AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Aerosol Elemental Analysis Using Atmospheric Glow Discharge Spectroscopy
LINA ZHENG, Pramod Kulkarni, Centers for Disease Control and Prevention, NIOSH
Abstract Number: 557 Working Group: Instrumentation and Methods
Abstract A new low-cost method has been developed for semi-continuous elemental analysis of aerosols using radio frequency glow discharge optical emission spectroscopy. The method involves microconcentration of aerosols on an electrode tip, followed by atomization and excitation of the particulate matter using atmospheric glow discharge initiated in the inter-electrode gap in an argon bath. The resulting atomic emissions are recorded using a spectrometer for elemental identification and quantification. The glow discharge plasma was characterized by measuring spatially resolved gas temperature (500 – 1500 K) and electron density (2 – 5 × 10$^(14) cm$^(-3) ). Spatial analysis of the spectral feature shows that the collision and excitation of the collected particles occurs in the region near the collection electrode. The signal intensity from the analyte decreases with time during the glow discharge. Sucrose particulate mass of 193 ng could be ablated in approximately 2 s using the continuous glow discharge. The system was calibrated using 100 nm particles containing C, Cd, Mn, and Na. The method provides limits of detection in the range of 0.055 – 1.0 ng in terms of absolute elemental mass, and a measurement reproducibility of 5 – 28%. The study demonstrates that the atmospheric glow discharge can be an excellent low-cost excitation source for development of portable aerosol elemental spectrometers.