Intralaboratory comparison of analytical methods for quantification of major phytocannabinoids.

This study compares alternative approaches for analyzing phytocannabinoids in different plant materials. Three chromatographic analytical methods (ultra-high-performance liquid chromatography with tandem mass spectrometric detection and gas chromatography with mass spectrometric and flame ionization detection) were evaluated regarding selectivity, sensitivity, analytical accuracy, and precision. The performance of the methods was compared and all three methods were demonstrated to be appropriate tools for analyzing phytocannabinoids in cannabis. Gas chromatography coupled with mass spectrometric detection showed slightly better accuracy in determining phytocannabinoid acids, which are often difficult to quantify owing to their limited stability. Aspects of sample preparation, such as material homogenization and extraction, were also considered. A single ultrasonic-assisted ethanolic extraction of dried and powdered plant samples of cannabis was shown to be exhaustive for extracting the samples prior to analysis.