Tandem mass spectrometry: a helpful tool in hair analysis for the forensic expert
Introduction
The 1998 International Workshop in Munich ‘Cannabinoids in Hair’ organized by the ‘Society of Hair Testing’ was presented in the laboratories of two local institutes. One of these institutes is the central police agency for Bavaria (Bavarian State Bureau of Investigation). This State Bureau is exclusively responsible for investigating criminal acts, but it is not responsible for investigation of civil law or administration law cases. No service laboratory for workplace testing has been established.
An essential field of a chemistry and toxicology department is hair analysis. Orders for hair testing will be sent from the court, from the prosecutor’s office and the police. The forensic expert’s skills based on hair analysis will be utilized as corroborative evidence. These skills are mainly used to scrutinize for chronic abuse of illegal drugs or as an adjunct to a medical and physiological examination in order to evaluate criminal responsibility.
In the description of these duties, it is important to emphasize that some clients have a special interest that their hair tests positive for illegal drugs. For example, with regard to the legal system in Germany, a person taken into custody for drug trafficking with no residues of drugs in his hair will probably be sentenced as a dealer. However, an accused with a lot of drugs in his hair could be treated as a supposed addict and will be guaranteed extenuating circumstances. For this reason, some clients are disappointed if the residues of drugs in the hair sample are minimal and not enormous.
Generally, particular information from the mandator about the individual subject can be important for a rendering of an expert opinion. Aspects that could be considered are, for example: when was the person taken into custody? What are the special allegations? Is there a self reported use?
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Chemicals and reagents
Methanol, acetonitrile, ethyl acetate, n-hexane, acetone, acetic acid and phosphoric acid were analytical grade (Merck, Darmstadt, Germany). The derivatizing agents penta-fluoropropionic anhydride and hexafluoroisopropanol were purchased from Aldrich (Steinheim, Germany). Reference standard solutions of D5-amphetamine, D5-methylenedioxymethamphetamine, D3-benzoylecgonine, D3-tetrahydrocannabinol, D3-methadone, D3-cocaine, D3-morphine, D3-dihydrocodeine, D3-codeine, D3-6-monoacetyl-morphine,
Results and discussion
The head is an anatomical area where hair samples are collected in the great majority of cases. However, approximately 10% of samples provided for hair analyses in the laboratories of the State Bureau were obtained from beard, pubic, axillary and chest region [1].
A convenient method to isolate drugs and metabolites that are incorporated in hair is methanol extraction [2]. The methanol extraction procedure is suitable for the determination of amphetamine, methamphetamine, MDA, MDMA (ecstasy),
Conclusion
Each forensic expert will appreciate the solid basis of reliable data. He will probably prefer two, three or even more data in order to evaluate the drug history of a certain person. A helpful tool for reaching this goal can be a gas chromatograph/tandem-mass spectrometer in order to detect components and metabolites in very low concentration.
Possible criteria for obtaining a positive hair result as used in the State Bureau are the following.
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Cocaine positive: only if cocaine exceeds 0.5 ng/mg
Acknowledgements
The author would like to thank, for their excellent support and engagement, Mrs. S. David and Mrs. G. Sichelstiel for sample preparation and Mr. X. Neumeier for performing GC/MS/MS analyses.
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Cocaine and metabolites in the hair of ancient Peruvian coca leaf chewers
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2011, Forensic Science InternationalCitation Excerpt :Table 2 shows the characteristics of head, pubic, axillary and beard hair. Each hair has three distinct stages during its life: anagen (the growing phase), catagen (the intermediate phase) and telogen (the resting phase) [1]. Three glands are associated with the hair follicle: the apocrine, sebaceous, and sweat glands [1].
A study on the concentrations of 11-nor-Δ<sup>9</sup>-tetrahydrocannabinol-9-carboxylic acid (THCCOOH) in hair root and whole hair
2011, Forensic Science InternationalCitation Excerpt :Studies on hair analysis for methamphetamine (MA), methylenedioxymethamphetamine (MDMA), cocaine, opiates and other drugs have been reported. In particular, the introduction of gas chromatography/tandem mass spectrometry (GC/MS/MS) enables sensitive analysis of low concentrations of THCCOOH in hair [1–5]. Drug concentrations in hair were classified into three or four categories as a guide for determining the level of use of MA [6,7], opiates [7–9], cocaine [7,10] and cannabinoids [7].
Simultaneous analysis of Δ9-tetrahydrocannabinol and 11-nor-9-carboxy-tetrahydrocannabinol in hair without different sample preparation and derivatization by gas chromatography-tandem mass spectrometry
2011, Journal of Pharmaceutical and Biomedical AnalysisHair analysis for Δ9-tetrahydrocannabinolic acid A-New insights into the mechanism of drug incorporation of cannabinoids into hair
2010, Forensic Science InternationalCitation Excerpt :This route was found to be the main route of incorporation, e.g. for fatty acid ethyl esters (FAEE) [13]. The main approach utilized in the past to differentiate active cannabis consumption from external contamination is the analysis for the major oxidative metabolite 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH), e.g. by GC-NCI–MS [8,14–17] or GC-NCI–MS/MS [7,12,18–20]. In early publications using GC–MS the reported THC-COOH hair concentrations were obviously much too high [5,6] and it is accepted that in general the concentrations lie in the low pg/mg range.
Analytical, toxicological and forensic aspects of drug-facilitated crimes: 10 years of experience
2010, Annales Pharmaceutiques FrancaisesChapter 20 Unconventional samples and alternative matrices
2008, Handbook of Analytical SeparationsCitation Excerpt :Among the proposed methods to discriminate between passive exposure and active drug consumption, there are two major criteria: the adoption of a cut-off value along with the use of metabolite-to-parent ratios, and the use of procedures for decontamination. In the first case, efforts have been made for the definition of cut-off values for each drug and criteria for the presence of metabolites have been recommended (Table 20.1) [25–28]. Two metabolites that are definitive indicators of use even without washing because they are formed in vivo, are cocaethylene in the case of ingestion of ethanol along with cocaine and 11-nor-delta9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) from use of cannabinoids.