A New Forensics Technique to Investigate the Presence

A New Forensics Technique to Investigate the Presence of Chemical “Finger. Prints” in Human Breath hit “esc” to quit hit any key to continue

Objectives • Test Ability to Collect and Analyze Trace Level Chemicals in Human Breath • Determine if Concentrations Increase upon Prolonged Exposure • Determine Whether Trace Chemicals can be Detected in Breath Samples Days after the Initial Exposure hit “esc” to quit hit any key to continue

Analyzing Volatile Organic Compounds in Breath • Clinical Diagnosis – Elevated Organic Compounds – Isotopic Labeling • Occupational Exposure Assessment • Law Enforcement – Non-Invasive Monitoring for Drugs of Abuse – Breath Fingerprinting hit “esc” to quit hit any key to continue

Chemicals in Human Breath as Forensic Tracers • The same mechanism that allows efficient transfer of O 2 and CO 2 through the alveoli also allows the exchange of other chemicals that are in the air as well • Once in the blood, chemicals may metabolize readily, or may dissolve into adipose tissue where they may release back into the blood over time, allowing them to be detected in exhaled breath. hit “esc” to quit hit any key to continue

Requirements of Breath Testing Application • Breath Sampling System • Inert chemical storage device • Effective (automated) analytical inlet system and GC/MS • Multi-sampler decontamination system hit “esc” to quit hit any key to continue

Selection of Sampling Device • Choices: Tedlar bags, Adsorbent tubes, stainless steel canisters. • Canisters advantages: – Ease of sampling (self contained vacuum) – Elimination of volume sampling errors – Ability to recover reactive and thermally labile compounds hit “esc” to quit hit any key to continue

Silonite. TM Coating Maximizes Inertness • Silonite coating provides a highly inert surface preventing surface reactions that can occur on stainless steel • Compounds that can be chromatographed can generally be stored in Silonite coated vessels. hit “esc” to quit hit any key to continue

Collecting Breath Samples into Mini. Cans Breath Sampler Prototype Last 20 -30% of Exhaled Breath is Captured in Tube The Breath Sample is Recovered into Mini. Can without Introduction of Room Air Breath Sampler Volume - 650 cc Mini. Can Volume - 380 cc hit “esc” to quit hit any key to continue

2 -Step Breath Sampling Procedure 1. Blow through disposable, check-valve to flush 0. 65 L tube volume 2. Connect evacuated Mini. Can to recover breath sample hit “esc” to quit hit any key to continue

Validating Proper Sampling of Breath • Tetrafluoroethane released into room • Participant inhales outside of room, walks into room and exhales through sampler • Sampled breath introduced into can • Second Mini. Can filled with room air for comparison hit “esc” to quit hit any key to continue

Low Volume Breath Sampler hit “esc” to quit hit any key to continue

Laboratory Analysis HP 5973 GCMS 7100 7032 L 4600 3 -Stage Preconcentrator 7032 L 21 -Position Mini. Can Autosampler 4600 Multi-Channel Standards Diluter hit “esc” to quit hit any key to continue

VOC Breath Analyzer SL I/O 6 MS Split Ctrl. GC 7100 hit “esc” to quit 7032 -L hit any key to continue

CO 2 and Water Elimination using Microscale Purge and Trap. TM MFC Removing Water and CO 2 PUMP CO 2 Helium Carrier Helium To GC H 2 O Glass Beads Internal Standard hit “esc” to quit Calibration Sample Standard VOCs Focuser Tenax Cryogen in hit any key to continue

Decontamination System Allowing Unlimited Reuse of Mini. Cans • Cleans Mini. Cans by Filling and Evacuating with Humidified Nitrogen. • Testing one Mini. Can after Cleaning Certifies all 21 hit “esc” to quit hit any key to continue

Testing Respiratory Adsorption and Desorption of VOCs • Test Breath at t=0 • Expose Participant to chemicals at less than 5% of OSHA PELs for 8 hours • Use personal Mini. Can sampler (IH 1200) to simultaneously collect air representative of what the participant is breathing • Test participants breath at the end of the day • Test participants breath on subsequent days hit “esc” to quit hit any key to continue

Tracer Chemicals Released Into Room for 8 Hour Exposure 1. Hexane Sur 2 2. 1, 4 -Dioxane 3. Methyl Methacrylate IS 3 Sur 1 IS 2 5 4. n-Butyl Acetate 5. 1, 3, 5 -Trimethyl Benzene 1 IS 1 3 4 2 hit “esc” to quit hit any key to continue

Chromatogram of Breath At Time=0 Hours 1 hit “esc” to quit 2 4 5 hit any key to continue

Chromatogram of Breath At Time=8 Hours hit “esc” to quit hit any key to continue

Single Ion Chromatogram of 1, 3, 5 -Trimethylbenzene in Breath after 8 Hour Exposure hit “esc” to quit hit any key to continue

Recovery of Chemicals in Breath hit “esc” to quit hit any key to continue

Conclusion • Analytical methodology has been developed which allows VOCs in human breath to be measured down to part-per-trillion levels • Factors other than exposure levels appear to play a part in the concentration and lifetime of VOCs recovered in breath samples • For this technique to be a practical forensics tool, the list of tracer chemicals would have to be somewhat unique. This may be the case in certain illegal drug manufacturing operations, although studies will have to be performed to substantiate this. hit “esc” to quit hit any key to continue