This study theorizes that conjugated metabolites of drugs are present in the hair of people who use drugs as a result of metabolic activity and excretion into the hair.
The authors of this study hypothesize that conjugated metabolites of drugs are present in the hair of people who use drugs as a result of metabolic activity and excretion into the hair. The authors conducted exploratory research to look for the presence of these metabolites in hair from people known to have used drugs using a variety of sample preparation and liquid chromatography – mass spectrometry (LC-MS) detection techniques. Data acquisition included targeted LC-MS/MS acquisition methods commonly employed in metabolite identification applications, as well as full scan high resolution non-targeted MS data acquisition. The objective of this project was to look for unique metabolites in hair that are indicators of consumption in addition to, or in place of, the parent drugs. The choice of metabolite is critical because some metabolites can be present as process impurities, meaning they may be present as a result of contamination by the parent compounds. Other metabolites may be degradation products formed because of exposure to hair care products subsequent to parent drug contamination. Also, it is possible that some parent drugs are converted to metabolites during analysis. In addition, some metabolites are commercially available drugs themselves. Phase II conjugated metabolites are ideal markers of use because they are not products of common degradation pathways, as is the case for many phase I metabolites, and are not commercially available for the purposes of therapeutic use or abuse.