Oral fluid as an alternative matrix to determine ethanol for forensic purposes

•Ten volunteers ingested 0.5 g of ethanol per kg of body weight.•Ethanol in oral fluid correlated well with ethanol in breath.•Promising use of oral fluid to monitor ethanol intake of drivers in traffic.

The present work aimed to evaluate whether it is possible to use oral fluid to monitor alcohol in drivers.In a control experiment the subjects ingested beer with an alcoholic percentage of 4.7%, in an amount that furnished 0.5 g ethanol per kg of body weight. Volunteer's urine, oral fluid, and breath were collected at 10, 30, 60, and 90 min after alcohol intake. Urine and oral fluid were analyzed by gas chromatography with FID (Flame Ionization Detector); breath was analyzed by Alcotest 7410 (Dräger).The absorption profiles correlated well. The Pearson correlation value between samples of oral fluid and urine, and oral fluid and exhaled air, was close to 1, showing that oral fluid is a promising matrix to monitor drivers in traffic or involved in accidents.