13 14 Pyrolysis-gas chromatography (Py-GC) has become well established as a simple, quick and reliable 15 analytical technique for a range of applications including the analysis of polymeric materials. Recent 16 developments in Py-GC technology and instrumentation include laser pyrolysis and non-discriminating 17 pyrolysis. Progress has also been made in the detection of low level polymer additives with the use of 18 novel Py-GC devices. Furthermore, it has been predicted that future advances in separation technology 19 such as the use of comprehensive two-dimensional gas chromatography will further enhance the 20 analytical scope of Py-GC. 21 22

The analysis of the chemical composition of fingerprints is important for the development and improvement of existing fingerprint enhancement techniques. This study demonstrates the first analysis of a latent fingerprint sample, using an optimized CE-MS method. In total 12 amino acids were detected in the fingerprint sample. MS/MS fragmentation was used to provide additional identity confirmation, for which eight of the twelve detected amino acids generated confirmatory product ions. Nine amino acids were quantified and their relative abundances were consistent with previous studies with serine and glycine being the most abundant. The successful detection of amino acids from latent fingerprints demonstrates that CE-MS is a potential future technique for further study of such compounds in fingerprint samples.

The explosive triacetone triperoxide (TATP), which can be prepared from commercially readily available reagents following an easy synthetic procedure, is one of the most common components of improvised explosive devices (IEDs). Molecularly-imprinted polymer (MIP) electrochemical sensors have proved useful for the determination of different compounds in different matrices with the required sensitivity and selectivity. In this work, a highly sensitive and selective molecularly imprinted polymer with electrochemical capabilities for the determination of TATP has been developed. The molecular imprinting has been performed via electropolymerisation onto a glassy carbon electrode surface by cyclic voltammetry from a solution of pyrrole functional monomer, TATP template and LiClO4. Differential Pulse Voltammetry of TATP, with LiClO4 as supporting electrolyte, was performed in a potential range of −2.0 V to +1.0 V (vs. Ag/AgCl). Three-factor two-level factorial design was used to optimise the monomer concentration at 0.1 mol·L−1, template concentration at 100 mmol·L−1 and the number of cyclic voltammetry scan cycles to 10. The molecularly imprinted polymer-modified glassy carbon electrode demonstrated good performance at low concentrations for a linear range of 82–44,300 μg·L−1 and a correlation coefficient of r2 = 0.996. The limits of detection (LoD) and quantification (LoQ) achieved were 26.9 μg·L−1 and 81.6 μg·L−1, respectively. The sensor demonstrated very good repeatability with precision values (n = 6, expressed as %RSD) of 1.098% and 0.55% for 1108 and 2216 μg·L−1, respectively. It also proved selective for TATP in the presence of other explosive substances such as PETN, RDX, HMX, and TNT.

Introduction

ABSTRACT:The NBOMe derivatives are phenethylamines derived from the 2C class of hallucinogens. Only a few human pharmacologic studies have been conducted on these drugs and several cases of intoxication and deaths have been reported. Presently, NBOMe are not a part of the routine drugs-of-abuse screening procedure for many police forces and there are no rapid immunoassay screening tests that can detect the presence of those compounds. In this paper, the voltammetric behavior of 25B NBOMe and 25I NBOMe were investigated and their electroanalytical characteristics determined for the first time. A novel, fast and sensitive screening method for the identification of the two most common NBOMes (25B-NBOMe and 25I-NBOMe) in real samples is reported. The method uses the electrochemical oxidation of these molecules to produce an analytical signal that can be related to the NBOMe concentration with an average lower limit of quantitation of 0.01mg/mL for both of them. The method is selective enough to identify the two compounds individually, even given the great similarity in their structure.