Bright NJ, Webb RP, Bleay S, Hinder S, Ward N, Watts JF, Kirkby KJ, Bailey MJ (2012) Determination of the deposition order of overlapping latent fingerprints and inks using Secondary Ion Mass Spectrometry (SIMS), Analytical Chemistry ACS Publications
A new protocol using time-of-flight secondary ion mass spectrometry (ToF-SIMS) has been developed to identify the deposition order of a fingerprint overlapping an ink line on paper. By taking line scans of fragment ions characteristic of the ink molecules (m/z 358.2 and 372.2) where the fingerprint and ink
overlap and by calculating the normalised standard deviation of the intensity variation across the line scan, it is possible to determine whether or not a fingerprint is above ink on a paper substrate. The
protocol adopted works for a selection of fingerprints from four donors tested here and for a fingerprint that was aged for six months; for one donor, the very faint fingerprints could not be visualized using
either standard procedures (ninhydrin development) or SIMS and therefore the protocol correctly gives an inconclusive result.
Bailey MJ, Bright NJ, Croxton RS, Francese S, Ferguson LS, Hinder S, Jickells S, Jones BJ, Jones BN, Kazarian SG, Ojeda JJ, Webb RP, Wolstenholme R, Bleay S (2012) Chemical characterization of latent fingerprints by matrix-assisted laser desorption ionization, time-of-flight secondary ion mass spectrometry, mega electron volt secondary mass spectrometry, gas chromatography/mass spectrometry, X-ray photoelectron spectroscopy, and attenuated total reflection Fourier transform infrared spectroscopic imaging: An intercomparison, Analytical Chemistry 84 (20) pp. 8514-8523
The first analytical intercomparison of fingerprint residue using equivalent samples of latent fingerprint residue and characterized by a suite of relevant techniques is presented. This work has never been undertaken, presumably due to the perishable nature of fingerprint residue, the lack of fingerprint standards, and the intradonor variability, which impacts sample reproducibility. For the first time, time-of-flight secondary ion mass spectrometry, high-energy secondary ion mass spectrometry, and X-ray photoelectron spectroscopy are used to target endogenous compounds in fingerprints and a method is presented for establishing their relative abundance in fingerprint residue. Comparison of the newer techniques with the more established gas chromatography/mass spectrometry and attenuated total reflection Fourier transform infrared spectroscopic imaging shows good agreement between the methods, with each method detecting repeatable differences between the donors, with the exception of matrix-assisted laser desorption ionization, for which quantitative analysis has not yet been established. We further comment on the sensitivity, selectivity, and practicability of each of the methods for use in future police casework or academic research. © 2012 American Chemical Society.
Bailey M (2014) Untitled, X-RAY SPECTROMETRY 43 (1) pp. 1-1
Ugarte M, Grime GW, Lord GM, Geraki K, Collingwood JF, Finnegan ME, Farnfield H, Merchant M, Bailey MJ, Ward NI, Foster PJ, Bishop PN, Osborne NN (2012) Concentration of various trace elements in the rat retina and their distribution in different structures, Metallomics: integrated biometal science
Bailey MJ, Ismail M, Bleay S, Bright N, Elad ML, Cohen Y, Geller B, Everson D, Costa C, Webb RP, Watts JF, De Puit M (2013) Enhanced imaging of developed fingerprints using mass spectrometry imaging, Analyst 138 (21) pp. 6246-6250
Latent fingermarks are invisible to the naked eye and normally require the application of a chemical developer followed by an optical imaging step in order to visualize the ridge detail. If the finger deposition is poor, or the fingermark is aged, it can sometimes be difficult to produce an image of sufficient quality for identification. In this work, we show for the first time how mass spectrometry imaging (in this case time-of-flight secondary ion mass spectrometry, ToF-SIMS) can be used to enhance the quality of partially recovered fingermarks. We show three examples of how chemical imaging can be used to obtain enhanced images of fingermarks deposited on aluminium foil, glass and the handle of a hand grenade compared with conventional development techniques. © 2013 The Royal Society of Chemistry.
Campana MG, Bower MA, Bailey MJ, Stock F, O'Connell TC, Edwards CJ, Checkley-Scott C, Knight B, Spencer M, Howe CJ (2010) A flock of sheep, goats and cattle: ancient DNA analysis reveals complexities of historical parchment manufacture, JOURNAL OF ARCHAEOLOGICAL SCIENCE 37 (6) pp. 1317-1325 ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
Webb M, Jeynes C, Gwilliam R, Too P, Kozanecki A, Domagala J, Royle A, Sealy B (2005) The influence of the ion implantation temperature and the dose rate on smart-cut (c) in GaAs, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 240 (1-2) pp. 142-145 ELSEVIER SCIENCE BV
Kaabar W, Daar E, Gundogdu O, Jenneson PM, Farquharson MJ, Webb M, Jeynes C, Bradley DA (2009) Metal deposition at the bone-cartilage interface in articular cartilage, APPLIED RADIATION AND ISOTOPES 67 (3) pp. 475-479 PERGAMON-ELSEVIER SCIENCE LTD
There are many technical challenges in the fabrication of devices from novel materials. The characterization of these materials is critical in the development of efficient photovoltaic systems. We show how the application of recent advances in MeV IBA, providing the self-consistent treatment of RBS (Rutherford backscattering) and PIXE (particle induced X-ray emission) spectra, makes a new set of powerful complementary depth profiling techniques available for all thin film technologies, including the chalcopyrite compound semiconductors. We will give and discuss a detailed analysis of a CuInAl metallic precursor film, showing how similar methods are also applicable to other films of interest.
Bright NJ, Webb RP, Kirkby KJ, Willson TR, Driscoll DJ, Reddy SM, Ward NI, Bailey MJ, Bleay S (2013) Chemical changes exhibited by latent fingerprints after exposure to vacuum conditions, Forensic Science International
The effect of vacuum exposure on latent fingerprint chemistry has been evaluated. Fingerprints were analysed using a quartz crystal microbalance to measure changes in mass, gas chromatography mass spectrometry to measure changes in lipid composition and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) to determine changes in the content of water, fatty acids and their esters after exposure to vacuum. The results are compared with samples aged under ambient conditions. It was found that fingerprints lose around 26% of their mass when exposed to vacuum conditions, equivalent to around 5 weeks ageing under ambient conditions. Further exposure to vacuum causes a significant reduction in the lipid composition of a fingerprint, in particular with the loss of tetradecanoic and pentadecanoic acid, that was not observed in ambient aged samples. There are therefore implications for sequence in which fingerprint development procedures (for example vacuum metal deposition) are carried out, as well as the use of vacuum based methods such as secondary ion mass spectrometry (SIMS) and matrix-assisted laser desorption ionisation (MALDI) in the study of fingerprint chemistry. © 2013.
Kaabar W, Daar E, Bunk O, Farquharson MJ, Laklouk A, Bailey M, Jeynes C, Gundogdu O, Bradley DA (2010) Elemental and structural studies at the bone-cartilage interface, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 652 (1) pp. 786-790
Christopher ME, Warmenhoeven JW, Romolo FS, Donghi M, Webb RP, Jeynes C, Ward NI, Kirkby KJ, Bailey MJ (2013) A new quantitative method for gunshot residue analysis by ion beam analysis., Analyst pp. 4649-4655 Royal Society of Chemistry
Imaging and analyzing gunshot residue (GSR) particles using the scanning electron microscope equipped with an energy dispersive X-ray spectrometer (SEM-EDS) is a standard technique that can provide important forensic evidence, but the discrimination power of this technique is limited due to low sensitivity to trace elements and difficulties in obtaining quantitative results from small particles. A new, faster method using a scanning proton microbeam and Particle Induced X-ray Emission (¼-PIXE), together with Elastic Backscattering Spectrometry (EBS) is presented for the non-destructive, quantitative analysis of the elemental composition of single GSR particles. In this study, the GSR particles were all Pb, Ba, Sb. The precision of the method is assessed. The grouping behaviour of different makes of ammunition is determined using multivariate analysis. The protocol correctly groups the cartridges studied here, with a confidence >99%, irrespective of the firearm or population of particles selected.
Bailey MJ, Randall EC, Costa C, Salter TL, Race AM, de Puit M, Koeberg M, Baumert M, Bunch J (2016) Analysis of urine, oral fluid and fingerprints by liquid extraction surface analysis coupled to high resolution MS and MS/MS - opportunities for forensic and biomedical science, ANALYTICAL METHODS 8 (16) pp. 3373-3382
ROYAL SOC CHEMISTRY
Bright NJ, Willson TR, Driscoll DJ, Reddy SM, Webb RP, Bleay S, Ward NI, Kirkby KJ, Bailey MJ (2013) Chemical changes exhibited by latent fingerprints after exposure to vacuum conditions, Forensic Science International 230 (1-3) pp. 81-86
The effect of vacuum exposure on latent fingerprint chemistry has been evaluated. Fingerprints were analysed using a quartz crystal microbalance to measure changes in mass, gas chromatography mass spectrometry to measure changes in lipid composition and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) to determine changes in the content of water, fatty acids and their esters after exposure to vacuum. The results are compared with samples aged under ambient conditions. It was found that fingerprints lose around 26% of their mass when exposed to vacuum conditions, equivalent to around 5 weeks ageing under ambient conditions. Further exposure to vacuum causes a significant reduction in the lipid composition of a fingerprint, in particular with the loss of tetradecanoic and pentadecanoic acid, that was not observed in ambient aged samples. There are therefore implications for sequence in which fingerprint development procedures (for example vacuum metal deposition) are carried out, as well as the use of vacuum based methods such as secondary ion mass spectrometry (SIMS) and matrix-assisted laser desorption ionisation (MALDI) in the study of fingerprint chemistry. © 2013 .
Bailey MJ, Kirkby KJ, Jeynes C (2009) Trace element profiling of gunshot residues by PIXE and SEM-EDS: a feasibility study, X-RAY SPECTROMETRY 38 (3) pp. 190-194 JOHN WILEY & SONS LTD
Bailey MJ, Bradshaw R, Francese S, Salter TL, Costa C, Ismail M, P Webb R, Bosman I, Wolff K, de Puit M (2015) Rapid detection of cocaine, benzoylecgonine and methylecgonine in fingerprints using surface mass spectrometry., Analyst 140 (18) pp. 6254-6259
Latent fingerprints provide a potential route to the secure, high throughput and non-invasive detection of drugs of abuse. In this study we show for the first time that the excreted metabolites of drugs of abuse can be detected in fingerprints using ambient mass spectrometry. Fingerprints and oral fluid were taken from patients attending a drug and alcohol treatment service. Gas chromatography mass spectrometry (GC-MS) was used to test the oral fluid of patients for the presence of cocaine and benzoylecgonine. The corresponding fingerprints were analysed using Desorption Electrospray Ionization (DESI) which operates under ambient conditions and Ion Mobility Tandem Mass Spectrometry Matrix Assisted Laser Desorption Ionization (MALDI-IMS-MS/MS) and Secondary Ion Mass Spectrometry (SIMS). The detection of cocaine, benzoylecgonine (BZE) and methylecgonine (EME) in latent fingerprints using both DESI and MALDI showed good correlation with oral fluid testing. The sensitivity of SIMS was found to be insufficient for this application. These results provide exciting opportunities for the use of fingerprints as a new sampling medium for secure, non-invasive drug detection. The mass spectrometry techniques used here offer a high level of selectivity and consume only a small area of a single fingerprint, allowing repeat and high throughput analyses of a single sample.
Webb M, Jeynes C, Gwilliam R, Royle A, Sealy B (2006) Characterising ion-cut in GaAs by Rutherford backscattering spectroscopy, Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 249 (1-2) pp. 429-431 Elsevier
Bailey MJ, Jones BN, Hinder S, Watts J, Bleay S, Webb RP (2010) Depth profiling of fingerprint and ink signals by SIMS and MeV SIMS, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 268 (11-12) pp. 1929-1932 ELSEVIER SCIENCE BV
Bailey MJ (2010) Depth Profiling of Fingerprint and Ink Signals by SIMS and MeV SIMS, Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 268 (11-12) pp. 1929-1932
Police institutions currently have no analytical method of knowing whether a fingerprint was deposited before or after the document was written or printed. The suitability of using MeV secondary ion mass spectrometry (i.e. SIMS with an MeV ion beam) to determine the order in which a fingerprint and written text were deposited on paper was therefore investigated. A 10 MeV O4+ beam was used to generate secondary ions from the surface of the samples and to map the molecular fragments from doped fingerprints and inks on paper. The images obtained and the sputtering behaviour of the samples was found to be indicative of the sequence of ink and fingerprint deposits.
Jeynes JCG, Webb M, Kirkby KJ, Kirkby NF, Bradley DA (2009) Proceedings of the First International Conference on Biomedical Applications of High Energy Ion Beams Preface, APPLIED RADIATION AND ISOTOPES 67 (3) pp. 369-370 PERGAMON-ELSEVIER SCIENCE LTD
Bailey MJ, Morgan RM, Comini P, Calusi S, Bull PA (2012) Evaluation of particle-induced X-ray emission and particle-induced ³-ray emission of quartz grains for forensic trace sediment analysis., Anal Chem 84 (5) pp. 2260-2267
The independent verification in a forensics context of quartz grain morphological typing by scanning electron microscopy was demonstrated using particle-induced X-ray emission (PIXE) and particle-induced ³-ray emission (PIGE). Surface texture analysis by electron microscopy and high-sensitivity trace element mapping by PIXE and PIGE are independent analytical techniques for identifying the provenance of quartz in sediment samples in forensic investigations. Trace element profiling of the quartz grain matrix separately from the quartz grain inclusions served to differentiate grains of different provenance and indeed went some way toward discriminating between different quartz grain types identified in a single sample of one known forensic provenance. These results confirm the feasibility of independently verifying the provenance of critical samples from forensic cases.
Howard KT, Bailey MJ, Berhanu D, Bland PA, Cressey G, Howard LE, Jeynes C, Matthewman R, Martins Z, Sephton MA, Stolojan V, Verchovsky S (2013) Biomass preservation in impact melt ejecta, Nature Geoscience 6 (12) pp. 1018-1022
Meteorites can have played a role in the delivery of the building blocks of life to Earth only if organic compounds are able to survive the high pressures and temperatures of an impact event. Although experimental impact studies have reported the survival of organic compounds, there are uncertainties in scaling experimental conditions to those of a meteorite impact on Earth and organic matter has not been found in highly shocked impact materials in a natural setting. Impact glass linked to the 1.2-km-diameter Darwin crater in western Tasmania is strewn over an area exceeding 400 km 2 and is thought to have been ejected by a meteorite impact about 800 kyr ago into terrain consisting of rainforest and swamp. Here we use pyrolysis-gas chromatography-mass spectrometry to show that biomarkers representative of plant species in the local ecosystem - including cellulose, lignin, aliphatic biopolymer and protein remnants - survived the Darwin impact. We find that inside the impact glass the organic components are trapped in porous carbon spheres. We propose that the organic material was captured within impact melt and preserved when the melt quenched to glass, preventing organic decomposition since the impact. We suggest that organic material can survive capture and transport in products of extreme impact processing, at least for a Darwin-sized impact event. © 2013 Macmillan Publishers Limited.
Ugarte M, Grime GW, Lord G, Geraki K, Collingwood JF, Finnegan ME, Farnfield H, Merchant M, Bailey MJ, Ward NI, Foster PJ, Bishop PN, Osborne NN (2012) Concentration of various trace elements in the rat retina and their distribution in different structures, Metallomics 4 (12) pp. 1245-1254
Inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify the total amount of trace elements in retina from adult male Sprague-Dawley rats (n = 6). Concentration of trace elements within individual retinal areas in frozen sections of the fellow eye was established with the use of two methodologies: (1) particle-induced X-ray emission (PIXE) in combination with 3D depth profiling with Rutherford backscattering spectrometry (RBS) and (2) synchrotron X-ray fluorescence (SXRF) microscopy. The most abundant metal in the retina was zinc, followed by iron and copper. Nickel, manganese, chromium, cobalt, selenium and cadmium were present in very small amounts. The PIXE and SXRF analysis yielded a non-homogenous pattern distribution of metals in the retina. Relatively high levels of zinc were found in the inner part of the photoreceptor inner segments (RIS)/outer limiting membrane (OLM), inner nuclear layer and plexiform layers. Iron was found to accumulate in the retinal pigment epithelium/choroid layer and RIS/OLM. Copper in turn, was localised primarily in the RIS/OLM and plexiform layers. The trace elements iron, copper, and zinc exist in different amounts and locations in the rat retina. © 2012 The Royal Society of Chemistry.
Jeynes JCG, Bailey MJ, Coley H, Kirkby KJ, Jeynes C (2010) Microbeam PIXE analysis of platinum resistant and sensitive ovarian cancer cells, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 268 (11-12) pp. 2168-2171 ELSEVIER SCIENCE BV
Jeynes C, Bailey MJ, Bright NJ, Christopher ME, Grime GW, Jones BN, Palitsin VV, Webb RP (2012) "total IBA" - Where are we?, Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms 271 pp. 107-118
The suite of techniques which are available with the small accelerators used for MeV ion beam analysis (IBA) range from broad beams, microbeams or external beams using the various particle and photon spectrometries (including RBS, EBS, ERD, STIM, PIXE, PIGE, NRA and their variants), to tomography and secondary particle spectrometries like MeV-SIMS. These can potentially yield almost everything there is to know about the 3-D elemental composition of types of samples that have always been hard to analyse, given the sensitivity and the spacial resolution of the techniques used. Molecular and chemical information is available in principle with, respectively, MeV-SIMS and high resolution PIXE. However, these techniques separately give only partial information ? the secret of ?Total IBA? is to find synergies between techniques used simultaneously which efficiently give extra information. We here review how far ?Total IBA? can be considered already a reality, and what further needs to be done to realise its full potential.
Bailey MJ, Howard KT, Kirkby KJ, Jeynes C (2009) Characterisation of inhomogeneous inclusions in Darwin glass using ion beam analysis, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 267 (12-13) pp. 2219-2224 ELSEVIER SCIENCE BV
Perusko D, Webb MJ, Milinovic V, Timotijevic B, Miosavljevic M, Jeynes C, Webb RP (2008) On the ion irradiation stability of Al/Ti versus AlN/TiN multilayers, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 266 (8) pp. 1749-1753 ELSEVIER SCIENCE BV
Webb R, Bailey M, Jeynes C, Grime G (2010) 19th International Conference on Ion Beam Analysis, Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms 268 (11-12)
Attard-Montalto N, Ojeda JJ, Reynolds A, Ismail M, Bailey M, Doodkorte L, De Puit M, Jones BJ (2014) Determining the chronology of deposition of natural fingermarks and inks on paper using secondary ion mass spectrometry, Analyst 139 (18) pp. 4641-4653
This study thoroughly explores the use of time-of-flight secondary ion mass spectrometry (ToF-SIMS) for determining the deposition sequence of fingermarks and ink on a porous paper surface. Our experimental work has demonstrated that mapping selected endogenous components present in natural fingermarks enables the observation of friction ridges on a laser-printed surface, only when a fingerprint is deposited over this layer of ink. Further investigations have shown limited success on ink-jet printing and ballpoint pen inks. 51 blind tests carried out on natural, latent fingermarks on laser-printed surfaces; up to 14th depletion with samples aged for up to 421 days have resulted in a 100% success rate. Development with ninhydrin was found to affect the fingermark residue through mobilisation of ions, therefore sequencing determination was compromised; whilst iodine fuming and 1,2-indanedione developers did not. This implied that selected development methods affected success in fingermark-ink deposition order determination. These results were further corroborated through inter-laboratory validation studies. The adopted protocol and extensive series of tests have therefore demonstrated the effectiveness and limitations of ToF-SIMS in providing chronological sequencing information of fingermarks on questioned documents; successfully resolving this order of deposition query. This journal is © the Partner Organisations 2014.
Bailey MJ, Jeynes C, Sealy BJ, Webb RP, Gwilliam RM (2010) On artefacts in the secondary ion mass spectrometry profiling of high fluence H+ implants in GaAs, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 268 (11-12) pp. 2051-2055 ELSEVIER SCIENCE BV
Bailey M (2010) Surface analysis techniques in forensic science, Surface and Interface Analysis 42 (5) pp. 339-340
Hashim S, Al-Ahbabi S, Bradley DA, Webb M, Jeynes C, Ramli AT, Wagiran H (2009) The thermoluminescence response of doped SiO2 optical fibres subjected to photon and electron irradiations, APPLIED RADIATION AND ISOTOPES 67 (3) pp. 423-427 PERGAMON-ELSEVIER SCIENCE LTD
Webb M, Jeynes C, Gwilliam RM, Tabatabaian Z, Royle A, Sealy BJ (2005) The influence of the ion implantation temperature and the flux on smart-cut (c) in GaAs, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 237 (1-2) pp. 193-196 ELSEVIER SCIENCE BV
Romolo FS, Christopher ME, Jeynes C, Webb RP, Kirkby KJ, Donghi M, Ripani L, Ward NI, Bailey MJ (2013) Integrated Ion Beam Analysis (IBA) in Gunshot Residue (GSR) characterisation, Forensic Science International 231 (1-3) pp. 219-228
Gunshot Residue (GSR) is residual material from the discharge of a firearm, which frequently provides crucial information in criminal investigations. Changes in ammunition manufacturing are gradually phasing out the heavy metals on which current forensic GSR analysis is based, and the latest Heavy Metal Free (HMF) primers urgently demand new forensic solutions. Proton scanning microbeam Ion Beam Analysis (IBA), in conjunction with the Scanning Electron Microscope equipped with an Energy Dispersive X-ray Spectrometer (SEM-EDS), can be introduced into forensic analysis to solve both new and old problems, with a procedure entirely commensurate with current forensic practice. Six cartridges producing GSR particles known to be interesting in casework by both experience and the literature were selected for this study. A standard procedure to relocate the same particles previously analysed by SEM-EDS, based on both secondary electron (SE) and X-ray imaging was developed and tested. Elemental Particle Induced X-ray Emission (PIXE) mapping of the emitted X-rays allowed relocation in a scan of 10¼m×10¼m of even a 1¼m GSR particle. The comparison between spectra from the same particle obtained by SEM-EDS and IBA-PIXE showed that the latter is much more sensitive at mid-high energies. Results that are very interesting in a forensic context were obtained with particles from a cartridge containing mercury fulminate in the primer. Particle-induced gamma-ray emission (PIGE) maps of a particles from HMF cartridges allowed identification of Boron and Sodium in particles from hands using the B(p,±³)Be, B(p,p³)B and Na(p,p³)Na reactions, which is extraordinary in a forensic context. The capability for quantitative analysis of elements within individual particles by IBA was also demonstrated, giving the opportunity to begin a new chapter in the research on GSR particles. The integrated procedure that was developed, which makes use of all the IBA signals, has unprecedented characterisation and discrimination power for GSR samples. © 2013 Elsevier Ireland Ltd.
Shcherbachev K, Bailey MJ (2011) Influence of implantation conditions of He+ ions on the structure of a damaged layer in GaAs(001), Physica Status Solidi (A) Applications and Materials 208 (11) pp. 2576-2581 Wiley
Bradley DA, Farquharson MJ, Gundogdu O, Al-Ebraheem A, Ismail EC, Kaabar W, Bunk O, Pfeiffer F, Falkenberge G, Bailey M (2010) Applications of condensed matter understanding to medical tissues and disease progression: Elemental analysis and structural integrity of tissue scaffolds, RADIATION PHYSICS AND CHEMISTRY 79 (2) pp. 162-175 PERGAMON-ELSEVIER SCIENCE LTD
Peng N, Jeynes C, Bailey MJ, Adikaari D, Stolojan V, Webb RP (2009) High concentration Mn ion implantation in Si, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS 267 (8-9) pp. 1623-1625 ELSEVIER SCIENCE BV
Surface mass spectrometry methods can be difficult to use effectively with low cost, portable mass spectrometers. This is because commercially available portable (single quadrupole) mass spectrometers lack the mass resolution to confidently differentiate between analyte and background signals. Additionally, current surface analysis methods provide no facility for chromatographic separation and therefore are vulnerable to ion suppression. Here we present a new analytical method where analytes are extracted from a sample using a solvent flushed across the surface under high pressure, separated using a chromatography column and then analysed using a portable mass spectrometer. The use of chromatography reduces ion suppression effects and this, used in combination with in-source fragmentation, increases selectivity, thereby allowing high sensitivity to be achieved with a portable and affordable quadrupole mass spectrometer. We demonstrate the efficacy of the method for the quantitative detection of cocaine and benzoylecgonine in urine and oral fluid. The method gives relative standard deviations below 15% (with one exception), and R2 values above 0.998. The limits of detection for these analytes in oral fluid and urine are
The CdS window layer in thin film solar cells is frequently grown by chemical bath deposition (CBD). Deposited films are typically less than 100 nm thick and the inability to identify the exact start of the deposition can make CBD an imprecise process. This paper describes the construction and testing of a simple optical fibre sensor that detects the start of the deposition process and also allows for its mechanism to be studied. The in situ optical fibre monitoring technique utilises the change in optical reflectance off the glass/deposited film/precursor solution interfaces at an operating wavelength of 1550 nm. A theoretical expression for the reflection of light from the interface is discussed and compared with experimental results. The monitoring technique shows the presence of two different deposition mechanisms. This result is confirmed by film densities calculated by Rutherford backscattering spectrometry and an optical model for ellipsometry measurements which indicates that the deposited CdS films consist of a double layer structure with a porous layer on top of a dense under layer. The application of the theoretical expression is optimised by assuming the refractive index of the CdS layer to be 2.02. The ellipsometry model shows that the refractive index of the CdS deposited is 2.14 for a two layer model of the film that included a porous upper layer through the effective medium approximation.
BACKGROUND: Paper spray mass spectrometry6 is a technique
that has recently emerged and has shown excellent
analytical sensitivity to a number of drugs in blood. As an
alternative to blood, fingerprints have been shown to
provide a noninvasive and traceable sampling matrix.
Our goal was to validate the use of fingerprint samples to
detect cocaine use.
METHODS: Samples were collected on triangular pieces
(168 mm2) of washed Whatman Grade I chromatography
paper. Following application of internal standard,
spray solvent and a voltage were applied to the paper
before mass spectrometry detection. A fingerprint visualization
step was incorporated into the analysis procedure
by addition of silver nitrate solution and exposing the
sample to ultraviolet light.
RESULTS: Limits of detection for cocaine, benzoylecgonine,
and methylecgonine were 1, 2, and 31 ng/mL respectively,
with relative standard deviations of less than 33%. No
matrix effects were observed. Analysis of 239 fingerprint
samples yielded a 99% true-positive rate and a 2.5%
false-positive rate, based on the detection of cocaine,
benzoylecgonine, or methylecgonine with use of a single
CONCLUSIONS: The method offers a qualitative and noninvasive
screening test for cocaine use. The analysis
method developed is rapid (4 min/sample) and requires
no sample preparation.
A fingerprint offers a convenient matrix for drug testing as samples can be deposited rapidly and securely. In this thesis, different strategies for quantitative analysis of fingerprint residues were explored. The variability in mass of a deposited fingerprint measured by a quartz crystal microbalance (QCM) was found to be up to 100% for multiple donors. Fingerprint depositions could be controlled to 21% for a single donor by washing hands, controlling the deposition pressure and wait time. With the aim of reducing the variability of analyte signals detected, the following approaches were tested for feasibility:
(a) Normalising the intensity of endogenous compounds to the measured mass
(b) Normalising the intensity of caffeine and its metabolites to endogenous compounds detected in multiple fingerprints using liquid chromatography-mass spectrometry (LC-MS) and in single fingerprints using liquid extraction surface analysis-mass spectrometry (LESA-MS)
(c) Developing fingerprints deposited on paper using ninhydrin and normalising to the signal intensity of Ruhemann?s purple, and to a ?photo scaling? method developed in this thesis.
(d) Normalisation to a ?fingerprint reader? developed by Intelligent Fingerprinting Limited, which gives a signal relating to the amount of fingerprint deposited on a glass slide.
Using approach (a) there was no clear relationship between the mass of fingerprint measured and the intensity of endogenous compounds measured by LC-MS. Using approach (b) it was possible to reduce (or at least maintain) the variability in replicate fingerprint depositions to below 20% as required of a quantitative method. Using approach (c) normalisation to the mean grey value and integrated density value improved variation in theobromine to below 20% in all samples. Finally using approach (d) normalisation to the ?fingerprint reader? reduced the variability below 20%. The thesis therefore concludes that either approach (b), (c), or (d) could be explored further in future work for quantification of fingerprint residues.
Recent publications have explored the
possibility of using fingerprints to confirm drug use, but
none has yet dealt with environmental contamination
from fingertips. Here we explored the possibility of establishing
an environmental cutoff for drug testing from
a single fingerprint.
Fingerprint samples (n=100) were collected
from the hands of 50 nondrug users before and after
handwashing to establish separate environmental cutoff
values and testing protocols for cocaine, benzoylecgonine,
heroin, and 6-monoacetylmorphine. The cutoff was challenged
by testing the fingerprints of drug-free volunteers
after shaking hands with drug users. Fingerprints from patients
who testified to taking cocaine (n = 32) and heroin
(n = 24) were also collected and analyzed.
A different cutoff value needed to be applied,
depending on whether the fingerprints were collected as
presented or after handwashing. Applying these cutoffs gave
a 0%false-positive rate from the drug-free volunteers. After
application of the cutoff, the detection rate (compared to
patient testimony) for washed hands of patients was 87.5%
for cocaine use and 100% for heroin use.
Fingerprints show enhanced levels of cocaine,
heroin, and their respective metabolites in patients
who testified to taking the substances, compared with the
population of na1¨ve drug users surveyed, and a cutoff
(decision level) can be established. The cutoff is robust
enough to account for small increases in analyte observed
after secondary transfer.