Improvements to separation and detection for forensic analysis of illicit substances

This article gives an overview of our recent research into separation and detection of analytes of forensic interest. This work has been carried out in collaboration with local forensic service providers and is based on our previous studies of chemiluminescence detection, flow analysis and capillary electrophoresis as applied to process analytical chemistry for the pharmaceutical industry. Chemiluminescence has the potential to provide low limits of detection in combination with high selectivity, while capillary electrophoresis allows for rapid, highly efficient separations. Examples of recent forensic applications are presented and future directions are discussed.</div

'Country life'? Rurality, folk music and 'Show of Hands'

This paper examines the contribution of folk music to understanding the dynamic, fluid and multi-experiential nature of the countryside. Drawing from literature on the geographies of music, it examines the work of 'Show of Hands', a contemporary folk band from Devon in England. Three areas are studied. First, the paper examines the musical style of Show of Hands in order to explore how hybridised, yet distinctive, styles of music emerge in particular places. Second, it demonstrates how Show of Hands' hybrid musical style has become closely associated with the Southwest of England. Finally, within these spatial and hybrid contexts, attention is given to the ways in which their music represents the 'everyday lives of the rural'. Taken together these themes assess the relevance of music in the understanding of rurality as hybrid space. © 2008 Elsevier Ltd. All rights reserved

Time-resolved fluorescence microscopy of gunshot residue: an application to forensic science

Time-resolved fluorescence microscopy has rapidly emerged as the technique of choice for many researchers aiming to gain specific insights into the dynamics of intricate biological systems. Although the unique advantages the technique provides over other methods have proven to be particularly useful in the biosciences, to date they have been largely unexploited by other research disciplines. In this paper, we demonstrate the capacity of time-resolved fluorescence microscopy as a practical analytical tool in the forensic sciences via the imaging of gunshot residues that are expelled when a firearm is discharged. This information may prove to be useful for determination of the true sequence of events that took place in a firearm related crime.<br /

A rapid test for heroin (3,6-Diacetylmorphine) based on two chemiluminescence reactions

A rapid method for screening drug seizure samples for 3,6-diacetylmorphine (heroin), which consists of a simple hydrolysis procedure and flow-injection analysis with two chemiluminescence reagents, is described. Before hydrolysis, 3,6-diacetylmorphine evokes an intense response with a tris(2,2\u27-bipyridyl)ruthenium(III) reagent (prepared by dissolving the perchlorate salt in acetonitrile), and a relatively weak chemiluminescence response with a second reagent: potassium permanganate in an aqueous acidic polyphosphate solution. However, the permanganate reagent is extremely sensitive toward the hydrolysis products of 3,6-diacetylmorphine (i.e., 6-monoacetylmorphine and morphine). Some compounds commonly found in drug laboratories may cause false positives with tris(2,2\u27-bipyridyl)ruthenium(III), but do not produce the markedly increased response with the permanganate reagent after the hydrolysis procedure. The combination of these two tests therefore provides an effective presumptive test for the presence of 3,6-diacetylmorphine, which we have verified with 14 samples obtained from a forensic science laboratory

Chemiluminescence detection of arginine-containing peptides seperated with monolithic high-performance liquid chromatography

The selective determination of arginine-containing peptides is hindered by the high pKa of the guanidine functional group, as most peptides are not stable at the pH often required to create an effective nucleophile [1]. Modifications of the Sakaguchi reaction-the spectrophotometric determination of arginine with hypohalites and phenols-have been extended to other guanidine compounds or arginine residues in proteins, but many inaccuracies have been uncovered [2] and [3]. For example, the 149-154 hexapeptide fragment (Ala-Asn-Thr-Pro-Asp-Arg) from chymotrypsin gave twice the response of the corresponding hydrolysate solution [2]. Alternatively, arginine residues will react with 9,10-phenanthrenequinone [2] and [4], p-nitrophenylglyoxal [3], or benzoin [1], [5] and [6] to form colored or fluorescent products; these reagents are generally more sensitive and accurate than the Sakaguchi reaction. Flow-analysis procedures for arginine or arginine-containing peptides that incorporate these chemistries require prior derivatization [6] or postcolumn reaction manifolds with numerous reagent lines [5] and [7] and in some cases a heated reaction coil [5]. We have recently developed an exceedingly simple and rapid method for the determination of arginine (in the presence of other amino acids) with a limit of detection of 0.1 μM, based on the chemiluminescent oxidation of arginine with hypobromite [8]. In this paper we present the determination of arginine-containing peptides separated with monolithic column chromatography. The highly porous monolithic column was selected as high flow rates can be applied at low pressure, without a significant decrease in efficiency. Therefore, in addition to a significant reduction in analysis time compared to conventional chromatography, the flow rates are more compatible with chemiluminescence detectors that have been developed for flow-injection analysis

A hybrid FIA/HPLC system incorporating monolithic column chromatography

We have combined the generation of solvent gradients using milliGAT pumps, chromatographic separations with monolithic columns and chemiluminescence detection in an instrument manifold that approaches the automation and separation efficiency of HPLC, whilst maintaining the positive attributes of flow injection analysis (FIA), such as manifold versatility, speed of analysis and portability. As preliminary demonstrations of this hybrid FIA/HPLC system, we have determined six opiate alkaloids (morphine, pseudomorphine, codeine, oripavine, ethylmorphine and thebaine) and four biogenic amines (vanilmandelic acid, serotonin, 5-hydroxyindole-3-acetic acid and homovanillic acid) in human urine, using tris(2,2&prime;-bipyridyl)ruthenium(III) and acidic potassium permanganate chemiluminescence detection.<br /

Chemiluminescence detection of 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) and related nitramine explosives

A simple controlled chemical reduction of 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) and related nitramine compounds with zinc amalgam generates species that elicit intense chemiluminescence with tris(2,2'-bipyridine)ruthenium(III), which extends this widely utilised chemiluminescence reagent to a new class of analyte and presents a sound chemical basis for a screening test for nitramine high explosives. Examination of the chemiluminescence profiles under stopped-flow conditions revealed contributions from multiple transient species formed in the initial reduction step