Milena M Madry,Andrea E Steuer, Matthias Vonmoos,Boris B Quednow, Markus R Baumgartner & Thomas Kraemer.
Zurich Institute of Forensic Medicine, Department of Forensic Pharmacology & Toxicology, University of Zurich, Switzerland.
Zurich Institute of Forensic Medicine, Center for Forensic Hair Analysis, University of Zurich, Switzerland.
Experimental & Clinical Pharmacopsychology, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Switzerland.


  • Keywords: Abstinence, nails, contamination, LC–MS/MS, norcocaine, cocaine, cocaethylene, benzoylecgonine
  • Aim of the study: Retrospective monitoring of cocaine consumption of recreational and dependent users
  • Application: Cocaine and metabolites analyses by LC-MS/MS
  • Sample name: Toenails
  • Material: FastPrep-24™ instrument, 2 ml Lysing Matrix S tubes containing metal beads

Protocols & Parameters

  1. Nail clippings were washed twice with 1 ml of water and acetone, respectively, by vortexing for 30s.
  2. They were cut into snippets and approximately 5 mg were weighed into Lysing Matrix Tubes containing metal beads for pulverization at 5.5 m/s (8-times for 60s) by a FastPrep-24™ instrument.


  • Toenails may be an alternative for retrospective monitoring of cocaine consumption/abstinence