was created in order to develop statistical models for predicting themembership of a specimen to a relevant source. Furthermore, theconservation of the carbon isotope ratio between a precursor and itsGHB end-product will be evaluated as well. This aspect is of majorimportance and could be extended to precursors profiling on aninternational level to develop refined geographical strategies to controlthem. GHB, GBL, and 1,4-BD samples were obtained from differentpolice departments in Switzerland, from internet retailers of variouscountries and several regular chemicals suppliers. Significant differ-ences in the carbon isotopic ratio (δ13C-values ranging from −23.1‰to −46‰) were found between all GBL samples. Accordingly, thismethod demonstrates a high potential to distinguish between GBL,GHB, or 1,4-BD samples of various sources.

doi:10.1016/j.scijus.2009.11.055

Optimisation of the separation of amphetamine-type stimulantsusing artificial neural networks for applications onlab-on-a-chip technologyA. Van Gramberga, A. Beavisa, P. Doblea, S. Milehamb

aUniversity of Technology, Sydney, Centre for Forensic Science, Broadway,AustraliabQueensland Health Forensic and Scientific Services, Brisbane, Australia

There is a technology gap for ‘in-field’ detection methods that arecapable of separating complex mixtures of precursor chemicals andactive ingredients of amphetamine-type stimulants (ATS). The AgilentBioanalyzer 2100 is a commercial lab-on-a-chip (LOC) devicedesigned toseparate and analyse DNA and RNA. Modification of the routineoperational procedures and buffers facilitates the analysis of compoundsthat the instrumentwas not originally designed for. The limiting factor isthe method of detection, which is restricted to laser-induced fluores-cence. Fluorescein isothiocyanate (FITC)-derivatizedATSwere chosen formethod optimization on conventional capillary electrophoresis (CE). Theinitial parameters altered for optimization were pH, sodium dodecylsulfate (SDS) concentration, and the amount and identity of organicmodifier added to the buffer. Preliminary results indicated that SDS didnot provide the sufficient resolving power to separate amphetaminecompounds under the extremely fast analysis times encountered in chip-based separations. Consequently, focus was shifted to separationmodelsusing cyclodextrins, chiral selectors that have a high resolving power.Artificial neural networkswere used to simplify the optimizationprocessand to limit the number of experiments needed to reach a ‘global’optimum. The model generated with the lowest training error was amultilayer perception network which was used to predict the electro-phoretic mobilities of the target compounds over a predetermined pHand surfactant concentration range. The optimized method was thenapplied to controlled ATS, such as methamphetamine and MDMA, withcollaboration from the Queensland Health, Forensic, and ScientificServices (QHFSS) for separation by LOC. This research demonstrated fastanalysis of both amines and amino acids by microchip electrophoresis.The speed and sensitivity demonstrated that the device has potential forin-field detection of amphetamine and related compounds.

doi:10.1016/j.scijus.2009.11.056

Comparative analysis of ephedrine and pseudoephedrine by usingstable isotope ratio mass spectrometry (IRMS)S. Schneiders, T. Holdermann, R. DahlenburgBundeskriminalamt, Forensic Science Institute, Wiesbaden, Germany

The isotope ratios of methamphetamine depend on both theprecursor and the synthetic pathway. Ephedrine and pseudoephedrine

are the commonly used precursors. The determination of 13C/12C and15N/14N isotope ratioswas reported someyears ago [1], but for 2H/1H and18O/16O isotope ratios only a little data is available [2]. This articlediscusses the potential and limitations of using isotope ratio massspectrometry for comparison purposes of ephedrine and pseudoephe-drine. On the one hand, the variation of the isotope ratios of samplesfrom one known sourcewas determined for intra-batch and inter-batchsamples. Additionally seized samples of unknown sources werecompared to these values.

40 samples of pseudoephedrine from one source and 34 seizedephedrine samples were available. 13C/12C, 15N/14N, 2H/1H, and 18O/16Oisotope ratioswere determinedusing elemental analyser (EA) and hightemperature conversion elemental analyser (TC/EA) coupled to anisotope ratio mass spectrometer (IRMS). The isotope ratios areexpressed in delta notation relative to primary international standards(e.g., V-PDB, Vienna Pee Dee Belemnite). Intra-batch samples ofpseudoephedrine were undistinguishable concerning all four deter-mined parameters, whilst significant differences between batchescould be identified. The determination of stable isotopes enhances thepossibilities of precursor characterisation, e.g., determining natural,semi-synthetic, or synthetic sources as well as sample comparison,including linking of seized samples and detection of possible tradingways. The results show that IRMS provides a high potential indifferentiating precursors for the clandestine production of ATS andidentifying their sources.

References

Kurashima, et al., 2004. Determination of origin of ephedrine used as precursor forillicit methamphetamine by δ13C and δ15N analysis. Anal. Chem. 76, 4233–4236.Ehleringer, J.R., et al., 2007. Forensic Science applications of stable isotope ratioanalysis. In: Blackledge, R.D. (Ed.), Forensic Science on the Cutting Edge: New Methodsfor Trace Evidence Analysis. John Wiley & Sons, Inc., Hoboken, New Jersey, USA,pp. 399–422.

doi:10.1016/j.scijus.2009.11.057

An investigation into the power of IRMS to discriminate batches ofMDMA by synthetic routeH.A.S. Buchanana, N. Nic Daeida, W.J. Kerra, W. Meier-Augensteinb,c,J.F. Carterd, H.F. KempcaUniversity of Strathclyde, Dept of Pure & Applied Chemistry,WestChem, Glasgow, United KingdombUniversity of Dundee, Centre for Anatomy & Human Identification,Dundee, United KingdomcScottish Crop Research Institute, Invergowrie, Dundee, United KingdomdMass Spec. Analytical, Bristol, United Kingdom

Drug profiling, or the ability to link batches of illicit drugs to acommon source or synthetic route, has long been a goal of law-enforcement agencies. Recently, research has been focused on theapplicability of isotope ratio mass spectrometry (IRMS) for this task. Inthe first study, 18 MDMA samples were synthesised in-house from thesame batch of starting ketone by three commonly used reductiveaminations (Al/Hg amalgam, NaBH4, and Pt/H2), and the resultingMDMA HCl was analysed by isotope ratio mass spectrometry (IRMS)for carbon, nitrogen, hydrogen, and oxygen isotope ratios. Accuratediscrimination of the samples by synthetic route was demonstratedusing δ2H values on their own or in combinationwith δ13C, δ15N, and/orδ18O. In the second study, a factorial design experiment was under-taken in which 32 MDMA HCl samples were synthesised by the mostcommonly used route (Pt/H2) in order to investigate the effect on theisotope profile of altering five of the reaction conditions (quantity ofmethylamine, quantity of PMK, stirring time allowed for imineformation, amount of catalyst, and time allowed for hydrogenation).

Abstract 41

Results indicate that four of these five factors affect the δ values of theproduct, thus rendering discrimination of MDMA by synthetic routemore difficult. Full results and conclusions from both of these studieswill be presented in this talk.

doi:10.1016/j.scijus.2009.11.058

Establishing links between explosives precursors and productsusing isotope ratio mass spectrometryC. Lock, M. BeardahDSTL, FEL, Sevenoaks, United Kingdom

Isotope Ratio Mass Spectrometry (IRMS) has been widely used inthe fields of geochemistry and hydrology. The potential for accessinginformation, such as sample origin and history, have seen IRMS beingadopted for a variety of forensic applications. The pharmaceutical anddrugs industry have utilised IRMS for establishing patent infringe-ments and characterising batches of illegal drugs. The technique hasalso been used to investigate human tissue, including hair and nails,to establish information about geographical movement, and hasassisted in several murder investigations. The Forensic ExplosivesLaboratory (FEL) has developed methods for carbon, nitrogen, andoxygen isotope analysis and applied this to samples with explosivessignificance. Part of the FEL's IRMS research effort has focused uponestablishing stronger links between precursor materials and synthe-sised explosives products. Future applications of this research couldinvolve establishing chemical links between precursors and theexplosives products synthesised at an improvised ‘bomb factory’, forexample. While circumstantial evidence of illegal manufacture ofexplosives may be strong due to equipment, literature, and chemicalsfound, the addition of a chemical link may complement existingevidence when presented in court. The initial research considered theWoolwich synthesis of RDX, and demonstrated the existence ofchemical links between the precursors and product, but alsoimproved the understanding of where direct links might be expectedin other reaction schemes. The formation and cleavage of bonds in anyreaction affects the direction of isotope change. An understanding of areaction scheme enables predictions about directions of isotopicchange between precursor and product resulting in broad discrimina-tion of potential precursor materials. Despite the very encouragingresults of the RDX research, this scenario is relatively unrealisticwithin the context of UK casework, but was a useful proof of concept.The synthesis of HMTD has been observed in several cases in the UK,and was selected as the target material for a second study. Severalbatches of HMTD were synthesised at FEL for isotope analysis. Theresults of this investigation are also presented.

doi:10.1016/j.scijus.2009.11.059

Contribution of isotope ratio mass spectrometry to the investigationof improvised explosives: Isotopic study of black powders andammonium nitratesN. Gentilea, R.T.W. Siegwolfb, O. DelémontaaUniversity of Lausanne, Institut de Police Scientifique, Dorigny,SwitzerlandbPaul Scherrer Institut, Laboratory of Atmospheric Chemistry, Villigen,Switzerland

The establishment of legislative rules about explosives in theeighties has reduced the illicit use of military and civilian explosives.However, bomb-makers have rapidly taken advantage of substanceseasily accessible and intended for licit uses to produce their ownexplosives. This change in strategy has given rise to an increase of

improvised explosive charges, which is moreover assisted by the easeof implementation of the recipes, widely available through opensources. While the nature of the explosive charges has evolved,instrumental methods currently used in routine, although moresensitive than before, have a limited power of discrimination andallow mostly the determination of the chemical nature of thesubstance. Isotope ratio mass spectrometry (IRMS) has been appliedto a wide range of forensic materials. Conclusions drawn from themajority of the studies stress its high power of discrimination.Preliminary studies conducted so far on the isotopic analysis of intactexplosives (pre-blast) have shown that samples with the samechemical composition and coming from different sources could bedifferentiated. The measurement of stable isotope ratios appearstherefore as a new and remarkable analytical tool for the discrimina-tion or the identification of a substance with a definite source.However, much research is still needed to assess the validity of theresults in order to use them either in an operational prospect or incourt. Through the isotopic study of black powders and ammoniumnitrates, this research aims at evaluating the contribution of isotoperatio mass spectrometry to the investigation of explosives, both froma pre-blast and from a post-blast approach. More specifically, the goalof the research is to provide additional elements necessary to a validinterpretation of the results, when used in explosives investigation.This work includes a fundamental study on the variability of theisotopic profile of black powder and ammonium nitrate in both spaceand time. On one hand, the inter-variability between manufacturersand, particularly, the intra-variability within a manufacturer has beenstudied. On the other hand, the stability of the isotopic profile overtime has been evaluated through the aging of these substancesexposed to different environmental conditions. The second part of thisproject considers the applicability of this high-precision technology totraces and residues of explosives, taking account of the characteristicsspecific to the field, including their sampling, a probable isotopicfractionation during the explosion, and the interferences with thematrix of the site.

doi:10.1016/j.scijus.2009.11.060

Targeting amino acids in latent fingermarks using bioconjugatedgold-citrate self-assembled monolayer nanoparticlesX. Spindlera,b, O. Hofstetterc, R. Wuhrerd, A. McDonaghb,C. Rouxb, C. LennardaaUniversity of Canberra, National Centre of Forensic Studies, Canberra,AustraliabUniversity of Technology, Sydney, Centre for Forensic Science, Broadway,AustraliacNorthern Illinois University, Chemistry & Biochemistry, DeKalb, UnitedStatesdUniversity of Technology, Sydney, Microstructural Analysis Unit,Broadway, Australia

Antibodies that are enantiospecific to l-amino acids have beentrialled as a novel antigenic fingermark enhancement reagent. Whenconjugated to gold nanospheres and placed in a non-aqueous suspen-sion, the antibodies targeted free amino acids and peptides present infingermark ridge detail with high specificity and sensitivity. Double-antibody sandwich enzyme-linked immunosorbent assays (ELISA),scanningelectronmicroscopy (SEM), and fingermark samples onporousand non-porous surfaces were used to determine the specificity andsensitivity of the conjugates. Trials using fingermark samples developedwith the conjugates andenhancedwitha fluorescently tagged secondaryantibody indicated that the method was most effective for dry and agedfingermarks on non-porous surfaces. The long wavelength fluorescentdyes selected for these experiments addressed issues associated with

Abstract42