title: Microwave assisted extraction for the determination of ethyl glucuronide in urine by gas chromatography-mass spectrometry.
abstract: Alcohol is the most frequently abused 'addictive substance' that causes serious social problems throughout the world; thus alcoholism is of particular interest in clinical and forensic medicine. Ethyl glucuronide (EtG) is a marker of recent alcohol consumption that detects alcohol use reliably over a definite time period. The present paper describes a new method for the determination of EtG in urine. It was based both on microwave assisted extraction (MAE) to extract the analyte from urine samples, and gas chromatography-mass spectrometry (GC-MS) to identify and quantify the EtG in selected ion monitoring (SIM) mode. The method was applied to 33 urine samples from alcohol users, obtaining positive results in all cases. It was fully validated including a linear range (0.1-100 microg ml(-1)) and the main precision parameters. In summary, the use of microwave assisted extraction turned out to be a substantially simpler, faster and more sensitive procedure than any other conventional sample preparations.
authors.affiliation: Institute of Legal Medicine, Forensic Toxicology Service, Faculty of Medicine, C/ San Francisco s/n, 15782 Santiago de Compostela, Spain.
authors.forename: Iván Alvarez
authors.initials: IA
authors.lastname: Freire
authors.forename: Ana María Bermejo
authors.initials: AM
authors.lastname: Barrera
authors.forename: Purificación Cid
authors.initials: PC
authors.lastname: Silva
authors.forename: María Jesús Tabernero
authors.initials: MJ
authors.lastname: Duque
authors.forename: Purificación Fernández
authors.initials: PF
authors.lastname: Gómez
authors.forename: Patricia López
authors.initials: PL
authors.lastname: Eijo
mesh_terms: D002138:Calibration; D000431:Ethanol / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry; D005965:Glucuronates / Q000652:urine*; D006801:Humans; D007202:Indicators and Reagents; D008872:Microwaves; D012015:Reference Standards; D015203:Reproducibility of Results; D052616:Solid Phase Extraction
chemical_list: D005965:Glucuronates; D007202:Indicators and Reagents; C093924:ethyl glucuronide; D000431:Ethanol