The separation and identification of natural mixtures of terpenes is challenging and laborious. A gas chromatographic method based on vacuum ultraviolet spectroscopic detection, which is characterized by full-scan absorption in the range of 125-240 nm, was developed and applied to analyze terpenes. In this study, the vacuum ultraviolet absorption spectra of 41 different standard terpenes were investigated and compared. The spectra were found to be highly featured and easily differentiated. Several commercial turpentine samples were analyzed and the vacuum ultraviolet detector demonstrated good specificity for qualitative identification of constituent terpenes. A total of 31 terpenes were detected in the four turpentine samples. α-Pinene was the predominant terpene ranging from 744.2 ± 9.7 to 917 ± 21 mg/mL. The other major constituents in the turpentines included β-pinene, δ-3-carene, camphene, and p-isopropyltoluene. Deconvolution of co-eluting signals of terpenes was achieved utilizing the data analysis software. The technique has been demonstrated to be a powerful tool for reliable and accurate qualitative and quantitative analysis of terpenes from complex natural mixtures.
Relatively new technology vacuum ultraviolet absorption spectroscopic (120-240 nm) detection for gas chromatography, was evaluated and shown to successfully differentiate cannabinoids, their metabolites, and derivatives thereof. The possibility to deconvolute co-eluting peaks due to additivity of overlapping absorbance spectra of the analytes was also demonstrated. This feature allows the use of faster temperature ramps, faster analysis time, and reduces the need to baseline resolve all analytes, without sacrificing sensitivity. The combination of vacuum ultraviolet spectroscopy with gas chromatography allows for the analysis of cannabinoids that have similar structures and molecular weight, and whose chromatographic separation can be difficult to obtain. The sensitivity of the approach (low ppm; low ng on-column) is currently sufficient for tracking cannabinoids in plant material, but significant sample enrichment would be needed to target cannabinoids and metabolites in biological samples.
K E Y W O R D S
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.