Determination of hydroxy metabolites of cocaine from hair samples and comparison with street cocaine samples. (July 2018)

• Record Type: Journal Article
• Authors: Franz, Thomas; Scheufler, Frank; Stein, Klaus; Uhl, Michael; Dame, Torsten; Schwarz, Gerlinde; Sachs, Hans; Skopp, Gisela; Musshoff, Frank
• Is Part Of: Forensic science international. Volume 288(2018)
• Page Start: 223
• Page End: 226
• Publication Date: 2018-07
• Subjects: Cocaine -- Hair testing -- Hydroxy metabolites; Medical jurisprudence -- Periodicals; Chemistry, Forensic -- Periodicals; Forensic Medicine -- Periodicals; Médecine légale -- Périodiques; Chimie légale -- Périodiques; Gerechtelijke geneeskunde; Gerechtelijke chemie; Gerechtelijke psychiatrie; Chemistry, Forensic; Medical jurisprudence; Electronic journals; Periodicals; Electronic journals; 614.1
• DOI: 10.1016/j.forsciint.2018.04.007
• Languages: English
• ISSNs: 0379-0738

Abstract

Highlights: Findings of hydroxy-cocainics in hair-samples were compared with street-cocaine samples. No hydroxy-metabolites of benzoylecgonine and norcocaine were found in seized material. New criteria for interpretation of cocaine consumption through hair analysis are proposed. Abstract: 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. The presence of hydroxy metabolites in street-cocaine (COC) has been discussed. To check if detection of hydroxy metabolites definitely proves ingestion, the presence of these metabolites in street COC samples has to be checked. It is expected that the more hydrophilic hydroxy metabolites of COC are incorporated into the hair-matrix to a lesser extent. For this study 576 COC positive hair samples (≥0.1 ng COC/mg hair) were analysed by LC–MS/MS for benzoylecgonine (BE), norcocaine (NC), cocaethylene (CE), ortho -, meta - and para -hydroxy COC ( o -, m -, p -OH-COC), meta - and para -hydroxy BE ( m -, p -OH-BE), and meta - and para -hydroxy NC ( m -, p -OH-NC). The results were compared with the respective metabolite/COC concentration ratios in 146 street COC samples, confiscated by the Bavarian police. Peak areas were used to estimate BE/COC, NC/COC, CE/COC and hydroxy metabolites/COC. Similar metabolic ratios were found for o -OH-COC in 88% of the samples, but for p -OH-COC and m -OH-COC only in 5.1% and 6.8%, respectively. Notably, p- and m- OH-BE as well as p- and m- OH-NC could not be identified from seized samples. We propose that area ratios exceeding the ratios of street COC more than twice or identification of OH-BE and OH-NC enable to differentiate COC consumption from contamination. Using these criteria, consumption of the drug could be proven in 92% of COC positive samples. As detection of meta - and para -hydroxy metabolites using the above mentioned criteria is a reliable tool to distinguish between ingestion and external contamination, it is recommended to implement their measurement into daily routine work.