The Detection of Clandestine Human Burials using Bio-amine Decomposition Products - PowerPoint Presentation

The Detection of Clandestine Human Burials using Bio-amine Decomposition Products Giorgio BlomJohn CassellaAlison DavidsonJamie Pringle08-01-14

Do you think that the current methods to detect clandestine graves (hidden human remains) are good enough? How do you think clandestine graves are discovered most commonly?

Introduction 1 2 534

Introduction 663 homicides reported in 2012200,000 people reported missing annually5,500 of those cases have a fatal outcomeNumber of people missing due to a homicide is indeterminate

Introduction Current procedures to detect clandestine gravesLimitations of these proceduresIdeal procedure to detect clandestine graves

Would the use of chemistry be able to aid in the detection of human remains? Soil Matrix Interactions in a Taphonomic Environment: Forensic Considerations

Introduction Putrescine and cadaverine are significant decomposition productsPutrescine and cadaverine are considered biomarkers for analytical instrument detection of clandestine gravesProminent researchers did not detect these compounds in grave headspace or soil

Theory Stage of decomposition DescriptionDetection methodsFreshCommences immediately after deathAutolysisFluid filled blisters on the skin, skin slippageMarbling of skin due to livor mortisVisual signs and areal photography (disturbance in soil and vegetation)GPRThermal imagingBloatingPutrefaction – destruction of soft tissues by microorganismsGreenish discolouration of the skinGas and fluid accumulation followed by purgingAnaerobic fermentationActive decayBloating has ceasedSkin usually broken in one or more placesRapid leaching from bodyLarge numbers of aerobic and anaerobic bacteriaExtensive insect activity Possible carnivore activityCollapse of abdominal cavityLoss of internal organs through insect activity or autolysisPossible adipocere formationCadaver dogGPRVisual (vegetation changes due to changes of soils chemical composition)DryNo carrion fauna remainingSmall amount of decaying tissueMummification of remaining skinBone exposure and skeletonisation ArchaeologyGPRTable 1: Stages of decomposition.

Theory Biogenic amines:PutrescineCadaverine Table 2: Physical properties.Figure 2: Decarboxylation reaction of ornithine to produce putrescine.Figure 3: Decarboxylation reaction of lysine to produce cadaverine.

Theory The use of gas chromatography The use of a derivatisation agentFigure 5: Putrescine PFB derivate.Figure 6: Step by step derivatisation procedure

A domestic pig (Sus domesticus scrofa) was as a proxy for a human cadaver due to the Human Tissue Act (2004) [Pringle et al. 2010]. Soil moisture and decomposition fluids pass into lysimeter through buried micro pore end. Lysimeter was emptied two days prior to sample collection, then resealed and placed under partial vacuum pressure [see Pringle et al. 2010]. The samples were collected, placed in labelled plastic bottles and frozen. Control samples were taken from a lysimeter 10m from the grave site.Samples were collected from a grave site at Keele University from 07-12-07.Figure 7: Photograph of the grave site.Sampling Procedure

Comparison of Different Extraction Methods Extraction Sample typeAnalysisLimit of detectionHeadspaceDrySPME-GC-FID< 0.007mg/lHeadspaceAqueous solutionSPME-GC-FID~ 16000mg/lSolvent with derivatisation Aqueous solutionGC-FID~ 0.02mg/lSolvent without derivatisationAqueous solutionGC-FID> 9600mg/lTable 3: Limit of detection of putrescine and cadaverine using different methods.

Analysis of Leachate Samples Figure 7: Detection of putrescine and cadaverine in the leachate samples over time.

High Performance Liquid Chromatography Failure to detect certain compounds by GC could be due to:Compounds are not volatile enough Compounds are not easily extracted from aqueous environment due to their high polarityGC data showed that volatile compounds such as bio-amines are not volatile when dissolved in waterHPLC is able to separate non volatile compounds HPLC will be able to analyse aqueous samples therefore no extraction and/or derivatisation is needed which can affect quantificationHPLC data will aid in the comparison of non volatile compounds and optimisation of GC method

+/- 1 Month post burial +/- 6 Months post burial +/- 12 Months post burial+/- 24 Months post burial

+/- 2 weeks post burial 19-12-07+/- 1.5 years post burial18-06-09+/- 3.3 years post burial18-04-11

Conclusion Putrescine and cadaverine were detected in the leachate samples from 181 days up to 902 days post burial by GC-FID. Methylamine was also detected around this time interval.There is no linear relationship for the concentration of putrescine and cadaverine over time.Putrescine and cadaverine are less volatile if dissolved in water. Water soluble compounds are present in the leachate which absorb UV light at a wavelength of 260nm. These compounds are present in the grave samples but not in the control samples and have different chemical compositions over time since burial.More chemicals are detected using HPLC-MS in comparison to HPLC-UV/Vis.

Further work Further analysis of leachate samples using LC-QTOF-MS (at the University of Huddersfield) to obtain more accurate results.Optimisation of extraction and derivatisation methods.Screening of l eachate with GC-MS for comparison with HPLC data.

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References Vass et al. (2004). Decompositional Odor Analysis Database. Journal of Forensic Sciences, 49, 760-769.Dekeirsschieter et al. (2009). Cadaveric volatile organic compounds released by decaying pig carcasses ( Sus domesticus L.) in different biotopes. Forensic Science International, 189, 46-53.Dent et al. (2004). Review of human decomposition in soil. Environmental geology, 45, 576-585.Pringle et al. (2010) Preliminary soilwater conductivity analysis to date clandestine burials of homicide victims. Forensic Science International, 198, 126-133. Ngim et al. (2000). Optimized procedures for analyzing primary alkylamines in wines by pentafluorobenzaldehyde derivatisation and GC-MS. Journal of agric. Food Chemistry, 48, 3311-3316.