Citation

Belchior de Andrade AF, Elie M, Weck C, Jardim Zacca J, de Souza MP, Caldas LNB, Gonzalez-Rodriguez J. Forensic Sci. Int. 2020; 312: e110306.

Affiliation

School of Chemistry, University of Lincoln, Brayford Pool, Lincoln LN6 7TS, UK.

Copyright

(Copyright © 2020, Elsevier Publishing)

DOI

10.1016/j.forsciint.2020.110306

PMID

32408040

Abstract

The continuous emergence of NPS over the last years poses a series of novel challenges for forensic analysts. Most of those new compounds are synthesized with minimal chemical modifications to the structure of already known chemicals in order to avoid regulations. Some of these new compounds may undergo chemical changes during analysis leading to misidentification and detrimental legal consequences. GC-MS is one of the most widely used analytical techniques employed by forensic laboratories all over the world for drug analysis. Nevertheless, thermolabile NPS, such as 25I-NBOH can generate artefacts in the traditional GC-MS analysis. In this paper, we describe the fragmentation mechanism of the 25I-NBOH into a major peak corresponding to 2C-I and a minor one corresponding to the associated ortho-phenolic benzyl ether (o-PBE), which exact identity is directly linked with the solvent used for the analysis. Also, a series of method adjustments is displayed, encompassing variation on the injector temperature, split ratio and flow ratio, although with no success to prevent 25I-NBOH thermo degradation in the GC injector. Furthermore, differential scanning calorimetry and thermogravimetric analysis demonstrated that 25I-NBOH's thermal stability is due to a smaller temperature window between fusion and decomposition points. Finally, we perform derivatization experiments and demonstrate how to overcome 25I-NBOH degradation in the GC/MS analysis.

Copyright © 2020 Elsevier B.V. All rights reserved.

Language: en

Keywords

25I-NBOH; Derivatization; NPS; Thermal degradation