Evidence based decontamination protocols for the removal of external Δ9-tetrahydrocannabinol (THC) from contaminated hair
| Autor: | Ruth J.P. Peeters, Teris A. van Beek, Michel W. F. Nielen, Wilco F. Duvivier |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
External contamination
Sample preparation 01 natural sciences Pathology and Forensic Medicine 03 medical and health sciences Forensic Toxicology Surface-Active Agents 0302 clinical medicine Humans 030216 legal & forensic medicine Dronabinol Directie Decontamination VLAG Forensics Smoke Chromatography Evidence-Based Medicine biology Mass spectrometry Chemistry Cannabinoids Methanol 010401 analytical chemistry Organic Chemistry Forensic toxicology Sodium Dodecyl Sulfate Human decontamination Contamination biology.organism_classification Organische Chemie 0104 chemical sciences Solvent Microscopy Electron Environmental chemistry Solvents Cannabis Δ9-tetrahydrocannabinol Law Chromatography Liquid Hair |
| Zdroj: | Forensic Science International 259 (2016) Forensic Science International, 259, 110-118 |
| ISSN: | 0379-0738 |
| DOI: | 10.1016/j.forsciint.2015.12.014 |
| Popis: | External contamination can cause false positive results in forensic hair testing for drugs of abuse and is therefore a major concern when hair evidence is used in court. Current literature about decontamination strategies is mainly focused on external cocaine contamination and no consensus on the best decontamination procedure for hair samples containing cannabinoids has been reached so far. In this study, different protocols with solvents, both organic as well as aqueous, were tested on blank and drug user hair for their performance on removing external cannabis contamination originating from either smoke or indirect contact with cannabis plant material. Smoke contamination was mimicked by exposing hair samples to smoke from a cannabis cigarette and indirect contact contamination by handling hair with cannabis contaminated gloves or hands. Δ9-tetrahydrocannabinol (THC) levels in the hair samples and wash solvents were determined using liquid chromatography tandem mass spectrometry (LC–MS/MS) analysis. Aqueous surfactant solutions removed more THC contamination compared to water, but much less than organic solvents. Methanol, dichloromethane and chloroform were most efficient in removing THC contamination. Due to its lower environmental impact, methanol was chosen as the preferred decontamination solvent. After testing of different sequential wash steps on externally contaminated blank hair, three protocols performed equally well, removing all normal level and more than 99% of unrealistically high levels of external cannabis contamination. Thorough testing on cannabis users’ hair, both as such and after deliberate contamination, showed that using these protocols all contamination could be washed from the hair while no incorporated THC was removed from truly positive samples. The present study provides detailed scientific evidence in support of the recommendations of the Society of Hair Testing: a protocol using a single methanol wash followed by a single aqueous SDS solution wash, followed by a Milli-Q water rinsing step, is suggested as the preferred decontamination protocol to remove external cannabis contamination from hair while preserving the incorporated compounds. |
| Databáze: | OpenAIRE |
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