<p><strong>🎤 Presenter:</strong> Kevin Hayes (Mount Royal University)</p><p>💾 <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/paper/32773"><strong>PDF presentation</strong></a></p><h3><strong>Abstract</strong></h3><p><strong>An elemental analysis was conducted on matched pairs of new and used aircraft engine oils for various aircraft engine types (piston, turboprop, and jet). The analysis aimed to determine what, if any, accumulation or loss of oil and fuel additives may occur with engine use. Losses in elemental loadings from new to used oils imply that there may be a possibility for the element-containing compounds to enter the pneumatic system of bleed air pressurized aircraft at a higher rate than that of oil attrition and potentially impact cabin air quality. Inductively Coupled Plasma Optical Emission Spectroscopy (ICP OES) was employed to complete the elemental analysis, and results describe a greater than twenty percent loss of phosphorus from new to used jet oils and a significant accumulation of lead in the oil of piston aircraft (Range: below LOD to 6821 ± 83 mg kg-1 ; n=2).</strong></p><p>In an effort to speciate and identify compounds of concern, the oil samples were introduced to a flow modulated GCxGC-TOFMS (SepSolv BenchTOF). Data was analyzed utilizing Chromspace and Analyzer Pro XD. The new and used oils were compared, and compounds exclusive to the used oils were screened to determine the possibility of increased risk associated with hazardous accumulations in the used oil. This used oil, which is adulterated by either amendment or contamination, is not fully described to individuals who may interact with the product, and therefore an apparent risk is potentially unmitigated.</p><h3><strong>Video transcription</strong></h3><h4><strong>2. Background: Aircraft Engine Oils</strong></h4><p>Aircraft engine oils are chemically complex and vary depending on:</p><ul><li>Manufacturer</li><li>Aircraft type</li><li>Engine type</li></ul><h5><strong>2.1 Piston Engine Oils</strong></h5><ul><li>Typically mineral oil-based</li><li>Simpler formulations</li><li>Lower temperature and pressure requirements</li></ul><h5><strong>2.2 Jet and Turboprop Oils</strong></h5><ul><li>Often based on pentaerythritol esters</li><li>Contain organophosphate additives</li><li>Designed to withstand high temperatures and pressures</li><li>May include aftermarket additives (sometimes required by FAA airworthiness directives)</li></ul><h4><strong>3. Engine Types and Fuels</strong></h4><p>The study included oils from:</p><ul><li>Jet aircraft</li><li>Turboprop aircraft</li><li>Piston engine aircraft</li></ul><h5><strong>3.1 Fuel Differences</strong></h5><ul><li><strong>Jet and turboprop aircraft</strong><ul><li>Jet A (U.S.)</li><li>Jet A-1 (international)</li><li>Jet B (naphtha-based, cold climates)</li><li>Kerosene-based fuels</li></ul></li><li><strong>Piston aircraft</strong><ul><li>Use aviation gasoline (avgas)</li><li>Notably contains tetraethyl lead (anti-knock additive)</li></ul></li></ul><h5><strong>3.2 Engine Construction Differences</strong></h5><ul><li>Jet/turboprop engines:<ul><li>Contain superalloys (steel alloys with molybdenum, nickel, etc.)</li></ul></li><li>Piston engines:<ul><li>Simpler construction</li><li>No need for high-temperature superalloys</li></ul></li></ul><h4><strong>4. Purpose of the Study</strong></h4><p>The research aimed to determine:</p><ol><li>Whether compounds are lost from oils during use</li><li>Whether oils accumulate new compounds during service</li><li>Whether these changes pose occupational health risks</li><li>Whether lost compounds could enter aircraft cabins via bleed air pathways (jet/turboprop engines)</li></ol><h4><strong>5. Elemental Analysis (ICP-OES)</strong></h4><h5><strong>5.1 Sample Collection</strong></h5><ul><li>Used oils from:<ul><li>University aviation fleet (piston aircraft)</li><li>Airport partners (turboprop)</li><li>European business jet operator (limited jet samples)</li></ul></li></ul><h5><strong>5.2 Analytical Technique</strong></h5><ul><li>Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES)</li></ul><h4><strong>6. Results: Wear Metals</strong></h4><p>Fresh oil:</p><ul><li>No wear metals detected (as expected)</li></ul><p>Used piston oils:</p><ul><li>Increased iron and nickel (expected wear metals)</li><li>Cadmium detected (potential concern)</li></ul><p>Used jet/turboprop oils:</p><ul><li>Lower wear metals overall</li><li>Presence of molybdenum (consistent with superalloys)</li></ul><h4><strong>7. Unexpected Findings</strong></h4><h5><strong>7.1 Sulfur</strong></h5><ul><li>Increased sulfur in piston oils</li><li>Expected due to aviation fuel allowances</li></ul><h5><strong>7.2 Lead (Major Finding)</strong></h5><ul><li>Extremely high levels (&gt;6000 mg/kg)</li><li>Lead content 7–8× higher in oil than in avgas</li><li>Oil actively accumulates lead from combustion</li></ul><p>Source:</p><ul><li>Tetraethyl lead in aviation gasoline</li></ul><h4><strong>8. Phosphorus Trends</strong></h4><h5><strong>8.1 Piston Engines</strong></h5><ul><li>~600 ppm phosphorus detected</li><li>Source unclear (likely additive-related)</li></ul><h5><strong>8.2 Jet and Turboprop Engines</strong></h5><ul><li>Phosphorus levels decreased during use</li><li>Likely linked to organophosphate additive depletion</li><li>Important because:<ul><li>Phosphorus stabilizes oil at high temperatures</li><li>Loss may indicate additive degradation</li><li>Possible availability to bleed air pathway</li></ul></li></ul><p><i>Note: Large jet aircraft often do not undergo traditional oil changes; oil is replenished continuously.</i></p><h4><strong>9. GC×GC Analysis</strong></h4><h5><strong>9.1 Method</strong></h5><ul><li>Oil diluted in hexane</li><li>High split ratio</li><li>Instrumentation:<ul><li>Agilent 7890 GC</li><li>Insight flow modulator</li><li>Benchtop mass spectrometer</li></ul></li><li>Hard ionization (70 eV)</li></ul><h4><strong>10. Organo-Phosphate Speciation</strong></h4><h5><strong>10.1 Jet and Turboprop Oils</strong></h5><p>Detected:</p><ul><li>Tricresyl phosphate (TCP) isomers<ul><li>Tri-meta-cresyl phosphate</li><li>Tri-para-cresyl phosphate</li></ul></li></ul><p>Unknown peaks:</p><ul><li>Likely additional TCP isomers</li></ul><p>Important:</p><ul><li>No confirmation yet of ortho-TCP</li><li>Ortho-TCP is neurotoxic</li><li>Historically responsible for "Jake Leg Syndrome"</li></ul><p>Conclusion:<br>Phosphorus loss likely linked to degradation of TCP molecules.</p><h4><strong>11. Oil Complexity After Use</strong></h4><p>Used oils showed:</p><ul><li>Increased chromatographic complexity</li><li>More peaks in early chromatogram</li><li>Likely degradation/pyrolysis products of pentaerythritol esters</li></ul><p>Work ongoing to identify these products.</p><h4><strong>12. Lead Speciation</strong></h4><h5><strong>12.1 Tetraethyl Lead Behavior</strong></h5><p>Characteristics:</p><ul><li>Early elution (low boiling point)</li><li>Distinctive fragmentation pattern</li><li>Easy to identify</li></ul><p>Finding:</p><ul><li>No tetraethyl lead detected in used oils</li></ul><p>Implication:</p><ul><li>Likely fully degraded during combustion</li><li>Remaining species likely lead oxide</li><li>Still toxic, but less dermally bioavailable than tetraethyl lead</li></ul><h4><strong>13. Phosphorus in Piston Oils</strong></h4><p>Expected:</p><ul><li>Tricresyl phosphate (TCP)</li></ul><p>Observed:</p><ul><li>Triphenyl phosphate</li><li>Possibly tert-butyl phenyl diphenyl phosphate (tentative identification)</li></ul><p>Significance:</p><ul><li>Different compound than expected</li><li>Less hazardous than ortho-TCP</li><li>2D separation critical to avoid misidentification</li></ul><h4><strong>14. Overall Conclusions</strong></h4><ul><li>Aircraft engine oils are chemically dynamic</li><li>Oils change significantly during service</li><li>Accumulation (e.g., lead) and depletion (e.g., phosphorus additives) both occur</li><li>Used oil composition differs from safety data sheet composition</li><li>ICP-OES provides screening-level insight</li><li>GC×GC enables detailed compound-level resolution</li></ul><p>The aviation oil space remains a promising area for continued research.</p><blockquote><p><strong>This text has been automatically transcribed from a video presentation using AI technology. It may contain inaccuracies and is not guaranteed to be 100% correct.</strong></p></blockquote>

Analysis of fresh and used aircraft oil: Exposure possibility to pollutants (Kevin Hayes, MDCW 2026)

<p><strong>🎤 Presenter:</strong> <strong>Barbara Grace Saunders </strong>(William &amp; Mary, Williamsburg, USA)</p><p>💾 <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/paper/32782"><strong>PDF presentation</strong></a></p><h3><strong>Abstract</strong></h3><p><strong>Gunshot residue (GSR) is expelled as a "plume" of vaporized material during a firearm discharge event. As it disperses, condenses, and settles on surfaces in vicinity of the discharge, it creates chemical depositions that provide essential information for forensic casework involving criminal firearm usage.</strong></p><p>GSR contains organic (OGSR) and inorganic (IGSR) components, both of which may carry evidentiary value. Traditional analyses involve the targeted point analysis of IGSR via scanning electron microscopy - energy dispersive x-ray spectroscopy (<a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library?search=SEM-EDS"><strong>SEM-EDS</strong></a>), and conclusions are drawn based on a well-established elemental and morphological profile "characteristic" to IGSR. This method has lost impact as a standard for forensic analysis due to increased use of "green" - heavy metal-free - ammunition, which omits the lead, barium, and antimony that are traditionally seen as the "characteristic" markers of GSR.</p><p>This study aimed to develop a holistic approach to the analysis of GSR using both SEM-EDS as a targeted approach to IGSR analysis and comprehensive two-dimensional gas chromatography – time-of-flight mass spectrometry (<a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?instrumentationItems=2-3-13"><strong>GC×GC-TOFMS</strong></a>) as a nontargeted approach to OGSR analysis. GSR samples were collected from the hands of shooters at a police firearms recertification training using the tape lift method. SEM-EDS was used to identify IGSR and develop new morphological and elemental profiles for heavy metal-free residues. OGSR components have been positively identified through sample analysis via liquid extraction, chromatographic separation via GC×GC-TOFMS, and data processing.</p><p>Future work on this project will include the optimization of data processing methods and the development of SPME as an alternative sample extraction method.</p><h3><strong>Video Transcription</strong></h3><p>The transition toward environmentally friendly “green” ammunition is creating new challenges for forensic laboratories. Traditional gunshot residue (GSR) analysis relies heavily on the detection of heavy-metal-containing particles produced during firearm discharge. However, modern ammunition formulations increasingly eliminate these metals, making conventional forensic protocols less effective.</p><p>This study presents the development of a combined analytical strategy for the characterization of <strong>green gunshot residue (GSR)</strong> by integrating:</p><ul><li><strong>Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDS)</strong> for inorganic GSR (IGSR)</li><li><strong>Comprehensive Two-Dimensional Gas Chromatography coupled to Time-of-Flight Mass Spectrometry (GC×GC-TOFMS)</strong> for organic GSR (OGSR)</li></ul><p>The ultimate goal is to provide forensic laboratories with a more complete and defensible analytical approach for firearm discharge investigations.</p><h4><strong>Why Green Gunshot Residue Is a Challenge</strong></h4><p>Gunshot residue consists of particulate matter expelled from firearms during discharge. Rapid increases in temperature and pressure vaporize materials originating from:</p><ul><li>primer compositions</li><li>bullets</li><li>cartridge cases</li><li>firearm components</li></ul><p>These materials rapidly condense and deposit on:</p><ul><li>hands</li><li>skin</li><li>hair</li><li>clothing</li><li>nearby surfaces</li></ul><p>Because GSR is directly associated with firearm discharge events, it remains an important source of forensic evidence.</p><p>Historically, forensic scientists have identified GSR using <strong>SEM-EDS</strong>, focusing on particles containing characteristic heavy metals.</p><p>However, ammunition manufacturers have increasingly removed heavy metals from primers due to health and environmental concerns. Modern green ammunition replaces traditional metallic components with more environmentally common elements, making classical identification criteria less reliable.</p><h4><strong>Project Objectives</strong></h4><p>The project was designed around three primary goals:</p><ol><li>Redevelop inorganic GSR classification criteria for green ammunition.</li><li>Develop a robust GC×GC-TOFMS workflow for organic GSR analysis.</li><li>Combine both approaches into a comprehensive forensic methodology suitable for future laboratory implementation.</li></ol><h4><strong>Collection of Green GSR Samples</strong></h4><p>Samples were collected using standard forensic SEM-compatible collection kits.</p><p>Each kit consisted of:</p><ul><li>an airtight glass vial</li><li>an aluminum SEM pin stub</li><li>black carbon adhesive for particle collection</li></ul><p>Sampling was performed by repeatedly dabbing the adhesive surface across:</p><ul><li>palms</li><li>backs of hands</li><li>forearms</li></ul><p>of volunteers.</p><p>To ensure authentic green GSR samples, collection took place during police firearms recertification training at a local firing range. All ammunition used was verified as green ammunition.</p><h4><strong>Redevelopment of Green IGSR Characterization by SEM-EDS</strong></h4><p>The first phase focused on updating SEM-EDS criteria for green ammunition residues.</p><p>Analysis of numerous samples revealed morphological and elemental characteristics that differed from traditional heavy-metal-containing GSR particles.</p><p>One notable observation was that many candidate particles exhibited a characteristic “sparkling” appearance against the SEM background. These particles often contained elevated metallic content, although not necessarily heavy metals.</p><p>The resulting profiles provided a more reliable framework for identifying inorganic components of green GSR.</p><p>Nevertheless, the approach still involved a degree of analyst judgment, motivating the development of a more objective complementary analytical strategy based on organic residue analysis.</p><h4><strong>Why GC×GC-TOFMS Was Selected</strong></h4><p>The second phase focused on characterization of <strong>organic gunshot residue (OGSR)</strong>.</p><p>Compared with conventional one-dimensional GC, GC×GC offers:</p><ul><li>increased chromatographic peak capacity</li><li>enhanced separation power</li><li>improved resolution of structurally similar compounds</li><li>better discrimination of constitutional isomers</li></ul><p>These advantages are particularly valuable for forensic samples, where highly complex mixtures often contain numerous nitroaromatic compounds and energetic materials.</p><p>The instrumentation used was a:</p><ul><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/37"><strong>LECO Pegasus BT GC×GC-TOFMS</strong></a></li></ul><p>which combines comprehensive two-dimensional gas chromatography with high-resolution time-of-flight mass spectrometric detection.</p><h4><strong>Development of the Organic GSR Extraction Method</strong></h4><p>Organic residues were extracted using a liquid extraction procedure adapted from OSAC recommendations for GC-MS analysis.</p><p>The workflow included:</p><ol><li>Extraction in methanol</li><li>Evaporation to dryness under nitrogen</li><li>Reconstitution</li><li>Transfer into GC×GC-compatible vials</li></ol><p>Additional vortexing and sonication steps were incorporated to maximize analyte recovery.</p><h4><strong>Comparison of Extraction Procedures</strong></h4><p>The newly developed in-house method was compared with a literature-based extraction protocol.</p><p>The results demonstrated that the in-house procedure:</p><ul><li>recovered more analytes</li><li>produced higher peak intensities</li><li>generated a larger average number of chromatographic peaks</li></ul><p>Important target compounds such as:</p><ul><li>diphenylamine</li><li>skin matrix compounds</li><li>nitroaromatic species</li></ul><p>were detected at significantly higher abundance levels.</p><p>Consequently, the in-house extraction method was selected for all subsequent experiments.</p><h4><strong>Optimization of the GC×GC Method</strong></h4><h5><strong>Carrier Gas Selection</strong></h5><p>Initial experiments compared helium and hydrogen carrier gases.</p><p>Hydrogen provided:</p><ul><li>improved chromatographic expansion</li><li>better compound visibility</li><li>enhanced separation</li></ul><p>Therefore, hydrogen was selected for the final method.</p><h5><strong>Inlet Temperature Optimization</strong></h5><p>Two inlet temperatures were evaluated:</p><ul><li>170 °C</li><li>200 °C</li></ul><p>Although the lower temperature generated a larger number of detected analytes overall, critical GSR target compounds such as:</p><ul><li>nitroglycerin (ethylene glycol dinitrate)</li><li>diphenylamine</li></ul><p>showed lower responses or were not detected.</p><p>As a result, <strong>200 °C</strong> was selected as the optimal inlet temperature.</p><h5><strong>Modulation Period Optimization</strong></h5><p>Three modulation periods were compared: 2.0 s / 2.5 s / 3.0 s</p><ul><li><strong>Two-Second Modulation:</strong> Produced wraparound effects where analytes could not fully elute within a modulation cycle.</li><li><strong>Three-Second Modulation: </strong>Created excessive unused chromatographic space and compressed analyte distributions.</li><li><strong>Two-and-a-Half-Second Modulation:</strong> Provided the best balance between resolution and chromatographic efficiency.</li></ul><p>Therefore, <strong>2.5 seconds</strong> was selected as the final modulation period.</p><h4><strong>Validation Using Analytical Standards</strong></h4><p>The optimized GC×GC method was validated using several reference standards.</p><h5><strong>Seven-Component Phthalate Standard</strong></h5><p>All seven analytes were successfully identified.</p><p>The compounds exhibited:</p><ul><li>excellent chromatographic resolution</li><li>reproducible retention behavior</li><li>clear separation across both chromatographic dimensions</li></ul><p>These retention regions subsequently helped identify corresponding compounds in authentic GSR samples.</p><h5><strong>Twelve-Component Nitroaromatic Standard</strong></h5><p>All twelve analytes were successfully identified.</p><p>Particularly important was the clear separation of compounds such as:</p><ul><li>TNT</li><li>DNT</li><li>nitrotoluenes</li></ul><p>which frequently appear in explosive and propellant formulations.</p><p>This experiment demonstrated the superior resolving power of GC×GC compared with conventional one-dimensional GC.</p><h5><strong>Nitroglycerin Standard</strong></h5><p>Nitroglycerin was successfully detected and its retention coordinates established.</p><p>These retention characteristics will serve as reference markers for future identification in authentic GSR samples.</p><h5><strong>Gun Surveillance Standard</strong></h5><p>The final validation mixture contained nine known compounds.</p><p>Seven components were successfully identified.</p><p>Two unexpected compounds:</p><ul><li>phenazine</li><li>benzothiazole</li></ul><p>appeared in the chromatograms, while one expected analyte overlapped with column bleed.</p><p>Although further refinement is required, the preliminary results demonstrated promising analytical performance.</p><h4><strong>Major Outcomes of the Study</strong></h4><p>The project has already produced several significant achievements:</p><h5><strong>Inorganic GSR Analysis</strong></h5><ul><li>Redesigned SEM-EDS classification profiles for green ammunition residues</li><li>Improved characterization of heavy-metal-free particles</li></ul><h5><strong>Organic GSR Analysis</strong></h5><ul><li>Optimized methanol-based extraction procedure</li><li>Fully developed GC×GC-TOFMS analytical workflow</li><li>Improved detection of key OGSR markers</li><li>Verified retention behavior of multiple relevant analytes</li></ul><h5><strong>Integrated Forensic Strategy</strong></h5><ul><li>Combined IGSR and OGSR characterization</li><li>Enhanced confidence in green GSR identification</li><li>Improved potential for courtroom-defensible evidence interpretation</li></ul><h4><strong>Future Work</strong></h4><p>Although the method successfully distinguishes the presence or absence of green GSR, additional validation remains necessary before routine forensic implementation.</p><p>Future investigations will focus on:</p><ul><li>comparison of sorbent-based extraction approaches with methanol extraction</li><li>acquisition of retention indices for stronger compound confirmation</li><li>further validation of target analyte identities</li><li>increased method robustness for forensic casework</li></ul><p>The ultimate objective is to establish a validated methodology suitable for routine forensic laboratory deployment in the era of green ammunition.</p><h4><strong>Conclusion</strong></h4><p>This study demonstrates that combining <strong>SEM-EDS</strong> and <strong>GC×GC-TOFMS</strong> provides a promising framework for the forensic analysis of modern green gunshot residue. By integrating inorganic and organic residue characterization, forensic scientists can generate a more comprehensive evidential profile of firearm discharge events. The optimized extraction protocol, chromatographic conditions, and preliminary validation results show strong potential for future implementation in forensic laboratories, helping maintain the evidential value of GSR as ammunition technologies continue to evolve.</p><blockquote><p><strong>This text has been automatically transcribed from a video presentation using AI technology. It may contain inaccuracies and is not guaranteed to be 100% correct.</strong></p></blockquote>

Developing a Combined Approach to Green Gunshot Residue Analysis in the Forensic Laboratory (Barbara Grace Saunders, MDCW 2026)

Article

Product

Events

Webinars

Application

Academy

Video

Poster

Scientists

Plastics

Environment

Food

Water

Health

Presentation

Scientific article

Interview

Toxicology

Popularization

Science and research

Software

Covid-19

Career

Laboratories

Various

Zaměření

Type of News

Focus

Workshop o vícerozměrné chromatografii (MDC) spojuje odborníky z této zajímavé oblasti, aby se podělili o svůj výzkum a diskutovali o něm.

The Multidimensional Chromatography Workshop

18th Mass Spectrometry School in Biotechnology and Medicine

28th International Symposium on Advances in Extraction Technologies (ExTech 2026)

The 22nd Biennial National Atomic Spectroscopy Symposium (BNASS 2026)

Measuring Diverse Samples with UV/VIS Spectrometers and Integrating Spheres

Bruker Fluorescence Microscopy Solutions: Automated Imaging and Light-Sheet Microscopy

Unlock Smarter Digestion: AI and the Smart Features that transform your daily routine