|Title||Improved forensic hair evidence for drugs of abuse by mass spectrometry|
|Source||University. Promotor(en): Michel Nielen, co-promotor(en): Teris van Beek. - Wageningen : Wageningen University - ISBN 9789462578159 - 194 p.|
RIKILT - Business unit Dierbehandelingsmiddelen
Laboratory for Organic Chemistry
|Publication type||Dissertation, internally prepared|
|Keyword(s)||forensic science - hair - analytical methods - spectrometry - forensische wetenschap - haar - analytische methoden - spectrometrie|
Forensic hair analysis can be used as alternative evidence next to body fluids, and to obtain retrospective timeline information of an individual’s drug exposure. Chapter 1 describes the general concepts of drug incorporation into hair, external contamination, and the current status and limitations of hair analysis methods are introduced. Furthermore, an overview of ambient ionization techniques is given, with emphasis on direct analysis in real time (DART).
A major issue in forensic hair analysis is the possibility of false-positive results due to external contamination. In Chapter 2, an evidence-based evaluation of decontamination protocols for the removal of cannabinoid contamination is presented, mainly focused on
A novel approach for the analysis of intact locks of hair consisting of DART combined with high resolution mass spectrometry (HRMS) is developed in Chapter 3. DART–HRMS settings were optimized for the analysis of THC and the accuracy of the probed hair zone was investigated using spiked blank hair samples. Intact locks of hair could be longitudinally scanned without the need of extensive sample preparation, resulting in analysis times of only minutes. Detection of THC was achieved in several hair samples from cannabis users. A quantitative liquid chromatography (LC)–MS/MS method was developed, in-house validated, and used to confirm the presence of THC in drug user hair samples. With a retrospective timeline accuracy of ±2 weeks, a significant improvement over conventional segmented hair analysis was achieved. Moreover, differentiation between zones of different THC content within a DART hair scan could be made, indicating possibilities for retrospective assessment of time of drug use.
The DART hair scan method has been improved and expanded in Chapter 4. Targeted detection of four commonly used drugs of abuse (amphetamine, cocaine, MDMA and THC) with structural confirmation was achieved by data-dependent product ion scans. Simultaneously,
When direct and/or ambient ionization techniques are used to analyze intact hair samples, endogenous isobaric ions can overlap with compounds of interest and yield
Chapter 6 demonstrates the application of forensic hair analysis techniques to veterinary control. Timeline information could be obtained from veterinary hair samples. For this purpose, a UPLC–MS/MS hair analysis method was adapted and optimized for smaller sample sizes.
Through the research presented in this thesis, novel approaches in hair analysis have been developed and the value of forensic hair evidence improved considerably. In Chapter 7, the main achievements of this thesis are discussed in detail and an insight in the future perspectives of hair analysis and ambient ionization is given. Potential further applications of the DART hair scan method, and ambient ionization in general, are presented, including some preliminary results of new decontamination strategies, hair analysis possibilities, and other forensic uses of DART ionization.