Date of Award

Spring 5-28-2024

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

Flavia Roveri

Abstract

Hair external contamination poses significant challenges to the interpretation of hair testing results. Previous studies have shown that cosmetic hair treatments can reduce the concentration of drugs already present in the hair shaft. However, the impact of these treatments on externally deposited drugs remains largely unexplored. This study aimed to investigate how gel and oil treatments affect external contamination by cocaine and benzoylecgonine. Fifteen authentic hair samples, with various colors and textures, were collected from volunteers and confirmed negative for cocaine and benzoylecgonine using a fully validated LC-MS/MS method. Each sample was divided into three groups: Group A underwent a cosmetic treatment followed by contamination with cocaine and benzoylecgonine; Group B was contaminated first and then treated cosmetically; and Group C was only contaminated. In-vitro contamination involved immersing the samples in a 1 μg/mL solution of cocaine or benzoylecgonine in water for 24 h, separately, followed by overnight drying. The samples were washed, extracted, filtered, and analyzed using reversed-phase LC-MS/MS. If hair was cosmetically treated prior to contamination, gel caused significant increases in both cocaine (n=15) and benzoylecgonine (n=15) with increasing averages of 442% and 291%, respectively. The application of Penetrating Argan Oil did not significantly alter the drug concentrations in either Group A or Group B compared to Group C. These findings illustrate that cosmetic treatments can influence drug concentrations by potentially increasing externally deposited cocaine and benzoylecgonine by affecting its uptake into the hair.

Included in

Toxicology Commons

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.