HPLC Method for Separation of Cannabidiol Hemp Seed Oil with Skin Lipids and Tandem HRMS Technology for Characterization of a Chemical Marker

Cannabidiol (CBD) hemp seed oil is a commercial raw material with antioxidant and anti-inflammatory benefits that has been formulated into body wash and skin care products. The biggest analytical challenge is how to simultaneously quantify CBD and hemp seed oil as they deposited on the skin surface. CBD is easily separated and quantified from skin surface extracts via a HPLC-mass spectrometry methodology. However, the structural skeleton of triacylglycerides (TAGs) in hemp seed oil is same as those from the skin surface sebum. The strong hydrophobicity with subtle structural difference challenges their separation. In this project, a new reverse phase HPLC-high resolution mass spectrometry methodology was developed with a strong mobile phase normal propanol. The separated hemp seed oil TAGs in the chromatogram were identified and characterized using data-dependent acquisition (DDA) technology. Based on the daughter ion characterization, the separated peak with an ammonium adduct at 890.7226 [M + NH4]+ was confirmed as the parent ion of glycerol with three omega-3 fatty acid chains. This is the first time TAG structure with direct HPLC-tandem mass spectrometry technology has been elucidated without a hydrolysis reaction. The confirmed TAG structure with an ammonium adduct at 890.7226 ± 0.0020 can be used as a representative chemical marker for the hemp seed oil quantification.