title: High-throughput salting-out assisted liquid-liquid extraction with acetonitrile for the determination of anandamide in plasma of hemodialysis patients with liquid chromatography tandem mass spectrometry.
abstract: Anandamide (AEA) is an endocannabinoid present in human plasma that is associated with several physiological functions and disease states. However, low AEA plasma levels pose challenges in terms of analytical characterization. Classical liquid-based lipid extraction and solid-phase extraction require complicated procedures and the drying down of relatively large volumes of solvents, making them unsuitable for high-throughput analysis. Here a high-throughput salting-out assisted liquid-liquid extraction (SALLE) method with acetonitrile and mass spectrometry compatible salts for liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of AEA in human plasma has been developed and validated. The seamless interface of SALLE and LC-MS eliminated the drying-down step, only 100 μL of plasma is required and minimal volumes of organic solvent are used. Good reproducibility, accuracy and precision were demonstrated during the method validation. The method is linear up to 10 ng/mL with a lower limit of quantitation of 0.1 ng/mL for AEA, the accuracy for AEA was from 93.3 to 96.7% and the precision was <8.57%. This new methodology was successfully applied to analysis of clinical samples from maintenance hemodialysis patients.
authors.affiliation: Department of Pharmacy, Peking University Third Hospital, Beijing, 100191, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Xiong
authors.affiliation: Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangdong, 510120, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Nephrology, Peking University Third Hospital, Beijing, 100191, People's Republic of China.
authors.forename: Litao
authors.initials: L
authors.lastname: Cheng
authors.affiliation: Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangdong, 510120, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Mao
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D001095:Arachidonic Acids / Q000097:blood* / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D063388:Endocannabinoids / Q000097:blood* / Q000302:isolation & purification*; D006801:Humans; D059625:Liquid-Liquid Extraction / Q000379:methods*; D053284:Polyunsaturated Alkamides / Q000097:blood* / Q000302:isolation & purification*; D006435:Renal Dialysis; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000097:Acetonitriles; D001095:Arachidonic Acids; D063388:Endocannabinoids; D053284:Polyunsaturated Alkamides; C078814:anandamide; C032159:acetonitrile
keywords: LC-MS/MS; anandamide; hemodialysis patients; salting-out assisted liquid-liquid extraction