Sampling nanoparticles for chemical analysis by low resolution electrical mobility classification.
The use of electrostatic classification to collect samples of aerosol nanoparticles for chemical analysis is discussed. Our technique exposes the aerosol to negative ions in a unipolar charger with subsequent mobility classification at low resolution and high sampling rate. The negative unipolar charger produces high charged fractions. The low-resolution mobility classifier enables the delivery of high mass concentrations in a well-defined mobility range. The mobility-classified particles are collected by electrostatic precipitation. We summarize experimental and computational work on the performance of the unipolar charger, and we describe the performance of the overall system when used to sample atmospheric particles. For a size distribution measured in Atlanta during a new particle formation event, calculated mass sampling rates of approximately 8 nm particles were about 150 pg/h.
McMurry
Peter H
PH
Department of Mechanical Engineering, University of Minnesota, 111 Church St. SE, Minneapolis, Minnesota 55455, USA. mcmurry@me.umn.edu
Ghimire
Ajaya
A
Ahn
Hyo-Kueh
HK
Sakurai
Hiromu
H
Moore
Katharine
K
Stolzenburg
Mark
M
Smith
James N
JN
D000336:Aerosols; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis*; D000465:Algorithms; D004784:Environmental Monitoring / Q000379:methods*; D007700:Kinetics; D015233:Models, Statistical; D053758:Nanoparticles / Q000032:analysis* / Q000737:chemistry*; D010316:Particle Size; D012984:Software; D055672:Static Electricity
D000336:Aerosols; D000393:Air Pollutants