AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Development Of An Online Measurement For Soluble And Total Cu In PM2.5
DONGBIN WANG, Martin Shafer, James Schauer, Constantinos Sioutas, University of Southern California
Abstract Number: 52 Working Group: Instrumentation and Methods
Abstract A novel monitor for online, in-situ measurement of copper (Cu) in ambient fine and ultrafine particulate matter (PM) was developed based on a recent published high flow rate Aerosol-Into-Liquid Collector. This Aerosol-Into-Liquid Collector operates at 200 liters per minute (L/min) flow and collects particles directly as highly concentrated slurry sample. The Cu concentration in slurry samples is subsequently determined by a cupric Ion Selective Electrode (ISE). Laboratory tests were conducted to evaluate the performance of the cupric ISE. The calibration curve of the cupric ISE was determined using Cu(NO3)2 standard solutions prepared by serial dilution. As part of the evaluation, the effect of ionic strength, temperature and pH of the aerosol slurry sample on the cupric ISE measurement was also evaluated. The Cu measurement system performance was evaluated by collecting and measuring samples of lab generating Cu(NO3)2 aerosols with known mass concentration. Overall, very good agreement between the theoretical and measured Cu concentrations was obtained, indicating the excellent overall collection efficiency and measurement accuracy of the Cu measurement system. Field evaluations of the cupric ISE measurements demonstrated very good agreement for total and water-soluble Cu concentrations with on-line measurements by inductively coupled plasma mass spectrometry (ICPMS) and demonstrated no interferences from other components of particulate matter in real world sampling. Moreover, the field tests indicated that the new Cu measurement system could achieve near-continuous (i.e. 3-4 hours) and unattended collection and measurements for at least 4 to 7 days without any obvious shortcomings in its operation. Both laboratory and field evaluations of the online Cu measurement system suggest that it is an effective and valuable technology for collection and characterization of ambient aerosols and provides the foundation for the wider use of ISE for metal analysis and speciation of aerosols.