Perchlorate has been observed in many environments on Earth and Mars but its sources remain poorly quantified. In this study, we use a global three-dimensional chemical transport model to simulate perchlorate's gas-phase photochemical production, atmospheric transport, deposition Earth's surface. Model predictions are compared newly compiled observations of concentrations, flux, oxygen isotopic...

I have reviewed the draft document dated January 11, 2011 as well as the online posted comments of external interested parties. I am an environmental epidemiologist with a primary research area outside of perchlorate and related health effects, but have done some work with perchlorate. I am pleased to have been given the opportunity to review this document and to offer some technical suggestion...

A method for the determination of perchlorate anion at sub ppb levels using ion chromatography/mass spectrometry (IC/MS) is described. The IC/MS method follows EPA Method 314 methodology originally developed for IC with conductivity detection at the single ppb range [1]. The IC/MS method is not affected by the addition of the interference matrix described in Method 314 on perchlorate recoveries...

Perchlorate (ClO(4)(-)) is a persistent contaminant found in drinking groundwater sources in the United States. Ion exchange (IX) with selective and disposable resins based on cross-linked styrene divinylbenzene (STY-DVB) beads is currently the most commonly utilized process for removing low concentrations of ClO(4)(-) (10-100 ppb) from contaminated drinking water sources. However, due to the l...

The title compounds, strontium perchlorate trihydrate {di-μ-aqua-aquadi-μ-perchlorato-strontium, [Sr(ClO4)2(H2O)3] n }, strontium perchlorate tetra-hydrate {di-μ-aqua-bis-(tri-aqua-diperchloratostrontium), [Sr2(ClO4)4(H2O)8]} and strontium perchlorate nona-hydrate {hepta-aqua-diperchloratostrontium dihydrate, [Sr(ClO4)2(H2O)7]·2H2O}, were crystallized at low temperatures according to the solid-...

Human exposure to perchlorate is commonplace because it is a contaminant of drinking water, certain foods, and breast milk. The U.S. Environmental Protection Agency (EPA) conducted a perchlorate risk assessment in 2002 that yielded a reference dose (RfD) based on both the animal and human toxicology data. This assessment has been superceded by a recent National Academy of Science (NAS) review t...

The objectives of this study were to determine the effects of prolonged exposure to perchlorate on (1) thyroid status and reproductive performance of adult zebrafish (Danio rerio) and (2) F1 embryo survival and early larval development. Using a static-renewal procedure, mixed sex populations of adult zebrafish were exposed to 0, 10, and 100 mg/l nominal concentrations of waterborne perchlorate ...

Poly(3-dodecyl-2,2’-bithiophene)(PDBT), Poly(3-dodecylthiophene)(PDT), and poly(3,4-dibutoxythiophene)(PDBOT) were chemically prepared and doped with copper(II) perchlorate. The conductivity, stability and spectral change of the doped polymers during storage in air were compared. The results suggest that copper(II) perchlorate is an effective oxidant. keywords: Coupling reactions, UV-Vis-NIR ab...