Master Forensic Science - Politieacademies programmes in Forensic Science in that it builds on a...

Master Forensic Science Research Projects 2011‐2012

Research projects 2011-2012

The University of Amsterdam's (UvA) Master's programme in Forensic Science, offered by the Faculty of Science, is unique in the Netherlands. The programme distinguishes itself from most international Master's programmes in Forensic Science in that it builds on a range of general science backgrounds, not on a specific forensic science Bachelor's programme. The goal of the programme is to train good scientists, armed with forensic knowledge and skills.

A part of the curriculum is a six-month internship during which scientific research is executed that is relevant to the forensic field. This document gives an overview of the capabilities of our students and the many ways in which a research project can be conducted.

For more information please contact: [email protected]

Research Projects 2011-2012

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Title Organisation Student Biological traces (non-DNA) Discrimination of areas by analysing soil organic matter for forensic purposes, using PyGC-MS

University of Amsterdam, Institute for Biodiversity and Ecosystem Dynamics

Roxanne Jansen

Blood stain (pattern) analysis Page 5 Determination of physical features of a bloodstain for locating the source of projected blood droplets

Academic Medical Centre Amsterdam & FO at the Utrecht Police force

Ben Stroeve

The spreading behavior of a blood drop when impacting on an inclined surface.

Academic Medical Centre Amsterdam

Aukje van Wijk

Digital Forensics Page 7 Research on PRNU Netherlands Forensic Institute Floris Gisolf Identification, visualization and analysis of processes from general ledger data

KPMG Forensic Technology Marcia Fissette

DNA analysis (Human) Page 9 Simultaneous forensic DNA profiling and microRNA-based body fluid identification.

University of Huddersfield, United Kingdom

Donny van der Meer

Cooperation of Dactyloscopy and DNA Analysis

Estonian Forensic Science Institute, Estonia

Anu Lehepuu

Development of a Highly Sensitive Method of STR analysis using Laser Capture Microdissection and Direct PCR.

New York City Office of Chief Medical Examiner

Jaimy Meeuwissen

The Expectations within the Criminal Justice System on the use of mobile DNA-Technologies at the Crime Scene.

Forensische Opsporing Kennemerland Nederlands Forensisch Instituut

Anna Mapes

DNA analysis (Non-human) Page 13 The development of a Short Tandem Repeat (STR) system for the individualization of dogs (Canis lupus familiaris)

Netherlands Forensic Institute, Non-Human Biological Traces

Daniëlle Hoogmoed

Quantitative Real-time PCR methods to detect animal specific fecal contamination

KWR Watercycle Research Institute

Kimberly Learbuch

Species identification of CITES listed mammalian species with SNPs

Flinders University, Adelaide, Australia

Melanie Rosenhart

Forensic identification of CITES protected Dendrobiinae orchids in Traditional Chinese Medicines (TCMs)

Naturalis Lucas Schwiebbe

Drug analysis Page 17 Development of a LC-QToF-MS screening method for prohibited substances

RIKILT Wageningen UR Suzanne Bosman

Explosives Page 18 Discrimination of areas by analysing soil organic matter for forensic purposes, using PyGC-MS

University of Amsterdam Sander Willemse

Fingerprint analysis Page 19 Functionalized Quantum Dots & Magnetic Particles and their Ability to Visualize/Label Components in Latent Fingermarks

Academisch Medisch Centrum, The Netherlands

Kevin van de Braak


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Toxicology Page 20 Postmortem Redistribution – Toxicological Results of Drugs in Multiple Biological Matrices

Netherlands Forensic Institute , Forensic Medicine, Toxicology

Loes Jeurissen


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Biological traces (non-DNA)

Student Roxanne Jansen Research carried out at

University of Amsterdam, Institute for Biodiversity and Ecosystem Dynamics

Supervisor Boris Jansen and Erik Cammeraat Title thesis Discrimination of areas by analysing soil

organic matter for forensic purposes, using PyGC-MS

Abstract The field between earth science and forensic science is still an area of research. There are examples known where the soil helps in to solving a case, but it is not always that simple. The aim of this research was to examine the differences in organic compounds in three different locations in the Schoorlse Duinen (heathland, broadleaf forest and coniferous forest). Also the differences within one location were analysed. The main goal of this research project was whether or not these differences are also present in organic samples collected from boots and if these boot samples could be linked to a certain area. This is done by collecting soil organic material (SOM) samples and boot samples (by walking through one area). These samples were analysed by pyrolysis GC-MS with the presence of TMAH. The results show in each area a few unique peak patterns of organic compounds, which are not present in the other two areas. In the heathland area there are two unidentified peaks and an alkane compound present. The S6 (part of syringol) compound is unique for the broadleaf forest and the fatty acid methyl ester 12 and 14 are unique for the coniferous forest. These peaks are also present in the boot samples. So, it is possible to discriminate between the three areas and it is possible to link the organic material underneath boots to a certain area. The results are significant, but further research is required.

Photograph of the heath land area were the organic samples were taken

Pyrogram of the organic material collected from the heathland


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Blood stain (pattern) analysis

Student Ben Stroeve Research carried out at

Forensische Opsporing Utrecht (Police) Academic Medical Centre Amsterdam

Supervisor Drs. S van Beest & Ir. H. Hardy Title thesis Determination of physical features of a

bloodstain for locating the source of projected blood droplets

Abstract This project is the fourth in the research line with as ultimate goal to accurately calculate the area of origin. In this project the focus lays on the determination of three important parameters of a stain needed for the calculation of the area of origin. These parameters are the droplet diameter, impact velocity and the angle of impact. In our study, human blood droplets (3 and 4.5mm diameter) were dropped from different heights (40, 120 and 180cm) on a tile placed under an angle of 90, 60, 30 and 10° from the vertical plain. Also anti-coagulant and a blood age test were performed to test the influence of both of them on the outcome of the experiments. The use of anti-coagulant did not show a significant difference with blood without anti-coagulant. The influence of the age of blood showed a significant difference for blood that was 2-3 weeks old and stored in the fridge. Further analysis were performed to approach the equations in literature that were used to resolve the problem of finding the location of the source of two similar sized stains. These equations were approached in our experiments for the surface under 90° with the use of the number of spikes. No spikes were visible for stains on the surface under an angle different than 90°. Thus the experiments indicate that the use of spikes for the determination of the area of origin is not applicable for a tile as used in this project.

Essence of this study: illustration of the difference between predicted area of origin by stringing and the real area of

Bloodstain as a result of a 4.5mm droplet dropped passively from 180cm on a horizontal surface (tile).


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Student Aukje van Wijk Research carried out at


Supervisor Drs. S. J. van Beest Title thesis The spreading behavior of a blood drop when

impacting on an inclined surface. Abstract The area of origin is the location of the blood

source at the time of the blood shedding event. To determine the area of origin three parameters need to be known; the impact angle, impact velocity and the droplet diameter. The impact angle can accurately be determined. However, to distinguish between whether a blood drop had a larger volume or a higher impact velocity is problematic, since both will result in a larger diameter of the bloodstain found on the crime scene. In this study blood droplets with varying diameter (2 mm and 4 mm) are released from different heights (0.4, 1.20 and 1.50 m) to vary impact velocity. The passively falling droplets impact on a smooth surface, which is placed under a certain angle (10⁰, 30⁰ or 60⁰) and monitored with a high speed camera. The high speed images are analyzed and the spreading behavior of a blood droplet is examined in order to obtain new parameters for deducing the impact velocity and droplet diameter from an bloodstain. Both the radially velocity as well as the velocity of the core are described, but unfortunately did this research project only partly provide information that could be used to deduce the impact velocity or the original diameter. More experiments are needed to gain additional information.

The area of origin is indicated by the blue circle.


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Digital Forensics

Student Floris Gisolf Research carried out at

Netherlands Forensic Institute

Supervisor Zeno Geradts Title thesis Research on PRNU Abstract Three topics regarding photo-response non-

uniformity (PRNU) were looked at during this internship. A PRNU pattern is the ‘fingerprint’ of a digital camera, which is left in the photos it takes. It can be extracted with digital filters and is used to identify the source camera of suspect photos. The first topic is to see if the PRNU pattern is stable over time. If not, it might result in lower evidential value, but may also allow time estimation. The results indicate that there is no loss in EV. There was not enough data to conclude if there is an effect of time on PRNU patterns. The second topic is to see if cropped images can increase PRNU extraction and comparison speed, without too much loss of evidential value. It is indeed possible; in some cases the cropped images performed better than the original sized images, in other cases they were even. Selecting an area optimal for PRNU extraction can improve results. The third topic is a comparison of a script by Goljan and Fridrich that uses Peak-to-correlation energy ratio (PCE) and PRNU Compare, the software made by the NFI. The script included a Fourier transform (FT) and a Wiener filter, which improved results on jpeg images. PCE itself did not seem to perform much better than the normal correlation used by PRNU Compare. The FT with a Wiener filter was added to PRNU Compare.

Camera Sensor Identification: 1 match, 7 mismatches.

PRNU pattern

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Student Marcia Fissette Research carried out at

KPMG Forensic Technology

Supervisor Marcel Worring (UvA), Thom Eijken (KPMG)

Title thesis Identification, visualization and analysis of processes from general ledger data

Abstract Fraud costs organizations a lot of money and eventually may result in bankruptcy. The increasing complexity of the general ledger data makes it more difficult and time-consuming for the auditor to detect irregularities in the data which may indicate signals of fraud. We therefore propose a new approach that provides fast insight into this type of data. Visualizing the series of transactions present in the general ledger data provides quick insight in how the money of an organization flows. Deviations from the expected money flow may indicate fraudulent behavior. To be able to analyze the money flow we need to examine the series of transactions. The general ledger does not explicitly state the series of transactions. Therefore, we develop a method that extracts these series from the general ledger. The result of the method applied to real-world general ledgers indicates that the method is capable of extracting the series of transactions. Subsequently, we develop a technique that visualizes the money flow in an intuitive way. The visualization gives an overview of how the money flows into the bank and how the money leaves the bank. The overview further shows how the money flows between subcategories of accounts. To obtain a comprehensible overview of the series of transactions of large real-world general ledgers we need a higher level of abstraction. The user evaluation shows that the visualization of the series of transactions provides insight in the general ledger. Users are able to quickly identify points for further investigation. These results show that the new approach is a promising investigative method. Several types of functionalities to further explore the visualization could be added so that users can gain even more insights from the visualization and backup their findings with the underlying data.

Example of the money flow between two accounts. Arrows indicate the total amount of money that flows between accounts. The number between brackets shows in how many transactions this happens.

Example of an overview of the series of transactions showing how money flows into an organizations bank.


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DNA analysis (Human)

Student Donny van der Meer Research carried out at

University of Huddersfield, United Kingdom

Supervisor Graham Williams Title thesis Simultaneous forensic DNA profiling and

microRNA-based body fluid identification. Abstract Identifying the tissue of origin of a biological

sample can be of vital importance in a case to confirm/falsify testimonies. At the same time, the amount of sample material may be limited, preventing multiple tests to be performed. In this project, a proof of concept for a single stream process is laid down to perform regular DNA profiling and identify a body fluid at the same time. Based on previous research, assays for the detection of microRNA species miR-205 and miR-451 were incorporated into the DNA profiling routine to indicate saliva and blood respectively. A co-extraction method for the simultaneous extraction of DNA and microRNAs was selected, a stem-loop reverse transcription step was introduced and custom labelled primers allowed the microRNA products to be amplified together with the DNA during PCR and be detected on a genetic analyser as well. The successful discrimination of DNA profiles from blood and saliva during this proof of concept stage is a first step towards a single test for DNA profiling and body fluid identification.

Schematic overview of the goal of this project: simultaneous extraction, amplification and analysis of body fluid specific microRNAs and genomic DNA

Example of an identified blood DNA profile, with the blood specific miR-451 peak on the left and the start of the DNA profile on the right.


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Chart showing average typing results (%) of controls and Cyanoacrylate followed by Basic Yellow treated samples. Error bars of standard deviation are shown.

Chart showing average typing results (%) of controls and Ninhydrin treated samples.

Student Anu Lehepuu Research carried out at

Estonian Forensic Science Institute, Estonia

Supervisor Riin Saarmäe Title thesis Cooperation of Dactyloscopy and DNA Analysis Abstract The process of DNA typing after dactyloscopic analysis

is very important, because it increases the amount of information that can be obtained from a piece of evidence. The effects of fingerprint analysis methods to LCN DNA analysis have, so far, been experimented on few types of substrates. Evidence can, however, be collected from theoretically any type of surface. Aiming for better understanding the general behaviour of some of the most used enhancement methods, this thesis proposes an experimental evaluation with a larger number of substrates. Specifically, four fingerprint enhancement methods were examined: Cyanoacrylate fuming (using minigrip bags, cartridge cases, varnished wood, plastic canister and micro slides as substrates); Cyanoacrylate fuming followed by Basic Yellow (using minigrip bags, cartridge cases, varnished wood, plastic canister and micro slides as substrates); Cyanoacrylate fuming followed by Gentian Violet (using brown packing tape as a substrate) and Ninhydrin (using cardboard, office paper and newspaper as substrates). Cyanoacrylate and Cyanoacrylate followed by Gentian Violet treatment did not show negative effect on DNA typing. However, when Basic Yellow was applied after Cyanoacrylate a noticeable decrease in success of obtaining a profile was observed in samples taken from cartridge cases. Samples collected from office paper and newspaper were also negatively affected by Ninhydrin treatment. In general, results showed that DNA analysis was affected by some fingerprint enhancement echniques. Despite this, no deleterious effect was observed. Therefore, it can be concluded that it is possible to obtain DNA profiles (although not always complete) after application of fingerprint enhancement methods. However, as results suggested, the effects of the enhancement methods on DNA analysis depend on the type of the substrate. In addition to an analysis of these enhancement methods, this thesis also presents the results of a small test investigating the possible inhibitory effect of cyclohexane on DNA analysis. Results suggested that cyclohexane does not influence DNA analysis. Finally, fingerprints archived for more than ten years were analysed in order to understand whether it is possible to successfully obtain DNA profiles from them or not. Results showed that it was not possible to obtain DNA profiles that match with the DNA profiles of the fingerprint donors.


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Student Jaimy Meeuwissen Research carried out at

New York City Office of Chief Medical Examiner, USA

Supervisor Dr. G. Axler-DiPerte Title thesis Development of a Highly Sensitive

Method of STR analysis using Laser Capture Microdissection and Direct PCR.

Abstract Samples collected after rape cases often contain only very small amounts of sperm cells, making STR analysis problematic. In this study a highly sensitive method of STR analysis of sperm samples was developed and optimized. Laser capture microdissection using the P.A.L.M. platform by ZeissTM was combined with a direct PCR method using Identifiler PlusTM reagents to boost sensitivity and minimize DNA loss. After optimization the method showed 96.4%±3.6% of alleles called when analyzing 25 individual sperm cells, where previously 150 sperm cells would have been needed for this result. Even for extremely low amounts of sperm the method is capable of producing good STR results (for 6 sperm cells 61.9%±16.1% and for 3 sperm cells 61.9%±20.1% of alleles called). The method is expected to be ready for use in forensic casework in New York within six months.

Average percentage of alleles called using Identifiler PlusTM 32 cycles and different

amounts of sperm cells (25; 12; 6; 3; n=3). Results show the method is capable of

calling 61.9%±20.1% of alleles for samples with as low as three individual (haploid)

sperm cells.

A laser microscope (ZeissTM P.A.L.M. LCM system) is used to cut a single sperm cell from a membrane before catapulting it directly into

the extraction/amplification mix.


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Based on studying the current Dutch forensic DNA-investigative process, the future use of mobile DNA-technologies at the crime scene indicate that fast forensic DNA-analysis, a higher capacity for researching valuable DNA-traces and an increase of forensic intelligence is expected within the criminal justice system.

Student: Anna Mapes Research carried out at

Forensische Opsporing Kennemerland (Police) Netherlands Forensic Institute

Supervisor Ron Kortekaas, Ate Kloosterman Title thesis The Expectations within the Criminal Justice

System on the use of mobile DNA-Technologies at the Crime Scene.

Abstract Mobile forensic DNA-technologies are currently under development. At the moment studies are performed towards creating fully integrated instruments for the analysis of DNA-profiles to be controlled at the crime scene by Scene of Crime Officers. In the near future Rapid human DNA Identification testing and DNA-profiling within two hours on the crime scene will be a reality. This will have a significant impact on the work of the specialists at the crime scene and the experts at the forensic DNA-laboratory. Understanding the expectations of the use of mobile DNA-technologies and the effect of the current way of operating at the crime scene and at the police forensic department is important knowledge. Reviewing previous serious crime- and high volume crime-cases during the year 2011 demonstrated that the present turnaround time (from crime scene to DNA-report) of a serious crime- and high volume crime-DNA-trace takes an average of 66 days and 44 days respectively. But also a maximum of 38% non-valuable DNA-traces can be filtered when future mobile DNA-technologies are at hand. As a consequence a rise in hits with the DNA-database, thereby identifying possible perpetrators is expected, making these systems not only very interesting for fast case-solving but also economically attractive. Scene of crime officers are positive towards operating these techniques as it will bring forensic intelligence on the crime scene and will benefit fast forensic case solving.


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DNA analysis (Non-human)

Student Daniëlle Hoogmoed Research carried out at

Dept. Non-Human Biological Traces at Netherlands Forensic Institute

Supervisor Drs Monique Wesselink Title thesis The development of a Short Tandem Repeat

(STR) system for the individualization of dogs (Canis lupus familiaris)

Abstract Dogs are often present in human environments, which can make dog traces very relevant for forensic casework. Dogs can be a victim, perpetrator or ‘silent witness’. This can make it relevant to individualize a dog, based on secured biological material. Dogs can be individualized with Short Tandem Repeat (STR) markers. Several dog STR kits were commercially available, but no forensically reliable STR systems are available anymore. Hence the need to develop a multiplex STR system for the individualization of dogs. An inventory of frequently used STR markers for the individualization of dogs in literature was made. Using several criteria, multiple STR markers and one gender determining marker were selected. All selected markers were submitted to optimization of PCR conditions and STR detection. One marker was excluded due to unsatisfactory performance. Ultimately, two STR multiplex reactions are developed for the individualization of dogs, named DaPa (Daniëlle’s Panels) Canine. In total, these include 17 STR markers and a gender indicating fragment. Already 130 different dogs were successfully DNA typed with both panels.

Canis lupus familiaris


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Student Kimberly Learbuch Research carried out at

KWR Watercycle Research Institute

Supervisor Ing. L. (Leo) Heijnen Title thesis Quantitative Real-time PCR methods to

detect animal specific fecal contamination

Abstract Water, contaminated with pathogenic microorganisms, can pose potential problems for public health. The microbiological quality of recreational- and drinking water is therefore monitored with techniques that detect the presence of fecal-indicator bacteria (like Escherichia coli). These indicator organisms are however, present in the fecal material from all warm blooded animals, and due to this wide distribution it is not possible determine the source of the fecal contamination. There have been several bacteria species, including Bacteroides, identified that are present in the intestines of a limited number of animalspecies. Specific DNA-makers, through which these bacteria species can be distinguished, are available to identify animal specific fecal contamination by making use of quantitative real-time PCR (qPCR). Detection of the origin of the fecal contamination is important, because then it is possible to take precautions to minimize the effect it has on public health and if possible take measures against the source of the infection. This research focused on the selection of promising methods to specifically detect fecal material from; human, bovine, ruminant, porcine and avian origin using quantitative real-time PCR (qPCR). The host specificity of the methods was determined and it was established whether these methods can be applied to environmental (water) samples. These methods can also be potentially helpful in forensic cases concerning illegal discharge of manure and the information about the animal source can give additional evidence against possible offenders. The ten different selected methods have been applied to fecal material from six different animal species to determine the specificity and sensitivity of each method. Furthermore the methods have also been applied to several different environmental (water) samples to see of the methods can be applied in the field. Results of this study demonstrate that there are seven promising methods specific for; general fecal bacteria, human (specificity 98.5%; sensitivity 78%), ruminant (97.8%; 97.5%), bovine(100%, ±84%) porcine (99.7%; 99.4%) and avian (67%; 93.8%) that identify host specific fecal material with high specificities, either in fecal samples or in environmental (water) samples. The results with the environmental (water) samples indicate that the methods can be applied in the field. To gain more understanding on the performance of the methods, and therefore the specificities and sensitivities of the assays, fecal material from more different animal species sources should be analyzed.


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Student Melanie Rosenhart Research carried out at

Flinders University, Adelaide, Australia

Supervisor Adrian Linacre Title thesis Species identification of CITES listed

mammalian species with SNPs

Abstract Traditional Chinese Medicines (TCM) contain besides herbal ingredients rarely endangered species. Populations of several species rapidly declined over the past decades such as endangered species the tiger (Panthera tigris species) and musk deer (Moschus species). One of the reasons is the illegal wildlife trade in the body parts of these species for the usage in TCM. These TCM are in forms of plasters, powders and potions wherefore morphological identification is impossible. Therefore enforcement of international and national laws requires a reliable and robust forensic method to identify species in seized TCM with a molecular approach. DNA typing is very difficult as TCM products are highly processed and only contain highly degraded DNA. This study aims to describe a novel, rapid and reliable method to identify endangered mammalian species, such as the tiger (Panthera tigris subspecies) and musk deer (Moschus species) in Traditional Chinese Medicine (TCM) with the use of species-specific single nucleotide polymorphisms (SNP) within the mitochondrial genome in the cytochrome b gene using the SNaPshot® assay. A 107 base pair DNA region from the cytochrome b gene with a tiger species-specific primer set could successfully be obtained from a Traditional Chinese Medicine plaster. With the SNaPshot® assay two tiger species-specific SNPs were obtained, whereby could confirmed that tiger was present in the TCM plaster. Unfortunately, no DNA of the musk deer could be obtained. Overall, the SNaPShot® assay in this study showed to be a promising method for forensic applications.

The electropherogram shows two peaks, which corresponds with the two tiger species-specific SNPs.

This photo shows a wrap of a Traditional Chinese Medicine plaster, which can contain endangered species such as the tiger.


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Example of a Traditional Chinese Medicine (TCM)

Dendrobium

Student Lucas Schwiebbe Research carried out at

Naturalis Biodiversity Center

Supervisor dr. Barbara Gravendeel Title thesis Forensic identification of CITES protected

Dendrobiinae orchids in Traditional Chinese Medicines (TCMs)

Abstract Plant species listed by the Convention on International Trade in Endangered Species (CITES) are increasingly used in Traditional Chinese Medicines (TCMs) The aims of this research project were to (1) identify species in 36 TCMs (dried pseudobulbs, tablets, capsules, flakes, patches and herbal teas) confiscated by the Dutch customs office at Schiphol airport. Sanger sequencing was applied targeting nrITS1 and compared to data from various reference datasets. Results. Presence of Dendrobiinae was confirmed in only 3 TCMs. Besides Dendrobiinae, DNA barcoding analysis retrieved 27 other plant species and 30 fungal species. Many of these plant species and a small portion of the fungal species are widely used in Chinese Medicine. Discussion. Results show that concerns about legality and safety of TCMs are justified. First of all, many species detected were not mentioned on the labels violating (inter)national food fraud laws. Secondly, endangered, trade-restricted species of Dendrobiinae and ginseng were discovered violating CITES legislation. Thirdly, several fungal species potentially harmful to human health were detected, violating food safety laws. Screening of TCMs using Sanger sequencing based barcoding therefore seems an efficient method to monitor illegal trade in endangered species and potential threats to public safety.


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Drug analysis

Student Suzanne Bosman Research carried out at

RIKILT Institute of Food Safety at Wageningen University and Research Centre

Supervisor Dr. Eva Taanom – de Rijke Title thesis Development of a LC-QToF-MS screening method for

prohibited substances Abstract This research project is the first step in the development

of a screening method for prohibited substances using LC-QToF-MS. Standards and spiked urine samples are measured to identify the mass peaks and characteristic fragments in MS spectra. The aim was to develop a suitable LC method for a set of compounds gathered at the RIKILT institute of Food Safety. The development of this separation method was successful due to full scan possibility of the QToF-MS and the characteristic fragments found for each compound. Problems in this research project were the noted difference in retention time between compounds dissolved in methanol and in urine matrix, probably caused by a pH difference between methanol and urine. This could be solved in future research by sample clean up. A database will be set up based on the retention times and characteristic fragments of the measured substances which will lead to an appropriate screening method. Gathered performance data of the method used for measuring the compound in this research project show that the separation is successful but the sensitivity is not low enough. Limits of detection of several compounds are still too high which should be lowered for the development of useful screening method. By expansion of the database and optimisation of the separation method and sample clean up, this method could be validated and suitable for rapid detection of drugs of abuse.


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Explosives

Explosive with TNT (trinitrotoluene)

Chromatograms of the real life TNT samples measured with the SIM method. The high broad peak around 3.00 min is the TNT peak.

Student Sander Willemse Research carried out at

University of Amsterdam

Supervisor Hanneke Brust and Peter Schoenmakers Title thesis Profiling of TNT impurities by vacuum-

outlet GC-MS Abstract The highest form of information gained

from analyzing explosive material is the identity of the material. The goal of this research was to chemically profile TNT samples and discriminate them based on their origin by studying the impurities in the sample. The different impurities/by-products of TNT were analyzed by vacuum-outlet GC-EI-MS. TNT profiles, obtained by GC-MS, depend on the manufacturing process, storage, age and the extent of purification. Therefore impurity profiles can be highly characteristic for the TNT sample in question. The aim was to perform a source level identification. A vacuum-outlet GC-MS method was developed during this research that could successfully discriminate between different TNT samples based on the constructed impurity profiles. The developed method was also able to identify the explosive RDX with a high narrow Gaussian-shaped peak. Vacuum-outlet GC-MS has the potential to analyze thermolabile compounds, because lower elution temperatures can be achieved. Therefore this system/method can in the future also be used as a fast screening method for organic explosives after optimizing the detection of thermolabile explosives.


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Fingerprint analysis

Student Kevin van de Braak Research carried out at


Supervisor Ir. H.J.J. Hardy Title thesis Functionalized Quantum Dots & Magnetic

Particles and their Ability to Visualize/Label Components in Latent Fingermarks

Abstract In criminal investigations fingermarks are still one of the most important evidence categories in forensic science. This research project has further investigated a new approach to look at fingermarks. Using this approach we want to get more information out of the chemical composition of a fingermark. This is done by treating fingermarks with antibody-magnetic particle and antibody-quantum dot conjugates. This was done to label specific constituents in a fingermark, left on nitrocellulose membrane. Three different antibodies (anti-dermcidin, anti-creatinine and anti-cathepsin-D) are used during this research. And it is determined that they are able to target their antigen in a latent fingermark. Also the best way to conjugate the antibodies with the magnetic particles and the quantum dots is determined. However the conjugation with anti-dermcidin was not successful. Further the non-specific binding encountered when using functionalized QDs and MPs is minimized by the usage of a block buffer. There are many constituents in a fingermark and these can be targeted to get different information about the fingermark. Some interesting targets for the age etermination of a fingermark can be squalene and fatty acids. And for gender urea and androstadienone. Suggestions that can be made to this method involve e.g. usability, the visualization of unclear fingermarks and how to deal with contamination. And more research is needed to investigate non-specific binding, to link IgM to visual enhancers, to be able to link QDs to antibodies. Also research needs to be done in determining useful constituents to target, to get more information out of the chemical composition of a fingermark.

Antibody magnetic particle conjugate

Interaction of functionalized MPs on fingermarks. Top: Cy3 fluorescence of secondary antibody. Bottom: Corresponding orange coloration of magnetic particles.


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Toxicology

Student Loes Jeurissen Research carried out at

Dept. Forensic Medicine (Toxicology) at Netherlands Forensic Institute

Supervisor dr. I.J. Bosman

Title thesis Postmortem Redistribution – Toxicological Results of Drugs in Multiple Biological Matrices

Abstract The interpretation of postmortem toxicological results is a challenging task in forensic science because concentrations of substances are affected by postmortem processes and mechanisms. This means that postmortem drug concentrations do not necessarily reflect concentrations at the time of death. It has been shown that concentrations in heart blood are higher than in femoral blood and that blood concentrations change with prolonged postmortem interval, as shown in the figure. Concentration ratios seem to stay constant in the postmortem period. By calculating the heart to femoral blood concentration ratio, the degree of postmortem redistribution can be assessed, reducing wrong interpretations due to concentration changes after death. The results obtained in this study confirm the value of heart blood to femoral blood concentrations ratios in assessing postmortem redistribution. It is advised that postmortem toxicological analysis should always include multiple matrices. The collection of circumstantial conditions, for example postmortem interval, may further help in the interpretation of postmortem toxicological results.

Mean concentrations of desmethyldiazepam in femoral blood and heart blood at different postmortem intervals, including standard error of the means.

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uva.nl/mfs msc‐forensic‐[email protected]

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