title: Development and validation of a sensitive UPLC-ESI-MS/MS method for the simultaneous quantification of 15 endocannabinoids and related compounds in milk and other biofluids.
abstract: The endocannabinoid (eCB) system has gained an increasing interest over the past decades since the discovery of anandamide and 2-arachidonoyl glycerol (2-AG). These, and structurally related compounds, are associated with a wide variety of physiological processes. For instance, eCB levels in milk have been associated with infants' feeding and sleeping behavior. A method based on ultraperformance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) was developed and validated for the simultaneous quantification of 15 eCBs and related compounds, including both fatty acid amides and glycerols. Linearity (0.9845 < R(2) < 1), limit of detection and quantification (0.52-293 pg on column), inter- and intraday accuracy (>70%) and precision (CV < 15%), stability, and recovery (in milk and plasma) were established in accordance to the U.S. Food and Drug Administration guidelines. The method was successfully applied to bovine and elk milk revealing species-specific eCB profiles, with significant different levels of 2-AG, 2-linoleoyl glycerol, docosahexaenoyl ethanolamide, palmitoyl ethanolamide, and oleoyl ethanolamide. Furthermore, stearoyl ethanolamide and docosatetraenoyl ethanolamide were only detected in elk milk. In summary, our UPLC-ESI-MS/MS method may be used for quantification of eCBs and related compounds in different biofluids and applied to investigations of the role of these emerging compounds in various physiological processes.
authors.affiliation: Department of Chemistry, Umeå University , 901 87 Umeå, Sweden.
authors.forename: Sandra
authors.initials: S
authors.lastname: Gouveia-Figueira
authors.forename: Malin L
authors.initials: ML
authors.lastname: Nording
mesh_terms: D000818:Animals; D002138:Calibration; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D063388:Endocannabinoids / Q000032:analysis*; D005227:Fatty Acids / Q000032:analysis*; D006801:Humans; D007223:Infant; D007774:Lactation; D057230:Limit of Detection; D008892:Milk / Q000737:chemistry*; D012015:Reference Standards; D012418:Ruminants; D013045:Species Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D013402:Sugar Alcohols / Q000032:analysis*; D053719:Tandem Mass Spectrometry
chemical_list: D063388:Endocannabinoids; D005227:Fatty Acids; D013402:Sugar Alcohols