A study of the effectiveness of commercially available drink test coasters for the detection of "date rape" drugs in beverages.

The use of illicit substances for the purpose of drug-facilitated sexual assault (DFSA) poses a significant problem. There has been an increase in public awareness of this problem, and a recent invention in the form of a drink coaster claims to detect whether or not a beverage has been spiked with a so-called date rape drug. A person is instructed to place a drop of the suspect beverage onto two spots of the test, smear gently, and wait until dry. If either spot turns to a darker blue color, then a possible date rape drug has been detected by the coaster test. In an effort to determine the effectiveness of the coasters, various drugs that have been associated with drug-facilitated sexual assault were tested at different concentrations in a variety of common alcoholic and non-alcoholic beverages. It was found that although the coasters do detect the presence of GHB and ketamine, two drugs that have been associated with DFSA, there are limiting factors such as the high concentration of the drugs required, hindrance of the reaction due to beverage matrix, and extensive time requirements for ketamine analysis.