Photothermal Desorption of Toluene from Carbonaceous Substrates Using Light Flash

Details

• Personal Author:
  Floyd EL ; Lungu CT ; Oh, Je M. ; Oni TM ; Sapag K ; Shedd JS
• Description:
  Millions of workers are occupationally exposed to volatile organic compounds (VOCs) annually. Current exposure assessment techniques primarily utilize sorbent based preconcentrators to collect VOCs, with analysis performed using chemical or thermal desorption. Chemical desorption typically analyzes 1 µL out of a 1 mL (0.1%) extraction volume providing limited sensitivity. Thermal desorption typically analyzes 100% of the sample which provides maximal sensitivity, but does not allow repeat analysis of the sample and often has greater sensitivity than is needed. In this study we describe a novel photothermal desorption (PTD) technique to bridge the sensitivity gap between chemical desorption and thermal desorption. We used PTD to partially desorb toluene from three carbonaceous substrates; activated carbon powder (AC-p), single-walled carbon nanotube (SWNT) powder (SWNT-p) and SWNT felts (SWNT-f). Sorbents were loaded with 435 ug toluene vapour and irradiated at four light energies. Desorption ranged from <0.007% to 0.86% with a single flash depending on substrate and flash energy. PTD was significantly greater and more consistent in SWNT-f substrates compared to AC-p or SWNT-p at all irradiation energies. We attribute the better performance of SWNT-f to greater utilization of its unique nanomaterials properties: high thermal conductivity along the nanotube axis, and greater interconnection within the felt matrix compared to the powdered form. [Description provided by NIOSH]
• Subjects:
  Environmental Exposure Hypersensitivity Occupational Health Risk Assessment Risk Factors Safety Solvents Toluene Volatile Organic Compounds Workplace
• Keywords:
  Author Keywords: Carbon Nanotubes Carbonaceous Substrates Carbon Nanotubes CNT Exposure Assessment Exposure Levels Nanomaterials Nanotechnology Nanotubes Photothermal Desorption Risk Factors Sampling Sensitization Thermal Desorption Toluene Toluenes Vapors VOCs Volatile Organic Compounds Work Environment Workers

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• ISSN:
  2079-4991
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Alabama ; Oklahoma ; OSHA Region 4 ; OSHA Region 6
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  12
• Issue:
  4
• NIOSHTIC Number:
  nn:20064657
• Citation:
  Nanomaterials 2022 Feb; 12(4):662
• Contact Point Address:
  Evan L. Floyd, Department of Occupational and Environmental Health, University of Oklahoma Health Sciences Center, Oklahoma, OK 73126
• Email:
  clungu@uab.edu
• CAS Registry Number:
  Carbon (CAS RN 7440-44-0) ; Carbon nanotubes (CAS RN 308068-56-6) ; Toluene (CAS RN 108-88-3)
• Federal Fiscal Year:
  2022
• Performing Organization:
  University of Alabama at Birmingham
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Nanomaterials
• End Date:
  20270630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:b960dca7c80590549487a9b2d05281bb73e2b5bf050d19712b6d89f043114382c49f67180ae3519fa061f625c7a63ca466c4f30391ee17f71c9d3a0d3c5645da
• Download URL:
  https://stacks.cdc.gov/view/cdc/223083/cdc_223083_DS1.pdf
• File Type:
  [PDF - 3.16 MB ]