Date of Award
Spring 5-15-2025
Document Type
Thesis
Degree Name
Master of Science (MS)
Department/Program
Forensic Science
Language
English
First Advisor or Mentor
Ana Pego
Second Reader
Marta Concheiro-Guisan
Third Advisor
Sarah Eller
Abstract
Hair testing is increasing in popularity in toxicology because of its long window of detection and ease of collection and sample storage. However, it has its limitations largely due to external contamination of drugs. In particular, cocaine (COC) is a common offender of this as it has several routes of consumption. Analyzing metabolites of COC may be the key to distinguishing between consumption and external contamination. The aim of the present study was to develop a quick, easy, and sensitive method for the detection and quantification of COC, benzoylecgonine (BE), norcocaine (NCOC), cocaethylene (CE), anhydroecgonine methyl ester (AEME), meta-hydroxy-cocaine (m-OH-COC), and meta-hydroxy-benzoylecgonine (m-OH-BE) in hair samples by LC-MS/MS. Hair samples underwent washing, homogenization, extraction, and analysis on the LC-MS/MS with a run time of only 5.5 minutes. The method was validated following the ANSI/ASB Standard 036 guidelines. The following parameters were successfully validated for the method: linearity, precision, bias, extraction efficiency, process efficiency, matrix effects, interference studies, and carryover. The method was applied to a total of 35 postmortem hair samples, where 13 were deemed positive for COC based on cut-offs set by the Society of Hair Testing. In addition to cut-offs, the use of m-OH-COC/COC and m-OH-BE/COC ratios may facilitate unambiguous differentiation between consumption and external contamination of COC. These results allow for the proposal of a decision model using hydroxy metabolites to apply to real hair samples to aid in reporting.
Recommended Citation
Mulkeen, Samantha C., "Quick and Easy Method for the Determination of Cocaine and Six Metabolites in Postmortem Hair" (2025). CUNY Academic Works.
https://academicworks.cuny.edu/jj_etds/346
