title: Application of dispersive liquid-liquid microextraction for the determination of phosphatidylethanol in blood by liquid chromatography tandem mass spectrometry.
abstract: Phosphatidylethanol (PEth) is a phospholipid which requires for its metabolic formation the presence of relatively high ethanol levels. PEth is thus a promising marker to quentify ethanol abuse. Dispersive liquid-liquid microextraction has become a popular technique because it is fast, inexpensive, easy to operate and consumes low volume of organic solvent. In this method, the appropriate mixture of extraction solvent (230 μL dichloromethane) and disperser solvent (630 μL acetone) are injected into the sample by syringe, rapidly. The liquid chromatography method using a reversed phase-C8 column and a negative ion mode electrospray ionization tandem mass spectrometry detection instrument was developed for the determination of small amounts of PEth that might be present in blood samples, using phosphatidylbutanol (PBut) as an internal standard. The sensitivity of detection obtained with tandem MS was better than that of previous methods. Good linearity was obtained for a range of LOQ-10 μg/mL for PEth, whereas all of the deviations in precision and accuracy were less than 15% except for the LLOQ, where it should not exceed 20%. A set of 50 blood samples were analyzed by such method and whole blood concentrations of PEth 16:0/18:1 ranged from LLOQ to 1.71 μg/mL.
authors.affiliation: Instituto de Ciencias Forenses. Servicio de Toxicología, Facultad de Medicina, Universidad de Santiago de Compostela, C/San Francisco s/n, 15782 Santiago de Compostela, Spain. pamela.cabarcos@usc.es
authors.forename: Pamela
authors.initials: P
authors.lastname: Cabarcos
authors.forename: José
authors.initials: J
authors.lastname: Ángel Cocho
authors.forename: Antonio
authors.initials: A
authors.lastname: Moreda
authors.forename: Martha
authors.initials: M
authors.lastname: Míguez
authors.forename: María
authors.initials: M
authors.lastname: Jesús Tabernero
authors.forename: Purificación
authors.initials: P
authors.lastname: Fernández
authors.forename: Ana
authors.initials: A
authors.lastname: María Bermejo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000097:blood; D002138:Calibration; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods*; D005260:Female; D020404:Glycerophospholipids / Q000097:blood* / Q000302:isolation & purification; D006801:Humans; D059627:Liquid Phase Microextraction / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D055815:Young Adult
chemical_list: D020404:Glycerophospholipids; C051521:phosphatidylethanol