Several cannabinoids were detected at parts-per-million (ppm) levels with surface enhanced Raman spectroscopy (SERS).
Background
The cannabinoid profile of cannabis-based products must be determined to support label claims and assure product quality. Traditionally, HPLC-MS measurements reveal THC, THCA, CBD, and CBDA quantities, as well as trace cannabinoids such as CBG and CBGA.1 However, HPLC-MS has certain drawbacks that can be avoided with other techniques such as Raman spectroscopy, which offers sensitivity, selectivity, reduced instrument size, non-destructive sampling, and simple implementation. In this study, Ocean Insight utilizes SERS, a variant of Raman spectroscopy, to enable trace level detection of these cannabinoids.
Experimental Conditions
The following analytical grade standards were diluted to 10 ppm in their respective solvents: cannabidiol (CBD), cannabidiolic acid (CBDA), tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), cannabigerol (CBG), and cannabigerolic acid (CBGA).
Microliter volumes were pipetted into colloidal solutions of gold nanoparticles, and measured with the Ocean Insight QE Pro-Raman+ spectrometer, at 3 seconds integration time, after interrogation with a 785 nm laser at 350 mW laser power.