The perchlorate anion (ClO4-) is an anthropogenic contaminant of increasing concern in water supplies, and has been shown to disrupt thyroid activity. Most perchlorate analyses are currently carried out by ion chromatography (IC) with suppressed conductivity detection (SCD). While this procedure has been demonstrated to provide acceptable performance for analysis of water samples, the determina...

Perchlorate ion (ClO4-) has been identified in samples of dormant salt cedar (Tamarix ramosissima) growing in the Las Vegas Wash. Perchlorate is an oxidant, but its reduction is kinetically hindered. Concern over thyroid effects caused the Environmental Protection Agency (EPA) to add perchlorate to the drinking water Contaminant Candidate List (CCL). Beginning in 2001, utilities will look for p...

BACKGROUND Environmental exposure of infants to perchlorate, thiocyanate, nitrate, might interfere with thyroid function. U.S. women with higher background perchlorate exposure have higher thyroid-stimulating hormone (TSH) and lower thyroxine (T4). There are no studies with individual measures of thyroid function and these goitrogens available in infants. OBJECTIVE We examined the association...

Perchlorate is known to be a minor component of the hyperarid Atacama Desert salts, and its origin has long been a subject of speculation. Here we report the first measurement of the triple-oxygen isotope ratios (18O/16O and 17O/16O) for both man-made perchlorate from commercial sources and natural perchlorate extracted from Atacama soils. We found that the delta 18O values (i.e., normalized 18...

Natural perchlorate is believed to be of atmospheric origin, yet no systematic study has been conducted to evaluate perchlorate deposition rate and possible seasonal or spatial variations. This study evaluated perchlorate concentrations in weekly composite wet deposition samples acquired through the National Atmospheric Deposition Program from 26 sites across the continental United States, Alas...

BACKGROUND Considering the controversial information regarding the effects of perchlorate on thyroid function of high risk population as neonates, and given the high prevalence rate of thyroid disorders specially congenital hypothyroidism in our region, this study aims to investigate for the first time in Iran, the relationship between drinking groundwater perchlorate and cord blood thyroid hor...

The present study was designed to evaluate the effects of reduced sulfur species on the adsorption of perchlorate on tailored granular activated carbon (TGAC); initial experiments focused on thiosulfate. Previous studies using Rapid Small Scale Column tests (RSSCT) showed that perchlorate broke through at 30,000-35,000 bed volumes (BV) when quaternary ammonium surfactants were preloaded onto ac...

Improper treatment and disposal of perchlorate can be an environmental hazard in regions where solid rocket motors are used, tested, or stored. The solubility and mobility of perchlorate lends itself to ground water contamination, and some of these sources are used for drinking water. Perchlorate in drinking water has been determined at sub-mug l(-1) levels by extraction of the ion-pair formed ...

Perchlorate, the oxidizer component in most solid rocket propellant formulations, is known to inhibit the uptake of iodide into the thyroid gland, thereby reducing production of the thyroid hormones, triiodothyronine and thyroxine (T4). Thyroid hormones regulate metabolism in endothermic organisms and are responsible for maintenance of homeothermic body temperatures. Little is known about the e...

A synthesized bis(dibenzoylmethanato)Co(II) complex (Co(DBM)(2)), has been used as a ionophore for the preparation of a new perchlorate ion-selective electrode. The electrode exhibits a Nernstian response over the perchlorate concentration range of 8.0x10(-7)-1.0x10(-1)M with a slope of 60.3+/-0.5 mV per decade of concentration. The limit of detection as determined from the intersection of the ...