Engineered metallic nanoparticles may enter aquatic environments through industrial process wastes or disposal of consumer products, and both the individual nanoparticles and heavy metals released upon dissolution may be toxic to aquatic organisms. In order to detect and quantify metals across both phases, analytical chemical techniques must first separate the nanoparticulate and dissolved forms, but conventional filtration means can be difficult or time-consuming for sizes 10 nm or less. This study examines a more rapid quantification method for the measurement of <10 nm nanoparticles and 5 nm quantum dots using size-exclusion chromatography with inductively coupled plasma � mass spectrometry (SEC-ICP-MS). Separation of nanoparticulate and dissolved forms was achieved within ten minutes only when using a 125-angstrom pore size SEC column with an eluent containing a surfactant to ensure nanoparticle dispersion and a complexing ligand (ethylenediaminetetraacetate) to prevent metal cation sorption to the column. Simultaneous detection of multiple metals is possible with ICP-MS, and detection limits were typically 1-10 ppb. Analytical operating conditions and performance evaluation will be presented for silver, gold, transition metal, and mixed-metal nanoparticles. The size limitations of an alternative method, single-particle ICP-MS, will be highlighted. The SEC method is expected to expedite nanoparticulate and quantum dot analysis in waste streams, natural waters, or laboratory experiments.

Separation of dissolved and nanoparticulate metals with SEC-ICP-MS

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.