Forensic Science International 103 (1999) 79–88 Simultaneous determination of trace benzodiazepines from drinks by using direct electrospray probe / mass spectrometry (DEP/ MS) a, b * Yu-Chie Chen , Anren Hu a Institute of Toxicology, Tzu Chi College of Medicine and Humanities, Hualien 970, Taiwan b Department of Medical Technology, Tzu Chi College of Medicine and Humanities, Hualien 970, Taiwan Received 28 January 1999; received in revised form 5 May 1999; accepted 18 May 1999 Abstract This study presents a novel means of rapidly determining benzodiazepines in various drinks. Electrospray mass spectrometry with a direct probe design is used as the analytical instrument. Samples are treated only by a simple liquid–liquid extraction prior to direct electrospray probe / mass spectrometry (DEP/ MS) analysis. The proposed method provides a relatively easy and efficient means of identifying the drugs in a very short time interval. On average, sample analysis is completed in less than five minutes including sample pretreatment. It is especially useful in forensic science since the technology can provide a rapid identification for unknown samples. Thus, the method proposed herein is highly appropriate for rapidly screening a large number of samples.  1999 Elsevier Science Ireland Ltd. All rights reserved. 1. Introduction Benzodiazepines are widely used for the relief of anxiety as well as hypnotic, sleep-promoting agents, frequently leading to dependence and abuse. For example, flunitrazepam has become a popular date rape drug or party drug owing to its quick onset of sedation, amnesic properties, and additive effects with alcohol. Most victims fall prey to drinking poisoned drinks. Analyzing any leftover substances obtained from the criminal scene is credible evidence for convicting criminals. Conventionally, immunoassay screening and gas chromatography / mass spectrometry *Corresponding author. 0379-0738 / 99 / $ – see front matter  1999 Elsevier Science Ireland Ltd. All rights reserved. PII: S0379-0738(99)00062-6