Next Article in Journal
Family Structure and Subsequent Anxiety Symptoms; Minorities’ Diminished Return
Next Article in Special Issue
Sales and Advertising Channels of New Psychoactive Substances (NPS): Internet, Social Networks, and Smartphone Apps
Previous Article in Journal
Neuromodulatory Treatments for Alcohol Use Disorder: A Review
Previous Article in Special Issue
Transitioning Bodies. The Case of Self-Prescribing Sexual Hormones in Gender Affirmation in Individuals Attending Psychiatric Services
Article Menu
Issue 6 (June) cover image

Export Article

Open AccessFeature PaperArticle
Brain Sci. 2018, 8(6), 96; https://doi.org/10.3390/brainsci8060096

A Study on Photostability of Amphetamines and Ketamine in Hair Irradiated under Artificial Sunlight

1
Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131 Padova, Italy
2
Legal Medicine and Toxicology, University Hospital of Padova, 35121 Padova, Italy
3
School of Specialization in Legal Medicine, University Hospital of Padova, 35121 Padova, Italy
*
Authors to whom correspondence should be addressed.
Received: 29 April 2018 / Revised: 23 May 2018 / Accepted: 24 May 2018 / Published: 28 May 2018
View Full-Text   |   Download PDF [2779 KB, uploaded 30 May 2018]   |  

Abstract

Drugs incorporated into hair are exposed to the environment, and cosmetic and chemical treatments, with possible decreases in their content. Knowledge concerning the effect of sunlight on drug content in hair can be helpful to forensic toxicologists, in particular, when investigating drug concentrations above or below pre-determined cut-offs. Twenty authentic positive hair samples were selected which had previously tested positive for amphetamines and/or ketamine. Washed hair were divided into two identical strands, with the former exposed at 765 W/m2 (300–800 nm spectrum of irradiance) for 48 h in a solar simulator, and the latter kept in the dark. Hair samples were extracted and analyzed by liquid chromatography high-resolution mass spectrometry detection. The percentage of photodegradation was calculated for each analyte (i.e., amphetamine, methamphetamine, methylendioxyamphetamine, ketamine, and norketamine). In parallel, photodegradation processes of standard molecules dissolved in aqueous and organic solutions were studied. In 20 hair samples positive for the targeted analytes, exposure to artificial sunlight induced an appreciable decrease in drug concentrations. The concentration ranges in the non-irradiated hair samples were 0.01–24 ng/mg, and 65% of samples exhibited a decrease in post-irradiation samples, with reduction from 3% to 100%. When more drugs were present in the same hair sample (i.e., MDMA and ketamine) the degradation yields were compound dependent. A degradation product induced by irradiation of ketamine in aqueous and methanol solutions was identified; it was also found to be present in a true positive hair sample after irradiation. Ketamine, amphetamines, and their metabolites incorporated in the hair of drug users undergo degradation when irradiated by artificial sunlight. Only for ketamine was a photoproduct identified in irradiated standard solutions and in true positive irradiated hair. When decisional cut-offs are applied to hair analysis, photodegradation must be taken into account since sunlight may produce false negative results. Moreover, new markers could be investigated as evidence of illicit drug use. View Full-Text
Keywords: hair; solar light; photodegradation; amphetamines; MDMA; ketamine hair; solar light; photodegradation; amphetamines; MDMA; ketamine
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Supplementary material

SciFeed

Share & Cite This Article

MDPI and ACS Style

Miolo, G.; Tucci, M.; Menilli, L.; Stocchero, G.; Vogliardi, S.; Scrivano, S.; Montisci, M.; Favretto, D. A Study on Photostability of Amphetamines and Ketamine in Hair Irradiated under Artificial Sunlight. Brain Sci. 2018, 8, 96.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Brain Sci. EISSN 2076-3425 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top