Synthetic cannabinoids (K2, spice) present problems in forensic investigations, because standard presumptive methods, such as immunoassays, are insufficiently specific for the wide range of potential target compounds. This issue can lead to problems with low sensitivity and yield false-negative results. A potential solution to this problem is SERS. The procedure involves mixing the analyte with gold nanoparticles prepared in a solution containing alkali or alkaline earth salt solutions. The salts produce aggregation of the nanoparticles with a resultant spectral enhancement due to the formation of spectral hotspots with enhanced field effects within the aggregate. Among the salts tested, 0.0167 M MgCl2 produced the lowest limit of detection and best overall sensitivity. The method produces clearly distinguishable spectra for each synthetic cannabinoid with detection limits as low as 18 ng/mL. Spiked urine samples were also analyzed, following a cleanup procedure that involved support liquid extraction. When using a portable Raman system, a higher concentration of MgCl2 was needed to produce similar a LOD. The results demonstrate that this procedure has great potential as a method for presumptive screening of synthetic cannabinoids. 1 graphical abstract (Publisher abstract modified)
Surface Enhanced Raman Spectroscopy (SERS) as a Method for the Toxicological Analysis of Synthetic Cannabinoids
NCJ Number
252345
Journal
Talanta Volume: 164 Dated: March 2017 Pages: 396-402
Date Published
March 2017
Length
7 pages
Annotation
This study analyzed a set of structurally similar synthetic cannabinoids using surface enhanced Raman spectroscopy (SERS).
Abstract