research UPLC-MS/MS Method for the Simultaneous Quantification of Caffeine and Illicit Psychoactive Drugs in Hair Using a Single-Step High-Speed Grinding Extraction – Insights into a Cut-Off Value for Caffeine Abuse
The conclusion is that a new method can measure caffeine and drugs in hair, finding caffeine abusers have 70 times more caffeine than normal, with a proposed cut-off value for abuse.