Analysis of Cannabinoids in Lotions Using High-Performance Liquid Chromatography

Recently, topical products advertising cannabinoid ingredients have gained popularity. Consumers are seeing an increase of commercial products containing ingredients from hemp oil to cannabidiol (CBD) due to health benefit claims. Cosmetic products containing cannabinoids are currently not regulated at the federal level. A laboratory experiment for undergraduate students in analytical and organic chemistry courses was developed utilizing high-performance liquid chromatography (HPLC) analysis to identify and quantify cannabinoid compounds present in commercially available topical products. Students used calibration curves of a cannabinoid standard to quantify cannabinoids present in the CBD products. By comparing relative retention times of the cannabinoids present in the standard, students were able to identify the cannabinoids present in their lotion sample. Responsibilities and assignments suit students ranging from introductory to advanced chemistry courses. Students are provided the opportunity to extract and experimentally calculate the amount of CBD and compare to the amounts advertised on product labels. Results showed that the average CBD amounts were higher than advertised for all lotions except CBDFx when analyzed using HPLC. This experiment can be modified to incorporate a variety of different topical water-based products including hair products, shampoo, and other cosmetics. Furthermore, an analysis of samples using gas chromatography mass spectrometry (GC-MS) was also developed to adapt to instrument availability.