Development of new cocaine hair testing guidelines: investigation of decontamination protocols, damage/adulteration evaluation, and cosmetic treatment impact

This project aims to address the current lack of standardized protocols for cocaine hair toxicological testing within the criminal justice system. The specific goals are three-fold: 1) to optimize the best decontamination procedure for cocaine hair testing; 2) to elaborate an assessment tool to determine degree of hair damage due to cosmetic treatments and adulteration procedures and decrease of cocaine and metabolites concentrations; 3) to investigate cosmetic treatments’ effect on preventing or removing external contamination or facilitating hair uptake of externally deposited cocaine. To optimize the decontamination procedure, hair samples from cocaine-users will be contaminated with labeled-cocaine, to differentiate between contamination (labeled-cocaine) and ingestion (cocaine). Procedures to be explored include different solvents, sequential washes, washing times, and agitation and/or ultrasounds. It is hypothesized that the best decontamination procedure will result in complete elimination of labeled-cocaine, while maintaining cocaine and metabolites concentrations in cocaine-users’ hair samples. To elaborate the hair assessment tool, hair samples from cocaine-users will be treated with different cosmetic treatments and adulteration products. The samples will be analyzed by three different microscopical/microanalytical techniques to evaluate hair damage and by liquid chromatography-tandem mass spectrometry to determine concentrations of cocaine and metabolites. The hypothesis is that highly damaged hairs will be identified by the microscopical/microanalytical techniques and will have decreased cocaine and metabolites concentrations. A newly developed damage scale will link degree of hair damage to potential concentration decreases. To investigate the effect of cosmetic treatments on external contamination, hair samples from non-cocaine-users will be submitted to cocaine contamination before or after cosmetic treatments and compared to only contaminated samples. Results from this study will provide insights on how cosmetic treatments prevent or remove external contamination, or facilitate hair uptake of external cocaine. The three parts of the project will include a high number of hair samples (n=400), covering a wide range of colors and shapes, allowing the generalization of the findings to all demographics. Scholarly publications in open-access and conference presentations from the project will serve as valuable resources for practitioners, policymakers, and stakeholders within the criminal justice system, facilitating collaborative efforts to address pressing challenges in forensic toxicological hair testing. This project will be conducted in an academic setting, enhancing the education of the future workforce in forensic sciences, and engaging minorities and female students to address the current gap in the field to ensure a more inclusive and equitable landscape in forensic sciences. CA/NCF