Proof of active cannabis use comparing 11-hydroxy-∆9-tetrahydrocannabinol with 11-nor-9-carboxy-tetrahydrocannabinol concentrations.

Testing hair for cannabis use has increasingly been scrutinised due to exposure to second-hand smoke or environmental contamination. Confirmation of drug use involving detection of metabolites such as 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (THC-COOH) and 11-hydroxy-delta-9-tetrahydrocannabinol (THC-OH) having very rarely been considered. We developed a new, simplified procedure with regard to expenditure of time and material to determine delta-9-tetrahydrocannabinol (THC, qualitatively), as well as THC-OH and THC-COOH (quantitatively) from 587 hair samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS) which was compared to hitherto established methods (n = 3).

Determination of hydroxy metabolites of cocaine from hair samples and comparison with street cocaine samples.

Drugs which are commonly smoked or sniffed (e.g. cocaine), can contaminate hair through smoke or dust; therefore testing for metabolites, especially hydroxy metabolites, is highly recommended.

Determination of hydroxy metabolites of cocaine in hair samples for proof of consumption.

Although hair is widely used to identify drug use, there is a risk of false positives due to environmental contamination. This especially applies to cocaine (COC). Several strategies such as detection of norcocaine (NCOC) or cocaethylene, metabolite concentration ratios or intricate washing procedures have been proposed to differentiate actual use from contamination.