Application of dispersive liquid–liquid microextraction for the determination of phosphatidylethanol in blood by liquid chromatography tandem mass spectrometry

• Published in: Talanta (Oxford) 2013-07, Vol.111, p.189-195
• Main Authors: Cabarcos, Pamela, Ángel Cocho, José, Moreda, Antonio, Míguez, Martha, Jesús Tabernero, María, Fernández, Purificación, María Bermejo, Ana
• Format: Article
• Language: English
• Subjects: acetone; Adult; Aged; Aged, 80 and over; Alcohol Drinking - blood; blood; Calibration; Chromatography, Liquid - instrumentation; Chromatography, Liquid - methods; Dispersive liquid liquid microextraction; Electrospray ionization; electrospray ionization mass spectrometry; ethanol; Female; Glycerophospholipids - blood; Glycerophospholipids - isolation & purification; Humans; LC-MS/MS; liquid chromatography; Liquid Phase Microextraction - methods; liquid-phase microextraction; liquids; Male; methylene chloride; Middle Aged; Phosphatidylbutanol; Phosphatidylethanol; phospholipids; Reproducibility of Results; solvents; tandem mass spectrometry; Tandem Mass Spectrometry - instrumentation; Tandem Mass Spectrometry - methods; Young Adult
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2013.03.008

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 (230μL dichloromethane) and disperser solvent (630μL 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-10μg/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 1.71μg/mL. •Phosphatidylethanol: a promising marker of ethanol abuse.•Novelty of the method: determination of phosphatidylethanol by DLLME.•Better LOD and LOQ are achieved with this new method.•Rate of degradation is slow; measurable up to 15–20 days after last intake of alcohol.