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hit “esc” to quit hit any key to continue Detection of Ignitable Liquids from Smoke Residues by Large Volume Static Headspace
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hit “esc” to quit hit any key to continue Presentation Overview Introduction to Large Volume Static Headspace (LVSH) Technique Analytical Procedure Data from Arson and Non Arson Fire Summary
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hit “esc” to quit hit any key to continue GC/MS Detection Limits vs Headspace Sample Volume 0.001 0.01 0.1 1.0 10 100 1000 PPM LODPPM LOD MINIMUM VOLUME REQUIRED (CC) Vol vs Conc. LoopPreconcentration 1000 100 10 1 0.1 0.01 10-3 10-4 10-5
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hit “esc” to quit hit any key to continue Lack of Water Management 400cc VOC STD, Full Scan 15-270 amu
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hit “esc” to quit hit any key to continue Large Volume Headspace Requires Preconcentration HP 5973 GCMS Volume ReductionLarge Volume Inlet or Autosampler
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hit “esc” to quit hit any key to continue Large Volume Static Headspace Autosampler Introduces 10-200cc of headspace to the 7100 Preconcentrator Accommodates solids and liquids Detection limits 100x lower than conventional loop injection headspace “See what your BDU can smell”
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hit “esc” to quit hit any key to continue LVSH Sample Platforms and Enclosures Evidence collection and analysis use the same enclosure reducing potential for contamination of samples. Sample Platforms use quick connects, simplifying removal for cleaning.
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hit “esc” to quit hit any key to continue 7032-LVSH / 7100 /5973 Large Volume Static Headspace Analyzer GC MS 6 71007032-LVSH SL I/O M1 M2 M3
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hit “esc” to quit hit any key to continue PCB Integrated wiring for improved reliability Modular design. Easy replacement of traps MFC downstream of traps 7100 Open Architecture
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hit “esc” to quit hit any key to continue Silonite tubing used throughout. Complete heating of sample flow path. Easily accessed for trap and tubing replacement. External Heaters outside each cryotrap 7100 Heated Flow Path 7100 Preconcentrator
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hit “esc” to quit hit any key to continue Internal Standard Calibration Standard Sample Glass BeadsTenax Cryogen in N2, O2 Focuser To GC Helium PUMPMFC Helium Carrier 7100 Water and CO2 Management Techniques Loading Internal Standard Sample
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hit “esc” to quit hit any key to continue Internal Standard Calibration Standard Sample Glass BeadsTenax Cryogen in Focuser To GC N2,O2 Helium PUMPMFC Helium Carrier Loading Calibration Standard 7100 Water and CO2 Management Techniques
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hit “esc” to quit hit any key to continue Internal Standard Calibration Standard Glass BeadsTenax Cryogen in N2, O2, Ar, CH4 Focuser To GC Helium PUMPMFC Helium Carrier VOCs H2O CO2 Loading Sample Sample 7100 Water and CO2 Management Techniques
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hit “esc” to quit hit any key to continue Internal Standard Calibration Standard Glass BeadsTenax Cryogen in N2, O2, Ar, CH4 Focuser To GC VOCs H2O Helium PUMPMFC Helium Carrier CO2 Flushing Traps Sample 7100 Water and CO2 Management Techniques
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hit “esc” to quit hit any key to continue Internal Standard Calibration Standard Glass BeadsTenax Cryogen in CO2 Focuser To GC VOCs H2O Helium PUMPMFC Helium Carrier Removing Water and CO2 Sample 7100 Water and CO2 Management Techniques
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hit “esc” to quit hit any key to continue Internal Standard Calibration Standard Glass BeadsTenax Cryogen in Focuser VOCs To GC Helium PUMPMFC Helium Carrier VOCs Focusing Sample before Injection Sample 7100 Water and CO2 Management Techniques
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hit “esc” to quit hit any key to continue Internal Standard Calibration Standard Glass BeadsTenax Cryogen in H2O Focuser To GC Helium PUMPMFC Helium Carrier Post-Injection Bakeout Sample 7100 Water and CO2 Management Techniques
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hit “esc” to quit hit any key to continue Evidence Collection Glass fragments from the room of origin are collected in glass jars. Analysis of the headspace dose not require transferring the sample
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hit “esc” to quit hit any key to continue Data Comparison: Room 1 vs Room 4 -100cc sample No Ignitable LiquidsGasoline-Diesel Mix
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hit “esc” to quit hit any key to continue ASTM Class 2 Data Comparison Xylenes & C3 Alkylbenzene No Ignitable LiquidsGasoline-Diesel Mix
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hit “esc” to quit hit any key to continue ASTM Class 2 Data Comparison Benzene & Toluene No Ignitable LiquidsGasoline-Diesel Mix
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hit “esc” to quit hit any key to continue ASTM Class 2 Data Comparison Naphthalines No Ignitable LiquidsGasoline-Diesel Mix
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hit “esc” to quit hit any key to continue Advantages of LVSH Sample Collection Samples can be collected if the point of origin has been obscured. Samples can be collected well after the fire has been extinguished. Clear jars allow evidence to be displayed at trial without compromising sample integrity. Small jars allow for easy sample transport. Samples can be split or co-located for defense.
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hit “esc” to quit hit any key to continue Conclusion Large Volume Static Headspace (LVSH) is a new analytical tool available to Forensic Chemists which enhances detection limits while using current GC and GCMS systems. ASTM Reference Compounds are easily Identified in High Concentration when Compared to Non Combustible Liquid Fires.
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