During the past 20 years, improvements in nanoscale materials synthesis and characterization have given scientists great control over the fabrication of materials with features between 1 and 100 nm, unlocking many unique size-dependent properties and, thus, promising many new and/or improved technologies. Recent years have found the integration of such materials into commercial goods; a current estimate suggests there are over 800 nanoparticle-containing consumer products (The Project on Emerging Nanotechnologies Consumer Products Inventory, , accessed Oct. 2008), accounting for 147 billion USD in products in 2007 (Nanomaterials state of the market Q3 2008: stealth success, broad impact, Lux Research Inc., New York, NY, 2008). Despite this increase in the prevalence of engineered nanomaterials, there is little known about their potential impacts on environmental health and safety. The field of nanotoxicology has formed in response to this lack of information and resulted in a flurry of research studies. Nanotoxicology relies on many analytical methods for the characterization of nanomaterials as well as their impacts on in vitro and in vivo function. This review provides a critical overview of these techniques from the perspective of an analytical chemist, and is intended to be used as a reference for scientists interested in conducting nanotoxicological research as well as those interested in nanotoxicological assay development.

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Limona ketone was synthesized to explore the secondary organic aerosol (SOA) formation mechanism from limonene ozonolysis and also to test group-additivity concepts describing the volatility distribution of ozonolysis products from similar precursors. Limona ketone SOA production is indistinguishable from alpha-pinene, confirming the expected similarity. However, limona ketone SOA production is significantly less intense than limonene SOA production. The very low vapor pressure of limonene ozonolysis products is consistent with full oxidation of both double bonds in limonene and furthermore with production of products other than ketones after oxidation of the exo double bond in limonene. Mass-balance constraints confirm that ketone products from exo double-bond ozonolysis have a minimal contribution to the ultimate product yield. These results serve as the foundation for an emerging framework to describe the effect on volatility of successive generations of organic compounds in the atmosphere.

A mast cell/fibroblast co-culture system is used as a model to assess the toxicity of Au nanoparticles over the course of 72 hours of exposure. Cellular uptake of nanoparticles was found to increase over the 72 hr exposure period and the nanoparticles localized within granular bodies of the primary culture mast cells. These granules were found to increase in volume with the addition of nanoparticles. There was no decrease in viability for 24 hr exposed cells but a slight viability decrease was found after 48 and 72 hr exposure. Carbon-fiber amperometry analysis of exocytosis of serotonin from mast cells revealed changing release profiles over the time course of exposure. In early exposure times, granular secretion of serotonin increased with exposure to Au nanoparticles whereas 72 hr exposure showed decreased secretion of serotonin with nanoparticle exposure. The kinetics of this release was also found to be affected by Au colloid exposure where the rate of serotonin expulsion decreased with increasing nanoparticle exposure. These results illustrate the dynamic nature of nanoparticle-cell interactions and the critical changes in cell behavior even when viability is unaffected.