AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
A Liquid Nebulization / Differential Mobility Analysis / Transmission Electron Microscopy Approach to Evaluate Nanoparticles in Environmentally-Relevant Water Matrices
BRIAN MADER, Mark Ellefson, Sue Wolf, 3M Company
Abstract Number: 116 Working Group: Instrumentation and Methods
Abstract A liquid nebulization-differential mobility analysis method (LN/DMA) was used in conjunction with Scanning Transmission Electron Microscopy (STEM) and Energy Dispersive Spectroscopy (EDS) for the evaluation of engineered nanoparticles (ENPs) in environmentally relevant aqueous matrices. The LN/DMA method was used to measure the size distribution and quantitative number concentration of ENPs in aqueous solutions; however the method alone cannot be used to directly determine the morphology and chemical composition of the ENPs. The LNS/DMA system was used in conjunction with the TSI 3089 Nanometer Aerosol Sampler; ENPs were aerosolized from aqueous media and deposited onto TEM grids for further evaluation of their morphology, size, and chemical composition using spectroscopic analysis techniques (TEM, STEM, EDS). To further evaluate the method, NIST-traceable reference materials were spiked into several aqueous matrices; aqueous media used in ecotoxicology testing, semiconductor grade ultra pure water, groundwater, and an industrial wastewater. For samples with significant signal to noise, the measured mean particle diameters of the reference materials were within the expected NIST-traceable size range for the materials. The method was also able to discern ENPs from other materials and non-volatile residues present in the native aqueous solutions. The optimum sampling parameters for the collection of ENPs onto TEM media by this method will also be discussed. Overall this method is particularly well suited for dose verification in ecotoxicology studies as well to support the studies of ENP behavior in aqueous matrices.