Accurate quantification of TiO2 nanoparticles collected on air filters using a microwave-assisted acid digestion method

Details

• Personal Author:
  Anthony, T. Renée ; Grassian VH ; Mudunkotuwa IA ; Peters TM
• Description:
  Titanium dioxide (TiO2) particles, including nanoparticles with diameters smaller than 100 nm, are used extensively in consumer products. In a 2011 current intelligence bulletin, the National Institute of Occupational Safety and Health (NIOSH) recommended methods to assess worker exposures to fine and ultrafine TiO2 particles and associated occupational exposure limits for these particles. However, there are several challenges and problems encountered with these recommended exposure assessment methods involving the accurate quantitation of titanium dioxide collected on air filters using acid digestion followed by inductively coupled plasma optical emission spectroscopy (ICP-OES). Specifically, recommended digestion methods include the use of several hazardous chemicals, such as perchloric acid, which are typically unavailable in most accredited industrial hygiene laboratories. Other alternative methods that are used typically involve the use of nitric acid or combination of nitric acid and sulfuric acid, which yield very poor recoveries for titanium dioxide. Therefore, given the current state of the science, it is clear that a newer safe, reliable method is needed for exposure assessment. In this current study, a microwave-assisted acid digestion method has been specifically designed to improve the recovery of titanium in TiO2 nanoparticles for analysis using ICP-OES. The optimum digestion conditions were determined by changing several variables including the acids used, digestion time and temperature. Consequently, the optimized digestion temperature of 210oC with concentrated sulfuric and nitric acid (2:1 v/v) resulted in a recovery of >90% for TiO2. The method is expected to provide for a more accurate quantification of airborne TiO2 particles in the workplace environment. [Description provided by NIOSH]
• Subjects:
  Acids Air Pollutants, Occupational Chemistry Environmental Monitoring Occupational Health Particulate Matter Risk Assessment Risk Factors Safety Spectrum Analysis
• Keywords:
  Air-filters Analytical-methods Analytical-processes Author Keywords: Inductively Coupled Plasma Optical Emission Spectroscopy Chemical-analysis Chemical-composition Chemical-properties Dioxides Exposure-assessment Exposure-levels Filters Microwave-assisted Digestion Mixed-cellulose Ester Filter Nanoparticles Nanotechnology Particulates Polyvinyl Chloride Filter Risk-factors Spectrographic-analysis Spectroscopes Titanium Dioxide

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• ISSN:
  1545-9624
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Iowa ; OSHA Region 7
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  30-39
• Volume:
  13
• Issue:
  1
• NIOSHTIC Number:
  nn:20046451
• Citation:
  J Occup Environ Hyg 2016 Jan; 13(1):30-39
• Contact Point Address:
  Thomas M. Peters, S331 CPHB, University of Iowa, Iowa City, IA 52242
• Email:
  thomas-m-peters@uiowa.edu
• CAS Registry Number:
  Titania (CAS RN 13463-67-7)
• Federal Fiscal Year:
  2016
• NORA Priority Area:
  Construction ; Manufacturing
• Performing Organization:
  University of Iowa
• Peer Reviewed:
  True
• Start Date:
  20100901
• Source Full Name:
  Journal of Occupational and Environmental Hygiene
• End Date:
  20130831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:12e5dad99bceac1baeb61fc7ec3eb3d529ca0a94f7625266c07d2c0114e32e4964092f9a4e5d5fe280676c322d499c6b82f03297ad277992e523cef7bb74a542
• Download URL:
  https://stacks.cdc.gov/view/cdc/201506/cdc_201506_DS1.pdf
• File Type:
  [PDF - 1.00 MB ]