detect adulterants / purity of an unknown substance for a number of reasons. However, a number of PubMed articles seem to be much more optimistic about the ability of these machines^2,3,4.

So, in short, I am curious what this forum's general opinion is on the possibility of a harm reduction group using a handheld Raman spectrometer to test for adulterants, specific and non, in "known" narcotics in a field setting⁵

¹Putting an Ecstasy Test Kit to the Test: Harm Reduction or Harm Induction?

²Rapid classification of simulated street drug mixtures using Raman spectroscopy and principal component analysis

³Classification of narcotics in solid mixtures using principal component analysis and Raman spectroscopy

⁴Qualitative analysis using Raman spectroscopy and chemometrics: a comprehensive model system for narcotics analysis

⁵Drug Checking as Strategy for Harm Reduction in Recreational Contests: Evaluation of Two Different Drug Analysis Methodologies (including this one because at the conclusion of the abstract they call for more "discriminatory on-site methods such as Raman or infrared spectrometry")