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Characterizing Metal-Based Nanoparticles in Surface Water by Single-Particle ICPMS
Citation:
HEITHMAR, E. M. Characterizing Metal-Based Nanoparticles in Surface Water by Single-Particle ICPMS. Presented at American Chemical Society National Meeting, Salt Lake City, UT, March 22 - 26, 2009.
Impact/Purpose:
Presentation
Description:
Engineered metal-based nanomaterials are being used in increasing quantities in consumer and industrial products. These materials may be introduced into surface waters by a variety of paths depending on usage, and will be superimposed on concentrations of other particles containing these metals. Monitoring trends in the concentration, size distribution, and metal content of nanoparticles in surface water over time can indicate potential exposure of ecosystems to engineered nanomaterials. These measurements have been made with hyphenated instrumental techniques such as flow-field flow fractionation coupled with ICPMS. Alternatively, metal concentrations of operationally defined size fractions have been estimated by filtration and ultrafiltration followed by elemental determination. ICPMS in the single particle (SP) mode measures the intensity and frequency of signal pulses resulting from ion plumes of a metal from individual nanoparticles in the ICP. SP-ICPMS can provide the number density of particles, as well as the mass of the measured metal in the particles. It can therefore estimate the size of particles, if composition is assumed; or it can provide information on possible compositions if particle size is known. SP-ICPMS of several monodisperse suspensions of metal-based nanoparticles is evaluated to elucidate the factors that influence the sensitivity, accuracy, and precision. SP-ICPMS of several metals in native and nanoparticle-amended surface water is presented.