NanoSpot(TM) Collector for Aerosol Sample Collection for Direct Microscopy and Spectroscopy Analysis

Details

• Personal Author:
  Dionysiou, Dionysios D. ; Keady, Patricia ; Kulkarni, Pramod ; Stump, Braden ; Zervaki, Orthodoxia
• Description:
  We describe design and characterization of an aerosol NanoSpotTM collector, designed for collection of airborne particles on a microscopy substrate for direct electron and optical microscopy, and laser spectroscopy analysis. The collector implements a water-based, laminar-flow, condensation growth technique, followed by impaction onto an optical/electron microscopy substrate or a transmission electron microscopy grid for direct analysis. The compact design employs three parallel growth tubes allowing a sampling flow rate of 1.2 L min-1. Each growth tube consists of three-temperature regions, for controlling the vapor saturation profile and exit dew point. Following the droplet growth, the three streams merge into one flow and a converging nozzle enhances focusing of grown droplets into a tight beam, prior to their final impaction on the warm surface of the collection substrate. Experiments were conducted for the acquisition of the size-dependent collection efficiency and the aerosol concentration effect on the NanoSpotTM collector. Particles as small as 7 nm were activated and collected on the electron microscopy stub. The collected particle samples were analyzed using electron microscopy and Raman spectroscopy for the acquisition of the particle spatial distribution, the spot sample uniformity, and the analyte concentration. A spot deposit of approximately 0.7-mm diameter is formed for particles over a broad particle diameter range, for effective coupling with microscopic and spectroscopic analysis. Finally, the NanoSpotTM collector's analytical measurement sensitivity for laser Raman analysis and counting statistics for fiber count measurement using optical microscopy were calculated and were compared with those of the conventional aerosol sampling methods. [Description provided by NIOSH]
• Subjects:
  Aerosols Air Pollutants, Occupational Occupational Health Particulate Matter Safety Solvents Temperature
• Keywords:
  Aerosol Sampling Airborne Particles Airborne Particulates Electron Microscopy Fibers Nanotechnology Particle Size Particulates Temperature Effects Vapors
• ISSN:
  0278-6826
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  Colorado ; Ohio ; OSHA Region 5 ; OSHA Region 8
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  14 pdf pages
• Volume:
  57
• Issue:
  4
• NIOSHTIC Number:
  nn:20066919
• Citation:
  Aerosol Sci Technol 2023 Apr; 57(4):342-354
• Contact Point Address:
  Pramod Kulkarni, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Cincinnati, OH
• Email:
  PSKulkarni@cdc.gov
• Federal Fiscal Year:
  2023
• NORA Priority Area:
  Construction ; Manufacturing
• Peer Reviewed:
  True
• Source Full Name:
  Aerosol Science and Technology
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:eb520a7cf7e326d85d82b33023c093a1c26bff153624a37a5554c20e66db4f7189594121f06eb23fefe5b592977eee4a01719cf21da932fec76e858c1b790c5e
• Download URL:
  https://stacks.cdc.gov/view/cdc/230715/cdc_230715_DS1.pdf
• File Type:
  [PDF - 3.17 MB ]