SMALL MOLECULE & Forensics Research.

Structure of Heroin.

Research Publications & Conference Presentations Equipment for forensic spectroscopy Forensic links Equipment links

Research:

We are interested in using Raman spectroscopy with multivariate analysis (chemometrics and machine-learning) to develop automated methods for the identification, classification, and quantification of small molecule active pharmaceutical ingredients (APIs) and illicit narcotics.  The same computational methods and spectroscopic techniques can be applied for both purposes.

• Currently (Feb. 13) we are working on a spectroscopic method for the analysis of solid state APIs and other materials used in the pharmaceutical industries.  This is being funded by Enterprise Ireland under the Pharmaceutical Manufacturing Technology Centre initiative. 
  
• Past Research covered a wide variety of topics including:  2009-10: automated analysis of home made explosives as part of an undergraduate research project. This project made use of various spectroscopic methods to probe these materials, coupled with chemometric analysis for quantitative analysis. 2003-07: Analyze-IQ, development of software tools for materials analysis.
  

Benefits of Raman Spectroscopy:  The Raman effect probes the vibrational energy levels of molecules and can provide immediate and useful information on the structure and identity of substances in solid, liquid and gaseous phases. The technique is non-contact, non-destructive and requires minimal or no sample preparation. Raman spectroscopy has been a well-established technique for the characterisation of materials such as thin hard films, polymers, proteins, tissue, DNA, and semiconductor devices. Raman spectroscopy has a number of distinct advantages over IR absorption spectroscopy. Sample preparation in many cases is not required, permitting analysis of bulk or microscopic materials in-situ. Unlike IR, water has a very weak Raman signal and so Raman spectra can be easily collected from aqueous solutions or moist materials. Micro-Raman spectroscopy can achieve a spatial resolution approaching 1 micron as opposed to 10-20 micron for IR absorption spectroscopy. This high spatial resolution has allowed the Raman analysis of discrete micron-sized particles, including the determination of drug levels in individual cells and the analysis of specific defect and/or cell adhesion regions of medical devices to determine the nature of any surface degradation. Using Raman spectroscopy, measurable parameters include conformational and structural changes in bio-films, chemical nature of microscopic inclusion defects in fabricated devices, and micro-stresses in ceramic materials. For polymer coatings and polymer fabricated medical devices, the rapid measurement of critical parameters such as crystallinity, film orientation, composition and degree of polymer cross-linking are possible.

Below are some Raman spectra of some common narcotics that we have collected on the new LabRam Infinity using 785 nm excitation. As you can see the sharp well defined bands in the spectra make identification and discrimination of the narcotics relatively easy in simple mixtures. Some typical Ramam spectra of narcotics are shown below, they were taken using 785 nm excitation.

The spectrum above is a mixture, some of the Cocaine bands are marked by (*) while the band marked (^) is due to the caffeine dilutant. The glucose bands are very weak and not as well defined as the more crystalline cocaine and caffeine.

We use multivariate analysis to generate quantitative models of narcotic concentrations in solid mixtures, the plot below shows the result of one such model in which cocaine was mixed with glucose and caffeine. In this case we could predict the cocaine concentration to an accuracy of +/- ~8% (twice the RMSEP value) from a single Raman spectrum. We are continuing to develop new approaches to quantifying narcotic concentrations.

Diagram taken from reference 5 (below).

Back to Top

Publications and Conference Presentations:

1. Quantitative Polymorph Contaminant Analysis in Tablets using Raman and Near Infra-red Spectroscopies.  M. C. Hennigan and A. G. Ryder.    Journal of Pharmaceutical and Biomedical Analysis, 72, 163-171, (2013). 
   DOI:  http://dx.doi.org/10.1016/j.jpba.2012.10.002 
2. A comparative study of the use of powder X-ray diffraction, Raman and NIR spectroscopy for quantification of binary polymorphic mixtures of Piracetam,  D.M. Croker, M.C. Hennigan, A. Maher, Y. Hu, A.G. Ryder, B.K. Hodnett.   Journal of Pharmaceutical and Biomedical Analysis, 63, 80-86, (2012). 
   DOI:   10.1016/j.jpba.2012.01.013
   
3. Quantitative Analysis of Sulfathiazole Polymorphs in Ternary Mixtures by Attenuated Total Reflectance Infrared, Near-infrared and Raman Spectroscopy, Y. Hu, A. Erxleben, A.G. Ryder, and P. McArdle,  Journal of Pharmaceutical and Biomedical Analysis, 53(3), 412-420, (2010). 
   DOI:  10.1016/j.jpba.2010.05.002 
4. Comparison of derivative pre-processing and automated polynomial baseline correction method for classification and quantification of narcotics in solid mixtures.  M.N. Leger and A.G. Ryder,  Applied Spectroscopy, 60(2), 182-193, (2006). DOI: 10.1366/000370206776023304 
   
5. Determination of the polymorphic forms of bicifadine hydrochloride by DSC-TG, XRPD, ATR-IR, and ATR-NIR.  P. McArdle, K. Gilligan, D. Cunningham, and A. Ryder,   Applied Spectroscopy,  59(11), 1365-1371, (2005). 
   DOI:  10.1366/000370205774783322 

1. Qualitative Analysis using Raman Spectroscopy and Chemometrics:  a comprehensive model system for narcotics analysis.  M.-L. O’Connell, A.G. Ryder, M.N. Leger, and T. Howley.  Applied Spectroscopy, 64(10), 1109-1121, (2010). 
   Online at:  http://www.opticsinfobase.org/abstract.cfm?URI="as-64-10-1109 .
   
2. Surface Enhanced Raman Scattering (SERS) for Narcotic detection and applications to Chemical Biology. A.G. Ryder, Current Opinion in Chemical Biology, 9(5), 489-493, (2005).
   
3. The Effect of Principal Component Analysis on Machine Learning Accuracy with High Dimensional Spectral Data.  T. Howley, M.G. Madden, M.-L. O’Connell, and A.G. Ryder, Knowledge-Based Systems ,  19(5), 363-370, (2006). 
   DOI: 10.1016/j.knosys.2005.11.014
   
4. Qualitative and quantitative analysis of chlorinated solvents using Raman spectroscopy and machine learning. J. Conroy, A.G. Ryder, M.N. Leger, K. Hennessey, and M.G. Madden.   Proc SPIE Int. Soc. Opt. Eng  .,  5826, 131-142, (2005). [  full paper]
   
5. Classification of a target analyte in solid mixtures using principal component analysis, support vector machines and Raman spectroscopy, M. O'Connell, A.G. Ryder, M.N. Leger, T. Howley, and M.G. Madden.   Proc SPIE  Int. Soc. Opt. Eng.,  5826, 340-350, (2005). [  full paper]
6. An improved genetic programming technique for the classification of Raman spectra. K. Hennessy, M. G. Madden, J. Conroy, and A.G. Ryder.  BCS Conference Series, Applications and Innovations in Intelligent Systems XII, Proceedings, 181-192, (2005).  Springer, ISBN 1-85233-908-X.
7. Combining Genetic Algorithms, Neural Networks and Wavelet Transforms for Analysis of Raman Spectra. K. Hennessy, M.G. Madden, and A.G. Ryder,  Proceedings of the 15th Irish Conference on Artificial Intelligence & Cognitive Science, Sept. 2004. [  full paper]
8. Machine Learning Methods for Quantitative Analysis of Raman Spectroscopy Data, M.G. Madden and A. G. Ryder, Proc SPIE vol. 4876, 1130-1139, (2003). [ Abstract]
9. Classification of narcotics in solid mixtures using Principal Component Analysis and Raman spectroscopy. A.G. Ryder, Journal of Forensic Sciences,  47(2), 275-284, (2002). [ Abstract]
10. Quantitative analysis of cocaine in solid mixtures using Raman spectroscopy and chemometric methods. A.G. Ryder, G.M. O’Connor, and T.J. Glynn, Journal of Raman Spectroscopy, 31(3), 221-227, (2000). [ Abstract]
11. Identifications and Quantitative Measurement of Narcotics in Solid Mixtures Using Near-IR Raman Spectroscopy and Multivariate Analysis, A.G. Ryder, G.M. O'Connor, and T.J. Glynn, Journal of Forensic Sciences, 44(5), 1013, (1999). [ Abstract]

Back to Top

Equipment for QUANTITATIVE & Forensic spectroscopy:

For these applications we use either the LabRam Infinity system (pictured below) or the Avalon Instruments Raman station, In  which now allows for High Throughput Screening (HTS) of samples. 

Jobin-Yvon LabRam Infinity system, installed in September 2000.  This system is located in the PAT lab in the Physical Chemistry section of the School of Chemistry. The system has a host of features including: Motorized XY sample stage for automated Raman Imaging, Motorized Z-stage for depth profiling, Dual laser excitation wavelengths: 785 nm & 488 nm, Fully confocal, LN2 cooled CCD detector, Cuvette & macro sample holder,

The LabRam Infinity system has a spatial resolution of about 1 micron which allows for the analysis of single particles. Research conducted at other centres worldwide has utilised Raman spectroscopy to look at gunshot residues, narcotic and drug particles, fibres, polymer fragments, car paints, chemicals, etc.

We also have a range of other research projects where the equipment could be used for forensic applications, a more detailed list of equipment is given on the Equipment Page.

In the summer of 2003 we used one of the the new generation of portable Raman ( GE Streetlab) systems for the analysis of narcotics, explosives, and hazardous materials.

In 2010 we have started using Delta Nu's handheld Rapid ID Raman spectrometer for the analysis of home made explosives.  We are evaluating its suitability for quantitative analysis. This handheld system uses a 785 nm laser diode excitation source coupled with a compact CCD detector.  The unit will run on internal batteries for ~ 4 hours so it can be taken out of the laboratory for filed use. Its very lightweight (~400 g) and has an onboard memory to store a Raman spectral library.  In an industrial context, these systems would be used for inventory and delivery control, allowing one to analyse (for identity) all incoming chemicals/materials used on a particular site (see the video on the Delta Nu website).

Back to Top

Forensic Links:

These are some of the sites that I regularly use. I hope to add more links and details in the near future. If there are problems with any of the links let me know.

Zeno's forensic page is the best collection of links and is kept more up to date than this links page....so bookmark it.

Technical Journals & Societies:
Applied Spectroscopy, Comprehensive spectroscopy journal with forensic applications featured from time to time: published by the Society for Applied Spectroscopy.
Journal of Forensic Sciences, (doesn't have a permanent page within the site..so you have go to the ASTM store section manually).
Journal of Clinical Forensic Medicine, Official journal of the Association of Police Surgeons and the Australia and New Zealand Forensic Medicine Society Inc.
Handbook of Forensic Services, and Forensic Science Communications, both from the FBI.
Forensic Science Society, UK based.

Forensics Research & courses:
Stephen Bell, Queens University Belfast, Raman analysis of MDMA tablets.
University of Strathclyde, offers B.Sc. & M.Sc. courses in Forensics.
University of Glasgow, courses and research.
South Bank University - London, B.Sc. courses in forensic science.
University of Bradford, B.Sc. & M.Sc. courses.
Los Alamos National Laboratory,

Governmental agencies:
An Garda Síochána, Ireland’s National Police Service.
Department of Justice, Equality and Law Reform, Ireland.
ENFSI, European Network of Forensic Science Institutes.
Europol, interesting site.
PSDB, Police Scientific Development Branch.
UN International Drug Control Programme.

Information Resources:
Forensic references page, fairly comprehensive, US site.
Zeno's Forensic site, very detailed and up to date, you can register and get regular updates by Email, based in the Netherlands.
Science Direct, lots of journals and full text access in many cases (very good resource).
Wiley Interscience huge collection of online journals which are searchable.

Back to Top

Equipment Links:

This is a selection of useful web-sites from a range of manufacturers who produce forensic equipment, it is by no means complete. I'll add more when I get the time.

GE Interlogix, Manufacture portable narcotics & explosives detectors, including a Raman system.
K9 Scene of the crime, UK based company.

Back to Top

• Disclaimer
• Privacy
• Copyright
• Accessibility