Development of an Electrodynamic Quadrupole Aerosol Concentrator

EPA Grant Number: R827354C006
Subproject: this is subproject number 006 , established and managed by the Center Director under grant R827354
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: Airborne PM - Rochester PM Center
Center Director: Oberd√∂rster, G√ľnter
Title: Development of an Electrodynamic Quadrupole Aerosol Concentrator
Investigators: Ensor, David
Institution: Research Triangle Institute
EPA Project Officer: Chung, Serena
Project Period: June 1, 1999 through May 31, 2004 (Extended to May 31, 2006)
RFA: Airborne Particulate Matter (PM) Centers (1999) RFA Text |  Recipients Lists
Research Category: Air Quality and Air Toxics , Particulate Matter , Air


The objective of this project is to develop a new approach for concentrating ultrafine particles for animal inhalation studies. The electrodynamic aerosol concentrator invented by Periasamy, Ensor, and Donovan (1995) uses an ac field quadrupole to deflect the particles to the center of a flowing gas stream between the electrodes. Experiments conducted earlier with monodisperse 14 µm oleic acid aerosols tagged with uranine dye and electrodynamic quadrupole demonstrated significant focusing. Two key questions are addressed in this research: (1) Can the performance be extended to sub 0.1 µm particles? (2) Can the device be scaled up to provide sufficient flow for laboratory studies?


Three activities will be conducted for this study: additional literature review, theoretical analysis, and initial laboratory experiments.

Three relevant but obscure papers from the Japanese literature have been retrieved (Aoyama and Masuda, 1970; Masuda and Fujibayashi, 1970; Masuda, et al., 1972). The Japanese researchers used approximations to analyze the problem and performed experiments with millimeter size particles to verify the theory.

A subcontract to perform theoretical analysis was issued to the University of Minnesota to support a postdoctoral student. The theoretical analysis was completed, and a computer program and final report was submitted to Research Triangle Institute (Park, et al., 2000). The initial theoretical analysis indicates that focusing and concentrating on particles smaller than 0.1 Fm at atmospheric pressure may be difficult. However, availability of the computer program will allow evaluation of various quadrupole configurations and to identify unstable operating conditions. Also, Dr. Park performed some limited tests with submicron particles under low-pressure, which has provided some insights with respect to electrode design.

A series of experiments will be conducted to repeat the earlier Research Triangle Institute (RTI) experiments with the original apparatus. A series of monodisperse oleic acid aerosols tagged with uranine dye from 15 down to 1 Fm is currently being conducted using the dye image formed during a experimental run on a filter placed after the quadrupole section. The focusing rate will be quantified with fluorometric analysis from concentric rings of the filter. (The focusing rate is a measure of the fraction of particle migrating to the center point.) These data will allow validation of the computer program that will be used to support design of a second-generation electrode system.

Expected Results:

The research expectation for this study is to develop a new approach for concentrating ultrafine particles to further research in the field of animal inhalation studies.

Supplemental Keywords:

pollution prevention, atmosphere, particulates, metals, sensitive population., RFA, Health, Scientific Discipline, Air, particulate matter, Virology, Environmental Chemistry, Health Risk Assessment, Epidemiology, Risk Assessments, Biochemistry, Atmospheric Sciences, ambient air quality, particle size, particulates, sensitive populations, cardiopulmonary responses, chemical characteristics, fine particles, human health effects, ambient air monitoring, electrodynamic quadrupole aerosol concentrator, pulmonary disease, susceptible populations, epidemelogy, particle exposure, environmental health effects, human exposure, chemical kinetics, particulate exposure, mortality, urban environment, aerosols, chemical speciation sampling

Progress and Final Reports:

  • 1999 Progress Report
  • 2000 Progress Report
  • 2001
  • 2002
  • 2003
  • 2004
  • Final

  • Main Center Abstract and Reports:

    R827354    Airborne PM - Rochester PM Center

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R827354C001 Characterization of the Chemical Composition of Atmospheric Ultrafine Particles
    R827354C002 Inflammatory Responses and Cardiovascular Risk Factors in Susceptible Populations
    R827354C003 Clinical Studies of Ultrafine Particle Exposure in Susceptible Human Subjects
    R827354C004 Animal Models: Dosimetry, and Pulmonary and Cardiovascular Events
    R827354C005 Ultrafine Particle Cell Interactions: Molecular Mechanisms Leading to Altered Gene Expression
    R827354C006 Development of an Electrodynamic Quadrupole Aerosol Concentrator
    R827354C007 Kinetics of Clearance and Relocation of Insoluble Ultrafine Iridium Particles From the Rat Lung Epithelium to Extrapulmonary Organs and Tissues (Pilot Project)
    R827354C008 Ultrafine Oil Aerosol Generation for Inhalation Studies