Grantee Research Project Results
1999 Progress Report: Development of an Electrodynamic Quadrupole Aerosol Concentrator
EPA Grant Number: R827354C006Subproject: 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: Oberdörster, Günter
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)
Project Period Covered by this Report: June 1, 1999 through May 31, 2000
RFA: Airborne Particulate Matter (PM) Centers (1999) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Particulate Matter , Air
Objective:
The objective of this pilot 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 ?m 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 ?m particles? (2) Can the device be scaled up to provide sufficient flow for laboratory studies?
Progress Summary:
Three activities have been under way during the first year: 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. Other than our own data, the transport of particles in the micrometer size range in quadrupoles is not in the literature.
A subcontract to perform theoretical analysis was issued to the University of Minnesota to support a postdoctoral student. Partial support was provided to Dr. Seok Joo Park, a recent Ph.D. graduate from the Korea Institute of Science and Technology (KAIST) who had his major support from KOSEF. The theoretical analysis was completed, and a computer program and final report was recently submitted to Research Triangle Institute (Park, et al., 2000). The initial theoretical analysis indicates that focusing and concentrating on particles smaller than 0.1 m 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 are underway 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 µm 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.
References:
Periasamy R, Ensor DS, Donovan RP. Device for focusing particles suspended in a gas stream. 1995. U.S. Patent 5,439,513.
Aoyama M, Masuda S. Electrical Engineering in Japan 1970;90:10-20.
Masuda S, Fujibayashi K. Proceedings of the 1st International Conference on Static Electricity, Vienna, Austria, 1970;1:384-397.
Masuda S, Fujibayashi K, Ishida K, Ogawa T. Transactions of the Institute of Electrical Engineers of Japan (IEEJ), 1972.
Park SJ, McMurry PH, Ensor DS. Electrodynamic focusing of charged fine particle using alternating 2-dimensional quadrupole electric field. March 27, 2000.
Future Activities:
We will continue the series of experiments that are underway. We will quantify the focusing rate with fluorometric analysis, and we will validate the computer program. We then will use the program to support design of a second generation electrode system. The computer program also will be compared to the approximate results reported by the Japanese.
Supplemental Keywords:
pollution prevention, atmosphere, particulates, metals, sensitive population., RFA, Health, Scientific Discipline, Air, particulate matter, Environmental Chemistry, Health Risk Assessment, Virology, Epidemiology, Risk Assessments, Biochemistry, Atmospheric Sciences, ambient air quality, particle size, particulates, sensitive populations, cardiopulmonary responses, fine particles, electrodynamic quadrupole aerosol concentrator, human health effects, ambient air monitoring, chemical characteristics, pulmonary disease, susceptible populations, epidemelogy, environmental health effects, particle exposure, human exposure, particulate exposure, chemical kinetics, mortality, urban environment, aerosols, ultrafine particlesRelevant Websites:
http://www2.envmed.rochester.edu/envmed/pmc/indexpmc.html Exit
Progress and Final Reports:
Original AbstractMain 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
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.