MICROSCALE EXTRACTION OF PERCHLORATE IN DRINKING WATER WITH LOW LEVEL DETECTION BY ELECTROSPRAY-MASS SPECTROMETRY.

EPA Science Inventory

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 ...

Determination of active oxygen in the presence of barium and lead

USGS Publications Warehouse

Fleischer, M.

1943-01-01

The method of Mrgudich and Clark is modified by substituting 5 per cent (by volume) perchloric acid for 50 per cent perchloric acid. Titration by potassium permanganate may be substituted for electrometric titration with ceric sulfate.

Factors Affecting the Extraction of Intact Ribonucleic Acid from Plant Tissues Containing Interfering Phenolic Compounds

PubMed Central

Newbury, H. John; Possingham, John V.

1977-01-01

Using conventional methods it is impossible to extract RNA as uncomplexed intact molecules from the leaves of grapevines (Vitis vinifera L.) and from a number of woody perennial species that contain high levels of reactive phenolic compounds. A procedure involving the use of high concentrations of the chaotropic agent sodium perchlorate prevents the binding of phenolic compounds to RNA during extraction. Analyses of the phenolics present in plant tissues used in these experiments indicate that there is a poor correlation between the total phenolic content and the complexing of RNA. However, qualitative analyses suggest that proanthocyanidins are involved in the tanning of RNA during conventional extractions. PMID:16660134

Supercritical Carbon Dioxide Extraction of Coronene in the Presence of Perchlorate for In Situ Chemical Analysis of Martian Regolith.

PubMed

McCaig, Heather C; Stockton, Amanda; Crilly, Candice; Chung, Shirley; Kanik, Isik; Lin, Ying; Zhong, Fang

2016-09-01

The analysis of the organic compounds present in the martian regolith is essential for understanding the history and habitability of Mars, as well as studying the signs of possible extant or extinct life. To date, pyrolysis, the only technique that has been used to extract organic compounds from the martian regolith, has not enabled the detection of unaltered native martian organics. The elevated temperatures required for pyrolysis extraction can cause native martian organics to react with perchlorate salts in the regolith and possibly result in the chlorohydrocarbons that have been detected by in situ instruments. Supercritical carbon dioxide (SCCO2) extraction is an alternative to pyrolysis that may be capable of delivering unaltered native organic species to an in situ detector. In this study, we report the SCCO2 extraction of unaltered coronene, a representative polycyclic aromatic hydrocarbon (PAH), from martian regolith simulants, in the presence of 3 parts per thousand (ppth) sodium perchlorate. PAHs are a class of nonpolar molecules of astrobiological interest and are delivered to the martian surface by meteoritic infall. We also determined that the extraction efficiency of coronene was unaffected by the presence of perchlorate on the regolith simulant, and that no sodium perchlorate was extracted by SCCO2. This indicates that SCCO2 extraction can provide de-salted samples that could be directly delivered to a variety of in situ detectors. SCCO2 was also used to extract trace native fluorescent organic compounds from the martian regolith simulant JSC Mars-1, providing further evidence that SCCO2 extraction may provide an alternative to pyrolysis to enable the delivery of unaltered native organic compounds to an in situ detector on a future Mars rover. Biomarkers-Carbon dioxide-In situ measurement-Mars-Search for Mars' organics. Astrobiology 16, 703-714.

Hexaacetato calix(6)arene as the novel extractant for palladium.

PubMed

Mathew, V J; Khopkar, S M

1997-10-01

A novel method is proposed for the solvent extraction of palladium. A superamolecular compound, hexaacetato calix(6)arene in low concentration in toluene quantitatively extracts microgram concentration of palladium at pH 7.5. It can be stripped from the organic phase with 2 M nitric acid and determined spectrophotometrically as its stannous chloride complex at 635 nm. The probable composition of the extracted species is Pd(HR)(2)Cl. As low as 1x10(-3) M of extractant is adequate for quantitative extraction. Toluene was the best diluent. With nitric and perchloric acid (1.5-3 M) the stripping was complete. Palladium was separated in large ratios from alkali and alkaline earths (1:50). The main group elements were tolerated in higher ratios (1:25), but ions like zinc, cadmium, iron, nickel, platinium, thorium, vanadium and molydenum were tolerated at low concentrations (1:1). The ions showing strong interference were copper, chromium. The relative standard deviation is +/-1.1%.

Extraction of glycogen on mild condition lacks AIG fraction.

PubMed

Ghafouri, Z; Rasouli, M

2016-12-01

Extraction of animal tissues with cold water or perchloric acid yields less glycogen than is obtained with hot-alkaline. Extraction with acid and alkaline gives two fractions, acid soluble (ASG) and insoluble glycogen (AIG). The aim of this work is to examine the hypothesis that not all liver glycogen is extractable by Tris-buffer using current techniques. Rat liver was homogenized with Tris-buffer pH 8.3 and extracted for the glycogen fractions, ASG and AIG. The degree of homogenization was changed to remove all glycogen. The content of glycogen was 47.7 ± 1.2 and 11.6 ± 0.8 mg/g wet liver in the supernatant and pellet of the first extraction respectively. About 24% of total glycogen is lost through the first pellet. Increasing the extent of homogenization from 30 to 180 sec and from 15000 to 20000 rpm followed with 30 sec ultrasonication did not improve the extraction. ASG and AIG constitute about 77% and 23% of the pellet glycogen respectively. Extraction with cold Tris-buffer failed to extract glycogen completely.  Increasing the extent of homogenization followed with ultrasonication also did not improve the extraction. Thus it is necessary to re-examine the previous findings obtained by extraction with cold Tris-buffer.

Kinetics of nonoxidative leaching of galena in perchloric, hydrobromic, and hydrochloric acid solutions

NASA Astrophysics Data System (ADS)

Núñez, C.; Espiell, F.; García-Zayas, J.

1988-08-01

Several kinetic studies are presented on the nonoxidative leaching of galena with solutions of hydrocloric, hydrobromic, and perchloric acid. The kinetic parameters were set up in terms of the mean ionic activities of the electrolytes. The apparent order of reaction for the mean ionic activity of perchloric acid is one. For hydrochloric acid the order of reaction over a wide range of concentrations is 3/2 with respect to its mean activity. For hydrobromic acid, whose anion has greater complex-forming power for lead than HC1, the order of reaction is 2. Activation energies are 64.4 kJ/mole for HC1, 71.5 kJ/mole for HC104, and 66.5 kJ mole for HBr. The complete kinetic equations are given for the three reactions.

Determination of low levels of perchlorate in lettuce and spinach using ion chromatography-electrospray ionization mass spectrometry (IC-ESI-MS).

PubMed

Seyfferth, Angelia L; Parker, David R

2006-03-22

A sample preparation method was developed to quantify environmentally relevant (low micrograms per liter) concentrations of perchlorate (ClO4(-)) in leafy vegetables using IC-ESI-MS. Lettuce and spinach were macerated, centrifuged, and filtered, and the aqueous extracts were rendered water-clear using a one-step solid-phase extraction method. Total time for extraction and sample preparation was 6 h. Ion suppression was demonstrated and was likely due to unknown organics still present in the extract solution after cleanup. However, this interference was readily eliminated using a Cl(18)O4(-) internal standard at 1 microg/L in all standards and samples. Hydroponically grown perchlorate-free butterhead lettuce was spiked to either 10.3 or 37.7 microg/kg of fresh weight (FW), and recoveries were between 91 and 98% and between 93 and 101%, respectively. Five types of lettuce and spinach from a local grocery store were then analyzed; they contained from 0.6 to 6.4 microg/kg of FW. Spike recoveries using the store-bought samples ranged from 89 to 100%. The method detection limit for perchlorate in plant extracts is 40 ng/L, and the corresponding minimum reporting limit is 200 ng/L or 0.8 microg/kg of FW.

Chlorine isotopic composition of perchlorate in human urine as a means of distinguishing among exposure sources.

PubMed

Poghosyan, Armen; Morel-Espinosa, Maria; Valentin-Blasini, Liza; Blount, Benjamin C; Ferreccio, Catterina; Steinmaus, Craig M; Sturchio, Neil C

2016-01-01

Perchlorate (ClO4(-)) is a ubiquitous environmental contaminant with high human exposure potential. Natural perchlorate forms in the atmosphere from where it deposits onto the surface of Earth, whereas synthetic perchlorate is manufactured as an oxidant for industrial, aerospace, and military applications. Perchlorate exposure can potentially cause adverse health effects in humans by interfering with the production of thyroid hormones through competitively blocking iodide uptake. To control and reduce perchlorate exposure, the contributions of different sources of perchlorate exposure need to be quantified. Thus, we demonstrate a novel approach for determining the contribution of different perchlorate exposure sources by quantifying stable and radioactive chlorine isotopes of perchlorate extracted from composite urine samples from two distinct populations: one in Atlanta, USA and one in Taltal, Chile (Atacama region). Urinary perchlorate from the Atlanta region resembles indigenous natural perchlorate from the western USA (δ(37)Cl=+4.1±1.0‰; (36)Cl/Cl=1 811 (±136) × 10(-15)), and urinary perchlorate from the Taltal, Chile region is similar to natural perchlorate in nitrate salt deposits from the Atacama Desert of northern Chile (δ(37)Cl=-11.0±1.0‰; (36)Cl/Cl=254 (±40) × 10(-15)). Neither urinary perchlorate resembled the isotopic pattern found in synthetic perchlorate. These results indicate that natural perchlorate of regional provenance is the dominant exposure source for the two sample populations, and that chlorine isotope ratios provide a robust tool for elucidating perchlorate exposure pathways.

Development of Systems for Delivery of Antiviral Drugs.

DTIC Science & Technology

1986-10-31

in an ice bath under a nitrogen atmosphere. Sodium dithionite (820 mg of Aldrich 85% technical grade; 4.0 mmol) was added; after 1 min a precipitate ...extracted with cold 0.5N perchloric acid (PCA) and the precipitated proteins were removed by centrifugation. The pH of the supernatnant was adjusted...four volumes of acetonitrile. The precipitated proteins were removed by centrifugation and the clear supernatant was evaporated to dryness under N2

Tissue Engineered Testicular Prostheses With Prolonged Testosterone Release

DTIC Science & Technology

2008-12-01

inguinal lymph nodes from a leaking testicular prosthesis: a cause for chronic fatigue? BJU Int., 86, 1090. Ebert, T ., F. Jockenhovel, A. Morales, and R ...NaOH, hydroxyproline oxidation was initiated by adding 1 ml chloramine- T to the extract. After gentle mixing and incubation for 20 minutes, the...chloramine- T was destroyed by addition of 1 ml perchloric acid to each tube. Finally, 1 ml p- dimethylamino-benzaldehyde solution was added and

Crystal structure of tin(II) perchlorate trihydrate

PubMed Central

Hennings, Erik; Schmidt, Horst; Köhler, Martin; Voigt, Wolfgang

2014-01-01

The title compound, [Sn(H2O)3](ClO4)2, was synthesized by the redox reaction of copper(II) perchlorate hexa­hydrate and metallic tin in perchloric acid. Both the trigonal–pyramidal [Sn(H2O)3]2+ cations and tetra­hedral perchlorate anions lie on crystallographic threefold axes. In the crystal, the cations are linked to the anions by O—H⋯O hydrogen bonds, generating (001) sheets. PMID:25552969

Atmospheric origins of perchlorate on Mars and in the Atacama

NASA Astrophysics Data System (ADS)

Catling, D. C.; Claire, M. W.; Zahnle, K. J.; Quinn, R. C.; Clark, B. C.; Hecht, M. H.; Kounaves, S.

2010-01-01

Isotopic studies indicate that natural perchlorate is produced on Earth in arid environments by the oxidation of chlorine species through pathways involving ozone or its photochemical products. With this analogy, we propose that the arid environment on Mars may have given rise to perchlorate through the action of atmospheric oxidants. A variety of hypothetical pathways can be proposed including photochemical reactions, electrostatic discharge, and gas-solid reactions. Because perchlorate-rich deposits in the Atacama desert are closest in abundance to perchlorate measured at NASA's Phoenix Lander site, we made a preliminary study of the means to produce Atacama perchlorate to help shed light on the origin of Martian perchlorate. We investigated gas phase pathways using a 1-D photochemical model. We found that perchlorate can be produced in sufficient quantities to explain the abundance of perchlorate in the Atacama from a proposed gas phase oxidation of chlorine volatiles to perchloric acid. The feasibility of gas phase production for the Atacama provides justification for future investigations of gas phase photochemistry as a possible source for Martian perchlorate.

Catalytic destruction of perchlorate in ferric chloride and hydrochloric acid solution with control of temperature, pressure and chemical reagents

DOEpatents

Gu, Baohua; Cole, David R.; Brown, Gilbert M.

2004-10-05

A method is described to decompose perchlorate in a FeCl.sub.3 /HCl aqueous solution such as would be used to regenerate an anion exchange resin used to remove perchlorate. The solution is mixed with a reducing agent, preferably an organic alcohol and/or ferrous chloride, and can be heated to accelerate the decomposition of perchlorate. Lower temperatures may be employed if a catalyst is added.

Determination of sub-microgram amounts of selenium in geological materials by atomic-absorption spectrophotometry with electrothermal atomisation after solvent extraction

USGS Publications Warehouse

Sanzolone, R.F.; Chao, T.T.

1981-01-01

An atomic-absorption spectrophotometric method with electrothermal atomisation has been developed for the determination of selenium in geological materials. The sample is decomposed with a mixture of nitric, perchloric and hydrofluoric acids and heated with hydrochloric acid to reduce selenium to selenium (IV). Selenium is then extracted into toluene from a hydrochloric acid - hydrobromic acid medium containing iron. A few microlitres of the toluene extract are injected into a carbon rod atomiser, using a nickel solution as a matrix modifier. The limits of determination are 0.2-200 p.p.m. of selenium in a geological sample. For concentrations between 0.05 and 0.2 p.p.m., back-extraction of the selenium into dilute hydrochloric acid is employed before atomisation. Selenium values for reference samples obtained by replicate analysis are in general agreement with those reported by other workers, with relative standard deviations ranging from 4.1 to 8.8%. Recoveries of selenium spiked at two levels were 98-108%. Major and trace elements commonly encountered in geological materials do not interfere. Arsenic has a suppressing effect on the selenium signals, but only when its concentration is greater than 1000 p.p.m. Nitric acid interferes seriously with the extraction of selenium and must be removed by evaporation in the sample-digestion step.

Non-invasive grading of astrocytic tumours from the relative contents of myo-inositol and glycine measured by in vivo MRS.

PubMed

Candiota, A P; Majós, C; Julià-Sapé, M; Cabañas, M; Acebes, J J; Moreno-Torres, A; Griffiths, J R; Arús, C

2011-01-01

MRI and MRS are established methodologies for evaluating intracranial lesions. One MR spectral feature suggested for in vivo grading of astrocytic tumours is the apparent myo-lnositol (ml) intensity (ca 3.55 ppm) at short echo times, although glycine (gly) may also contribute in vivo to this resonance. The purpose of this study was to quantitatively evaluate the ml + gly contribution to the recorded spectral pattern in vivo and correlate it with in vitro data obtained from perchloric acid extraction of tumour biopsies. Patient spectra (n = 95) at 1.5T at short (20-31 ms) and long (135-136 ms) echo times were obtained from the INTERPRET MRS database (http://gabrmn.uab.eslinterpretvalidateddbl). Phantom spectra were acquired with a comparable protocol. Spectra were automatically processed and the ratios of the (ml + gly) to Cr peak heights ((ml + gly)/Cr) calculated. Perchloric acid extracts of brain tumour biopsies were analysed by high-resolution NMR at 9.4T. The ratio (ml + gly)/Cr decreased significantly with astrocytic grade in vivo between low-grade astrocytoma (A2) and glioblastoma multiforme (GBM). In vitro results displayed a somewhat different tendency, with anaplastic astrocytomas having significantly higher (ml + gly)/Cr than A2 and GBM. The discrepancy between in vivo and in vitro data suggests that the NMR visibility of glycine in glial brain tumours is restricted in vivo.

Determination of perchlorate from tea leaves using quaternary ammonium modified magnetic carboxyl-carbon nanotubes followed by liquid chromatography-tandem quadrupole mass spectrometry.

PubMed

Zhao, Yong-Gang; Zhang, Yun; Wang, Feng-Lian; Zhou, Jian; Zhao, Qi-Ming; Zeng, Xiu-Qiong; Hu, Mei-Qin; Jin, Mi-Cong; Zhu, Yan

2018-08-01

The novel quaternary ammonium modified magnetic carboxyl-carbon nanotubes (QA-Mag-CCNTs) have been synthesised and characterized. QA-Mag-CCNTs were applied in magnetic dispersive solid phase extraction (Mag-dSPE) for preconcentration of perchlorate from tea leaves prior to liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS) analysis. The Mag-dSPE procedure for preconcentration of perchlorate succeed in overcoming the flaw (containing target analyte randomly) of commercially available SPE cartridge. Under optimal conditions, the results showed higher extraction efficiency of QA-Mag-CCNTs, with recoveries between 85.2% and 107%. And the satisfactory precision with inter-day and intra-day RSD values were lower than 8.0%. Furthermore, QA-Mag-CCNTs were evaluated for reuse up to 20 times. The limit of quantification (LOQ) for perchlorate was 8.21 ng kg -1 . The developed method was successfully applied in tea leaves for food-safety risk monitoring in Zhejiang province, China. The results showed the concentrations of perchlorate in 229 out of 240 collected samples were in the range of 0.082-988 μg kg -1 . It was confirmed that QA-Mag-CCNTs were highly effective materials used for preconcentration of perchlorate. Copyright © 2018 Elsevier B.V. All rights reserved.

Catalytic behavior of perchloric acid on silica mesoporous SBA-15 as a green heterogeneous Bronsted acid in heterocyclic multicomponent reactions

NASA Astrophysics Data System (ADS)

Baghban, Ali; Doustkhah, Esmail; Rostamnia, Sadegh

2018-04-01

Catalytic behavior of perchloric acid when supported to mesoporous silica SBA-15 (SBA-15/HClO4) was investigated as a heterogeneous Bronsted acid. Its reactivity and leaching possibility were studied in cascade ring opening-cyclocondensation sequence of diketene and alcohol with aldehyde in the presence of either of urea or ammonium acetate. Results showed that this catalyst can be highly recyclable for several cycles.

Isolation and Characterization of a Novel Nuclear Protein from Pollen Mother Cells of Lily

PubMed Central

Sasaki, Yoh; Yasuda, Hideyo; Ohba, Yoshiki; Harada, Hiroshi

1990-01-01

Pollen mother cells of the lily (Lilium speciosum) were found to have a histone-H1-like protein (PMCP) not detected in other tissues. The PMCP appears from the late S-G2 period of premeiosis and is present in mature pollen. PMCP and H1 were extracted from pollen mother cells with 5% perchloric acid and isolated by reverse-phase high-performance liquid chromatography. The amino acid composition of PMCP differs from that of somatic H1. However, PMCP is similar to H1t in mammalian testis with regard to amino acid composition. Images Figure 1 Figure 2 Figure 3 Figure 5 PMID:16667855

Removal of an acid fume system contaminated with perchlorates located within hot cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosenberg, K.E.; Henslee, S.P.; Vroman, W.R.

1992-09-01

An add scrubbing system located within the confines of a highly radioactive hot cell at Argonne National Laboratory-West (ANL-W) was remotely removed. The acid scrubbing system was routinely used for the dissolution of irradiated reactor fuel samples and structural materials. Perchloric acid was one of the acids used in the dissolution process and remained in the system with its inherent risks. Personnel could not enter the hot cell to perform the dismantling of the acid scabbing system due to the high radiation field and the explosion potential associated with the perchlorates. A robot was designed and built at ANL-W andmore » used to dismantle the system without the need for personnel entry into the hot cell. The robot was also used for size reduction of removed components and loading of the removed components into waste containers.« less

Chlorine Isotopic Composition of Perchlorate in Human Urine as a Means of Distinguishing Among Natural and Synthetic Exposure Sources

PubMed Central

Poghosyan, Armen; Morel-Espinosa, Maria; Valentín-Blasini, Liza; Blount, Benjamin C.; Ferreccio, Catterina; Steinmaus, Craig M.; Sturchio, Neil C.

2015-01-01

Perchlorate (ClO4−) is a ubiquitous environmental contaminant with high human exposure potential; it has both natural and man-made sources in the environment. Natural perchlorate forms in the atmosphere from where it deposits onto the surface of Earth, whereas synthetic perchlorate is manufactured as an oxidant for industrial, aerospace, and military applications. Perchlorate exposure can potentially cause adverse health effects in humans by interfering with the production of thyroid hormones through competitively blocking iodide uptake. To control and reduce perchlorate exposure, the contributions of different sources of perchlorate exposure need to be quantified. Thus, we demonstrate a novel approach for determining the contribution of different perchlorate exposure sources by quantifying stable and radioactive chlorine isotopes of perchlorate extracted from composite urine samples from two distinct populations: one in Atlanta, USA and one in Taltal, Chile (Atacama region). Urinary perchlorate from the Atlanta region resembles indigenous natural perchlorate from the southwestern USA [δ37Cl = +4.1 ± 1.0 ‰; 36Cl/Cl = 1811 (± 136) × 10−15], and urinary perchlorate from the Taltal, Chile region is similar to natural perchlorate in nitrate salt deposits from the Atacama Desert of northern Chile [δ37Cl = −11.0 ± 1.0 ‰; 36Cl/Cl = 254 (± 40) × 10−15]. Neither urinary perchlorate resembled the isotopic pattern found in synthetic perchlorate. These results indicate that natural perchlorate of regional provenance is the dominant exposure source for the two sample populations, and that chlorine isotope ratios provide a robust tool for elucidating perchlorate exposure pathways. PMID:25805252

Determination of silver, antimony, bismuth, copper, cadmium and indium in ores, concentrates and related materials by atomic-absorption spectrophotometry after methyl isobutyl ketone extraction as iodides.

PubMed

Donaldson, E M; Wang, M

1986-03-01

Methods for determining ~ 0.2 mug g or more of silver and cadmium, ~ 0.5 mug g or more of copper and ~ 5 mug g or more of antimony, bismuth and indium in ores, concentrates and related materials are described. After sample decomposition and recovery of antimony and bismuth retained by lead and calcium sulphates, by co-precipitation with hydrous ferric oxide at pH 6.20 +/- 0.05, iron(III) is reduced to iron(II) with ascorbic acid, and antimony, bismuth, copper, cadmium and indium are separated from the remaining matrix elements by a single methyl isobutyl ketone extraction of their iodides from ~2M sulphuric acid-0.1M potassium iodide. The extract is washed with a sulphuric acid-potassium iodide solution of the same composition to remove residual iron and co-extracted zinc, and the extracted elements are stripped from the extract with 20% v v nitric acid-20% v v hydrogen peroxide. Alternatively, after the removal of lead sulphate by filtration, silver, copper, cadmium and indium can be extracted under the same conditions and stripped with 40% v v nitric acid-25% v v hydrochloric acid. The strip solutions are treated with sulphuric and perchloric acids and ultimately evaporated to dry ness. The individual elements are determined in a 24% v v hydrochloric acid medium containing 1000 mug of potassium per ml by atomic-absorption spectrophotometry with an air-acetylene flame. Tin, arsenic and molybdenum are not co-extracted under the conditions above. Results obtained for silver, antimony, bismuth and indium in some Canadian certified reference materials by these methods are compared with those obtained earlier by previously published methods.

Perchlorate and halophilic prokaryotes: implications for possible halophilic life on Mars.

PubMed

Oren, Aharon; Elevi Bardavid, Rahel; Mana, Lily

2014-01-01

In view of the finding of perchlorate among the salts detected by the Phoenix Lander on Mars, we investigated the relationships of halophilic heterotrophic microorganisms (archaea of the family Halobacteriaceae and the bacterium Halomonas elongata) toward perchlorate. All strains tested grew well in NaCl-based media containing 0.4 M perchlorate, but at the highest perchlorate concentrations, tested cells were swollen or distorted. Some species (Haloferax mediterranei, Haloferax denitrificans, Haloferax gibbonsii, Haloarcula marismortui, Haloarcula vallismortis) could use perchlorate as an electron acceptor for anaerobic growth. Although perchlorate is highly oxidizing, its presence at a concentration of 0.2 M for up to 2 weeks did not negatively affect the ability of a yeast extract-based medium to support growth of the archaeon Halobacterium salinarum. These findings show that presence of perchlorate among the salts on Mars does not preclude the possibility of halophilic life. If indeed the liquid brines that may exist on Mars are inhabited by salt-requiring or salt-tolerant microorganisms similar to the halophiles on Earth, presence of perchlorate may even be stimulatory when it can serve as an electron acceptor for respiratory activity in the anaerobic Martian environment.

Oxidation of alginate and pectate biopolymers by cerium(IV) in perchloric and sulfuric acid solutions: A comparative kinetic and mechanistic study.

PubMed

Fawzy, Ahmed

2016-03-15

The kinetics of oxidation of alginate (Alg) and pectate (Pec) carbohydrate biopolymers was studied by spectrophotometry in aqueous perchloric and sulfuric acid solutions at fixed ionic strengths and temperature. In both acids, the reactions showed a first order dependence on [Ce(IV)], whereas the orders with respect to biopolymer concentrations are less than unity. In perchloric acid, the reactions exhibited less than unit orders with respect to [H(+)] whereas those proceeded in sulfuric acid showed negative fractional-first order dependences on [H(+)]. The effect of ionic strength and dielectric constant was studied. Probable mechanistic schemes for oxidation reactions were proposed. In both acids, the final oxidation products were characterized as mono-keto derivatives of both biopolymers. The activation parameters with respect to the slow step of the mechanisms were computed and discussed. The rate laws were derived and the reaction constants involved in the different steps of the mechanisms were calculated. Copyright © 2015 Elsevier Ltd. All rights reserved.

Release of volatile mercury from vascular plants

NASA Technical Reports Server (NTRS)

Siegel, S. M.; Puerner, N. J.; Speitel, T. W.

1974-01-01

Volatile, organic solvent soluble mercury has been found in leaves and seeds of several angiosperms. Leaves of garlic vine, avocado, and haole-koa release mercury in volatile form rapidly at room temperature. In garlic vine, the most active release is temperature dependent, but does not parallel the vapor-pressure temperature relationship for mercury. Mercury can be trapped in nitric-perchloric acid digestion fluid, or n-hexane, but is lost from the hexane unless the acid mixture is present. Seeds of haole-koa also contain extractable mercury but volatility declines in the series n-hexane (90%), methanol (50%), water (10%). This suggests that reduced volatility may accompany solvolysis in the more polar media.

DETERMINATION OF PERCHLORATE IN SOME FERTILIZERS AND PLANT TISSUE BY RAMAN SPECTROSCOPY

EPA Science Inventory

We have successfully used Raman spectroscopy for the direct qualitative and quantitative analysis of perchlorate in fertilizer extracts without the need for chromatographic separation. This approach is attractive because Raman is not hindered by the presence of water or of high ...

DETERMINATION OF PERCHLORATE AT PARTS-PER-BILLION LEVELS IN PLANTS BY ION CHROMATOGRAPHY

EPA Science Inventory

A method for the analysis of perchlorate in plants was developed, based on dry weight, and applied to the analysis of plant organs, foodstuffs, and plant products. The method reduced greatly the ionic interferences in water extracts of plant materials. The high background conduct...

RAMAN ANALYSIS OF FERTILIZER AND PLANT TISSUE EXTRACTS FOR PERCHLORATE CONTAMINATION

EPA Science Inventory

Recently, we and others found perchlorate at high levels (approximately 500 - 8000 mg/kg) in ~ 90% of 25+ fertilizers products (primarily lawn-and-garden type) with no known link to mined nitrate-bearing Chilean ore. This ore is used, albeit in small scale, in fertilizer product...

METHOD FOR THE DETERMINATION OF PERCHLORATE ANION IN PLANT AND SOLID MATRICES BY ION CHROMATOGRAPHY

EPA Science Inventory

A standardized method for the analysis of perchlorate in plants was developed, based on dry weight, and applied to the analysis of plant organs, foodstuffs, and plant products. The procedure greatly reduced the ionic interferences in water extracts of plant materials. Ion chro...

DETERMINATION OF PERCHLORATE AT PARTS-PER-BILLION LEVELS IN PLANTS BY ION CHROMATOGRAPHY

EPA Science Inventory

A standardized method for the analysis of perchlorate in plants was developed, based on dry weight, and applied to the analysis of plant organs, foodstuffs, and plant products. The procedure greatly reduced the ionic interferences in water extracts of plant materials. The high ba...

Effects of Perchlorate on Organic Molecules under Simulated Mars Conditions

NASA Astrophysics Data System (ADS)

Carrier, B. L.; Kounaves, S. P.

2014-12-01

Perchlorate (ClO4-) was discovered in the northern polar region of Mars by the Mars Phoenix Lander in 2008 and has also been recently detected by the Curiosity Rover in Gale Crater [1,2]. Perchlorate has also been shown to be formed under current Mars conditions via the oxidation of mineral chlorides, further supporting the theory that perchlorate is present globally on Mars [3]. The discovery of perchlorate on Mars has raised important questions about the effects of perchlorate on the survival and detection of organic molecules. Although it has been shown that pyrolysis in the presence of perchlorate results in the alteration or destruction of organic molecules [4], few studies have been conducted on the potential effects of perchlorate on organic molecules under martian surface conditions. Although perchlorate is typically inert under Mars-typical temperatures [5], perchlorate does absorb high energy UV radiation, and has been shown to decompose to form reactive oxychlorine species such as chlorite (ClO2-) when exposed to martian conditions including UV or ionizing radiation [6,7]. Here we investigate the effects of perchlorate on the organic molecules tryptophan, benzoic acid and mellitic acid in order to determine how perchlorate may alter these compounds under Mars conditions. Experiments are performed in a Mars Simulation Chamber (MSC) capable of reproducing the temperature, pressure, atmospheric composition and UV flux found on Mars. Soil simulants are prepared consisting of SiO2 and each organic, as well as varying concentrations of perchlorate salts, and exposed in the MSC. Subsequent to exposure in the MSC samples are leached and the leachate analyzed by HPLC and LC-MS to determine the degree of degradation of the original organic and the identity of any potential decomposition products formed by oxidation or chlorination. References: [1] Kounaves et al., J. Geophys. Res. Planets, Vol. 115, p. E00E10, 2010 [2] Glavin et al., J. Geophys. Res. Planets, Vol. 118, p. 1955, 2013 [3] Carrier & Kounaves (2014), Abstract #2570, 45th Lunar and Planetary Science Conference, [4] Kerr, Science, Vol. 340, p. 138, 2013 [5] Catling et al., J. Geophys. Res., Vol. 115, p. E00E11, 2010 [6] Martucci (2012), National Conference of Undergraduate Research [7] Quinn et al, Astrobiology, Vol. 13(6) p. 515-20, 2013

Modeling In Situ Bioremediation of Perchlorate-Contaminated Groundwater

NASA Astrophysics Data System (ADS)

Goltz, M. N.; Secody, R. E.; Huang, J.; Hatzinger, P. B.

2007-12-01

Perchlorate-contaminated groundwater is a significant national problem. An innovative technology was recently developed which uses a pair of dual-screened treatment wells to mix an electron donor into perchlorate- contaminated groundwater in order to effect in situ bioremediation of the perchlorate by indigenous perchlorate reducing bacteria (PRB) without the need to extract the contaminated water from the subsurface. The two treatment wells work in tandem to establish a groundwater recirculation zone in the subsurface. Electron donor is added and mixed into perchlorate-contaminated groundwater flowing through each well. The donor serves to stimulate biodegradation of the perchlorate by PRB in bioactive zones that form adjacent to the injection screens of the treatment wells. In this study, a model that simulates operation of the technology was calibrated using concentration data obtained from a field-scale technology evaluation project at a perchlorate-contaminated site. The model simulates transport of perchlorate, the electron donor (citrate, for this study), and competing electron acceptors (oxygen and nitrate) in the groundwater flow field induced by operation of the treatment well pair. A genetic algorithm was used to derive a set of best-fit model parameters to describe the perchlorate reduction kinetics in this field-scale evaluation project. The calibrated parameter values were then used to predict technology performance. The model qualitatively predicted the salient characteristics of the observed data. It appears the model may be a useful tool for designing and operating this technology at other perchlorate-contaminated sites.

Sources of error in determinations of carnitine and acylcarnitine in plasma.

PubMed

Fishlock, R C; Bieber, L L; Snoswell, A M

1984-02-01

Radioactive and nonradioactive L-carnitine and acyl-L-carnitine were used to evaluate the washing procedures used during the determination of free, total, short-chain, and long-chain acylcarnitine in human and sheep plasma. The volume of fluid trapped by the protein precipitated by perchloric acid is approximately 24% of the total fluid volume and thus contains 24% of free carnitine and short-chain acylcarnitine. Washing twice with distilled water removes about 25% of the long-chain acylcarnitine along with the trapped free carnitine and short-chain acylcarnitines. Washing the pellet twice with a 60 g/L solution of perchloric acid completely removes the trapped free carnitine and short-chain acylcarnitine but does not remove the bound long-chain acylcarnitines. Thus washing with perchloric acid is essential for accurate measurement of long-chain acylcarnitines in plasma samples.

Synthesis and thermal characterization of xylan-graft-polyacrylonitrile.

PubMed

Ünlü, Cüneyt H; Öztekin, N Simge; Atıcı, Oya Galioğlu

2012-10-01

In this study emulsion polymerization of acrylonitrile using xylan from agricultural waste material (corn cob) and cerium ammonium nitrate was investigated in terms of catalyst acid. Stock ceric solutions were prepared using either nitric or perchloric acid as catalyst. Optimum conditions were determined using different parameters such as reaction time, temperature, and component concentrations. Nitric acid catalyzed reactions resulted in maximum conversion ratio (96%) at 50°C, 1 h where ceric ion, acrylonitrile, xylan, and catalyst concentrations were 21.7 mmol l(-1), 0.5 mol l(-1), 0.2% (w/v), and 0.1 mol l(-1), respectively. However, 83% conversion was obtained with perchloric acid catalysis at 27 °C, 1 h where concentrations were 5.4 mmol l(-1), 0.8 mol l(-1), 0.5% (w/v), and 0.2 mol l(-1), respectively. Copolymer synthesis using perchloric acid was realized at milder conditions than using nitric acid. Thermal analyses of obtained polymers were conducted to characterize copolymers. Results showed that calculated activation energy, maximum degradation temperature, and heat of thermal decomposition changed relying mainly on molecular weight. Copyright © 2012 Elsevier Ltd. All rights reserved.

Homogenization versus homogenization-free method to measure muscle glycogen fractions.

PubMed

Mojibi, N; Rasouli, M

2016-12-01

The glycogen is extracted from animal tissues with or without homogenization using cold perchloric acid. Three methods were compared for determination of glycogen in rat muscle at different physiological states. Two groups of five rats were kept at rest or 45 minutes muscular activity. The glycogen fractions were extracted and measured by using three methods. The data of homogenization method shows that total glycogen decreased following 45 min physical activity and the change occurred entirely in acid soluble glycogen (ASG), while AIG did not change significantly. Similar results were obtained by using "total-glycogen-fractionation methods". The findings of "homogenization-free method" indicate that the acid insoluble fraction (AIG) was the main portion of muscle glycogen and the majority of changes occurred in AIG fraction. The results of "homogenization method" are identical with "total glycogen fractionation", but differ with "homogenization-free" protocol. The ASG fraction is the major portion of muscle glycogen and is more metabolically active form.

Electrochemistry and analytical determination of lysergic acid diethylamide (LSD) via adsorptive stripping voltammetry.

PubMed

Merli, Daniele; Zamboni, Daniele; Protti, Stefano; Pesavento, Maria; Profumo, Antonella

2014-12-01

Lysergic acid diethylamide (LSD) is hardly detectable and quantifiable in biological samples because of its low active dose. Although several analytical tests are available, routine analysis of this drug is rarely performed. In this article, we report a simple and accurate method for the determination of LSD, based on adsorptive stripping voltammetry in DMF/tetrabutylammonium perchlorate, with a linear range of 1-90 ng L(-1) for deposition times of 50s. LOD of 1.4 ng L(-1) and LOQ of 4.3 ng L(-1) were found. The method can be also applied to biological samples after a simple extraction with 1-chlorobutane. Copyright © 2014 Elsevier B.V. All rights reserved.

Soil Flushing Through a Thick Vadose Zone: Perchlorate Removal Documented at Edwards AFB, California

NASA Astrophysics Data System (ADS)

Battey, T. F.; Shepard, A. J.; Tait, R. J.

2007-12-01

There are currently few viable alternatives for perchlorate remediation in the vadose zone, particularly for the relatively thick vadose zones that are typical in the arid southwest where many perchlorate sites occur. Perchlorate in the vadose zone occurs in the form of highly soluble salts that may represent a risk to human or ecological receptors, and may also represent a threat to the underlying groundwater. A soil flushing treatability study was conducted at Edwards Air Force Base in the Mojave Desert of southern California at a site with a 129-foot thick vadose zone consisting primarily of clayey sand. This study utilized an infiltration gallery in conjunction with extraction, treatment, and re-injection of groundwater at the site, which contained perchlorate-contaminated soil and groundwater. The study objective was to evaluate the effectiveness of the infiltration gallery to 1) introduce treated groundwater back into the aquifer and 2) wash the perchlorate from the vadose zone soils to the aquifer. The infiltration gallery consisted of slotted PVC pipes within a highly permeable engineered bed of washed gravel. The initial water introduced into the gallery was amended with potassium bromide tracer. A downhole neutron probe was used to track the movement of the wetting front downward and outward from the gallery. Successive neutron measurements in vertical access tubes revealed that the introduced water reached the 125-foot bottom of the access tubes 14 weeks after the water was introduced into the gallery. The bromide tracer was detected in groundwater immediately below the gallery approximately 1 week later. The infiltration gallery was able to sustain an average flow rate of 2.3 gallons per minute. Prior to infiltration, the perchlorate concentration in groundwater below the gallery was 4,500 µg/L. Approximately 18 weeks after the start of infiltration, a perchlorate spike of 72,400 µg/L was detected below the gallery. The increase in perchlorate groundwater concentrations indicates the transfer of perchlorate from the vadose zone to the saturated zone, where it was readily captured by an adjacent groundwater extraction well. Continued flushing of treated water through the vadose and saturated zones resulted in a rapid decline in perchlorate groundwater concentrations. Confirmation soil boreholes documented the effectiveness of the soil treatment after perchlorate groundwater concentrations returned to their pre-soil flushing levels. This treatability study demonstrates that perchlorate can be removed from a thick sandy vadose zone by controlled infiltration with associated hydraulic control of groundwater to capture the leached perchlorate. The treatability study results also indicates that an infiltration gallery may provide 1) a cost-effective alternative to injection wells for reintroducing treated groundwater to the aquifer and 2) an effective mechanism for the delivery of amendments to the vadose zone and aquifer for promoting enhanced biodegradation of perchlorate in soil and groundwater.

Generation of Free Radicals during Cold Injury and Rewarming

DTIC Science & Technology

1988-01-01

a mixture of sodium citrate (0.05 M) and sodium acetate (0.03 M) (pH 4.5); 50 ; 1 of 70% perchloric acid was then added to the mixture. The resultant...products of salicylic acid were eluted with buffer (degassed and filtered) containing 0.03 M sodium acetate and 0.05 M sodium citrate 6 (pH 4.5) at a...Malonaldehyde was measured as an index for lipid peroxidation. Plasma (0.5 ml) was added to 0.5 ml ice-cold perchloric acid (15%) and then treated with

Atmospheric Production of Perchlorate on Earth and Mars

NASA Astrophysics Data System (ADS)

Claire, M.; Catling, D. C.; Zahnle, K. J.

2009-12-01

Natural production and preservation of perchlorate on Earth occurs only in arid environments. Isotopic evidence suggests a strong role for atmospheric oxidation of chlorine species via pathways including ozone or its photochemical derivatives. As the Martian atmosphere is both oxidizing and drier than the driest places on Earth, we propose an atmospheric origin for the Martian perchlorates measured by NASA's Phoenix Lander. A variety of hypothetical formation pathways can be proposed including atmospheric photochemical reactions, electrostatic discharge, and gas-solid reactions. Here, we investigate gas phase formation pathways using a 1-D photochemical model (Catling et al. 2009, accepted by JGR). Because perchlorate-rich deposits in the Atacama desert are closest in abundance to perchlorate measured at NASA's Phoenix Lander site, we start with a study of the means to produce Atacama perchlorate. We found that perchlorate can be produced in sufficient quantities to explain the abundance of perchlorate in the Atacama from a proposed gas phase oxidation of chlorine volatiles to perchloric acid. These results are sensitive to estimated reaction rates for ClO3 species. The feasibility of gas phase production for the Atacama provides justification for further investigations of gas phase photochemistry as a possible source for Martian perchlorate. In addition to the Atacama results, we will present a preliminary study incorporating chlorine chemistry into an existing Martian photochemical model (Zahnle et al. JGR 2008).

Perchlorate and Volatiles in the Brine of Lake Vida (antarctica): Implication for the Analysis of Mars Sediments

NASA Astrophysics Data System (ADS)

Kenig, F. P. H.; Chou, L.; McKay, C.; Jackson, W. A.; Doran, P. T.; Murray, A. E.; Fritsen, C. H.

2015-12-01

A cold (-13.4 °C), saline (188 psu) evaporative brine is encapsulated in the thick (> 27 m) ice of Lake Vida (McMurdo Dry Valleys, Antarctica). The Lake Vida brine (LVBr), which contains abundant dissolved organic carbon (48.2 mmol/L), support an active but slow microbial community. LVBr contains oxychlorines with 50 μg/L of perchlorate and 11 μg/L of chlorate. The McMurdo Dry Valleys have often been considered as a good Mars analog. The oxychlorine-rich brine of Lake Vida constitutes a potential equivalent to perchlorate-rich preserved saline liquid water on Mars. We report here on the artifacts created by oxychlorines upon analysis of volatiles and volatile organic compounds (VOCs) of LVBr by direct immersion (DI) and head space (HS) solid phase micro extraction (SPME) gas chromatography-mass spectrometry (GCMS). We compare analytical blanks to a standard containing 40 μg/L of perchlorate and to actual LVBr sample runs. All blanks, perchlorate blanks and samples were analyzed using two types of SPME fibers, CarboxenTM/polydimethylsiloxane (PDMS) and divinylbenzene (DVB)/ PDMS. The similarities and differences between our results and those obtained by the Sample Analysis at Mars instruments of the rover Curiosity are discussed. The volatiles evolved from LVBr upon analysis with DI- and HS-SPME GCMS are dominated by CO2, dichloromethane, HCl, and volatile organic sulfur compounds (VOSCs, such as DMS, DMDS). The volatiles also include oxygenated compounds such as acids and ketones, aromatic compounds, hydrocarbons, chlorinated compounds (dominated by dichloromethane). Apart from the VOSCs, short chain hydrocarbons and some functionalized compounds derived from the brine itself, all compounds observed are artifacts formed upon oxychlorine breakdown in the injector of the GCMS. The distribution of aromatic compounds seems to be directly dependant on the type of SPME fiber used. The perchlorate blanks show a clear pattern of carbon limitation, likely affecting the type and abundance of compounds produced. This suggests that carbon limited perchlorates blanks are not satisfactory for comparison to the analysis of oxychlorine containing samples. Acknowledgment: NASA ASTEP NAG5-12889 (PTD), NSF awards ANT-0739681 (AEM, CHF) and ANT-0739698 (PTD, FK) supported this work.

Analysis of Mixed Aryl/Alkyl Esters by Pyrolysis Gas Chromatography-Mass Spectrometry in the Presence of Perchlorate

NASA Technical Reports Server (NTRS)

Burton, A. S.; Locke, D. R.; Lewis, E. K.

2017-01-01

Mars is an important target for Astrobiology. A key goal of the MSL mission was to determine whether Mars was habitable in the past, a que-tion that has now been definitely determined to be yes. Another key goal for Mars exploration is to understand the origin and distribution of organic material on Mars; this question is being addressed by the SAM instrument on MSL, and will also be informed by two upcoming Mars exploration missions, ExoMars and Mars 2020. These latter two missions have instrumentation capable of detecting and characterize organic molecules. Over the next decade, these missions will analyze organics in surface, near-surface and sub-surface samples. Each mission has the capability to analyze organics by different methods (pyrolysis gas chromatography-mass spectrometry [py-GC-MS]; laser desorption and thermal volatilization GC-MS; and Raman spectroscopy). Plausibly extraterrestrial organics were recently discovered by the Mars Science Laboratory (MSL), providing an important first step towards understanding the organic inventory on Mars [1]. The compounds detected were chlorobenzenes and chloroalkanes, but it was argued that chlorination of these compounds occurred during pyrolysis of samples containing unchlorinated organics in the presence of perchlorate. A recent report analyzed a suite of aromatic (benzene, toluene, benzoic acid, phthalic acid, and mellitic acid) and aliphatic (acetic acid, propane, propanol, and hexane) by pyrolysis under SAM-like conditions in the presence of perchlorate to attempt to constrain possible precursor molecules for the organic molecules detected on Mars. For aromatic compounds, the aromatic acids all readily produced SAM-relevant chlorobenzes, whereas benzene and toluene did not. This observation suggests that the chlorobenzene detected on Mars could have derived from compounds like mellitic acid, consistent with the previous hypothesis by Benner et al. [3]. Among the aliphatic molecules, it was shown that pyrolysis of alkanes and alcohols in the presence of perchlorates produced polychlorine containing chloro-alkanes similar to what was observed on Mars. Surpris-ingly, however, similar treatment of acetic acid pro-duced chloroketones, instead, and no chloroalkanes were reported. This suggests that the chloroalkanes detected in the Sheepbed mudstone were not derived from aliphatic carboxylic acids, but instead were from more reduced alcohols or even alkanes, or perhaps were degradation products of more complicated organic material. Because organics analyses on mars will rely heavily on py-GC-MS of perchlorate-containing samples over the next decade, it is important to understand the fate of organic molecules of biotic and abiotic origin under such conditions. In this work we begin a series of experiments to improve our understanding of products generated during py-GC-MS of increasingly complex organic molecules (esters, amides, peptides, nucleic acids, fatty acids) in the presence of perchlorate.

Potential Influence of Perchlorate on Heavy Metals and Organic Carbon in Serpentine Soil; Implications for Martian Regolith

NASA Astrophysics Data System (ADS)

Oze, C.; Kumarathilaka, P. R.; Indraratne, S.; Vithanage, M. S.

2015-12-01

Prasanna Kumarathilaka Chemical and Environmental Systems Modeling Research Group, National Institute of Fundamental Studies, Kandy, Sri LankaPerchlorate (ClO4-) concentrations as high as 1 Wt.% have been reported in Martian regolith. Perchlorate is a strong oxidizer capable of accelerating heavy and/or trace metal release into regolith/soil and reacting with organic matter/compounds (if present). Here, we assess interactions between perchlorate and an analogous Martian regolith (i.e., serpentine soil) to simulate and understand the fate of Mn, Ni and Co and organic carbon. Pre-characterized serpentine soil collected from Sri Lanka was used for this study. Incubation experiments were performed with three perchlorate concentrations (1, 0.75 and 0.5 w/w) and sequential and single extractions assessed solid phase metal fractionation in serpentine sediments after 3 weeks and 1 year, respectively. Additionally, total organic carbon (TOC) of the residues were analyzed. These experiments demonstrate a high release of Mn compared to Ni and Co. Metal concentrations in exchangeable and bioavailable fractions increased with increasing perchlorate concentrations. Exchangeable Ni, Mn and Co increased 5.9, 69.6 and 44.6% and bioavailable Ni, Mn and Co increased 5.5, 92.3 and 72.8%, respectively, after 1 year compared to 3 weeks. Additionally, TOC decreased with increasing perchlorate concentration. For example, TOC decreased by 14.3% after 1 year compared to a 3 week incubation period. Overall, this study confirms the accelerated release of metals and the removal of organic carbon with increasing perchlorate concentrations. Furthermore, this study illustrates how perchlorate may present additional challenges to current Martian life studies and the future human habitation of Mars.Prasanna Kumarathilaka Chemical and Environmental Systems Modeling Research Group, National Institute of Fundamental Studies, Kandy, Sri LankaPerchlorate (ClO4-) concentrations as high as 1 Wt.% have been reported in Martian regolith. Perchlorate is a strong oxidizer capable of accelerating heavy and/or trace metal release into regolith/soil and reacting with organic matter/compounds (if present). Here, we assess interactions between perchlorate and an analogous Martian regolith (i.e., serpentine soil) to simulate and understand the fate of Mn, Ni and Co and organic carbon. Pre-characterized serpentine soil collected from Sri Lanka was used for this study. Incubation experiments were performed with three perchlorate concentrations (1, 0.75 and 0.5 w/w) and sequential and single extractions assessed solid phase metal fractionation in serpentine sediments after 3 weeks and 1 year, respectively. Additionally, total organic carbon (TOC) of the residues were analyzed. These experiments demonstrate a high release of Mn compared to Ni and Co. Metal concentrations in exchangeable and bioavailable fractions increased with increasing perchlorate concentrations. Exchangeable Ni, Mn and Co increased 5.9, 69.6 and 44.6% and bioavailable Ni, Mn and Co increased 5.5, 92.3 and 72.8%, respectively, after 1 year compared to 3 weeks. Additionally, TOC decreased with increasing perchlorate concentration. For example, TOC decreased by 14.3% after 1 year compared to a 3 week incubation period. Overall, this study confirms the accelerated release of metals and the removal of organic carbon with increasing perchlorate concentrations. Furthermore, this study illustrates how perchlorate may present additional challenges to current Martian life studies and the future human habitation of Mars.

Deproteinizing methods evaluated for determination of uric acid in serum by reversed-phase liquid chromatography with ultraviolet detection.

PubMed

Sakuma, R; Nishina, T; Kitamura, M

1987-08-01

We evaluated six deproteinizing methods for determination of uric acid in serum by "high-performance" liquid chromatography with ultraviolet detection: those involving zinc hydroxide, sodium tungstate, trichloroacetic acid, perchloric acid, acetonitrile, and centrifugal ultrafiltration (with Amicon MPS-1 devices). We used a Toyosoda ODS-120A reversed-phase column. The mobile phase was sodium phosphate buffer (40 mmol/L, pH 2.2) containing 20 mL of methanol per liter. Absorbance of the eluate was monitored at 284 nm. The precipitation method with perchloric acid gave high recoveries of uric acid and good precision, and results agreed with those by the uricase-catalase method of Kageyama (Clin Chim Acta 1971;31:421-6).

Hydrolysis of aceto-hydroxamic acid under UREX+ conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alyapyshev, M.; Paulenova, A.; Tkac, P.

2007-07-01

Aceto-hydroxamic acid (AHA) is used as a stripping agent In the UREX process. While extraction yields of uranium remain high upon addition of AHA, hexavalent plutonium and neptunium are rapidly reduced to the pentavalent state while the tetravalent species and removed from the product stream. However, under acidic conditions, aceto-hydroxamic acid undergoes hydrolytic degradation. In this study, the kinetics of the hydrolysis of aceto-hydroxamic acid in nitric and perchloric acid media was investigated at several temperatures. The decrease of the concentration of AHA was determined via its ferric complex using UV-Vis spectroscopy. The data obtained were analyzed using the methodmore » of initial rates. The data follow the pseudo-first order reaction model. Gamma irradiation of AHA/HNO{sub 3} solutions with 33 kGy/s caused two-fold faster degradation of AHA. The rate equation and thermodynamic data will be presented for the hydrolysis reaction with respect to the concentrations of aceto-hydroxamic acid, nitrate and hydronium ions, and radiation dose. (authors)« less

Development of an enzymatic assay to measure lactate in perchloric acid-precipitated cerebrospinal fluid.

PubMed

Lu, Jun; Genzen, Jonathan R; Grenache, David G

2018-04-27

Individuals with inherited deficiencies of the pyruvate dehydrogenase complex or the respiratory chain complex can have increased concentrations of cerebrospinal fluid (CSF) lactate. Such measurements are clinical useful when measured in conjunction with pyruvate in order to calculate the lactate:pyruvate (L:P) ratio, a useful surrogate of cytosolic redox status. CSF pyruvate is measured in a protein-free supernatant prepared by the addition of CSF to perchloric acid while lactate is measured in untreated CSF. Utilizing the same sample for both lactate and pyruvate measurements is desirable. To develop a method to measure lactate in perchloric-acid precipitated CSF and validate the L:P ratio as calculated from the analysis of both analytes in the same sample. Samples were prepared by the addition of 1 mL CSF to 2 mL 8% (w/v) cold perchloric acid, incubated on ice for 10 min, then centrifuged to obtain a protein-free supernatant. Lactate was measured by its oxidation to pyruvate and hydrogen peroxide using lactate oxidase and the absorbance of the resulting chromogen determined at 540 nm on a Roche cobas c501 chemistry analyzer. Method accuracy, linearity, imprecision and sensitivity were determined and a reference interval was verified. To assess accuracy, this method was compared to lactate determined in unaltered CSF at another laboratory using 41 specimens with lactate concentrations from 0.6-11.9 mmol/L. Linear regression produced a slope of 1.09 and y-intercept of 0.26 (R 2  = 1.00). Recovery was performed by ad-mixes of a high lactate standard and a CSF pool in different ratios to create a set of 19 samples prior to preparing protein-free supernatants. Recovery was 94.6-100% (mean ± SD was 97.4 ± 1.4%) at lactate concentrations of 2.68 to 12.63 mmol/L. Linearity was determined by combining two supernatants with low and high lactate concentrations in different ratios to create a set of six samples (0.15-12.70 mmol/L) that were tested in duplicate. Linear regression generated a slope of 1.01, y-intercept of -0.04 (R 2  = 1.00). Precision was verified by analyzing quality control materials (acid-treated lactate standard) in 3 replicates each day for 5 days. Within-laboratory imprecision was 2.3% at 1.5 mmol/L and 1.5% at 10.5 mmol/L. The limit of blank was 0.05 mmol/L as determined by the mean added to three standard deviations determined from 10 replicates of perchloric-acid treated saline pool. The limit of detection was determined to be 0.12 mmol/L calculated from 10 replicates of a patient sample treated with perchloric-acid. The manufacturer's reference interval of 1.1-2.4 mmol/L was verified using 20 residual patient CSF samples. CSF lactate can be measured with accuracy and precision using the same perchloric-acid treated sample that is used for pyruvate. Copyright © 2018 Elsevier B.V. All rights reserved.

Silver nanoplate-decorated copper wire for the on-site microextraction and detection of perchlorate using a portable Raman spectrometer.

PubMed

Zhu, Sha; Zhang, Xiaoli; Cui, Jingcheng; Shi, Yu-E; Jiang, Xiaohong; Liu, Zhen; Zhan, Jinhua

2015-04-21

Perchlorate, which causes health concerns because of its effects on the thyroid function, is highly soluble and mobile in the environment. In this study, diethyldithiocarbamate (DDTC)-modified silver nanoplates were fabricated on a copper wire to perform the on-site microextraction and detection of perchlorate. This fiber could be inserted into water or soil to extract perchlorate through electrostatic interaction and then can be detected by a portable Raman spectrometer, owing to its surface-enhanced Raman (SERS) activity. A relatively stable vibrational mode (δ(HCH)(CH3), (CH2)) of DDTC at 1273 cm(-1) was used as an internal standard, which was negligibly influenced by the absorption of ClO4(-). The DDTC-modified Ag/Cu fiber showed high uniformity, good reusability and temporal stability under continuous laser radiation each with an RSD lower than 10%. The qualitative and quantitative detection of perchlorate were also realized. A log-log plot of the normalized SERS intensity against perchlorate concentration showed a good linear relationship. The fiber could be also directly inserted into the perchlorate-polluted soil, and the perchlorate could thereby be detected on site. The detection limit in soil reached 0.081 ppm, which was much lower than the EPA-published safety standard. The recovery of the detection was 105% and comparable with the ion chromatography. This hyphenated method of microextraction with direct SERS detection may find potential application for direct pollutant detection free from complex sample pretreatment.

Surrogate analyte approach for quantitation of endogenous NAD(+) in human acidified blood samples using liquid chromatography coupled with electrospray ionization tandem mass spectrometry.

PubMed

Liu, Liling; Cui, Zhiyi; Deng, Yuzhong; Dean, Brian; Hop, Cornelis E C A; Liang, Xiaorong

2016-02-01

A high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS) assay for the quantitative determination of NAD(+) in human whole blood using a surrogate analyte approach was developed and validated. Human whole blood was acidified using 0.5N perchloric acid at a ratio of 1:3 (v:v, blood:perchloric acid) during sample collection. 25μL of acidified blood was extracted using a protein precipitation method and the resulting extracts were analyzed using reverse-phase chromatography and positive electrospray ionization mass spectrometry. (13)C5-NAD(+) was used as the surrogate analyte for authentic analyte, NAD(+). The standard curve ranging from 0.250 to 25.0μg/mL in acidified human blood for (13)C5-NAD(+) was fitted to a 1/x(2) weighted linear regression model. The LC-MS/MS response between surrogate analyte and authentic analyte at the same concentration was obtained before and after the batch run. This response factor was not applied when determining the NAD(+) concentration from the (13)C5-NAD(+) standard curve since the percent difference was less than 5%. The precision and accuracy of the LC-MS/MS assay based on the five analytical QC levels were well within the acceptance criteria from both FDA and EMA guidance for bioanalytical method validation. Average extraction recovery of (13)C5-NAD(+) was 94.6% across the curve range. Matrix factor was 0.99 for both high and low QC indicating minimal ion suppression or enhancement. The validated assay was used to measure the baseline level of NAD(+) in 29 male and 21 female human subjects. This assay was also used to study the circadian effect of endogenous level of NAD(+) in 10 human subjects. Copyright © 2015 Elsevier B.V. All rights reserved.

Biochemistry and molecular biology of the Caenorhabditis elegans dauer larva

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wadsworth, W.G.

1989-01-01

Biochemical and molecular techniques have been used to study the formation and recovery of the developmentally arrested, non-feeding dauer stage of the nematode Caenorhabditis elegans. While investigating developmental transitions in energy metabolism, a major metabolite isolated from perchloric acid extracts has been identified as a modified uridine nucleotide. The compound was isolated by gel filtration and ion-exchange chromatography and its structure was determined by {sup 1}H NMR and {sup 13}C NMR spectroscopy. This compound is the most abundant metabolite detected in {sup 31}PMR spectra of perchloric acid extracts from growing larvae. In the absence of phosphoarginine or phosphocreatine, this modifiedmore » nucleotide may have an important function in the nematode's energy metabolism, and it may also be found in several other invertebrates. During recovery from the dauer stage, metabolic activation is accompanied by a decrease in intracellular pH (pH{sub i}). Although metabolic activation has been associated with an alkaline pH{sub i} shift in other organisms, in vivo {sup 31}P NMR analysis of recovering dauer larvae shows a pH{sub i} decrease from {approximately}7.3 to {approximately}6.3 within 3 hr after the animals encounter food. This shift occurs before feeding begins, and coincides with, or soon follows, the development commitment to recover from the dauer stage, suggesting that control of pH{sub i} may be important in the regulation of larval development in nematodes. A library enriched for sequences expressed specifically during the L2d (predauer) stage was made by selecting plaques from a genomic lambda library that hybridized to subtracted L2d cDNA probes. Ultimately, three clones that were shown to hybridize only to L2d RNA were selected.« less

Recovery correction technique for NMR spectroscopy of perchloric acid extracts using DL-valine-2,3-d2: validation and application to 5-fluorouracil-induced brain damage.

PubMed

Nakagami, Ryutaro; Yamaguchi, Masayuki; Ezawa, Kenji; Kimura, Sadaaki; Hamamichi, Shusei; Sekine, Norio; Furukawa, Akira; Niitsu, Mamoru; Fujii, Hirofumi

2014-01-01

We explored a recovery correction technique that can correct metabolite loss during perchloric acid (PCA) extraction and minimize inter-assay variance in quantitative (1)H nuclear magnetic resonance (NMR) spectroscopy of the brain and evaluated its efficacy in 5-fluorouracil (5-FU)- and saline-administered rats. We measured the recovery of creatine and dl-valine-2,3-d2 from PCA extract containing both compounds (0.5 to 8 mM). We intravenously administered either 5-FU for 4 days (total, 100 mg/kg body weight) or saline into 2 groups of 11 rats each. We subsequently performed PCA extraction of the whole brain on Day 9, externally adding 7 µmol of dl-valine-2,3-d2. We estimated metabolite concentrations using an NMR spectrometer with recovery correction, correcting metabolite concentrations based on the recovery factor of dl-valine-2,3-d2. For each metabolite concentration, we calculated the coefficient of variation (CEV) and compared differences between the 2 groups using unpaired t-test. Equivalent recoveries of dl-valine-2,3-d2 (89.4 ± 3.9%) and creatine (89.7 ± 3.9%) in the PCA extract of the mixed solution indicated the suitability of dl-valine-2,3-d2 as an internal reference. In the rat study, recovery of dl-valine-2,3-d2 was 90.6 ± 9.2%. Nine major metabolite concentrations adjusted by recovery of dl-valine-2,3-d2 in saline-administered rats were comparable to data in the literature. CEVs of these metabolites were reduced from 10 to 17% before to 7 to 16% after correction. The significance of differences in alanine and taurine between the 5-FU- and saline-administered groups was determined only after recovery correction (0.75 ± 0.12 versus 0.86 ± 0.07 for alanine; 5.17 ± 0.59 versus 5.66 ± 0.42 for taurine [µmol/g brain tissue]; P < 0.05). A new recovery correction technique corrected metabolite loss during PCA extraction, minimized inter-assay variance in quantitative (1)H NMR spectroscopy of brain tissue, and effectively detected inter-group differences in concentrations of brain metabolites between 5-FU- and saline-administered rats.

Morphological changes of porphine films on graphite by perchloric and phosphoric electrolytes. An electrochemical-AFM study

NASA Astrophysics Data System (ADS)

Yivlialin, Rossella; Penconi, Marta; Bussetti, Gianlorenzo; Biroli, Alessio Orbelli; Finazzi, Marco; Duò, Lamberto; Bossi, Alberto

2018-06-01

Organic molecules have been proposed as promising candidates for electrode protection in acidic electrolytes. The use of tetraphenyl-porphines (H2TPP) as graphite surface-protecting agents in sulphuric acid (H2SO4) is one of the newest. With the aim of unveiling the mechanism of such a protective effect, in this paper we test the stability of a H2TPP thin film immersed in perchloric and phosphoric acid solutions that differently interact with porphyrins. The protective role of H2TPP is tested in the electrochemical potential range where the pristine graphite undergoes an oxidation process that erodes the surface and eventually exfoliate the stratified crystal. The electrochemical analysis is performed in a three-electrode cell, while the surface morphology is monitored ex-situ and in-situ by atomic force microscopy. Electrospray mass analysis is also employed to investigate the presence of H2TPP fragments in the solution. We find that the organic film is not stable in perchloric solution, while it is stable and avoids graphite surface corrosion in phosphoric acid solution. These results provide a rationale for the role played by free-base porphines in graphite protection.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farrokhzadeh, Abdolkarim; Modarresi-Alam, Ali Reza, E-mail: modaresi@chem.usb.ac.ir

Poly [(±)-2-(sec-butyl) aniline]/silica-supported perchloric acid composites were synthesized by combination of poly[(±)-2-sec-butylaniline] base (PSBA) and the silica-supported perchloric acid (SSPA) as dopant solid acid in solid-state. The X-ray photoelectron spectroscopy (XPS) and CHNS results confirm nigraniline oxidation state and complete doping for composites (about 75%) and non-complete for the PSBA·HCl salt (about 49%). The conductivity of samples was (≈0.07 S/cm) in agreement with the percent of doping obtained of the XPS analysis. Also, contact resistance was determined by circular-TLM measurement. The morphology of samples by the scanning electron microscopy (SEM) and their coating were investigated by XPS, SEM-map and energy-dispersivemore » X-ray spectroscopy (EDX). The key benefits of this work are the preparation of conductive chiral composite with the delocalized polaron structure under green chemistry and solid-state condition, the improvement of the processability by inclusion of the 2-sec-butyl group and the use of dopant solid acid (SSPA) as dopant. - Highlights: • The solid-state synthesis of the novel chiral composites of poly[(±)-2-(sec-butyl)aniline] (PSBA) and silica-supported perchloric acid (SSPA). • It takes 120 h for complete deprotonation of PSBA.HCl salt. • Use of SSPA as dopant solid acid for the first time to attain the complete doping of PSBA. • The coating of silica surface with PSBA.« less

Ruthenium(III) catalyzed oxidation of sugar alcohols by dichloroisocyanuric acid—A kinetic study

NASA Astrophysics Data System (ADS)

Lakshman Kumar, Y.; Venkata Nadh, R.; Radhakrishnamurti, P. S.

2016-02-01

Kinetics of ruthenium(III) catalyzed oxidation of biologically important sugar alcohols (myo-inositol, D-sorbitol, and D-mannitol) by dichloroisocyanuric acid was carried out in aqueous acetic acid—perchloric medium. The reactions were found to be first order in case of oxidant and ruthenium(III). Zero order was observed with the concentrations of sorbitol and mannitol whereas, a positive fractional order was found in the case of inositol concentration. An inverse fractional order was observed with perchloric acid in oxidation of three substrates. Arrhenius parameters were calculated and a plausible mechanism was proposed.

Quantitative liquid chromatographic determination of bromadoline and its N-demethylated metabolites in blood, plasma, serum, and urine samples.

PubMed

Peng, G W; Sood, V K; Rykert, U M

1985-03-01

Bromadoline and its two N-demethylated metabolites were extracted into ether:butyl chloride after the addition of internal standard and basification of the various biological fluids (blood, plasma, serum, and urine). These compounds were then extracted into dilute phosphoric acid from the organic phase and separated on a reversed-phase chromatographic system using a mobile phase containing acetonitrile and a buffer of 1,4-dimethylpiperazine and perchloric acid. The overall absolute extraction recoveries of these compounds were approximately 50-80%. The background interferences from the biological fluids were negligible and allowed quantitative determination of bromadoline and the metabolites at levels as low as 2-5 ng/mL. At mobile phase flow rate of 1 mL/min, the sample components and the internal standard were eluted at the retention times within approximately 7-12 min. The drug- and metabolite-to-internal standard peak height ratios showed excellent linear relationships with their corresponding concentrations. The analytical method showed satisfactory within- and between-run assay precision and accuracy, and has been utilized in the simultaneous determination of bromadoline and its two N-demethylated metabolites in biological fluids collected from humans and from dogs after administration of bromadoline maleate.

Perchlorate Formation on Mars Through Surface Radiolysis-Initiated Atmospheric Chemistry: A Potential Mechanism

NASA Technical Reports Server (NTRS)

Wilson, Eric H.; Atreya, Sushil K.; Kaiser, Ralf I.; Mahaffy, Paul R.

2016-01-01

Recent observations of the Martian surface by the Phoenix lander and the Sample Analysis at Mars indicate the presence of perchlorate (ClO4). The abundance and isotopic composition of these perchlorates suggest that the mechanisms responsible for their formation in the Martian environment may be unique in our solar system. With this in mind, we propose a potential mechanism for the production of Martian perchlorate: the radiolysis of the Martian surface by galactic cosmic rays, followed by the sublimation of chlorine oxides into the atmosphere and their subsequent synthesis to form perchloric acid (HClO4) in the atmosphere, and the surface deposition and subsequent mineralization of HClO4 in the regolith to form surface perchlorates. To evaluate the viability of this mechanism, we employ a one-dimensional chemical model, examining chlorine chemistry in the context of Martian atmospheric chemistry. Considering the chlorine oxide, OClO, we find that an OClO flux as low as 3.2 x 10(exp 7) molecules/sq cm/s sublimated into the atmosphere from the surface could produce sufficient HClO4 to explain the perchlorate concentration on Mars, assuming an accumulation depth of 30 cm and integrated over the Amazonian period. Radiolysis provides an efficient pathway for the oxidation of chlorine, bypassing the efficient Cl/HCl recycling mechanism that characterizes HClO4 formation mechanisms proposed for the Earth but not Mars.

Evaluation of Military Field-Water Quality. Volume 3. Opportunity Poisons

DTIC Science & Technology

1987-12-01

Acidic chemical cleaners fluoric acid, nitric acid, perchloric Spent acid acid, sulfuric acid Alkalies Miscellaneous caustic products Ammonia, lime...calcium oxide), potassium Alkaline battery fluid hydroxide, sodium hydroxide, sodium Caustic wastewater silicate Cleaning solutions Lye Nonhalogenated...Laboratory chemicals chloride, polychlorinated biphenyls, zinc Paint and varnish removers naphthenate , copper naphthenate , dichloro- Capacitors and

Perchlorate radiolysis on Mars and the origin of martian soil reactivity.

PubMed

Quinn, Richard C; Martucci, Hana F H; Miller, Stephanie R; Bryson, Charles E; Grunthaner, Frank J; Grunthaner, Paula J

2013-06-01

Results from the Viking biology experiments indicate the presence of reactive oxidants in martian soils that have previously been attributed to peroxide and superoxide. Instruments on the Mars Phoenix Lander and the Mars Science Laboratory detected perchlorate in martian soil, which is nonreactive under the conditions of the Viking biology experiments. We show that calcium perchlorate exposed to gamma rays decomposes in a CO2 atmosphere to form hypochlorite (ClO(-)), trapped oxygen (O2), and chlorine dioxide (ClO2). Our results show that the release of trapped O2 (g) from radiation-damaged perchlorate salts and the reaction of ClO(-) with amino acids that were added to the martian soils can explain the results of the Viking biology experiments. We conclude that neither hydrogen peroxide nor superoxide is required to explain the results of the Viking biology experiments.

(Per)chlorate Reduction by the Thermophilic Bacterium Moorella perchloratireducens sp. nov., Isolated from Underground Gas Storage▿

PubMed Central

Balk, Melike; van Gelder, Ton; Weelink, Sander A.; Stams, Alfons J. M.

2008-01-01

A thermophilic bacterium, strain An10, was isolated from underground gas storage with methanol as a substrate and perchlorate as an electron acceptor. Cells were gram-positive straight rods, 0.4 to 0.6 μm in diameter and 2 to 8 μm in length, growing as single cells or in pairs. Spores were terminal with a bulged sporangium. The temperature range for growth was 40 to 70°C, with an optimum at 55 to 60°C. The pH optimum was around 7. The salinity range for growth was between 0 and 40 g NaCl liter−1 with an optimum at 10 g liter−1. Strain An10 was able to grow on CO, methanol, pyruvate, glucose, fructose, cellobiose, mannose, xylose, and pectin. The isolate was able to respire with (per)chlorate, nitrate, thiosulfate, neutralized Fe(III) complexes, and anthraquinone-2,6-disulfonate. The G+C content of the DNA was 57.6 mol%. On the basis of 16S rRNA analysis, strain An10 was most closely related to Moorella thermoacetica and Moorella thermoautotrophica. The bacterium reduced perchlorate and chlorate completely to chloride. Key enzymes, perchlorate reductase and chlorite dismutase, were detected in cell extracts. Strain An10 is the first thermophilic and gram-positive bacterium with the ability to use (per)chlorate as a terminal electron acceptor. PMID:17981952

Phenotypic and genotypic description of Sedimenticola selenatireducens strain CUZ, a marine (per)chlorate-respiring gammaproteobacterium, and its close relative the chlorate-respiring Sedimenticola strain NSS.

PubMed

Carlström, Charlotte I; Loutey, Dana E; Wang, Ouwei; Engelbrektson, Anna; Clark, Iain; Lucas, Lauren N; Somasekhar, Pranav Y; Coates, John D

2015-04-01

Two (per)chlorate-reducing bacteria, strains CUZ and NSS, were isolated from marine sediments in Berkeley and San Diego, CA, respectively. Strain CUZ respired both perchlorate and chlorate [collectively designated (per)chlorate], while strain NSS respired only chlorate. Phylogenetic analysis classified both strains as close relatives of the gammaproteobacterium Sedimenticola selenatireducens. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) preparations showed the presence of rod-shaped, motile cells containing one polar flagellum. Optimum growth for strain CUZ was observed at 25 to 30 °C, pH 7, and 4% NaCl, while strain NSS grew optimally at 37 to 42 °C, pH 7.5 to 8, and 1.5 to 2.5% NaCl. Both strains oxidized hydrogen, sulfide, various organic acids, and aromatics, such as benzoate and phenylacetate, as electron donors coupled to oxygen, nitrate, and (per)chlorate or chlorate as electron acceptors. The draft genome of strain CUZ carried the requisite (per)chlorate reduction island (PRI) for (per)chlorate respiration, while that of strain NSS carried the composite chlorate reduction transposon responsible for chlorate metabolism. The PRI of strain CUZ encoded a perchlorate reductase (Pcr), which reduced both perchlorate and chlorate, while the genome of strain NSS included a gene for a distinct chlorate reductase (Clr) that reduced only chlorate. When both (per)chlorate and nitrate were present, (per)chlorate was preferentially utilized if the inoculum was pregrown on (per)chlorate. Historically, (per)chlorate-reducing bacteria (PRB) and chlorate-reducing bacteria (CRB) have been isolated primarily from freshwater, mesophilic environments. This study describes the isolation and characterization of two highly related marine halophiles, one a PRB and the other a CRB, and thus broadens the known phylogenetic and physiological diversity of these unusual metabolisms. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Reduction of pertechnetate by acetohydroxamic acid: Formation of [TcNO(AHA)2(H2O)]+ and implications for the UREX process.

DOE Office of Scientific and Technical Information (OSTI.GOV)

1Harry Reid Center for Environmental Studies, Nuclear Science and Technology Division, University of Nevada, Las Vegas, Las Vegas, NV, 89154-4006; Gong, Cynthia-May S; Poineau, Frederic

2008-02-26

Reductive nitrosylation and complexation of ammonium pertechnetate by acetohydroxamic acid has been achieved in aqueous nitric and perchloric acid solutions. The kinetics of the reaction depend on the relative concentrations of the reaction components and are accelerated at higher temperatures. The reaction does not occur unless conditions are acidic. Analysis of the x-ray absorption fine structure spectroscopic data is consistent with a pseudo-octahedral geometry with the linear Tc-N-O bond typical of technetium nitrosyl compounds, and electron spin resonance spectroscopy is consistent with a the d{sup 5} Tc(II) nitrosyl complex. The nitrosyl source is generally AHA, but may be augmented bymore » products of reaction with nitric acid. The resulting low-valency trans-aquonitrosyl(diacetohydroxamic)-technetium(II) complex (1) is highly soluble in water, extremely hydrophilic, and is not extracted by tri-n-butylphosphate in a dodecane diluent. Its extraction properties are not pH-dependent; titration studies indicate a single species from pH 4.5 down to -0.6 (calculated). This molecule is resistant to oxidation by H{sub 2}O{sub 2}, even at high pH, and can undergo substitution to form other technetium nitrosyl complexes. The formation of 1 may strongly impact the fate of technetium in the nuclear fuel cycle.« less

Uptake of N-nitrosodimethylamine (NDMA) from water by phreatophytes in the absence and presence of perchlorate as a co-contaminant.

PubMed

Yifru, Dawit D; Nzengung, Valentine A

2006-12-01

The uptake and fate of the emerging contaminants N-nitrosodimethylamine (NDMA) and perchlorate in phreatophytes was studied in a hydroponics system under greenhouse conditions. NDMA is a potent carcinogen, and perchlorate disrupts the functioning ofthe human thyroid gland. The rate of removal of NDMA from solution by rooted cuttings of black willow (Salix nigra) and hybrid poplar (Populus deltoides x nigra, DN34) trees varied seasonally, with faster removal in summer months when transpiration rates were highest. A linear correlation between the volume of water transpired and mass of NDMA removed from the root zone was observed, especially at higher NDMA concentrations. In bioreactors dosed with both NDMA (0.7-1.0 mg L(-1)) and perchlorate (27 mg L(-1)), no competitive uptake of NDMA and perchlorate was observed. While NDMA was primarily removed from solution by plant uptake, perchlorate was predominantly removed by rhizodegradation. In the presence of NDMA, a slower rate of rhizodegradation of perchlorate was observed, but still significantly faster than the rate of NDMA uptake. For experiments conducted with radiolabeled NDMA, 46.4 +/- 1.1% of the total 14C-activity was recovered in the plant tissues and 47.5% was phytovolatilized. The 46.4 +/- 1.1% recovered in the plants was distributed as follows: 18.8 +/- 1.4% in leaves, 15.9 +/- 5.9% in stems, 7.6 +/- 3.2% in branches, and 3.5 +/- 3.3% in roots. The poor extractability of NDMA with methanol-water (1:1 v/v) from stem and leaf tissues suggested that some fraction of NDMA was assimilated. The calculated transpiration stream concentration factor (TSCF) of 0.28 +/- 0.06 suggests that NDMA is passively taken up by phreatophytes, and mainly phytovolatilized.

Evaluation of radiochemical neutron activation analysis methods for determination of arsenic in biological materials.

PubMed

Paul, Rick L

2011-01-01

Radiochemical neutron activation analysis (RNAA) with retention on hydrated manganese dioxide (HMD) has played a key role in the certification of As in biological materials at NIST. Although this method provides very high and reproducible yields and detection limits at low microgram/kilogram levels, counting geometry uncertainties may arise from unequal distribution of As in the HMD, and arsenic detection limits may not be optimal due to significant retention of other elements. An alternate RNAA procedure with separation of arsenic by solvent extraction has been investigated. After digestion of samples in nitric and perchloric acids, As(III) is extracted from 2 M sulfuric acid solution into a solution of zinc diethyldithiocarbamate in chloroform. Counting of (76)As allows quantitation of arsenic. Addition of an (77)As tracer solution prior to dissolution allows correction for chemical yield and counting geometries, further improving reproducibility. The HMD and solvent extraction procedures for arsenic were compared through analysis of SRMs 1577c (bovine liver), 1547 (peach leaves), and 1575a (pine needles). Both methods gave As results in agreement with certified values with comparable reproducibility. However, the solvent extraction method yields a factor of 3 improvement in detection limits and is less time-consuming than the HMD method. The new method shows great promise for use in As certification in reference materials.

Radiochemical separation of gallium by amalgam exchange

USGS Publications Warehouse

Ruch, R.R.

1969-01-01

An amalgam-exchange separation of radioactive gallium from a number of interfering radioisotopes has been developed. A dilute (ca. 0.3%) gallium amalgam is agitated with a slightly acidic solution of 72Ga3+ containing concentrations of sodium thiocyanate and either perchlorate or chloride. The amalgam is then removed and the radioactive gallium stripped by agitation with dilute nitric acid. The combined exchange yield of the perchlorate-thiocyanate system is 90??4% and that of the chloride-thiocyanate system is 75??4%. Decontamination yields of most of the 11 interfering isotopes studied were less than 0.02%. The technique is applicable for use with activation analysis for the determination of trace amounts of gallium. ?? 1969.

Perchlorate Radiolysis on Mars and the Origin of Martian Soil Reactivity

PubMed Central

Martucci, Hana F.H.; Miller, Stephanie R.; Bryson, Charles E.; Grunthaner, Frank J.; Grunthaner, Paula J.

2013-01-01

Abstract Results from the Viking biology experiments indicate the presence of reactive oxidants in martian soils that have previously been attributed to peroxide and superoxide. Instruments on the Mars Phoenix Lander and the Mars Science Laboratory detected perchlorate in martian soil, which is nonreactive under the conditions of the Viking biology experiments. We show that calcium perchlorate exposed to gamma rays decomposes in a CO2 atmosphere to form hypochlorite (ClO−), trapped oxygen (O2), and chlorine dioxide (ClO2). Our results show that the release of trapped O2 (g) from radiation-damaged perchlorate salts and the reaction of ClO− with amino acids that were added to the martian soils can explain the results of the Viking biology experiments. We conclude that neither hydrogen peroxide nor superoxide is required to explain the results of the Viking biology experiments. Key Words: Mars—Radiolysis—Organic degradation—in situ measurement—Planetary habitability and biosignatures. Astrobiology 13, 515–520. PMID:23746165

Physical proprieties of low viscosity estolide 2-ethylhexyl esters

USDA-ARS?s Scientific Manuscript database

Acetic- and butyric-capped oleic estolide 2-ethylhexyl (2-EH) esters were synthesized in a perchloric acid catalyzed (0.05 equiv) one-pot process from industrial 90% oleic acid and either acetic or butyric fatty acids at two different ratios. This was directly followed by the esterification process ...

Effects of oxidizing adulterants on detection of 11-nor-delta9-THC-9-carboxylic acid in urine.

PubMed

Paul, Buddha D; Jacobs, Aaron

2002-10-01

Bleach, nitrite, chromate, and hydrogen peroxide-peroxidase are effective urine adulterants used by the illicit drug users to conceal marijuana-positive results. Methods for detecting nitrite and chromate are available. Effects of other oxidizing agents that could possibly be used as adulterants and are difficult to detect or measure are presented in this report. Urine samples containing 40 ng/mL of 11-nor-delta9-THC-9-carboxylic acid (THC-acid) were treated with 10 mmol/L of commonly available oxidizing agents. Effects of horseradish peroxidase of activity 10 unit/mL and extracts from 2.5 g of red radish (Raphanus sativus, Radicula group), horseradish (Armoracia rusticana), Japanese radish (Raphanus sativus, Daikon group), and black mustard seeds (Brassica nigra), all with 10 mmol/L of hydrogen peroxide, were also examined. After 5 min, 16 h and 48 h of exposure at room temperature (23 degrees C) the specimens were tested by a gas chromatographic-mass spectrometric method for THC-acid. A control group treated with sodium hydrosulfite to reduce the oxidants, was also tested to investigate the effect of oxidizing agents on THC-acid in the extraction method. THC-acid was lost completely in the extraction method when treated with chromate, nitrite, oxone, and hydrogen peroxide/ferrous ammonium sulfate (Fenton's reagent). Some losses were also observed with persulfate and periodate (up to 25%). These oxidants, and other oxidizing agents like permanganate, periodate, peroxidase, and extracts from red radish, horseradish, Japanese radish and black mustard seeds destroyed most of the THC-acid (> 94%) within 48 h of exposure. Chlorate, perchlorate, iodate, and oxychloride under these conditions showed little or no effect. Complete loss was observed when THC-acid was exposed to 50 mmol/L of oxychloride for 48 h. Several oxidizing adulterants that are difficult to test by the present urine adulterant testing methods showed considerable effects on the destruction of THC-acid. The time and temperature for these effects were similar to those used by most laboratories to collect and test specimens. In several cases, the loss of THC-acid was > 94%.

[Analysis of primary elemental speciation distribution in mungbean during enzymatic hydrolization].

PubMed

Li, Ji-Hua; Huang, Mao-Fang; Zhu, De-Ming; Zheng, Wei-Wan; Zhong, Ye-Jun

2009-03-01

In the present paper, trace elements contents of cuprum, zincum, manganese and ferrum in mungbean and their primary speciation distribution during enzymatic hydrolization were investigated with ICP-AES OPTIMA 5300DV plasma emission spectroscopy. The trace elements were separated into two forms, i.e. dissolvable form and particulate form, by cellulose membrane with 0.45 microm of pore diameter. All the samples were digested by strong acid (perchloric acid and nitric acid with 1 : 4 ratio ). The parameters of primary speciations of the four elements were calculated and discussed. The results showed: (1) Contents of cuprum, zincum, manganese and ferrum in mungbean were 12.77, 31.26, 18.14 and 69.38 microg x g(-1) (of dry matter), respectively. Different treatment resulted in different elemental formulation in product, indicating that more attention should be paid to the trace elements pattern when producing mungbean beverage with different processes. (2) Extraction rates of cuprum, zincum, manganese and ferrum in extract were 68.84%, 51.84%, 63.97% and 30.40% with enzymatic treatments and 36.22%, 17.58%, 7.85% and 22.99% with boil treatment, respectively. Both boil and enzymatic treatments led to poor elemental extraction rates, which proved that it was necessary to take deep enzymatic hydrolysis treatment in mungbean beverage process as the trace element utilization rate was concerned. (3) Amylase, protease and cellulose showed different extraction effectiveness of the four trace elements. Generally, protease exhibited highest efficiency for the four elements extraction. All of the four trace elements were mostly in dissolvable form in all hydrolysates and soup. (4) Relative standard deviations and recovery yields are within 0.12%-0.90% (n = 11) and 98.6%-101.4%, respectively. The analysis method in this paper proved to be accurate.

Kinetics of gibbsite dissolution under low ionic strength conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ganor, J.; Mogollon, J.L.; Lasaga, A.C.

1999-06-01

Experiments measuring synthetic gibbsite dissolution rates were carried out using both a stirred-flow-through reactor and a column reactor at 25 C, and pH range of 2.5--4.1. All experiments were conducted under far from equilibrium conditions ({Delta}G < {minus}1.1 kcal/mole). The experiments were performed with perchloric acid under relatively low (and variable) ionic strength conditions. An excellent agreement was found between the results of the well-mixed flow-through experiments and those of the (nonmixed) column experiments. This agreement shows that the gibbsite dissolution rate is independent of the stirring rate and therefore supports the conclusion of Bloom and Erich (1987) that gibbsitemore » dissolution reaction is surface controlled and not diffusion controlled. The Brunauer-Emmett-Teller (BET) surface area of the gibbsite increased during the flow-through experiments, while in the column experiments no significant change in surface area was observed. The significant differences in the BET surface area between the column experiments and the flow-through experiments, and the excellent agreement between the rates obtained by both methods, enable the authors to justify the substitution of the BET surface area for the reactive surface area. The dissolution rate of gibbsite varied as a function of the perchloric acid concentration. The authors interpret the gibbsite dissolution rate as a result of a combined effect of proton catalysis and perchlorate inhibition. Following the theoretical study of Ganor and Lasaga (1998) they propose specific reaction mechanisms for the gibbsite dissolution in the presence of perchloric acid. The mathematical predictions of two of these reaction mechanisms adequately describe the experimental data.« less

In vitro Inhibitory Effect of Gymnema sylvestre Extracts and Total Gymnemic Acids Fraction on Select Cytochrome P450 Activities in Rat Liver Microsomes.

PubMed

Vaghela, Madhuri; Iyer, Krishna; Pandita, Nancy

2018-04-01

Gymnema sylvestre R. Br. is a well-known Indian medicinal herb. Gymnemic acids are pentacyclic triterpenes saponins and active phytoconstituents of Gymnema sylvestre. The study aimed at evaluation of the in vitro rat liver cytochrome P450 (CYP) inhibition potential of extracts and total gymnemic acid (TA)-enriched fractions from G. sylvestre. Standardization of G. sylvestre [ethanolic (EL), hydroethanolic (HE), total acid of ethanolic (TAE), total acid of hydroethanolic (TAHE) and total acid of aqueous (TAAQ) extract] was done with respect to deacyl gymnemic acid (DAGA), using reverse phase-high performance liquid chromatography (RP-HPLC). Total triterpenoid content was determined by vanillin perchloric acid assay. Total triterpene content was found to be the highest in TAAQ (59.86 ± 0.005% w/w) and TAE (49.77 ± 0.009% w/w). TAAQ showed IC 50  ≤ 50 µg/ml for all selected CYP activities. Testosterone 6β-hydroxylation was strongly inhibited by TAE (IC 50 : 15.48 ± 2.13 µg/ml) and was moderately by TAAQ and EL with IC 50  ≥ 50 µg/ml. Flurbiprofen 4'-hydroxylation was subject to strong, weak and moderate inhibition by TAAQ (IC 50 : 34.67 ± 1.38 µg/ml), TAE (IC 50 : ≥ 50 µg/ml) and EL (IC 50 : > 50 µg/ml), respectively. Dextromethorphan O-demethylation was inhibited by TAHE and TAAQ. In vitro inhibition studies suggested that TA strongly inhibits activity of selected CYP. This inhibition may possibly be due to triterpenoids and gymnemic acids that have been reported to be present in it. Data also suggest a potential for possible in vivo herb-drug interactions involving G. sylvestre and other medications that are metabolized by the same CYP.

Reduction of Pertechnetate By Acetohydroxamic Acid: Formation of [tc**II(NO)(AHA)(2)(H(2)O)]**+ And Implications for the UREX Process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gong, C.-M.S.; Lukens, W.W.; Poineau, F.

2009-05-18

Reductive nitrosylation and complexation of ammonium pertechnetate by acetohydroxamic acid has been achieved in aqueous nitric and perchloric acid solutions. The kinetics of the reaction depend on the relative concentrations of the reaction components and are accelerated at higher temperatures. The reaction does not occur unless conditions are acidic. Analysis of the X-ray absorption fine structure spectroscopic data is consistent with a pseudo-octahedral geometry and the linear Tc-N-O bond typical of technetium nitrosyl compounds, and electron spin resonance spectroscopy is consistent with a d{sup 5} Tc(II) nitrosyl complex. The nitrosyl source is generally AHA, but it may be augmented bymore » some products of the reaction with nitric acid. The resulting low-valency trans-aquonitrosyl(diacetohydroxamic)-technetium(II) complex ([Tc{sup II}(NO)(AHA){sub 2}H{sub 2}O]{sup +}, 1) is highly soluble in water, extremely hydrophilic, and is not extracted by tri-n-butylphosphate in a dodecane diluent. Its extraction properties are not pH-dependent: potentiometric-spectrophotometric titration studies indicate a single species from pH 4 down to -0.6 (calculated). This molecule is resistant to oxidation by H{sub 2}O{sub 2}, even at high pH, and can undergo substitution to form other technetium nitrosyl complexes. The potential formation of 1 during reprocessing may strongly impact the fate of technetium in the nuclear fuel cycle.« less

A study of the kinetics of the reduction of neptunium(VI) by acetohydroxamic acid in perchloric acid

NASA Astrophysics Data System (ADS)

Matteson, Brent S.; Precek, Martin; Paulenova, Alena

2010-03-01

The kinetics of reduction of NpO22+ to NpO2+ by acetohydroxamic acid in 1 mol·L-1perchloric acid media at 10 and 22°C were studied. The reaction rate was monitored using stopped-flow and standard infrared spectroscopy. Under conditions such that acetohydroxamic acid was in excess relative to Np, the reduction rate of NpO22+ is described by the following: where k = 2.57x103 mol-1·L·sec-1 at 10°C. However, when neptunium is in a significant molar excess relative to acetohydroxamic acid, the reduction mechanism is dictated by two distinct reactions. An initial and incomplete reduction occurs as the result of the oxidation of AHA, while a slower and partial reduction of NpO22+ is likely caused by the oxidation products of AHA. The reaction rate of this first-order mechanism was calculated as 3.7x10-4 sec-1 at 10°C and 0.001 sec-1 at 22°C.

Structure cristalline, caractérisation spectroscopique, calcul DFT et analyse de surface Hirshfeld du perchlorate de p-toluidinium.

PubMed

Ben Jomaa, Meriam; Chebbi, Hammouda; Fakhar Bourguiba, Noura; Zid, Mohamed Faouzi

2018-02-01

The synthesis of p -toluidinium perchlorate (systematic name: 4-methyl-anilinium perchlorate), C 7 H 10 N + ·ClO 4 - , was carried out from an aqueous reaction of perchloric acid with p -toluidine. This compound was characterized by powder XRD, IR and UV-Vis spectroscopy. The structure was further confirmed by a single-crystal X-ray diffraction study. The crystal structure is formed by a succession of two-dimensional mol-ecular layers consisting of perchlorate anions and organic cations parallel to the (100) plane and located at x = 2 n  + ½ ( n ∈ Z ). Each mixed layer is formed by infinite chains {C 7 H 10 N + ·ClO 4 - } n parallel to the [010] direction and developing along the c axis, generating R 2 4 (8), R 2 2 (4) and R 4 4 (12) graph-set motifs. The results of a theoretical study using the DFT method at the B3LYP/6-311++G(d,p) level are in good agreement with the experimental data. Hirshfeld surface and fingerprint plots reveal that the structure is dominated by O⋯H/H⋯O (54.2%), H⋯H (26.9%) and C-H ⋯π (14.3%) contacts. The studied crystal was refined as a two-component twin.

Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer

USGS Publications Warehouse

Hatzinger, P.B.; Bohlke, John Karl; Sturchio, N.C.; Gu, B.; Heraty, L.J.; Borden, R.C.

2009-01-01

An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification. During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h. After correction for dilution (using Br– as a conservative tracer of the injectate), perchlorate concentrations decreased by 78% and nitrate concentrations decreased by 82% during the initial 8.6 h after the injection. The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (e18O/e37Cl) was 2.6, which is similar to that observed in the laboratory using pure cultures (2.5). Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of ~0.8 (e18O/e15N), which is within the range of values reported previously for denitrification. However, the magnitudes of the individual apparent in situ isotope fractionation effects for perchlorate and nitrate were appreciably smaller than those reported in homogeneous closed systems (0.2 to 0.6 times), even after adjustment for dilution. These results indicate that (1) isotope fractionation factor ratios (e18O/e37Cl, e18O/e15N) derived from homogeneous laboratory systems (e.g. pure culture studies) can be used qualitatively to confirm the occurrence of in situ biodegradation of both perchlorate and nitrate, but (2) the magnitudes of the individual apparent e values cannot be used quantitatively to estimate the in situ extent of biodegradation of either anion.

Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hatzinger, Paul B.; Bohlke, J. K.; Sturchio, N. C.

An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification. During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h. After correction for dilution (using Br-as a conservative tracer of themore » injectate), perchlorate concentrations decreased by 78 % and nitrate concentrations decreased by 87 %, during the initial 8.6 h after the injection. The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (ε18O/ε37Cl) was 2.6, which is similar to that observed in the laboratory using pure cultures (2.5). Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of approximately 0.8 (ε18O/ε15N), which is within the range of values reported previously for denitrification. However, the magnitudes of the individual apparent in situ isotope fractionation effects for perchlorate and nitrate were appreciably smaller than those reported in homogeneous closed systems (0.2 to 0.6 times), even after adjustment for dilution. These results indicate that (1) isotope fractionation factor ratios (ε18O/ε37Cl, ε18O/ε15N) derived from homogeneous laboratory systems (e.g., pure culture studies) can be used qualitatively to confirm the occurrence of in situ biodegradation of both perchlorate and nitrate, but (2) the magnitudes of the individual apparent  values cannot be used quantitatively to estimate the in situ extent of biodegradation of either anion.« less

Improvement of the classical assay method for liver glycogen fractions: ASG is the main and metabolic active fraction.

PubMed

Shokri-Afra, H; Ostovar-Ravari, A; Rasouli, M

2016-10-01

Acid digestion of animal tissues yields two fractions of glycogen, acid soluble (ASG) and insoluble (AIG). The current study was performed to improve the assay method for glycogen fractions in rat liver in different physiological states. All steps of the assay were manipulated and optimized to measure the content of ASG and AIG in fed and starved rat liver. In postmortem liver tissue, total glycogen was decreased slowly at 4°C and rapidly at 25°C but was well stabilized at -20°C and -70°C. At room temperature, ASG underwent autolysis at the rate of 1.3% and decreased by half at 35 min, while AIG increased slightly. The yield of the recovery of ASG during four successive extractions depends on the tissue concentration, and at the ratio of 50 mg tissue per 2 mL perchloric acid (PCA) was about 93.2%, 6.3%, 0.3% and 0.05% respectively. The increase in the time and extent of homogenization of the tissue with cold PCA and using ultrasonication had not any significant effect on the extraction yield of ASG. The time of centrifugation of the tissue extract could be reduced from 15 to 7.5 minutes with no significant decrease in the recovery of ASG. On extraction with ethanol, the yield of recovery of ASG reached the maximal level of 97.5% at a final ethanol concentration of 60%. The recovery of ASG was not improved in the presence of KCl. During 24 starvation, total glycogen depleted completely and the change occurred entirely in ASG, while AIG did not change significantly. The CV% was less than 5% for the optimized assays of glycogen fractions. ASG is the main and metabolically active portion of glycogen in rat liver.

In vivo chemistry of iofetamine HCl iodine-123 (IMP)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baldwin, R.M.; Wu, J.L.

1988-01-01

Application of chemical methods for characterizing the in vivo behavior of iofetamine HCI /sup 123/I (IMP) has shed light on the metabolism of iofetamine in animals and humans. A successful technique consists of ethyl acetate extraction of the metabolites from tissue samples acidified with perchloric acid, separation of the mixture by high performance liquid chromatography, and quantitation of the radioactive components with a sensitive scintillation detector. Metabolism of iofetamine HCI /sup 123/I proceeds sequentially from the N-isopropyl group on the amphetamine side chain. The first step, dealkylation to the primary amine p-iodoamphetamine (PIA), occurs readily in the brain, lungs, andmore » liver; activity in the brain and lungs consists of only IMP and PIA even 24 hr after administration. The rate-limiting step appears to be deamination to give the transitory intermediate p-iodophenylacetone, which is rapidly degraded to p-iodobenzoic acid and conjugated with glycine in the liver to give the end product of metabolism, p-iodohippuric acid, which is excreted through the kidneys in the urine.« less

Synthesis and physical properties of new coco-oleic estolide branched esters

USDA-ARS?s Scientific Manuscript database

Oils derived from vegetable oils tend to not meet the standards for industrial lubricants because of unacceptable low temperature properties, pour point (PP), and/or cloud point (CP). However, a catalytic amount of perchloric acid with oleic and coconut (coco) fatty acids produced a coco-oleic estol...

New method for the measurement of osmium isotopes applied to a New Zealand Cretaceous/Tertiary boundary shale

USGS Publications Warehouse

Lichte, F.E.; Wilson, S.M.; Brooks, R.R.; Reeves, R.D.; Holzbecher, J.; Ryan, D.E.

1986-01-01

The determination of osmium content and isotopic abundances in geological materials has received increasing attention in recent years following the proposal of Alvarez et al.1 that mass extinctions at the end of the Cretaceous period were caused by the impact of a large (???10km) meteorite which left anomalously high iridium levels as a geochemical signature in the boundary shales. Here we report a new and simple method for measuring osmium in geological materials, involving fusion of the sample with sodium peroxide, distillation of the osmium as the tetroxide using perchloric acid, extraction into chloroform, and absorption of the chloroform extract onto graphite powder before instrumental neutron activation analysis. In a variant of this technique, the chloroform extract is back-extracted into an aqueous phase and the osmium isotopes are determined by plasma-source mass spectrometry (ICPMS). We have used this method on the Woodside Creek (New Zealand) Cretaceous/Tertiary boundary clay and have obtained the first osmium content (6g ng g-1) for this material. The 187Os/186Os ratio is 1.12??0.16, showing a typical non-crustal signature. This combined distillation-extraction- ICPMS method will prove to be useful for measuring osmium isotopes in other geological materials. ?? 1986 Nature Publishing Group.

Nitrogen and phosphorus resorption in a neotropical rain forest of a nutrient-rich soil.

PubMed

Martínez-Sánchez, José Luis

2005-01-01

In tropical forests with nutrient-rich soil tree's nutrient resorption from senesced leaves has not always been observed to be low. Perhaps this lack of consistence is partly owing to the nutrient resorption methods used. The aim of the study was to analyse N and P resorption proficiency from tropical rain forest trees in a nutrient-rich soil. It was hypothesised that trees would exhibit low nutrient resorption in a nutrient-rich soil. The soil concentrations of total N and extractable P, among other physical and chemical characteristics, were analysed in 30 samples in the soil surface (10 cm) of three undisturbed forest plots at 'Estaci6n de Biologia Los Tuxtlas' on the east coast of Mexico (18 degrees 34' - 18 degrees 36' N, 95 degrees 04' - 95 degrees 09' W). N and P resorption proficiency were determined from senescing leaves in 11 dominant tree species. Nitrogen was analysed by microkjeldahl digestion with sulphuric acid and distilled with boric acid, and phosphorus was analysed by digestion with nitric acid and perchloric acid. Soil was rich in total N (0.50%, n = 30) and extractable P (4.11 microg g(-1) n = 30). As expected, trees showed incomplete N (1.13%, n = 11) and P (0.11%, n = 1) resorption. With a more accurate method of nutrient resorption assessment, it is possible to prove that a forest community with a nutrient-rich soil can have low levels of N and P resorption.

Trace detection of perchlorate in industrial-grade emulsion explosive with portable surface-enhanced Raman spectroscopy.

PubMed

Nuntawong, N; Eiamchai, P; Limwichean, S; Wong-ek, B; Horprathum, M; Patthanasettakul, V; Leelapojanaporn, A; Nakngoenthong, S; Chindaudom, P

2013-12-10

Recent analyses by ion-exchange chromatography (IC) showed that, beside nitrate, the majority of the industrial-grade emulsion explosives, extensively used by most separatists in the southern Thailand insurgency, contained small traces of perchlorate anions. In demand for the faster, reliable, and simple detection methods, the portable detection of nitrate and perchlorate became the great interest for the forensic and field-investigators. This work proposed a unique method to detect the trace amount of perchlorate in seven industrial-grade emulsion explosives under the field tests. We utilized the combination of the portable Raman spectroscope, the developed surfaced-enhanced Raman substrates, and the sample preparation procedures. The portable Raman spectroscope with a laser diode of 785 nm for excitation and a thermoelectric-cooled CCD spectrometer for detection was commercially available. The SERS substrates, with uniformly distributed nanostructured silver nanorods, were fabricated by the DC magnetron sputtering system, based on the oblique-angle deposition technique. The sample preparation procedures were proposed based on (1) pentane extraction technique and (2) combustion technique, prior to being dissolved in the purified water. In comparison to the ion chromatography and the conventional Raman measurements, our proposed methods successfully demonstrated the highly sensitive detectability of the minimal trace amount of perchlorate from five of the explosives with minimal operating time. This work was therefore highly practical to the development for the forensic analyses of the post-blast explosive residues under the field-investigations. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Quantitation of intracellular metabolites of [35S]-6-mercaptopurine in L5178Y cells grown in time-course incubates.

PubMed

Breter, H J; Zahn, R K

1979-09-01

6-Mercaptopurine (6MP) metabolism was quantitatively determined in L5178Y murine lymphoma. Cells grown in time-course incubates with [35S]-6MP were extracted with cold perchloric acid, and the buffered extracts were subjected to high-performance liquid cation-exchange chromatography prior to and after hydrolysis with alkaline phosphatase. Free sulfate, 6-thiouric acid, 6-thioxanthosine, 6-thioguanosine, 6-thioinosine, free 6MP, and 6-methylthioinosine were separated from each other; identified in the radiochromatograms by elution volume, UV spectroscopic data, and enzymatic peak-shifting analyses with purine nucleoside phosphorylase; and quantitatively determined by means of 35S radioactivity. Gross intracellular 35S concentrations remained constant at 5 x 10(-5) M after 1 hr of incubation. 6MP metabolism in L5178Y cells was distinguished into an early phase (to 1 hr of incubation) in which 6MP was predominantly catabolized to 6-thiouric acid and free sulfate, into an intermediate phase (to 8 hr) in which substantial amounts of free 6MP and of ribonucleotides of 6-thioxanthosine and 6-thioguanosine were present while the concentrations of nonnucleotide oxidation products sharply decreased, and into a late phase (to 24 hr) in which the ribonucleotides of 6MP, of 6-thioguanosine and, in particular, of 6-methylthioinosine were the most abundant metabolites.

Perchlorate and Halogen-Free High Energy Dense Oxidizers (HEDO)

DTIC Science & Technology

2011-06-01

nitric acid indicate that the covalent oxalic acid dinitrate ester should be more stable than the ionic dinitronium oxalate . The following three...synthetic strategies were developed to generate compound 11 (Scheme 17). Strategy I is the nitration of anhydrous oxalic acid with nitric acid (100...temperatures (25 to –30 °C) and in all dry solvents used. Scheme 17: Synthetic strategies for the production of oxalic acid dinitrate ester (11

Environmental Statement. Disposition of Orange Herbicide by Incineration

DTIC Science & Technology

1974-11-01

and will follow all applicable maritime regulations. The vessel has operated for about two years without encountering a situation which required... hypochlorous acid , chlorous acid , chloric acid , perchloric acid , chlorine hydrate, and phosgene. All of these compounds are highly corrosive and toxic...effluent gas stack were operated isokinetically. The system used to sample for TCDD and the butyl esters and acids (of 2,4-D and 2,4,5-T) was not

Acidic intracellular pH shift during Caenorhabditis elegans larval development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wadsworth, W.G.; Riddle, D.L.

1988-11-01

During recovery from the developmentally arrested, nonfeeding dauer stage of the nemotode Caenorhabditis elegans, metabolic activation is accompanied by a decrease in intracellular pH (pH{sub i}). Phosphorus-31 nuclear magnetic resonance ({sup 31}P NMR) analyses of perchloric acid extracts show that inorganic phosphate predominates in dauer larvae, whereas ATP and other high-energy metabolites are abundant within 6 hr after dauer larvae have been placed in food to initiate development. Although metabolic activation has been associated with an alkaline pH{sub i} shift in other organisms, in vivo {sup 31}P NMR analysis of recovering dauer larvae shows a pH{sub i} decrease from {approx}more » 7.3 to {approx} 6.3 within 3 hr after the animals encounter food. This shift occurs before feeding begins, and it coincides with, or soon follows, the developmental commitment to recover from the dauer stage, suggesting that control of pH{sub i} may be important in the regulation of larval development in nematodes.« less

Determination of germanium by AAS in chloride-containing matrices.

PubMed

Anwari, M A; Abbasi, H U; Volkan, M; Ataman, O Y

1996-06-01

Interference effects of NaCl on the ET-AAS determination of Ge have been studied. The use of several matrix modifiers to alleviate this problem such as Ni and Zn perchlorates and nitrates, nitric acid, ammonium nitrate are reported. The stabilizing effect of Zn and Ni perchlorates allows the use of high pretreatment temperatures. NaCl is thus thermally volatilized from the atomizer by employing pretreatment temperatures higher than 1500 degrees C resulting in an improved sensitivity. Germanium levels in zinc plant slag samples, have been determined and compared to those obtained for the same samples spiked with NaCl with platform and wall atomization using nickel perchlorate as a matrix modifier. The results were compared with those from a hydride generation system equipped with a liquid nitrogen trap. The recoveries for germanium have been almost complete and amount to 99% for the original slag samples and 80% for 15% (w/w) NaCl containing spiked samples.

Constants and thermodynamics of the acid-base equilibria of triglycine in water-ethanol solutions containing sodium perchlorate at 298 K

NASA Astrophysics Data System (ADS)

Pham Tkhi, L.; Usacheva, T. R.; Tukumova, N. V.; Koryshev, N. E.; Khrenova, T. M.; Sharnin, V. A.

2016-02-01

The acid-base equilibrium constants for glycyl-glycyl-glycine (triglycine) in water-ethanol solvents containing 0.0, 0.1, 0.3, and 0.5 mole fractions of ethanol are determined by potentiometric titration at 298.15 K and an ionic strength of 0.1, maintained with sodium perchlorate. It is established that an increase in the ethanol content in the solvent reduces the dissociation constant of the carboxyl group of triglycine (increases p K 1) and increases the dissociation constant of the amino group of triglycine (decreases p K 2). It is noted that the weakening of the acidic properties of a triglycinium ion upon an increase of the ethanol content in the solvent is due to the attenuation of the solvation shell of the zwitterionic form of triglycine, and to the increased solvation of triglycinium ions. It is concluded that the acid strength of triglycine increases along with a rise in the EtOH content in the solvent, due to the desolvation of the tripeptide zwitterion and the enhanced solvation of protons.

Effects of Additives on Electrochemical Growth of Cu Film on Co/SiO2/Si Substrate by Alternating Underpotential Deposition of Pb and Surface-Limited Redox Replacement by Cu

NASA Astrophysics Data System (ADS)

Fang, J. S.; Lin, L. Y.; Wu, C. L.; Cheng, Y. L.; Chen, G. S.

2017-11-01

The effects of additives to an acidic electrolyte for electrochemical deposition of copper film to prevent corrosion of the Co/SiO2/Si substrate have been investigated. A sacrificial Pb layer was formed by underpotential deposition (UPD), then a Cu layer was prepared using surface-limited redox replacement (SLRR) to exchange the UPD-Pb layer in an acidic copper electrolyte with trisodium citrate, sodium perchlorate, and ethylenediamine as additives. The additives significantly affected the replacement of UPD-Pb by Cu and prevented galvanic corrosion of the Co/SiO2/Si substrate in the acidic Cu electrolyte. The results showed that both sodium perchlorate and ethylenediamine reduced the corrosion of the Co substrate and resulted in Cu film with low electrical resistivity. However, residual Pb was present in the Cu film when using trisodium citrate, as the citrate ions slowed copper displacement. The proposed sequential UPD-Pb and SLRR-Cu growth method may enable electrochemical deposition for fabrication of Cu interconnects on Co substrate from acidic Cu electrolyte.

Inhibiting effects of some oxadiazole derivatives on the corrosion of mild steel in perchloric acid solution

NASA Astrophysics Data System (ADS)

Lebrini, Mounim; Bentiss, Fouad; Vezin, Hervé; Lagrenée, Michel

2005-11-01

The efficiency of 3,5-bis( n-pyridyl)-1,3,4-oxadiazole ( n-POX, n = 1, 2, 3), as corrosion inhibitors for mild steel in 1 M perchloric acid (HClO 4) have been determined by weight loss measurements and electrochemical studies. The results show that these inhibitors revealed a good corrosion inhibition even at very low concentrations. Comparison of results among those obtained by the studied oxadiazoles shows that 3-POX was the best inhibitor. Polarisation curves indicate that n-pyridyl substituted-1,3,4-oxadiazoles are mixed type inhibitors in 1 M HClO 4. The adsorption of these inhibitors follows a Langmuir isotherm model. The electronic properties of n-POX, obtained using the AM1 semi-empirical quantum chemical approach, were correlated with their experimental efficiencies using the linear resistance model (LR).

4,4′-Bipyridinium bis(perchlorate)–4-aminobenzoic acid–4,4′-bipyridine–water (1/4/2/2)

PubMed Central

Meng, Qun-Hui; Han, Lu; Hou, Jian-Dong; Luo, Yi-Fan; Zeng, Rong-Hua

2009-01-01

In the structure of the title compound, C10H10N2 2+·2ClO4 −·4C7H7NO2·2C10H8N2·2H2O, the 4,4′-bipyridinium cation has a crystallographically imposed centre of symmetry. The cation is linked by N—H⋯N hydrogen bonds to adjacent 4,4′-bipyridine mol­ecules, which in turn inter­act via O—H⋯N hydrogen bonds with 4-amino­benzoic acid mol­ecules, forming chains running parallel to [30]. The chains are further connected into a three-dimensional network by N—H⋯O and O—H⋯O hydrogen-bonding inter­actions involving the perchlorate anion, the water mol­ecules and the 4-amino­benzoic acid mol­ecules. In addition, π–π stacking inter­actions with centroid–centroid distances ranging from 3.663 (6) to 3.695 (6) Å are present. The O atoms of the perchlorate anion are disordered over two sets of positions, with refined site occupancies of 0.724 (9) and 0.276 (9). PMID:21581593

Novel perchlorate and phosphate salts of vinpocetine: Characterization, relative solid-state stability evaluation and Hirshfeld surface analysis

NASA Astrophysics Data System (ADS)

Ma, Yu-heng; Ge, Shu-wang; Wang, Wei; Zheng, Qiang; Zuo, Yun-wei; Zhong, Chang-jiang; Sun, Bai-wang

2016-02-01

Salt formation is a very common and effective method of improving a drug's physicochemical properties such as hygroscopicity and physical stability at different humidity conditions. Aqueous solubility is another important parameter that can be improved by salt formation; however this strategy has not yet been evaluated for the important alkaloid drug, Vinpocetine. A poorly water-soluble basic drug (water solubility value≈ 5 μg/ml and pKa value of 7.31), vinpocetine was converted into two novel salts in this work, with perchloric acid and phosphoric acid in a 1: 1 M ratio. However, an unexpected phase transformation occurred in one of the salts after the stability test, which is a major concern in studies on dosage form. The conversion of the salt to free base could be related to the temperature-humidity profile of the type II salt (formed by vinpocetine and phosphoric acid). When the temperature was more than 70 °C under high humidity conditions of more than 80%, the phase transformation occurred immediately. To gain further understanding of this phenomenon, single crystals of the two novel salts were prepared and characterized by single crystal X-ray diffraction, Powder-XRD, infrared spectroscopy, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Constituents of the crystalline phase were also investigated in terms of Hirshfeld surface. The structures were found to be stabilized by H⋯H, C-H⋯O, O-H⋯N and C-H⋯π intermolecular interactions. Our stability studies showed that both these two novel salts could improve the stability of vinpocetine, however the type I salt (formed by vinpocetine and perchloric acid) offers more advantages. This finding will provide valuable information for vinpocetine dosage form development.

Perchlorate (ClO4) and Perchlorate Salts

Integrated Risk Information System (IRIS)

Perchlorate ( ClO4 - ) and Perchlorate Salts CASRN 7790 - 98 - 9 Ammonium perchlorate CASRN 7791 - 03 - 9 Lithium perchlorate CASRN 7778 - 74 - 7 Potassium perchlorate CASRN 7601 - 89 - 0 Sodium perchlorate This U.S . EPA IRIS Summary is based on the U.S . Government - sponsored technical review of

Degradation of Adenine on the Martian Surface in the Presence of Perchlorates and Ionizing Radiation: A Reflectron Time-of-flight Mass Spectrometric Study

NASA Astrophysics Data System (ADS)

Góbi, Sándor; Bergantini, Alexandre; Kaiser, Ralf I.

2017-04-01

The aim of the present work is to unravel the radiolytic decomposition of adenine (C5H5N5) under conditions relevant to the Martian surface. Being the fundamental building block of (deoxy)ribonucleic acids, the possibility of survival of this biomolecule on the Martian surface is of primary importance to the astrobiology community. Here, neat adenine and adenine-magnesium perchlorate mixtures were prepared and irradiated with energetic electrons that simulate the secondary electrons originating from the interaction of the galactic cosmic rays with the Martian surface. Perchlorates were added to the samples since they are abundant—and therefore relevant oxidizers on the surface of Mars—and they have been previously shown to facilitate the radiolysis of organics such as glycine. The degradation of the samples were monitored in situ via Fourier transformation infrared spectroscopy and the electron ionization quadruple mass spectrometric method; temperature-programmed desorption profiles were then collected by means of the state-of-the-art single photon photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS), allowing for the detection of the species subliming from the sample. The results showed that perchlorates do increase the destruction rate of adenine by opening alternative reaction channels, including the concurrent radiolysis/oxidation of the sample. This new pathway provides a plethora of different radiolysis products that were identified for the first time. These are carbon dioxide (CO2), isocyanic acid (HNCO), isocyanate (OCN-), carbon monoxide (CO), and nitrogen monoxide (NO); an oxidation product containing carbonyl groups (R1R2-C=O) with a constrained five-membered cyclic structure could also be observed. Cyanamide (H2N-C≡N) was detected in both irradiated samples as well.

Lab-on-a-Chip Sensor for Monitoring Perchlorate in Ground and Surface Water

DTIC Science & Technology

2012-02-01

uses zwitterionic surfactants was immobilized on either a conventional or membrane-based stationary phase (electrostatic ion chromatography ) em...substantially higher than that of drinking water. A novel extraction method incorporat- ing the fundamentals of electrostatic ion chromatography (EIC) was...electrostatic ion chromatography (EIC), is presented as a way to overcome this challenge. Two extraction formats, employing either a packed bed or a monolith

METHOD OF DISSOLVING URANIUM METAL

DOEpatents

Slotin, L.A.

1958-02-18

This patent relates to an economicai means of dissolving metallic uranium. It has been found that the addition of a small amount of perchloric acid to the concentrated nitric acid in which the uranium is being dissolved greatly shortens the time necessary for dissolution of the metal. Thus the use of about 1 or 2 percent of perchioric acid based on the weight of the nitric acid used, reduces the time of dissolution of uranium by a factor of about 100.

Ubiquity and Diversity of Dissimilatory (Per)chlorate-Reducing Bacteria

PubMed Central

Coates, John D.; Michaelidou, Urania; Bruce, Royce A.; O’Connor, Susan M.; Crespi, Jill N.; Achenbach, Laurie A.

1999-01-01

Environmental contamination with compounds containing oxyanions of chlorine, such as perchlorate or chlorate [(per)chlorate] or chlorine dioxide, has been a constantly growing problem over the last 100 years. Although the fact that microbes reduce these compounds has been recognized for more than 50 years, only six organisms which can obtain energy for growth by this metabolic process have been described. As part of a study to investigate the diversity and ubiquity of microorganisms involved in the microbial reduction of (per)chlorate, we enumerated the (per)chlorate-reducing bacteria (ClRB) in very diverse environments, including pristine and hydrocarbon-contaminated soils, aquatic sediments, paper mill waste sludges, and farm animal waste lagoons. In all of the environments tested, the acetate-oxidizing ClRB represented a significant population, whose size ranged from 2.31 × 103 to 2.4 × 106 cells per g of sample. In addition, we isolated 13 ClRB from these environments. All of these organisms could grow anaerobically by coupling complete oxidation of acetate to reduction of (per)chlorate. Chloride was the sole end product of this reductive metabolism. All of the isolates could also use oxygen as a sole electron acceptor, and most, but not all, could use nitrate. The alternative electron donors included simple volatile fatty acids, such as propionate, butyrate, or valerate, as well as simple organic acids, such as lactate or pyruvate. Oxidized-minus-reduced difference spectra of washed whole-cell suspensions of the isolates had absorbance maxima close to 425, 525, and 550 nm, which are characteristic of type c cytochromes. In addition, washed cell suspensions of all of the ClRB isolates could dismutate chlorite, an intermediate in the reductive metabolism of (per)chlorate, into chloride and molecular oxygen. Chlorite dismutation was a result of the activity of a single enzyme which in pure form had a specific activity of approximately 1,928 μmol of chlorite per mg of protein per min. Analyses of the 16S ribosomal DNA sequences of the organisms indicated that they all belonged to the alpha, beta, or gamma subclass of the Proteobacteria. Several were closely related to members of previously described genera that are not recognized for the ability to reduce (per)chlorate, such as the genera Pseudomonas and Azospirllum. However, many were not closely related to any previously described organism and represented new genera within the Proteobacteria. The results of this study significantly increase the limited number of microbial isolates that are known to be capable of dissimilatory (per)chlorate reduction and demonstrate the hitherto unrecognized phylogenetic diversity and ubiquity of the microorganisms that exhibit this type of metabolism. PMID:10583970

In Situ Bioremediation of Perchlorate in Vadose Zone Source Areas

DTIC Science & Technology

2011-01-01

agricultural bags (e.g., ITRC, 2008; Evans et al., 2008). Phytoremediation has also been tested for soil treatment (ITRC, 2008). However, these...within the saturated zone (through in situ bioremediation or groundwater extraction and ex-situ treatment), phytoremediation , which is unlikely to

Composite technique for regional neurochemical studies: measurement of energy and neurotransmitter metabolites in single tissue sample.

PubMed

Djuricic, B M; Ueki, Y; Spatz, M

1985-06-01

A combined method is described for the determination of various metabolites from a single tissue sample of the brain. It comprises a quick inactivation of cerebral enzymes by microwave irradiation, easy separation of the desired brain regions, and perchloric acid extraction of tissue substances, which are assayed either by specific enzymatic techniques or by HPLC with electrochemical detection. The obtained values of most energy and neurotransmitter metabolites in the brain are in agreement with those reported using other methods. However, this technique, in contrast to the brain freezing in vitro or freeze-blowing, provides a more efficient procedure for rapid arrest of cerebral metabolism even in the deep brain structures and is therefore suitable for detection of early changes particularly those occurring in experimental pathological conditions such as ischemia.

Thermometric titration of thorium with EDTA in the presence of large excess of neutral sodium salts.

PubMed

Doi, K

1980-11-01

The thermometric titration of Th(IV) in the presence of neutral sodium salts, sulphuric acid or acetic acid with EDTA has been studied. The effect of each on the observed heat values for the titration is discussed. For sodium perchlorate media, DeltaH values of -9 and -21 kJ/mole have been estimated for the formation of the Th(IV)-EDTA chelate at mu --> 0 and mu = 0.5 (NaClO(4)), respectively. The -DeltaH values increase steadily with increase in concentration of sodium perchlorate up to at least 3M. For the titration of Th(IV) in the presence of a large excess of sodium nitrate the use of sodium iodide as a masking reagent has been examined: large amounts of Bi and Cu(II) are masked and a masking effect is observed for small amounts of Ni.

Phase-change related epigenetic and physiological changes in Pinus radiata D. Don.

PubMed

Fraga, Mario F; Cañal, Maria Jesús; Rodríguez, Roberto

2002-08-01

DNA methylation and polyamine levels were analysed before and after Pinus radiata D. Don. phase change in order to identify possible molecular and physiological phase markers. Juvenile individuals (without reproductive ability) were characterised by a degree of DNA methylation of 30-35% and a ratio of free polyamines to perchloric acid-soluble polyamine conjugates greater than 1, while mature trees (with reproductive ability) had 60% 5-methylcytosine and a ratio of free polyamines to perchloric acid-soluble polyamine conjugates of less than 1. Results obtained with trees that attained reproductive capacity during the experimental period confirmed that changes in the degree of DNA methylation and polyamine concentrations found among juvenile and mature states come about immediately after the phase change. We suggest that both indicators may be associated with the loss of morphogenic ability during ageing, particularly after phase change, through a number of molecular interactions, which are subsequently discussed.

Emerging Disinfection By-Products and Other Emerging Environmental Contaminants: What’s New

EPA Science Inventory

This presentation will cover new research and concerns regarding drinking water disinfection by-products (DBPs) and other emerging environmental contaminants, such as perfluorooctanoic acid (PFOA), pharmaceuticals, perchlorate, benzotriazoles, fuel additives (e.g., ethylene dibro...

Comparative Demonstration of Active and Semi-Passive In Situ Bioremediation Approaches for Perchlorate-Impacted Groundwater (Longhorn Army Ammunition Plant)

DTIC Science & Technology

2009-01-01

citric acid , or ethanol have been used in field applications, and it may be possible to use mobile forms of emulsified vegetable oil, methyl esters and...70 5.7.5 Results of Volatile Fatty Acids Analysis .................................................................. 77 5.7.6 Results of...gases DNA deoxyribonucleic acid do dissolved oxygen DoD Department of Defense DOE Department of Energy DOT Department of Transportation EISB

Comparative Demonstration of Active and Semi-Passive In Situ Bioremediation Approaches for Perchlorate-Impacted Groundwater at Longhorn Army Ammunitions Plant

DTIC Science & Technology

2009-01-01

lactate, citric acid , or ethanol have been used in field applications. Biomass grows rapidly during the active phase when high concentrations of...6.7.4 Results of Oxidation Reduction Potential (ORP) Monitoring.............39 6.7.5 Results of Volatile Fatty Acids (VFA) Analysis...trinitrotoluene USEPA U.S. Environmental Protection Agency VC vinyl chloride VFA volatile fatty acid VOC volatile organic compounds Technical

A NMR study of parasitized Tenebrio molitor and Hymenolepis diminuta cysticercoids.

PubMed

Schoen, J; Modha, A; Maslow, K; Novak, M; Blackburn, B J

1996-07-01

In vivo NMR spectra of uninfected and Hymenolepis diminuta-infected Tenebrio molitor fed D-(1-13C)glucose showed that infected beetles of both sexes had a significantly higher ratio for (glycogen C1/lipid (CH2)n) than the corresponding controls. Quantitative metabolic profiles and the per cent 13C-label in metabolites, based on NMR of perchloric acid extracts, are presented for control and infected beetles fed D-(1-13C)glucose and for H. diminuta cysticercoids. Female beetles, both control and infected, contained more glycogen than their male counterparts and infected beetles of both sexes possessed less glycerophos-phocholine, but more glycogen and a higher percentage label in glucose and trehalose than their respective controls. Label was also incorporated into glycogen, succinate, acetate, alanine and lactate. Extracts of cysticercoids from beetles fed D-(1-13C)glucose contained the following labelled compounds, in order of decreasing per cent 13C label: glucose, trehalose, alanine, succinate, lactate, glycogen and acetate. In vitro cultivation experiments, employing D-(1-13C)glucose, revealed that trehalose found in cysticercoids was of parasite, and not beetle, origin.

Theoretical problems associated with the use of acetic anhydride as a co-solvent for the non-aqueous titration of hydrohalides of organic bases and quaternary ammonium salts.

PubMed

Völgyi, Gergely; Béni, Szabolcs; Takács-Novák, Krisztina; Görög, Sándor

2010-01-05

A potentiometric titration study of organic base hydrohalides and quaternary ammonium salts using perchloric acid as the titrant and a mixture of acetic anhydride and acetic acid as the solvent was carried out and the titration mixture was analysed by NMR in order to clarify the chemistry of the reactions involved. It was found that in contrast to the general belief the formation of acetyl halides and titratable free acetate ion does not take place prior to the titration but NMR spectra proved the formation of acetyl halides in the course of the titration. This observation and the fact that the shape of the titration curves depends on the nature of the hydrohaloic acid bound to the base or of the anion in the quaternary ammonium salts led to the conclusion that the titrating agent is acetyl perchlorate formed in situ during the titration. Equations of the reactions involved in the titration process are shown in the paper.

Comparative Demonstration of Active and Semi-Passive In Situ Bioremediation Approaches for Perchlorate Impacted Groundwater: Active In Situ Bioremediation Demonstration

DTIC Science & Technology

2013-04-01

demonstration test . 5.1 CONCEPTUAL EXPERIMENTAL DESIGN In concept, the active biobarrier approach involved the use of alternating extraction and injection...16 4.3 GROUNDWATER CHEMISTRY ....................................................................... 18 5.0 TEST DESIGN...20 5.1 CONCEPTUAL EXPERIMENTAL DESIGN

Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer

USGS Publications Warehouse

Hatzinger, P.B.; Böhlke, J.K.; Sturchio, N.C.; Gu, B.; Heraty, L.J.; Borden, R.C.

2009-01-01

Environmental context. Perchlorate (ClO4-) and nitrate (NO3-) are common co-contaminants in groundwater, with both natural and anthropogenic sources. Each of these compounds is biodegradable, so in situ enhanced bioremediation is one alternative for treating them in groundwater. Because bacteria typically fractionate isotopes during biodegradation, stable isotope analysis is increasingly used to distinguish this process from transport or mixing-related decreases in contaminant concentrations. However, for this technique to be useful in the field to monitor bioremediation progress, isotope fractionation must be quantified under relevant environmental conditions. In the present study, we quantify the apparent in situ fractionation effects for stable isotopes in ClO4- (Cl and O) and NO3- (N and O) resulting from biodegradation in an aquifer. Abstract. An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification. During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h. After correction for dilution (using Br- as a conservative tracer of the injectate), perchlorate concentrations decreased by 78% and nitrate concentrations decreased by 82% during the initial 8.6 h after the injection. The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (18O/37Cl) was 2.6, which is similar to that observed in the laboratory using pure cultures (2.5). Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of ???0.8 (18O/15N), which is within the range of values reported previously for denitrification. However, the magnitudes of the individual apparent in situ isotope fractionation effects for perchlorate and nitrate were appreciably smaller than those reported in homogeneous closed systems (0.2 to 0.6 times), even after adjustment for dilution. These results indicate that (1) isotope fractionation factor ratios (18O/37Cl, 18O/15N) derived from homogeneous laboratory systems (e.g. pure culture studies) can be used qualitatively to confirm the occurrence of in situ biodegradation of both perchlorate and nitrate, but (2) the magnitudes of the individual apparent values cannot be used quantitatively to estimate the in situ extent of biodegradation of either anion. ?? CSIRO 2009.

High energy density electrochemical cell

NASA Technical Reports Server (NTRS)

Byrne, J. J.; Williams, D. L.

1970-01-01

Primary cell has an anode of lithium, a cathode containing dihaloisocyanuric acid, and a nonaqueous electrolyte comprised of a solution of lithium perchlorate in methyl formate. It produces an energy density of 213 watt hrs/lb and can achieve a high current density.

Comparison of Methods to Assay Liver Glycogen Fractions: The Effects of Starvation

PubMed Central

Mojibi, Nastaran

2017-01-01

Introduction There are several methods to extract and measure glycogen in animal tissues. Glycogen is extracted with or without homogenization by using cold Perchloric Acid (PCA). Aim Three procedures were compared to determine glycogen fractions in rat liver at different physiological states. Materials and Methods The present study was conducted on two groups of rats, one group of five rats were fed standard rodent laboratory food and were marked as controls, and another five rats were starved overnight (15 hour) as cases. The glycogen fractions were extracted and measured by using three methods: classical homogenization, total-glycogen-fractionation and homogenization-free protocols. Results The data of homogenization methods showed that following 15 hour starvation, total glycogen decreased (36.4±1.9 vs. 27.7±2.5, p=0.01) and the change occurred entirely in Acid Soluble Glycogen (ASG) (32.0±1.1 vs. 22.7±2.5, p=0.01), while Acid Insoluble Glycogen (AIG) did not change significantly (4.9±0.9 vs. 4.6±0.3, p=0.7). Similar results were achieved by using the method of total-glycogen-fractionation. Homogenization-free procedure indicated that ASG and AIG fractions compromise about 2/3 and 1/3 of total glycogen and the changes occurred in both ASG (24.4±2.6 vs. 16.7±0.4, p<0.05) and AIG fraction (8.7±0.8 vs. 7.1±0.3, p=0.05). Conclusion The findings of ‘homogenization assay method’ indicate that ASG is the major portion of liver glycogen and is more metabolically active form. The same results were obtained by using ‘total-glycogen-fractionation method’. ‘Homogenization-free method’ gave different results, because AIG has been contaminated with ASG fraction. In both ‘homogenization’ and ‘homogenization-free’ methods ASG must be extracted at least twice to prevent contamination of AIG with ASG. PMID:28511372

Perchlorate adsorption and desorption on activated carbon and anion exchange resin.

PubMed

Yoon, In-Ho; Meng, Xiaoguang; Wang, Chao; Kim, Kyoung-Woong; Bang, Sunbaek; Choe, Eunyoung; Lippincott, Lee

2009-05-15

The mechanisms of perchlorate adsorption on activated carbon (AC) and anion exchange resin (SR-7 resin) were investigated using Raman, FTIR, and zeta potential analyses. Batch adsorption and desorption results demonstrated that the adsorption of perchlorate by AC and SR-7 resin was reversible. The reversibility of perchlorate adsorption by the resin was also proved by column regeneration test. Solution pH significantly affected perchlorate adsorption and the zeta potential of AC, while it did not influence perchlorate adsorption and the zeta potential of resin. Zeta potential measurements showed that perchlorate was adsorbed on the negatively charged AC surface. Raman spectra indicated the adsorption resulted in an obvious position shift of the perchlorate peak, suggesting that perchlorate was associated with functional groups on AC at neutral pH through interactions stronger than electrostatic interaction. The adsorbed perchlorate on the resin exhibited a Raman peak at similar position as the aqueous perchlorate, indicating that perchlorate was adsorbed on the resin through electrostatic attraction between the anion and positively charged surface sites.

Pathophysiology of Non-Freezing Cold Injury

DTIC Science & Technology

1989-07-01

the leg. Salicylic acid was injected through the femoral vein at the end of some experiments to assay hydroxy radical (OH*). Our results demonstrated...pH 4.5); 50 J1 of 70% perchloric acid was then added to the mixtur,". The resultant mixture was degassed and filtered through a Rainin Nylon-66...consisting of a Model 510 pump and a Model 460 electrochemical detector. The hydroxylated products of salicylic acid were eluted with buffer (degassed and

Comparative Demonstration of Active and Semi-Passive in Situ Bioremediation Approaches for Perchlorate-Impacted Groundwater at Longhorn Army Ammunitions Plant

DTIC Science & Technology

2009-01-01

wells in order to achieve the desired electron donor coverage. Soluble electron donors such as sodium lactate, citric acid , or ethanol have been used in...ORP) Monitoring.............39 6.7.5 Results of Volatile Fatty Acids (VFA) Analysis............................39 6.7.6 Results of Sulfate Analysis...VC vinyl chloride VFA volatile fatty acid VOC volatile organic compounds Technical material contained in this report has been approved for

Application of a macrocyclic compound, bambus[6]uril, in tailor-made liquid membranes for highly selective electromembrane extractions of inorganic anions.

PubMed

Šlampová, Andrea; Šindelář, Vladimír; Kubáň, Pavel

2017-01-15

A tailor-made liquid membrane consisting of a resistive organic solvent (nitrobenzene, NB) and a highly selective non-ionic macrocyclic compound (bambus[6]uril, BU6) was employed for electromembrane extraction (EME) of inorganic anions. BU6 facilitates strong host-guest interactions of its internal cavity with selected inorganic anions only and its presence in the liquid membrane ensured excellent selectivity of the EME process. EME transfers were directly related to association constants between BU6 and inorganic anions and nearly absolute selectivity was achieved for EMEs of iodide, bromide and perchlorate. Major inorganic anions (chloride, nitrate, sulphate and carbonate), which exhibit low interactions with BU6 cavity, were efficiently eliminated from the EME transfer. No interferences were observed for EMEs of target analytes from samples containing up to 100.000-fold higher concentrations of the major anions. Addition of species-specific macrocyclic modifiers to free and supported liquid membranes might thus open new directions in fine-tuning of EME selectivity. At optimized EME conditions (polypropylene hollow fiber impregnated with NB + 3% (w/w) BU6, extraction voltage 25 V, extraction time 15 min, deionized water as acceptor solution) perchlorate was selectively extracted from tap water at concentrations below the guideline value recommended by United States Environmental Protection Agency. Excellent selectivity of the tailor-made liquid membrane was further demonstrated by EME of bromide from sea water. Copyright © 2016 Elsevier B.V. All rights reserved.

Perchlorate Reduction by Yeast for Mars Exploration

NASA Technical Reports Server (NTRS)

Sharma, Alaisha

2015-01-01

Martian soil contains high levels (0.6 percentage by mass) of calcium perchlorate (Ca(ClO4)2), which readily dissociates into calcium and the perchlorate ion (ClO4-) in water. Even in trace amounts, perchlorates are toxic to humans and have been implicated in thyroid dysfunction. Devising methods to lessen perchlorate contamination is crucial to minimizing the health risks associated with human exploration and colonization of Mars. We designed a perchlorate reduction pathway, which sequentially reduces perchlorate to chloride (Cl-) and oxygen (O2), for implementation in the yeast Saccharomyces cerevisiae. Using genes obtained from perchlorate reducing bacteria Azospira oryzae and Dechloromonas aromatica, we plan to assemble this pathway directly within S. cerevisiae through recombinational cloning. A perchlorate reduction pathway would enable S. cerevisiae to lower perchlorate levels and produce oxygen, which may be harvested or used directly by S. cerevisiae for aerobic growth and compound synthesis. Moreover, using perchlorate as an external electron acceptor could improve the efficiency of redox-imbalanced production pathways in yeast. Although several perchlorate reducing bacteria have been identified and utilized in water treatment systems on Earth, the widespread use of S. cerevisiae as a synthetic biology platform justifies the development of a perchlorate reducing strain for implementation on Mars.

Quantitative bioluminescent detection of bacteria

NASA Technical Reports Server (NTRS)

Chappelle, E. W.; Picciolo, G. L.

1976-01-01

Phosphoflavins in sample are measured using photobacterial luciferase assay technique for flavin mononucleotide (FMN). Boiling perchloric acid is used to rupture cells to free bound flavin and to hydrolyze flavin adenine dinucleotide to FMN. Base-stabilized water solution of sodium borohydride is used as reactant.

Peptide Biomarkers as Evidence of Perchlorate Biodegradation▿ †

PubMed Central

Bansal, Reema; Crawford, Ronald L.; Paszczynski, Andrzej J.

2011-01-01

Perchlorate is a known health hazard for humans, fish, and other species. Therefore, it is important to assess the response of an ecosystem exposed to perchlorate contamination. The data reported here show that a liquid chromatography-mass spectrometry-based proteomics approach for the detection of perchlorate-reducing enzymes can be used to measure the ability of microorganisms to degrade perchlorate, including determining the current perchlorate degradation status. Signature peptides derived from chlorite dismutase (CD) and perchlorate reductase can be used as biomarkers of perchlorate presence and biodegradation. Four peptides each derived from CD and perchlorate reductase subunit A (PcrA) and seven peptides derived from perchlorate reductase subunit B (PcrB) were identified as signature biomarkers for perchlorate degradation, as these sequences are conserved in the majority of the pure and mixed perchlorate-degrading microbial cultures examined. However, chlorite dismutase signature biomarker peptides from Dechloromonas agitata CKB were found to be different from those in other cultures used and should also be included with selected CD biomarkers. The combination of these peptides derived from the two enzymes represents a promising perchlorate presence/biodegradation biomarker system. The biomarker peptides were detected at perchlorate concentrations as low as 0.1 mM and at different time points both in pure cultures and within perchlorate-reducing environmental enrichment consortia. The peptide biomarkers were also detected in the simultaneous presence of perchlorate and an alternate electron acceptor, nitrate. We believe that this technique can be useful for monitoring bioremediation processes for other anthropogenic environmental contaminants with known metabolic pathways. PMID:21115710

Direct Measurement of Perchlorate Exposure Biomarkers in a Highly Exposed Population: A Pilot Study

PubMed Central

Wong, Michelle; Copan, Lori; Olmedo, Luis; Patton, Sharyle; Haas, Robert; Atencio, Ryan; Xu, Juhua; Valentin-Blasini, Liza

2011-01-01

Exposure to perchlorate is ubiquitous in the United States and has been found to be widespread in food and drinking water. People living in the lower Colorado River region may have perchlorate exposure because of perchlorate in ground water and locally-grown produce. Relatively high doses of perchlorate can inhibit iodine uptake and impair thyroid function, and thus could impair neurological development in utero. We examined human exposures to perchlorate in the Imperial Valley among individuals consuming locally grown produce and compared perchlorate exposure doses to state and federal reference doses. We collected 24-hour urine specimen from a convenience sample of 31 individuals and measured urinary excretion rates of perchlorate, thiocyanate, nitrate, and iodide. In addition, drinking water and local produce were also sampled for perchlorate. All but two of the water samples tested negative for perchlorate. Perchlorate levels in 79 produce samples ranged from non-detect to 1816 ppb. Estimated perchlorate doses ranged from 0.02 to 0.51 µg/kg of body weight/day. Perchlorate dose increased with the number of servings of dairy products consumed and with estimated perchlorate levels in produce consumed. The geometric mean perchlorate dose was 70% higher than for the NHANES reference population. Our sample of 31 Imperial Valley residents had higher perchlorate dose levels compared with national reference ranges. Although none of our exposure estimates exceeded the U. S. EPA reference dose, three participants exceeded the acceptable daily dose as defined by bench mark dose methods used by the California Office of Environmental Health Hazard Assessment. PMID:21394205

Growth Stimulation by Catecholamines in Plant Tissue/Organ Cultures 1

PubMed Central

Protacio, Calixto M.; Dai, Yao-ren; Lewis, Eldrin F.; Flores, Hector E.

1992-01-01

Addition of catecholamines at micromolar concentrations caused a dramatic stimulation of growth of tobacco (Nicotiana tabacum) thin cell layers (TCLs) and Acmella oppositifolia “hairy” root cultures. A threefold increase in the rate of ethylene evolution was observed in the catecholamine-treated explants. Aminooxyacetic acid and silver thiosulfate, inhibitors of ethylene biosynthesis and action, respectively, reduced the growth-promoting effect of dopamine. However, these compounds alone could also inhibit the growth of the TCL explants. When ethylene in the culture vessel was depleted by trapping with mercuric perchlorate, dopamine-stimulated growth was still obtained, suggesting that ethylene does not mediate the dopamine effect. Dopamine potentiated the growth of TCLs grown in Murashige and Skoog medium supplemented with indoleacetic acid (IAA) and kinetin. When IAA was replaced by 2,4-dichlorophenoxyacetic acid, dopamine addition showed no growth-promoting effect. Instead, 2,4-dichlorophenoxyacetic acid stimulated the growth of TCL explants to the same extent as that obtained with IAA plus dopamine. Because synthetic auxins do not appear to be substrates for IAA oxidizing enzymes, we hypothesized that catecholamines exert their effect by preventing IAA oxidation. Consistent with this explanation, dopamine (25 micromolar) inhibited IAA oxidase activity by 60 to 100% in crude enzyme extracts from tobacco roots and etiolated corn coleoptiles, but had no effect on peroxidase activity in the same extracts. Furthermore, addition of dopamine to TCL cultures resulted in a fourfold reduction in the oxidative degradation of [1-14C]IAA fed to the explants. Because the growth enhancement by catecholamines is observed in both IAA-requiring and IAA-independent cultures, we suggest that these aromatic amines may have a role in the regulation of IAA levels in vivo. ImagesFigure 2 PMID:16668653

Fast determination of four polar contaminants in soy nutraceutical products by liquid chromatography coupled to tandem mass spectrometry.

PubMed

Domingos Alves, Renata; Romero-González, Roberto; López-Ruiz, Rosalía; Jiménez-Medina, M L; Garrido Frenich, Antonia

2016-11-01

An analytical method based on a modified QuPPe (quick polar pesticide) extraction procedure coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was evaluated for the determination of four polar compounds (chlorate, fosetyl-Al, maleic hydrazide, and perchlorate) in nutraceutical products obtained from soy. Experimental conditions including extraction such as solvent, acidification, time, and clean-up sorbents were varied. Acidified acetonitrile (1 % formic acid, v/v) was used as extraction solvent instead of methanol (conventional QuPPe), which provides a doughy mixture which cannot be injected into the LC. Clean-up or derivatization steps were avoided. For analysis, several stationary phases were evaluated and Hypercarb (porous graphitic carbon) provided the best results. The optimized method was validated and recoveries ranged between 46 and 119 %, and correction factors can be used for quantification purposes bearing in mind that inter-day precision was equal to or lower than 17 %. Limits of quantification (LOQs) ranged from 4 to 100 μg kg -1 . Soy-based nutraceutical products were analyzed and chlorate was detected in five samples at concentrations between 63 and 1642 μg kg -1 . Graphical Abstract Analysis of polar compounds in soy-based nutraceutical products.

SFG study of platinum electrodes in perchloric acid solutions

NASA Astrophysics Data System (ADS)

Zheng, W. Q.; Pluchery, O.; Tadjeddine, A.

2002-04-01

Infrared-visible sum-frequency generation (SFG) spectroscopy has been used to study the structure of water molecules (and/or its derivatives OH -, H 3O + etc.) at aqueous electrolyte/electrode interfaces. For Pt(1 1 0) and Pt(1 0 0) electrodes in 0.1 M perchloric acid solution, we did not observe any significant O-H stretching resonance. In striking contrast to the resonant SFG signal, the nonresonant SFG (NRSFG) signal varies sensitively with the applied electrochemical potential, indicating that the interaction of water molecules with platinum electrodes is relatively weak as compared to that of H + and ClO 4- ions. From changes in the NRSFG signal and on the basis of an ionic adsorption model, we can also deduce that the potential of zero charge of Pt(1 1 0) in 0.1 M HClO 4 should be located at about 0.22 V (vs. NHE). This value is in good agreement with that measured recently by electrochemical method.

Degradation of Adenine on the Martian Surface in the Presence of Perchlorates and Ionizing Radiation: A Reflectron Time-of-flight Mass Spectrometric Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Góbi, Sándor; Bergantini, Alexandre; Kaiser, Ralf I., E-mail: ralfk@hawaii.edu

The aim of the present work is to unravel the radiolytic decomposition of adenine (C{sub 5}H{sub 5}N{sub 5}) under conditions relevant to the Martian surface. Being the fundamental building block of (deoxy)ribonucleic acids, the possibility of survival of this biomolecule on the Martian surface is of primary importance to the astrobiology community. Here, neat adenine and adenine–magnesium perchlorate mixtures were prepared and irradiated with energetic electrons that simulate the secondary electrons originating from the interaction of the galactic cosmic rays with the Martian surface. Perchlorates were added to the samples since they are abundant—and therefore relevant oxidizers on the surfacemore » of Mars—and they have been previously shown to facilitate the radiolysis of organics such as glycine. The degradation of the samples were monitored in situ via Fourier transformation infrared spectroscopy and the electron ionization quadruple mass spectrometric method; temperature-programmed desorption profiles were then collected by means of the state-of-the-art single photon photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS), allowing for the detection of the species subliming from the sample. The results showed that perchlorates do increase the destruction rate of adenine by opening alternative reaction channels, including the concurrent radiolysis/oxidation of the sample. This new pathway provides a plethora of different radiolysis products that were identified for the first time. These are carbon dioxide (CO{sub 2}), isocyanic acid (HNCO), isocyanate (OCN{sup −}), carbon monoxide (CO), and nitrogen monoxide (NO); an oxidation product containing carbonyl groups (R{sub 1}R{sub 2}–C=O) with a constrained five-membered cyclic structure could also be observed. Cyanamide (H{sub 2}N–C≡N) was detected in both irradiated samples as well.« less

Automation of liquid-liquid extraction-spectrophotometry using prolonged pseudo-liquid drops and handheld CCD for speciation of Cr(VI) and Cr(III) in water samples.

PubMed

Chen, Wen; Zhong, Guanping; Zhou, Zaide; Wu, Peng; Hou, Xiandeng

2005-10-01

A simple spectrophotometric system, based on a prolonged pseudo-liquid drop device as an optical cell and a handheld charge coupled device (CCD) as a detector, was constructed for automatic liquid-liquid extraction and spectrophotometric speciation of trace Cr(VI) and Cr(III) in water samples. A tungsten halogen lamp was used as the light source, and a laboratory-constructed T-tube with two open ends was used to form the prolonged pseudo-liquid drop inside the tube. In the medium of perchloric acid solution, Cr(VI) reacted with 1,5-diphenylcarbazide (DPC); the formed complex was automatically extracted into n-pentanol, with a preconcentration ratio of about 5. The organic phase with extracted chromium complex was then pumped through the optical cell for absorbance measurement at 548 nm. Under optimal conditions, the calibration curve was linear in the range of 7.5 - 350 microg L(-1), with a correlation coefficient of 0.9993. The limit of detection (3sigma) was 7.5 microg L(-1). That Cr(III) species cannot react with DPC, but can be oxidized to Cr(VI) prior to determination, is the basis of the speciation analysis. The proposed speciation analysis was sensitive, yet simple, labor-effective, and cost-effective. It has been preliminarily applied for the speciation of Cr(VI) and Cr(III) in spiked river and tap water samples. It can also be used for other automatic liquid-liquid extraction-spectrophotometric determinations.

Anti-aging Potential of Extracts Prepared from Fruits and Medicinal Herbs Cultivated in the Gyeongnam Area of Korea

PubMed Central

Shon, Myung-Soo; Lee, Yunjeong; Song, Ji-Hye; Park, Taehyun; Lee, Jun Kyoung; Kim, Minju; Park, Eunju; Kim, Gyo-Nam

2014-01-01

Many recent studies have focused on maintaining a healthy life by preventing and/or postponing the aging process. Numerous studies have reported that continuous exposure to reactive oxygen species can stimulate skin aging and that excessive accumulation of fat can cause an impaired skin barrier and tissue structure alterations. Thus, the maintenance of antioxidant homeostasis and the suppression of adipose accumulation are important strategies for skin anti-aging. Here, we prepared three types of extracts [whole juice, acetone-perchloric acid (PCA), and ethanol] from 20 fruits and medicinal herbs native to the Gyeongnam area of Korea. The total phenolic content of each extract was analyzed, and we observed higher total phenolic contents in the medicinal herbs. Consistent with this, the results of the oxygen radical absorbance activity capacity assay indicated that the in vitro antioxidant activities of the medicinal herb extracts were stronger than those of the fruit extracts. The fruits and medicinal herbs had strong effects on cell-based systems, including H2O2-induced oxidative stress in human keratinocytes and 3T3-L1 lipid accumulation. Nishimura Wase persimmon, Taishu persimmon, wrinkled giant hyssop, sweet wormwood, Chinese cedar, red perilla, tan shen, hiyodori-jogo, and cramp bark may be natural anti-aging materials with effective antioxidant and anti-adipogenic activities. Taken together, our findings may provide scientific evidence supporting the development of functional foods and nutraceuticals from fruits and medicinal herbs. PMID:25320715

Perchlorate exposure in lactating women in an urban community in New Jersey.

PubMed

Borjan, Marija; Marcella, Stephen; Blount, Benjamin; Greenberg, Michael; Zhang, Junfeng Jim; Murphy, Eileen; Valentin-Blasini, Liza; Robson, Mark

2011-01-01

Perchlorate is most widely known as a solid oxidant for missile and rocket propulsion systems although it is also present as a trace contaminant in some fertilizers. It has been detected in drinking water, fruits, and vegetables throughout New Jersey and most of the United States. At sufficiently high doses, perchlorate interferes with the uptake of iodine into the thyroid and may interfere with the development of the skeletal system and the central nervous system of infants. Therefore, it is important to quantify perchlorate in breast milk to understand potential perchlorate exposure in infants. In this study we measured perchlorate in breast milk, urine, and drinking water collected from 106 lactating mothers from Central New Jersey. Each subject was asked to provide three sets of samples over a 3-month period. The average±SD perchlorate level in drinking water, breast milk, and urine was 0.168±0.132 ng/mL (n=253), 6.80±8.76 ng/mL (n=276), and 3.19±3.64 ng/mL (3.51±6.79 μg/g creatinine) (n=273), respectively. Urinary perchlorate levels were lower than reference range values for women of reproductive age (5.16±11.33 μg/g creatinine, p=0.03), likely because of perchlorate secretion in breast milk. Drinking water perchlorate levels were ≤1.05 ng/mL and were not positively correlated with either breast milk or urine perchlorate levels. These findings together suggest that drinking water was not the most important perchlorate exposure source for these women. Creatinine-adjusted urine perchlorate levels were strongly correlated with breast milk perchlorate levels (r=0.626, p=<0.0005). Breast milk perchlorate levels in this study are consistent with widespread perchlorate exposure in lactating women and thus infants. This suggests that breast milk may be a source of exposure to perchlorate in infants. Copyright © 2010 Elsevier B.V. All rights reserved.

Bio-reduction of free and laden perchlorate by the pure and mixed perchlorate reducing bacteria: Considering the pH and coexisting nitrate.

PubMed

Shang, Yanan; Wang, Ziyang; Xu, Xing; Gao, Baoyu; Ren, Zhongfei

2018-08-01

Pure bacteria cell (Azospira sp. KJ) and mixed perchlorate reducing bacteria (MPRB) were employed for decomposing the free perchlorate in water as well as the laden perchlorate on surface of quaternary ammonium wheat residuals (QAWR). Results indicated that perchlorate was decomposed by the Azospira sp. KJ prior to nitrate while MPRB was just the reverse. Bio-reduction of laden perchlorate by Azospira sp. KJ was optimal at pH 8.0. In contrast, bio-reduction of laden perchlorate by MPRB was optimal at pH 7.0. Generally, the rate of perchlorate reduction was controlled by the enzyme activity of PRB. In addition, perchlorate recovery (26.0 mg/g) onto bio-regenerated QAWR by MPRB was observed with a small decrease as compared with that (31.1 mg/g) by Azospira sp. KJ at first 48 h. Basically, this study is expected to offer some different ideas on bio-regeneration of perchlorate-saturated adsorbents using biological process, which may provide the economically alternative to conventional methods. Copyright © 2018 Elsevier Ltd. All rights reserved.

Characteristics of electron transport chain and affecting factors for thiosulfate-driven perchlorate reduction.

PubMed

Zhang, Chao; Guo, Jianbo; Lian, Jing; Lu, Caicai; Ngo, Huu Hao; Guo, Wenshan; Song, Yuanyuan; Guo, Yankai

2017-10-01

The mechanism for perchlorate reduction was investigated using thiosulfate-driven (T-driven) perchlorate reduction bacteria. The influences of various environmental conditions on perchlorate reduction, including pH, temperature and electron acceptors were examined. The maximum perchlorate removal rate was observed at pH 7.5 and 40 °C. Perchlorate reduction was delayed due to the coexistence of perchlorate-chlorate and perchlorate-nitrate. The mechanism of the T-driven perchlorate reduction electron transport chain (ETC) was also investigated by utilizing different inhibitors. The results were as follows: firstly, the NADH dehydrogenase was not involved in the ETC; secondly, the FAD dehydrogenase and quinone loop participated in the ETC; and thirdly, cytochrome oxidase was the main pathway in the ETC. Meanwhile, microbial consortium structure analysis indicated that Sulfurovum which can oxidize sulfur compounds coupled to the reduction of nitrate or perchlorate was the primary bacterium in the T-driven and sulfur-driven consortium. This study generates a better understanding of the mechanism of T-driven perchlorate reduction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Exposure to perchlorate induces the formation of macrophage aggregates in the trunk kidney of zebrafish and mosquitofish

USGS Publications Warehouse

Capps, T.; Mukhi, S.; Rinchard, J.J.; Theodorakis, C.W.; Blazer, V.S.; Patino, R.

2004-01-01

Environmental contamination of ground and surface waters by perchlorate, derived from ammonium perchlorate (AP) and other perchlorate salts, is of increasing concern. Exposure to perchlorate can impair the thyroid endocrine system, which is thought to modulate renal and immune function in vertebrates. This study with zebrafish Danio rerio and eastern mosquitofish Gambusia holbrooki examined the histological effects of perchlorate on the trunk kidney, which in teleosts serves excretory and hemopoietic functions and therefore may be a target of perchlorate effects. Adult zebrafish of both sexes were exposed in the laboratory to waterborne, AP-derived perchlorate at measured concentrations of 18 mg/L for 8 weeks. Adult male mosquitofish were exposed to waterborne sodium perchlorate at measured perchlorate concentrations of 1-92 mg/L for 8 weeks. Control fish were kept in untreated water. The region of the body cavity containing the trunk kidney was processed from each fish for histological analysis. Macrophage aggregates (MAs), possible markers of contaminant exposure or immunotoxic effect, were present in the hemopoietic region of the kidney in both species exposed to perchlorate. The estimated percent area of kidney sections occupied by MAs was greater in zebrafish exposed to perchlorate at 18 mg/L (P < 0.05) than in controls. In male mosquitofish, the incidence of renal MAs increased proportionally with sodium perchlorate concentration and was significantly different from that of controls at 92 mg/L (P < 0.05). These observations confirm that in fish the kidney is affected by exposure to perchlorate. The concentrations of perchlorate at which the effects were noted are relatively high but within the range reported in some contaminated habitats.

Energy Systems Fabrication Laboratory | Energy Systems Integration Facility

Science.gov Websites

Fabrication The fuel cell fabrication hub includes laboratory spaces with local exhaust and chemical fume hoods that support electrolysis and other chemical process research. Key Infrastructure Perchloric acid washdown hood, local exhaust, specialty gas manifolding, deionized water, chemical fume hoods, glassware

Computational study on nitronium and nitrosonium oxalate: potential oxidizers for solid rocket propulsion?

PubMed

Gökçinar, Elif; Klapötke, Thomas M; Kramer, Michael P

2010-08-26

The enthalpies of formation for solid ionic nitrosonium oxalate, [NO](2)[O(2)C-CO(2)], nitronium oxalate, [NO(2)](2)[O(2)C-CO(2)], as well as covalent bis(nitroso)oxalic acid, ON-O(2)C-CO(2)-NO, and oxalic acid dinitrate ester, O(2)N-O(2)C-CO(2)-NO(2), were calculated using the complete basis set (CBS-4M) method of Petersson and coworkers to obtain very accurate energies. For the nitrosonium species, the ionic form ([NO](2)[O(2)C-CO(2)]) was identified as the more stable isomer, whereas for the nitrosonium compound, the covalently bound dinitrate ester (O(2)N-O(2)C-CO(2)-NO(2)) was found to be more stable. The combustion parameters with respect to possible use as ingredients in solid rocket motors for both stable species were calculated using the EXPLO5 and the ICT code. The performance of an aluminized formulation with covalently bound dinitrate ester (O(2)N-O(2)C-CO(2)-NO(2)) was shown to be comparable to that of ammonium perchlorate/aluminum. This makes oxalic acid dinitrate ester a potentially interesting perchlorate-free and environmentally benign oxidizer for solid rocket propulsion.

The Effect of Gamma Radiation on Mars Mineral Matrices: Implications for Perchlorate Formation on Mars

NASA Astrophysics Data System (ADS)

Fox, A. C.; Eigenbrode, J. L.; Pavlov, A.; Lewis, J.

2017-12-01

Observations by the Phoenix Wet Chemistry Lab of the Martian surface indicate the presence of perchlorate in high concentrations. Additional observations by the Sample Analysis at Mars and the Viking Landers indirectly support the presence of perchlorate at other localities on Mars. The evidence for perchlorate at several localities on Mars coupled with its detection in Martian meteorite EETA79001 suggests that perchlorate is present globally on Mars. The presence of perchlorate on Mars further complicates the search for organic molecules indicative of past life. While perchlorate is kinetically limited in Martian conditions, the intermediate species associated with its formation or decomposition, such as chlorate or chlorite, could oxidize Martian organic species. As a result, it is vital to understand the mechanism of perchlorate formation on Mars in order to determine its role in the degradation of organics. Here, we explore an alternate mechanism of formation of perchlorate by bombarding Cl-salts and Mars-relevant mineral mixtures with gamma radiation both with and without the presence of liquid water, under vacuum. Previous work has shown that OClO can form from both UV radiation and energetic electrons bombardment of Cl-ices or Cl-salts, which then reacts with either OH- or O-radicals to produce perchlorate. Past research has suggested that liquid water or ice is the source of these hydroxyl and oxygen radicals, which limits the location of perchlorate formation on Mars. We demonstrate that trace amounts of perchlorate are potentially formed in samples containing silica dioxide or iron oxide and Cl-salts both with and without liquid water. Perchlorate was also detected in a portion of samples that were not irradiated, suggesting possible contamination. We did not detect perchlorate in samples that contained sulfate minerals. If perchlorate was formed without liquid water, it is possible that oxide minerals could be a potential source of oxygen radicals required to produce perchlorate. This finding could help explain the global presence of perchlorate and has implications for the survival of organic molecules on Mars.

Perchlorate disrupts embryonic androgen synthesis and reproductive development in threespine stickleback without changing whole-body levels of thyroid hormone

PubMed Central

Petersen, Ann M.; Dillon, Danielle; Bernhardt, Richard A.; Torunsky, Roberta; Postlethwait, John H.; von Hippel, Frank A.; Buck, C. Loren; Cresko, William A.

2014-01-01

Perchlorate, an environmental contaminant, disrupts normal functioning of the thyroid. We previously showed that perchlorate disrupts behavior and gonad development, and induces external morphological changes in a vertebrate model organism, the threespine stickleback. Whether perchlorate alters these phenotypes via a thyroid-mediated mechanism, and the extent to which the effects depend on dose, are unknown. To address these questions, we chronically exposed stickleback to control conditions and to three concentrations of perchlorate (10, 30 and 100 ppm) at various developmental stages from fertilization to reproductive maturity. Adults chronically exposed to perchlorate had increased numbers of thyroid follicles and decreased numbers of thyrocytes. Surprisingly, T4 and T3 levels in larval, juvenile, and adult whole fish chronically exposed to perchlorate did not differ from controls, except at the lowest perchlorate dose, suggesting a non-monotonic dose response curve. We found no detectable abnormalities in external phenotype at any dose of perchlorate, indicating that the increased number of thyroid follicles compensated for the disruptive effects of these doses. In contrast to external morphology, gonadal development was altered substantially, with the highest dose of perchlorate causing the largest effects. Perchlorate increased the number both of early stage ovarian follicles in females and of advanced spermatogenic stages in males. Perchlorate also disrupted embryonic androgen levels. We conclude that chronic perchlorate exposure may not result in lasting adult gross morphological changes but can produce lasting modifications to gonads when compensation of T3 and T4 levels occurs by thyroid follicle hyperplasia. Perchlorate may therefore affect vertebrate development via both thyroidal and non-thyroidal mechanisms. PMID:25448260

Interaction between perchlorate and iodine in the metamorphosis of Hyla versicolor

USGS Publications Warehouse

Sparling, D.; Harvey, G.; Nzengung, V.; ,

2003-01-01

Perchlorate (ClO4-) is a water-soluble, inorganic anion that is often combined with ammonium, potassium or other cations for use in industry and agriculture. Ammonium perchlorate, for example, is a potent oxidizer and is used in various military applications including rocket fuel. It has also been found in an historically widely used fertilizer, Chilean nitrate and in other fertilizers. It has been found in ground and surface waters of over 30 states and is considered a human health risk. Because of its similar atomic radius and volume, perchlorate competes with iodide for thyroid uptake and storage and thereby inhibits production of thyroid hormones. Amphibians may be particularly affected by perchlorate because they rely on the thyroid for metamorphosis. This study exposed early larval Hyla versicolor to concentrations of perchlorate ranging from 2.2 to 50 ppm to determine the effects of perchlorate on a native amphibian. In addition, three controls, 0 perchlorate, 0 perchlorate with 0.10 ppm iodide (C + I) and 50 ppm perchlorate + 0.10 ppm iodide (50 + I) were tested. Mortality (< 11% with all treatments) and growth appeared to be unaffected by perchlorate. Inhibition of development started with 2.2 ppm perchlorate and little or no development occurred at 22.9 ppm and above. This inhibition was particularly apparent at the latter stages of development including hindlimb formation and metamorphosis. The estimated EC50 for total inhibition of metamorphosis at 70 days of treatment was 3.63 ppm. There was no evidence of inhibition of development with the 50 + I, C + I, or controls, indicating that the presence of small concentrations of iodide could counter the effects of perchlorate. When tadpoles that had been inhibited by perchlorate were subsequently treated with iodide, development through prometamorphosis progressed but mortality was very high.

Interaction between perchlorate and iodine in the metamorphosis of Hyla versicolor

USGS Publications Warehouse

Sparling, D.W.; Harvey, G.; Nzengung, V.; Linder, Gregory L.; Krest, Sherry K.; Sparling, Donald W.; Little, Edward E.

2003-01-01

Perchlorate (ClO4-) is a water-soluble, inorganic anion that is often combined with ammonium, potassium or other cations for use in industry and agriculture. Ammonium perchlorate, for example, is a potent oxidizer and is used in various military applications including rocket fuel. It has also been found in an historically widely used fertilizer, Chilean nitrate and in other fertilizers. It has been found in ground and surface waters of over 30 states and is considered a human health risk. Because of its similar atomic radius and volume, perchlorate competes with iodide for thyroid uptake and storage and thereby inhibits production of thyroid hormones. Amphibians may be particularly affected by perchlorate because they rely on the thyroid for metamorphosis. This study exposed early larval Hyla versicolor to concentrations of perchlorate ranging from 2.2 to 50 ppm to determine the effects of perchlorate on a native amphibian. In addition, three controls, 0 perchlorate, 0 perchlorate with 0.10 ppm iodide (C + I) and 50 ppm perchlorate + 0.10 ppm iodide (50 + I) were tested. Mortality (<11% with all treatments) and growth appeared to be unaffected by perchlorate. Inhibition of development started with 2.2 ppm perchlorate and little or no development occurred at 22.9 ppm and above. This inhibition was particularly apparent at the latter stages of development including hindlimb formation and metamorphosis. The estimated EC50 for total inhibition of metamorphosis at 70 days of treatment was 3.63 ppm. There was no evidence of inhibition of development with the 50 + I, C + I, or controls, indicating that the presence of small concentrations of iodide could counter the effects of perchlorate. When tadpoles that had been inhibited by perchlorate were subsequently treated with iodide, development through prometamorphosis progressed but mortality was very high.

Particle size distribution and perchlorate levels in settled dust from urban roads, parks, and roofs in Chengdu, China.

PubMed

Li, Yiwen; Shen, Yang; Pi, Lu; Hu, Wenli; Chen, Mengqin; Luo, Yan; Li, Zhi; Su, Shijun; Ding, Sanglan; Gan, Zhiwei

2016-01-01

A total of 27 settled dust samples were collected from urban roads, parks, and roofs in Chengdu, China to investigate particle size distribution and perchlorate levels in different size fractions. Briefly, fine particle size fractions (<250 μm) were the dominant composition in the settled dust samples, with mean percentages of 80.2%, 69.5%, and 77.2% for the urban roads, roofs, and the parks, respectively. Perchlorate was detected in all of the size-fractionated dust samples, with concentrations ranging from 73.0 to 6160 ng g(-1), and the median perchlorate levels increased with decreasing particle size. The perchlorate level in the finest fraction (<63 μm) was significantly higher than those in the coarser fractions. To our knowledge, this is the first report on perchlorate concentrations in different particle size fractions. The calculated perchlorate loadings revealed that perchlorate was mainly associated with finer particles (<125 μm). An exposure assessment indicated that exposure to perchlorate via settled road dust intake is safe to both children and adults in Chengdu, China. However, due to perchlorate mainly existing in fine particles, there is a potential for perchlorate to transfer into surface water and the atmosphere by runoff and wind erosion or traffic emission, and this could act as an important perchlorate pollution source for the indoor environment, and merits further study.

Intracellular nucleotide and nucleotide sugar contents of cultured CHO cells determined by a fast, sensitive, and high-resolution ion-pair RP-HPLC.

PubMed

Kochanowski, N; Blanchard, F; Cacan, R; Chirat, F; Guedon, E; Marc, A; Goergen, J-L

2006-01-15

Analysis of intracellular nucleotide and nucleotide sugar contents is essential in studying protein glycosylation of mammalian cells. Nucleotides and nucleotide sugars are the donor substrates of glycosyltransferases, and nucleotides are involved in cellular energy metabolism and its regulation. A sensitive and reproducible ion-pair reverse-phase high-performance liquid chromatography (RP-HPLC) method has been developed, allowing the direct and simultaneous detection and quantification of some essential nucleotides and nucleotide sugars. After a perchloric acid extraction, 13 molecules (8 nucleotides and 5 nucleotide sugars) were separated, including activated sugars such as UDP-glucose, UDP-galactose, GDP-mannose, UDP-N-acetylglucosamine, and UDP-N-acetylgalactosamine. To validate the analytical parameters, the reproducibility, linearity of calibration curves, detection limits, and recovery were evaluated for standard mixtures and cell extracts. The developed method is capable of resolving picomolar quantities of nucleotides and nucleotide sugars in a single chromatographic run. The HPLC method was then applied to quantify intracellular levels of nucleotides and nucleotide sugars of Chinese hamster ovary (CHO) cells cultivated in a bioreactor batch process. Evolutions of the titers of nucleotides and nucleotide sugars during the batch process are discussed.

Basis of the Massachusetts reference dose and drinking water standard for perchlorate.

PubMed

Zewdie, Tsedash; Smith, C Mark; Hutcheson, Michael; West, Carol Rowan

2010-01-01

Perchlorate inhibits the uptake of iodide in the thyroid. Iodide is required to synthesize hormones critical to fetal and neonatal development. Many water supplies and foods are contaminated with perchlorate. Exposure standards are needed but controversial. Here we summarize the basis of the Massachusetts (MA) perchlorate reference dose (RfD) and drinking water standard (DWS), which are considerably lower and more health protective than related values derived by several other agencies. We also review information regarding perchlorate risk assessment and policy. MA Department of Environmental Protection (DEP) scientists, with input from a science advisory committee, assessed a wide range of perchlorate risk and exposure information. Health outcomes associated with iodine insufficiency were considered, as were data on perchlorate in drinking water disinfectants. We used a weight-of-the-evidence approach to evaluate perchlorate risks, paying particular attention to sensitive life stages. A health protective RfD (0.07 microg/kg/day) was derived using an uncertainty factor approach with perchlorate-induced iodide uptake inhibition as the point of departure. The MA DWS (2 microg/L) was based on risk management decisions weighing information on perchlorate health risks and its presence in certain disinfectant solutions used to treat drinking water for pathogens. Current data indicate that perchlorate exposures attributable to drinking water in individuals at sensitive life stages should be minimized and support the MA DEP perchlorate RfD and DWS. Widespread exposure to perchlorate and other thyroid toxicants in drinking water and foods suggests that more comprehensive policies to reduce overall exposures and enhance iodine nutrition are needed.

18,21-Anhydroaldosterone and derivatives.

PubMed

Harnik, M; Kashman, Y; Cojocaru, M; Lewicka, S; Vecsei, P

1989-07-01

18,21-Anhydroaldosterone 8, 18,21-anhydro-19-noraldosterone 9, and 3 alpha, 5 beta-tetrahydro-18,21-anhydro-19-noraldosterone 13, which may be present in acid-processed urine, were prepared by cleaving their 20-ketal derivatives 2, 3, and 12 with hot mineral acid. Compounds 8 and 9 were also made by direct dehydration of aldosterone 5 and 19-noraldosterone 10 in good yield. The reverse ring opening of 8 to 5 could be carried out in moderate yield with an acetic acid-acetic anhydride-perchloric acid mixture, while an analogous ring opening of 9 gave only a poor yield of 10.

Determination of tertiary amines and salts of organic acids in acetic acid by catalytic thermometric titration.

PubMed

Vajgand, V J; Gaál, F F

1967-03-01

A new method of determination of tertiary amines and salts of organic adds in acetic acid solution, to which about 2 % of water and 8% acetic anhydride are added, is described. After the equivalence point, the excess of perchloric acid catalyses the exothermic reaction of water with acetic anhydride. The end-point is determined from the graph of temperature against volume of added titrant. If a slightly soluble compound is produced during the titration, the precision of the new method is superior to that of the potentiometric method.

Perchlorate reduction by autotrophic bacteria in the presence of zero-valent iron.

PubMed

Yu, Xueyuan; Amrhein, Christopher; Deshusses, Marc A; Matsumoto, Mark R

2006-02-15

A series of batch experiments were performed to study the combination of zero-valent iron (ZVI) with perchlorate-reducing microorganisms (PRMs) to remove perchlorate from groundwater. In this method, H2 produced during the process of iron corrosion by water is used by PRMs as an electron donor to reduce perchlorate to chloride. Perchlorate degradation rates followed Monod kinetics, with a normalized maximum utilization rate (rmax) of 9200 microg g(-1) (dry wt) h(-1) and a half-velocity constant (Ks) of 8900 microg L(-1). The overall rate of perchlorate reduction was affected by the biomass density within the system. An increase in the OD600 from 0.025 to 0.08 led to a corresponding 4-fold increase of perchlorate reduction rate. PRM adaptation to the local environment and initiation of perchlorate reduction was rapid under neutral pH conditions. At the initial OD600 of 0.015, perchlorate reduction followed pseudo-first-order reaction rates with constants of 0.059 and 0.033 h(-1) at initial pH 7 and 8, respectively. Once perchlorate reduction was established, the bioreductive process was insensitive to the increases of pH from near neutral to 9.0. In the presence of nitrate, perchlorate reduction rate was reduced, but not inhibited completely.

Effects of solvation on partition and dimerization of benzoic acid in mixed solvent systems.

PubMed

Yamada, H; Yajima, K; Wada, H; Nakagawa, G

1995-06-01

The partition of benzoic acid between 0.1M perchloric acid solution and two kinds of mixed solvents has been carried out at 25 degrees C. The partition and dimerization constants of benzoic acid have been determined in the 1-octanol-benzene and 2-octanone-benzene systems. In both the mixed solvent systems, with increasing content of 1-octanol and 2-octanone in each mixed solvent, the partition constant of benzoic acid has been found to increase, and the dimerization constant of benzoic acid in each organic phase to decrease. These phenomena are attributable to solvation of monomeric benzoic acid by 1-octanol and 2-octanone molecules in each mixed solvent.

Perchlorate in the Hydrologic Cycle - An Overview of Sources and Occurrence

NASA Astrophysics Data System (ADS)

Stonestrom, D. A.; Jackson, W.; Mayer, K.; Orris, G. J.

2007-12-01

Perchlorate (ClO4-) in water and food is of concern due to deleterious health affects associated with hypothyroidism. The presence of widespread perchlorate in 0-to-28 ka-old pristine ground water of the Middle Rio Grande Basin (Plummer et al., 2006, ES&T, DOI:10.1021/es051739h), in ground water >1 mile from agricultural activities in the Southern High Plains (Rajagapolan et al., 2006, ES&T, DOI:10.1021/es052155i), and in unsaturated zones throughout the arid and semiarid southwestern United States (Rao et al., 2007, ES&T, DOI:10.1021/es062853i) clearly indicates that perchlorate is a non-exotic component of the hydrologic cycle, at least in dry environments. The natural system has been greatly perturbed in places by human activities. Most anthropogenic inputs are associated with the manufacture and use of explosives and rocket fuel, providing concentrated sources of excess perchlorate to the hydrologic cycle. Perchlorate-containing fertilizers and irrigation provide dispersed sources within and down-gradient from agricultural areas. Natural sources include photochemically mediated reactions involving ozone at the land surface and in the lower atmosphere. A growing body of work indicates that a small, but persistent, meteoric source acting over thousands of years can explain observed accumulations of unsaturated-zone perchlorate in arid regions. In addition to meteoric sources, oxyanions produced during volcanogenic processes can include appreciable amounts of natural perchlorate. Terrestrial plants take up perchlorate in soil water, with some species of xerophytic succulents concentrating the anion to high levels. Similarly, perchlorate in marine plants indicates that perchlorate is part of marine biochemical cycles. Perchlorate-bearing marine sediments of late Tertiary age suggest that perchlorate has been part of global geochemical cycles for millions of years and, furthermore, can be preserved in the subsurface despite the nearly ubiquitous presence of perchlorate-reducing bacteria in natural environments. New methods involving various combinations of ion chromatography, mass spectroscopy, and molecular biology are providing improved tools for understanding perchlorate in natural and perturbed systems. With large-scale sampling underway, a better understanding of the sources, sinks, and transformations of perchlorate in the hydrologic cycle is starting to emerge.

Rechargeable lithium/polymer cathode batteries

NASA Astrophysics Data System (ADS)

Osaka, Tetsuya; Nakajima, Toshiki; Shiota, Koh; Owens, Boone B.

1989-06-01

Polypyrrole (PPy) and polyaniline (PAn) were investigated for cathode materials of rechargeable lithium batteries. PPy films prepared with PF6(-) anion and/or platinum substrate precoated with nitrile butadiene rubber (NBR) were excellent cathode materials because of rough and/or highly oriented film structure. PAn films were successfully prepared from non-aqueous propylene carbonate solution containing aniline, CF3COOH and lithium perchlorate. Its acidity strongly affects the anion doping-undoping behavior. The PAn cathode prepared in high acidic solution (e.g., 4:1 ratio of acid:aniline) gives the excellent battery performance.

Dissolution mechanism of aluminum hydroxides in acid media

NASA Astrophysics Data System (ADS)

Lainer, Yu. A.; Gorichev, I. G.; Tuzhilin, A. S.; Gololobova, E. G.

2008-08-01

The effects of the concentration, temperature, and potential at the hydroxide/electrolyte interface on the aluminum hydroxide dissolution in sulfuric, hydrochloric, and perchloric acids are studied. The limiting stage of the aluminum hydroxide dissolution in the acids is found to be the transition of the complexes that form on the aluminum hydroxide surface from the solid phase into the solution. The results of the calculation of the acid-base equilibrium constants at the oxide (hydroxide)/solution interface using the experimental data on the potentiometric titration of Al2O3 and AlOOH suspensions are analyzed. A mechanism is proposed for the dissolution of aluminum hydroxides in acid media.

Perchlorate as an emerging contaminant in soil, water and food.

PubMed

Kumarathilaka, Prasanna; Oze, Christopher; Indraratne, S P; Vithanage, Meththika

2016-05-01

Perchlorate ( [Formula: see text] ) is a strong oxidizer and has gained significant attention due to its reactivity, occurrence, and persistence in surface water, groundwater, soil and food. Stable isotope techniques (i.e., ((18)O/(16)O and (17)O/(16)O) and (37)Cl/(35)Cl) facilitate the differentiation of naturally occurring perchlorate from anthropogenic perchlorate. At high enough concentrations, perchlorate can inhibit proper function of the thyroid gland. Dietary reference dose (RfD) for perchlorate exposure from both food and water is set at 0.7 μg kg(-1) body weight/day which translates to a drinking water level of 24.5 μg L(-1). Chromatographic techniques (i.e., ion chromatography and liquid chromatography mass spectrometry) can be successfully used to detect trace level of perchlorate in environmental samples. Perchlorate can be effectively removed by wide variety of remediation techniques such as bio-reduction, chemical reduction, adsorption, membrane filtration, ion exchange and electro-reduction. Bio-reduction is appropriate for large scale treatment plants whereas ion exchange is suitable for removing trace level of perchlorate in aqueous medium. The environmental occurrence of perchlorate, toxicity, analytical techniques, removal technologies are presented. Copyright © 2016 Elsevier Ltd. All rights reserved.

Basis of the Massachusetts Reference Dose and Drinking Water Standard for Perchlorate

PubMed Central

Zewdie, Tsedash; Smith, C. Mark; Hutcheson, Michael; West, Carol Rowan

2010-01-01

Objective Perchlorate inhibits the uptake of iodide in the thyroid. Iodide is required to synthesize hormones critical to fetal and neonatal development. Many water supplies and foods are contaminated with perchlorate. Exposure standards are needed but controversial. Here we summarize the basis of the Massachusetts (MA) perchlorate reference dose (RfD) and drinking water standard (DWS), which are considerably lower and more health protective than related values derived by several other agencies. We also review information regarding perchlorate risk assessment and policy. Data sources MA Department of Environmental Protection (DEP) scientists, with input from a science advisory committee, assessed a wide range of perchlorate risk and exposure information. Health outcomes associated with iodine insufficiency were considered, as were data on perchlorate in drinking water disinfectants. Data synthesis We used a weight-of-the-evidence approach to evaluate perchlorate risks, paying particular attention to sensitive life stages. A health protective RfD (0.07 μg/kg/day) was derived using an uncertainty factor approach with perchlorate-induced iodide uptake inhibition as the point of departure. The MA DWS (2 μg/L) was based on risk management decisions weighing information on perchlorate health risks and its presence in certain disinfectant solutions used to treat drinking water for pathogens. Conclusions Current data indicate that perchlorate exposures attributable to drinking water in individuals at sensitive life stages should be minimized and support the MA DEP perchlorate RfD and DWS. Widespread exposure to perchlorate and other thyroid toxicants in drinking water and foods suggests that more comprehensive policies to reduce overall exposures and enhance iodine nutrition are needed. PMID:20056583

Maternal perchlorate exposure in pregnancy and altered birth outcomes.

PubMed

Rubin, Rainbow; Pearl, Michelle; Kharrazi, Martin; Blount, Benjamin C; Miller, Mark D; Pearce, Elizabeth N; Valentin-Blasini, Liza; DeLorenze, Gerald; Liaw, Jane; Hoofnagle, Andrew N; Steinmaus, Craig

2017-10-01

At high medicinal doses perchlorate is known to decrease the production of thyroid hormone, a critical factor for fetal development. In a large and uniquely exposed cohort of pregnant women, we recently identified associations between environmental perchlorate exposures and decreased maternal thyroid hormone during pregnancy. Here, we investigate whether perchlorate might be associated with birthweight or preterm birth in the offspring of these women. Maternal urinary perchlorate, serum thyroid hormone concentrations, birthweight, gestational age, and urinary nitrate, thiocyanate, and iodide were collected in 1957 mother-infant pairs from San Diego County during 2000-2003, a period when the county's water supply was contaminated with perchlorate. Associations between perchlorate exposure and birth outcomes were examined using linear and logistic regression analyses adjusted for maternal age, weight, race/ethnicity, and other factors. Perchlorate was not associated with birth outcomes in the overall population. However, in analyses confined to male infants, log 10 maternal perchlorate concentrations were associated with increasing birthweight (β=143.1gm, p=0.01), especially among preterm births (β=829.1g, p<0.001). Perchlorate was associated with male preterm births ≥2500g (odds ratio=3.03, 95% confidence interval=1.09-8.40, p-trend=0.03). Similar associations were not seen in females. This is the first study to identify associations between perchlorate and increasing birthweight. Further research is needed to explore the differences we identified related to infant sex, preterm birth, and other factors. Given that perchlorate exposure is ubiquitous, and that long-term impacts can follow altered birth outcomes, future research on perchlorate could have widespread public health importance. Copyright © 2017 Elsevier Inc. All rights reserved.

Determination of biogenic amines in chocolate by ion chromatographic separation and pulsed integrated amperometric detection with implemented wave-form at Au disposable electrode.

PubMed

Pastore, Paolo; Favaro, Gabriella; Badocco, Denis; Tapparo, Andrea; Cavalli, Silvano; Saccani, Giovanna

2005-12-09

A rapid and selective cation exchange chromatographic method coupled to integrated pulsed amperometric detection (PAD) has been developed to quantify biogenic amines in chocolate. The method is based on gradient elution of aqueous methanesulfonic acid with post column addition of strong base to obtain suitable conditions for amperometric detection. A potential waveform able to keep long time performance of the Au disposable electrode was set up. Total analysis time is less than 20min. Concentration levels of dopamine, serotonin, tyramine, histamine and 2-phenylethylamine were measured, after extraction with perchloric acid from 2g samples previously defatted twice with petroleum ether. The method was used to determine the analytes in chocolate real matrices and their quantification was made with standard addition method. Only dopamine, histamine and serotonin were found in the analysed real samples. Repeatabilities of their signals, computed on their amounts in the real samples, were 5% for all of them. Repeatabilities of tyramine and phenethylamine were relative to standard additions to real samples (close to 1mg/l in the extract) and were 7 and 3%, respectively. Detection limits were computed with the 3s of the baseline noise combined with the calibration plot regression parameters. They were satisfactorily low for all amines: 3mg/kg for dopamine, 2mg/kg for tyramine, 1mg/kg for histamine, 2mg/kg for serotonin, 3mg/kg for 2-phenylethylamine.

(13)C heteronuclear NMR studies of the interaction of cultured neurons and astrocytes and aluminum blockade of the preferential release of citrate from astrocytes.

PubMed

Meshitsuka, Shunsuke; Aremu, David A

2008-02-01

Citrate has been identified as a major tricarboxylic acid (TCA) cycle constituent preferentially released by astrocytes. We undertook the present study to examine further the nature of metabolic compartmentation in central nervous system tissues using (13)C-labeled glucose and to provide new information on the influence of aluminum on the metabolic interaction between neurons and astrocytes. Metabolites released into the culture medium from astrocytes and neuron-astrocyte coculture, as well as the perchloric acid extracts of the cells were analyzed using 2D (1)H and (13)C NMR spectroscopy. Astrocytes released citrate into the culture medium and the released citrate was consumed by neurons in coculture. Citrate release by astrocytes was blocked in the presence of aluminum, with progressive accumulation of citrate within the cells. We propose citrate supply is a more efficient energy source than lactate for neurons to produce ATP, especially in the hypoglycemic state on account of it being a direct component of the TCA cycle. Astrocytes may be the cellular compartment for aluminum accumulation as a citrate complex in the brain.

Effects of perchlorate on growth of four wetland plants and its accumulation in plant tissues.

PubMed

He, Hongzhi; Gao, Haishuo; Chen, Guikui; Li, Huashou; Lin, Hai; Shu, Zhenzhen

2013-10-01

Perchlorate contamination in water is of concern because of uncertainties about toxicity and health effects, impact on ecosystems, and possible indirect exposure pathways to humans. Therefore, it is very important to investigate the ecotoxicology of perchlorate and to screen plant species for phytoremediation. Effects of perchlorate (20, 200, and 500 mg/L) on the growth of four wetland plants (Eichhornia crassipes, Acorus calamus L., Thalia dealbata, and Canna indica) as well as its accumulation in different plant tissues were investigated through water culture experiments. Twenty milligrams per liter of perchlorate had no significant effects on height, root length, aboveground part weight, root weight, and oxidizing power of roots of four plants, except A. calamus, and increasing concentrations of perchlorate showed that out of the four wetland plants, only A. calamus had a significant (p<0.05) dose-dependent decrease in these parameters. When treated with 500 mg/L perchlorate, these parameters and chlorophyll content in the leaf of plants showed significant decline contrasted to control groups, except the root length of E. crassipes and C. indica. The order of inhibition rates of perchlorate on root length, aboveground part weight and root weight, and oxidizing power of roots was: A. calamus > C. indica > T. dealbata > E. crassipes and on chlorophyll content in the leaf it was: A. calamus > T. dealbata > C. indica > E. crassipes. The higher the concentration of perchlorate used, the higher the amount of perchlorate accumulation in plants. Perchlorate accumulation in aboveground tissues was much higher than that in underground tissues and leaf was the main tissue for perchlorate accumulation. The order of perchlorate accumulation content and the bioconcentration factor in leaf of four plants was: E. crassipes > C. indica > T. dealbata > A. calamus. Therefore, E. crassipes might be an ideal plant with high tolerance ability and accumulation ability for constructing wetland to remediate high levels of perchlorate polluted water.

Sensitivity and adaptability of methanogens to perchlorates: Implications for life on Mars

NASA Astrophysics Data System (ADS)

Kral, Timothy A.; Goodhart, Timothy H.; Harpool, Joshua D.; Hearnsberger, Christopher E.; McCracken, Graham L.; McSpadden, Stanley W.

2016-01-01

In 2008, the Mars Phoenix Lander discovered perchlorate at its landing site, and in 2012, the Curiosity rover confirmed the presence of perchlorate on Mars. The research reported here was designed to determine if certain methanogens could grow in the presence of three different perchlorate salt solutions. The methanogens tested were Methanothermobacter wolfeii, Methanosarcina barkeri, Methanobacterium formicicum and Methanococcus maripaludis. Media were prepared containing 0%, 0.5%, 1.0%, 2%, 5% and 10% wt/vol magnesium perchlorate, sodium perchlorate, or calcium perchlorate. Organisms were inoculated into their respective media followed by incubation at each organism's growth temperature. Methane production, commonly used to measure methanogen growth, was measured by gas chromatography of headspace gas samples. Methane concentrations varied with species and perchlorate salt tested. However, all four methanogens produced substantial levels of methane in the presence of up to 1.0% perchlorate, but not higher. The standard procedure for growing methanogens typically includes sodium sulfide, a reducing agent, to reduce residual molecular oxygen. However, the sodium sulfide may have been reducing the perchlorate, thus allowing for growth of the methanogens. To investigate this possibility, experiments were conducted where stainless steel nails were used instead of sodium sulfide as the reducing agent. Prior to the addition of perchlorate and inoculation, the nails were removed from the liquid medium. Just as in the prior experiments, the methanogens produced methane at comparable levels to those seen with sodium sulfide as the reductant, indicating that sodium sulfide did not reduce the perchlorate to any significant extent. Additionally, cells metabolizing in 1% perchlorate were transferred to 2%, cells metabolizing in 2% were transferred to 5%, and finally cells metabolizing in 5% were transferred to 10%. All four species produced methane at 2% and 5%, but not 10% indicating some success in adapting cells to concentrations higher than 1%. The results reported here indicate that the presence of perchlorate on Mars does not rule out the possible existence of methanogens.

Simultaneous detection of perchlorate and bromate using rapid high-performance ion exchange chromatography-tandem mass spectrometry and perchlorate removal in drinking water.

PubMed

West, Danielle M; Mu, Ruipu; Gamagedara, Sanjeewa; Ma, Yinfa; Adams, Craig; Eichholz, Todd; Burken, Joel G; Shi, Honglan

2015-06-01

Perchlorate and bromate occurrence in drinking water causes health concerns due to their effects on thyroid function and carcinogenicity, respectively. The purpose of this study was threefold: (1) to advance a sensitive method for simultaneous rapid detection of perchlorate and bromate in drinking water system, (2) to systematically study the occurrence of these two contaminants in Missouri drinking water treatment systems, and (3) to examine effective sorbents for minimizing perchlorate in drinking water. A rapid high-performance ion exchange chromatography-tandem mass spectrometry (HPIC-MS/MS) method was advanced for simultaneous detection of perchlorate and bromate in drinking water. The HPIC-MS/MS method was rapid, required no preconcentration of the water samples, and had detection limits for perchlorate and bromate of 0.04 and 0.01 μg/L, respectively. The method was applied to determine perchlorate and bromate concentrations in total of 23 selected Missouri drinking water treatment systems during differing seasons. The water systems selected include different source waters: groundwater, lake water, river water, and groundwater influenced by surface water. The concentrations of perchlorate and bromate were lower than or near to method detection limits in most of the drinking water samples monitored. The removal of perchlorate by various adsorbents was studied. A cationic organoclay (TC-99) exhibited effective removal of perchlorate from drinking water matrices.

Spatial Variability of Perchlorate along a Traverse Route from Zhongshan Station to Dome A, East Antarctica

NASA Astrophysics Data System (ADS)

Jiang, S.; Cole-Dai, J.; Li, Y.; An, C.

2016-12-01

Snow deposition and accumulation on the Antarctic ice sheet preserve records of climatic change, as well as those of chemical characteristics of the environment. Chemical composition of snow and ice cores can be used to track the sources of important substances including pollutants and to investigate relationships between atmospheric chemistry and climatic conditions. Recent development in analytical methodology has enabled the determination of ultra-trace levels of perchlorate in polar snow. We have measured perchlorate concentrations in surface snow samples collected along a traverse route from Zhongshan Station to Dome A in East Antarctica to determine the level of atmospheric perchlorate in East Antarctica and to assess the spatial variability of perchlorate along the traverse route. Results show that the perchlorate concentrations vary between 32 and 200 ng kg-1, with an average of 104.3 ng kg-1. And perchlorate concentration profile presents regional variation patterns along the traverse route. In the coastal region, perchlorate concentration displays an apparent decreasing relationship with increasing distance inland; it exhibits no apparent trend in the intermediate region from 200 to 1000 km. The inland region from 1000 to 1244 km presents a generally increasing trend of perchlorate concentration approaching the dome. Different rates of atmospheric production, dilution by snow accumulation and re-deposition of snow-emitted perchlorate (post-depositional change) are the three possible factors influencing the spatial variability of perchlorate over Antarctica.

Effect of nitrate, acetate and hydrogen on native perchlorate-reducing microbial communities and their activity in vadose soil

PubMed Central

Nozawa-Inoue, Mamie; Jien, Mercy; Yang, Kun; Rolston, Dennis E.; Hristova, Krassimira R.; Scow, Kate M.

2011-01-01

Effect of nitrate, acetate and hydrogen on native perchlorate-reducing bacteria (PRB) was examined by conducting microcosm tests using vadose soil collected from a perchlorate-contaminated site. The rate of perchlorate reduction was enhanced by hydrogen amendment and inhibited by acetate amendment, compared to unamendment. Nitrate was reduced before perchlorate in all amendments. In hydrogen-amended and unamended soils, nitrate delayed perchlorate reduction, suggesting the PRB preferentially use nitrate as an electron acceptor. In contrast, nitrate eliminated the inhibitory effect of acetate amendment on perchlorate reduction and increased the rate and the extent, possibly because the preceding nitrate reduction/denitrification decreased the acetate concentration which was inhibitory to the native PRB. In hydrogen-amended and unamended soils, perchlorate reductase gene (pcrA) copies, representing PRB densities, increased with either perchlorate or nitrate reduction, suggesting either perchlorate or nitrate stimulates growth of the PRB. In contrast, in acetate-amended soil pcrA increased only when perchlorate was depleted: a large portion of the PRB may have not utilized nitrate in this amendment. Nitrate addition did not alter the distribution of the dominant pcrA clones in hydrogen-amended soil, likely because of the functional redundancy of PRB as nitrate-reducers/denitrifiers, whereas acetate selected different pcrA clones from those with hydrogen amendment. PMID:21284679

Perchlorate in Water Supplies: Sources, Exposures, and Health Effects

PubMed Central

Steinmaus, Craig M.

2016-01-01

Perchlorate exposure occurs from ingestion of natural or manmade perchlorate in food or water. Perchlorate is used in a variety of industrial products including missile fuel, fireworks, and fertilizers, and industrial contamination of drinking water supplies has occurred in a number of areas. Perchlorate blocks iodide uptake into the thyroid, and decreases the production of thyroid hormone, a critical hormone for metabolism, neurodevelopment, and other physiologic functions. Occupational and clinical dosing studies have not identified clear adverse effects, but may be limited by small sample sizes, short study durations, and the inclusion of mostly healthy adults. Expanding evidence suggests that young children, pregnant women, fetuses, and people co-exposed to similarly acting agents may be especially susceptible to perchlorate. Given the ubiquitous nature of perchlorate exposure, and the importance of thyroid hormone for brain development, studying the impact of perchlorate on human health could have far-reaching public health implications. PMID:27026358

Perchlorate in fish from a contaminated site in east-central Texas.

PubMed

Theodorakis, Christopher; Rinchard, Jacques; Anderson, Todd; Liu, Fujun; Park, June-Woo; Costa, Filipe; McDaniel, Leslie; Kendall, Ronald; Waters, Aaron

2006-01-01

Perchlorate, a known thyroid endocrine disruptor, contaminates surface waters near military instillations where solid fuel rocket motors are manufactured or assembled. To assess potential perchlorate exposure to fish and the human population which may feed on them, fish were collected around the Naval Weapons Industrial Reserve Plant in McLennan County, TX, and analyzed for the presence of the perchlorate anion. The sampling sites included Lake Waco and Belton Lake, and several streams and rivers within their watersheds. The general tendency was that perchlorate was only found in a few species sampled, and perchlorate was not detected in every individual within these species. When detected in the fish, perchlorate tissue concentrations were greater than that in the water. This may be due to highly variable perchlorate concentrations in the water coupled with individual-level variation in elimination from the body, or to routes of exposure other than water.

An upper-bound assessment of the benefits of reducing perchlorate in drinking water.

PubMed

Lutter, Randall

2014-10-01

The Environmental Protection Agency plans to issue new federal regulations to limit drinking water concentrations of perchlorate, which occurs naturally and results from the combustion of rocket fuel. This article presents an upper-bound estimate of the potential benefits of alternative maximum contaminant levels for perchlorate in drinking water. The results suggest that the economic benefits of reducing perchlorate concentrations in drinking water are likely to be low, i.e., under $2.9 million per year nationally, for several reasons. First, the prevalence of detectable perchlorate in public drinking water systems is low. Second, the population especially sensitive to effects of perchlorate, pregnant women who are moderately iodide deficient, represents a minority of all pregnant women. Third, and perhaps most importantly, reducing exposure to perchlorate in drinking water is a relatively ineffective way of increasing iodide uptake, a crucial step linking perchlorate to health effects of concern. © 2014 Society for Risk Analysis.

Energy Barriers and Hysteresis in Martensitic Phase Transformations

DTIC Science & Technology

2008-08-01

glacial acetic acid (CH3COOH) and 10-15% perchloric acid (HCLO4) by volume, the cathode was stainless steel , the anode was stainless steel or Ti, the...Submitted to Acta Materialia Energy barriers and hysteresis in martensitic phase transformations Zhiyong Zhang, Richard D. James and Stefan Müller...hysteresis based on the growth from a small scale of fully developed austenite martensite needles. In this theory the energy of the transition layer plays a

Freezing-Enhanced Dissolution of Iron Oxides: Effects of Inorganic Acid Anions.

PubMed

Jeong, Daun; Kim, Kitae; Min, Dae Wi; Choi, Wonyong

2015-11-03

Dissolution of iron from mineral dust particles greatly depends upon the type and amount of copresent inorganic anions. In this study, we investigated the roles of sulfate, chloride, nitrate, and perchlorate on the dissolution of maghemite and lepidocrocite in ice under both dark and UV irradiation and compared the results with those of their aqueous counterparts. After 96 h of reaction, the total dissolved iron in ice (pH 3 before freezing) was higher than that in the aqueous phase (pH 3) by 6-28 times and 10-20 times under dark and UV irradiation, respectively. Sulfuric acid was the most efficient in producing labile iron under dark condition, whereas hydrochloric acid induced the most dissolution of the total and ferrous iron in the presence of light. This ice-induced dissolution result was also confirmed with Arizona Test Dust (AZTD). In the freeze-thaw cycling test, the iron oxide samples containing chloride, nitrate, or perchlorate showed a similar extent of total dissolved iron after each cycling while the sulfate-containing sample rapidly lost its dissolution activity with repeating the cycle. This unique phenomenon observed in ice might be related to the freeze concentration of protons, iron oxides, and inorganic anions in the liquid-like ice grain boundary region. These results suggest that the ice-enhanced dissolution of iron oxides can be a potential source of bioavailable iron, and the acid anions critically influence this process.

Perchlorate and iodide in whole blood samples from infants, children, and adults in Nanchang, China.

PubMed

Zhang, Tao; Wu, Qian; Sun, Hong Wen; Rao, Jia; Kannan, Kurunthachalam

2010-09-15

Perchlorate, ClO(4)(-), interferes with iodide (I(-)) uptake by the sodium-iodide symporter (NIS) and thereby affects thyroid hormone production in the body. Studies have reported human exposures to perchlorate based on measurements in urine, but little is known about the levels in blood. In this study, we determined concentrations of perchlorate, iodide, and other anions (e.g., chlorate [ClO(3)(-)], bromate [BrO(3)(-)], bromide [Br(-)]) in 131 whole blood samples collected from Chinese donors aged 0.4 to 90 yr, in Nanchang, China. Perchlorate, iodide, and bromide were detected in all of the samples analyzed, whereas chlorate was found in only 27% of the samples and bromate was found in only 2%. The mean (range) concentrations of perchlorate, iodide, and bromide were 2.68 (0.51-10.5), 42.6 (1.58-812), and 2120 (1050-4850) ng/mL, respectively. Perchlorate levels in blood from Nanchang adults were 10-fold greater than levels that have been previously reported for U.S. adults. The iodide/perchlorate molar ratio ranged from 3.05 to 15.3 for all age groups, and the ratio increased with age (r = 0.732, p < 0.01). Perchlorate and bromide concentrations decreased significantly with age, whereas iodide concentrations increased with age. No significant gender-related differences in blood perchlorate, iodide, or bromide levels were found. A significant negative correlation was found between the concentrations of perchlorate and iodide in blood. Exposure doses of perchlorate were estimated for infants, toddlers, children, adolescents, and adults based on the measured concentrations in blood, using a simple pharmacokinetic model. The mean exposure doses of perchlorate for our age groups ranged from 1.12 (adults) to 2.22 μg/kg bw/day (infants), values higher than the United States Environmental Protection Agency's (USEPA) reference dose (RfD: 0.7 μg/kg bw/day). This is the first study on perchlorate and iodide levels in whole blood from infants, toddlers, children, adolescents, and adults from a city in China with known high perchlorate levels.

Thermometric titrations of amines with nitrosyl perchlorate in acetonitrile solvent.

PubMed

Gündüz, T; Kiliç, E; Cakirer, O

1996-05-01

Thirteen aliphatic and four aromatic amines, namely diethylamine, triethylamine, n-propylamine, di-n-propylamine, tri-n-butylamine, isopropylamine, di-isopropylamine, n-butylamine, di-n-butylamine, tri-n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, aniline, N,N-dimethylaniline, 2-nitroaniline and 4-nitroaniline were titrated thermometrically with nitrosyl perchlorate in acetonitrile solvent. All the aliphatic amines gave very well-shaped thermometric titration curves. The calculated recovery values of the amines were very good. In comparison, the aromatic amines, aniline and N,N-dimethylaniline gave rather well-shaped titration curves, but the recovery values were fairly low. 2-Nitro- and 4-nitro anilines gave no thermometric response at all. The heats of reaction of the amines with nitrosyl perchlorate are rather high. However, the average heat of reaction of the aromatic amines is approximately two-thirds that of the average heat of the aliphatic amines. To support this method all the amines were also titrated potentiometrically and very similar results to those obtained with the thermometric method are seen. The nitrosyl ion is a Lewis acid, strong enough to titrate quantitatively aliphatic amines in acetonitrile solvent, but not strong enough to titrate aromatic amines at the required level in the same solvent.

Rapid measurement of perchlorate in polar ice cores down to sub-ng L(-1) levels without pre-concentration.

PubMed

Peterson, Kari; Cole-Dai, Jihong; Brandis, Derek; Cox, Thomas; Splett, Scott

2015-10-01

An ion chromatography-electrospray ionization-tandem mass spectrometry (IC-ESI-MS/MS) method has been developed for rapid and accurate measurement of perchlorate in polar snow and ice core samples in which perchlorate concentrations are expected to be as low as 0.1 ng L(-1). Separation of perchlorate from major inorganic species in snow is achieved with an ion chromatography system interfaced to an AB SCIEX triple quadrupole mass spectrometer operating in multiple reaction monitoring mode. Under optimized conditions, the limit of detection and lower limit of quantification without pre-concentration have been determined to be 0.1 and 0.3 ng L(-1), respectively, with a linear dynamic range of 0.3-10.0 ng L(-1) in routine measurement. These represent improvements over previously reported methods using similar analytical techniques. The improved method allows fast, accurate, and reproducible perchlorate quantification down to the sub-ng L(-1) level and will facilitate perchlorate measurement in the study of natural perchlorate production with polar ice cores in which perchlorate concentrations are anticipated to vary in the low and sub-ng L(-1) range. Initial measurements of perchlorate in ice core samples from central Greenland show that typical perchlorate concentrations in snow dated prior to the Industrial Revolution are about 0.8 ng L(-1), while perchlorate concentrations are significantly higher in recent (post-1980) snow, suggesting that anthropogenic sources are a significant contributor to perchlorate in the current environment.

Standard methods for chemical analysis of steel, cast iron, open-hearth iron, and wrought iron

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1973-01-01

Methods are described for determining manganese, phosphorus, sulfur, selenium, copper, nickel, chromium, vanadium, tungsten, titanium, lead, boron, molybdenum ( alpha -benzoin oxime method), zirconium (cupferron --phosphate method), niobium and tantalum (hydrolysis with perchloric and sulfurous acids (gravimetric, titrimetric, and photometric methods)), and beryllium (oxide method). (DHM)

Uptake, elimination, and relative distribution of perchlorate in various tissues of channel catfish

USGS Publications Warehouse

Park, J.-W.; Bradford, C.M.; Rinchard, J.; Liu, F.; Wages, M.; Waters, A.; Kendall, R.J.; Anderson, T.A.; Theodorakis, C.W.

2007-01-01

This study was undertaken to determine the kinetics of uptake and elimination of perchlorate in channel catfish, Ictalurus punctatus. Perchlorate - an oxidizer used in solid fuel rockets, fireworks, and illuminating munitions - has been shown to effect thyroid function, causing hormone disruption and potential perturbations of metabolic activities. For the uptake study, catfish were exposed to 100 mg/L sodium perchlorate for 12 h to 5 d in the laboratory. Perchlorate in tissues was analyzed using ion chromatography. The highest perchlorate concentrations were found in the head and fillet, indicating that these tissues are the most important tissues to analyze when determining perchlorate uptake into large fish. To calculate uptake and elimination rate constants for fillet, gills, G-I tract, liver, and head, fish were exposed to 100 ppm sodium perchlorate for 5 days, and allowed to depurate in clean water for up to 20 days. The animals rapidly eliminated the perchlorate accumulated showing the highest elimination in fillet (Ke = 1.67 day -1) and lowest elimination in liver (Ke = 0.79 day -1). ?? 2007 American Chemical Society.

PERCHLORATE CROP INTERACTIONS VIA CONTAMINATED IRRIGATION WATER

EPA Science Inventory

Perchlorate has contaminated water and sods at several locations in the United States. Perchlorate is water soluble, exceedingly mobile in aqueous systems, and can persist for many decades under typical ground- and surface water conditions. Perchlorate is of concern because of un...

ACCUMULATION OF PERCHLORATE IN TOBACCO PLANTS AND TOBACCO PRODUCTS

EPA Science Inventory

Previous field and laboratory studies with vascular plants have shown that perchlorate is transported from perchlorate fortified soils and is accumulated in the plant tissues and organs. This paper reports results of initial investigations on the accumulation of perchlorate in t...

ACCUMULATION OF PERCHLORATE IN TOBACCO PLANTS: DEVELOPMENT OF A PLANT KINETIC MODEL

EPA Science Inventory

Previous studies have shown that tobacco plants are tolerant of perchlorate and will accumulate perchlorate in plant tissues. This research determined the uptake, translocation, and accumulation of perchlorate in tobacco plants. Three hydroponics growth studies were completed u...

PERCHLORATE PHYTOREMEDIATION USING HARDWOOD TREES AND VASCULAR PLANTS

EPA Science Inventory

Perchlorate has contaminated water and soils at several locations in the United States. Perchlorate is
water soluble, exceedingly mobile in aqueous systems, and can persist for many decades under typical ground and surface water conditions. Perchlorate is of concern because of...

DETERMINATION OF PERCHLORATE IN TOBACCO PLANTS AND TOBACCO PRODUCTS

EPA Science Inventory

Previous field and laboratory studies with vascular plants have shown that perchlorate is transported from perchlorate fortified soils and is accumulated in the plant tissues and organs. This paper reports results of initial investigations on the accumulation of perchlorate in t...

DEVELOPMENT AND VALIDATION OF AN ION CHROMATOGRAPHIC METHOD FOR DETERMINING PERCHLORATE IN FERTILIZERS

EPA Science Inventory

A method has been developed for the determination of perchlorate in fertilizers. Materials are leached with deionized water to dissolve any soluble perchlorate compounds. Ion chromatographic separation is followed by suppressed conductivity for detection. Perchlorate is retained ...

Simple and rapid determination of serotonin and catecholamines in biological tissue using high-performance liquid chromatography with electrochemical detection.

PubMed

Patel, Bhavik Anil; Arundell, Martin; Parker, Kim H; Yeoman, Mark S; O'Hare, Danny

2005-04-25

Using the CNS of Lymnaea stagnalis a method is described for the rapid analysis of neurotransmitters and their metabolites using high performance liquid chromatography coupled with electrochemical detection. Tissue samples were homogenised in ice-cold 0.1 M perchloric acid and centrifuged. Using a C(18) microbore column the mobile phase was maintained at a flow rate of 100 microl/min and consisted of sodium citrate buffer (pH 3.2)-acetonitrile (82.5:17.5, v/v) with 2 mM decane-sulfonic acid sodium salt. The potential was set at +750 mV versus Ag|AgCl reference electrode at a sensitivity of 50 nA full scale deflection. The detection limit for serotonin was 11.86 ng ml(-1) for a 5 microl injection. Preparation of tissue samples in mobile phase reduced the response to dopamine and serotonin compared with perchloric acid. In addition it was found that the storage of tissue samples at -20 degrees C caused losses of dopamine and serotonin. As a result of optimising the sample preparation and mobile phase the total time of analysis was substantially reduced resulting in a sample preparation and assay time of 15-20 min.

Perchlorate in the Great Lakes: isotopic composition and origin.

PubMed

Poghosyan, Armen; Sturchio, Neil C; Morrison, Candice G; Beloso, Abelardo D; Guan, Yunbin; Eiler, John M; Jackson, W Andrew; Hatzinger, Paul B

2014-10-07

Perchlorate is a persistent and mobile contaminant in the environment with both natural and anthropogenic sources. Stable isotope ratios of oxygen (δ(18)O, Δ(17)O) and chlorine (δ(37)Cl) along with the abundance of the radioactive isotope (36)Cl were used to trace perchlorate sources and behavior in the Laurentian Great Lakes. These lakes were selected for study as a likely repository of recent atmospheric perchlorate deposition. Perchlorate concentrations in the Great Lakes range from 0.05 to 0.13 μg per liter. δ(37)Cl values of perchlorate from the Great Lakes range from +3.0‰ (Lake Ontario) to +4.0‰ (Lake Superior), whereas δ(18)O values range from -4.1‰ (Lake Superior) to +4.0‰ (Lake Erie). Great Lakes perchlorate has mass-independent oxygen isotopic variations with positive Δ(17)O values (+1.6‰ to +2.7‰) divided into two distinct groups: Lake Superior (+2.7‰) and the other four lakes (∼+1.7‰). The stable isotopic results indicate that perchlorate in the Great Lakes is dominantly of natural origin, having isotopic composition resembling that measured for indigenous perchlorate from preindustrial groundwaters of the western USA. The (36)Cl/Cl ratio of perchlorate varies widely from 7.4 × 10(-12) (Lake Ontario) to 6.7 × 10(-11) (Lake Superior). These (36)ClO4(-) abundances are consistent with an atmospheric origin of perchlorate in the Great Lakes. The relatively high (36)ClO4(-) abundances in the larger lakes (Lakes Superior and Michigan) could be explained by the presence of (36)Cl-enriched perchlorate deposited during the period of elevated atmospheric (36)Cl activity following thermonuclear bomb tests in the Pacific Ocean.

Perchlorate contamination in Chile: Legacy, challenges, and potential solutions.

PubMed

Vega, Marcela; Nerenberg, Robert; Vargas, Ignacio T

2018-07-01

This paper reviews the unique situation of perchlorate contamination in Chile, including its sources, presence in environmental media and in the human population, and possible steps to mitigate its health impacts. Perchlorate is a ubiquitous water contaminant that inhibits thyroid function. Standards for drinking water range from 2 to 18 µg L -1 in United States and Europe. A major natural source of perchlorate contamination is Chile saltpeter, found in the Atacama Desert. High concentrations of perchlorate have presumably existed in this region, in soils, sediments, surface waters and groundwaters, for millions of years. As a result of this presence, and the use of Chile saltpeter as a nitrogen fertilizer, perchlorate in Chile has been found at concentrations as high as 1480 µg L -1 in drinking water, 140 µg/kg -1 in fruits, and 30 µg L -1 in wine. Health studies in Chile have shown concentrations of 100 µg L - 1 in breast milk and 20 µg L -1 in neonatal serum. It is important to acknowledge perchlorate as a potential health concern in Chile, and assess mitigation strategies. A more thorough survey of perchlorate in Chilean soils, sediments, surface waters, groundwaters, and food products can help better assess the risks and potentially develop standards. Also, perchlorate treatment technologies should be more closely assessed for relevance to Chile. The Atacama Desert is a unique biogeochemical environment, with millions of years of perchlorate exposure, which can be mined for novel perchlorate-reducing microorganisms, potentially leading to new biological treatment processes for perchlorate-containing waters, brines, and fertilizers. Copyright © 2018 Elsevier Inc. All rights reserved.

The Investigation of Perchlorate/Iron Phase Mixtures as A Possible Source of Oxygen Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater, Mars

NASA Technical Reports Server (NTRS)

Sutter, B.; Heil, E.; Morris, R. V.; Archer, P. D.; Ming, D. W.; Niles, P. B.; Eigenbrode, J. L.; Franz, H.; Freissinet C.; Glavin, D. P.;

Influence of variation in mobile phase pH and solute pK(a) with the change of organic modifier fraction on QSRRs of hydrophobicity and RP-HPLC retention of weakly acidic compounds.

PubMed

Han, Shu-ying; Liang, Chao; Zou, Kuan; Qiao, Jun-qin; Lian, Hong-zhen; Ge, Xin

2012-11-15

The variation in mobile phase pH and ionizable solute dissociation constant (pK(a)) with the change of organic modifier fraction in hydroorganic mobile phase has seemingly been a troublesome problem in studies and applications of reversed phase high performance liquid chromatography (RP-HPLC). Most of the early studies regarding the RP-HPLC of acid-base compounds have to measure the actual pH of the mixed mobile phase rigorously, sometimes bringing difficulties in the practices of liquid chromatographic separation. In this paper, the effect of this variation on the apparent n-octanol/water partition coefficient (K(ow)″) and the related quantitative structure-retention relationship (QSRR) of logK(ow)″ vs. logk(w), the logarithm of retention factor of analytes in neat aqueous mobile phases, was investigated for weakly acidic compounds. This QSRR is commonly used as a classical method for K(ow) measurement by RP-HPLC. The theoretical and experimental derivation revealed that the variation in mobile phase pH and solute pK(a) will not affect the QSRRs of acidic compounds. This conclusion is proved to be suitable for various types of ion-suppressors, i.e., strong acid (perchloric acid), weak acid (acetic acid) and buffer salt (potassium dihydrogen phosphate/phosphoric acid, PBS). The QSRRs of logK(ow)″ vs. logk(w) were modeled by 11 substituted benzoic acids using different types of ion-suppressors in a binary methanol-water mobile phase to confirm our deduction. Although different types of ion-suppressor all can be used as mobile phase pH modifiers, the QSRR model obtained by using perchloric acid as the ion-suppressor was found to have the best result, and the slightly inferior QSRRs were obtained by using acetic acid or PBS as the ion-suppressor. Copyright © 2012 Elsevier B.V. All rights reserved.

Project Overview: PERCHLORATE ENVIRONMENTAL CONTAMINATION - TOXICOLOGICAL REVIEW AND RISK CHARACTERIZATION

EPA Science Inventory

The human health and ecological assessment issues related to environmental contamination by perchlorate are complex and continue to emerge. Perchlorate, ClO4-, is an anion that originates as a contaminant from the solid salts of ammonium, potassium or sodium perchlorate. These ...

PERCHLORATE-CROP INTERACTIONS FROM CONTAMINATED IRRIGATION WATER AND FERTILIZER APPLICATIONS

EPA Science Inventory

Perchlorate has contaminated water and soils at several locations in the United States. Perchlorate is water soluble, exceedingly mobile in aqueous systems, and can persist for many decades under typical ground and surface water conditions. Perchlorate is of concern because of un...

Perchlorate as an environmental contaminant.

PubMed

Urbansky, Edward Todd

2002-01-01

Perchlorate anion (ClO4-) has been found in drinking water supplies throughout the southwestern United States. It is primarily associated with releases of ammonium perchlorate by defense contractors, military operations, and aerospace programs. Ammonium perchlorate is used as a solid oxidant in missile and rocket propulsion systems. Traces of perchlorate are found in Chile saltpeter, but the use of such fertilizer has not been associated with large scale contamination. Although it is a strong oxidant, perchlorate anion is very persistent in the environment due to the high activation energy associated with its reduction. At high enough concentrations, perchlorate can affect thyroid gland functions, where it is mistakenly taken up in place of iodide. A safe daily exposure has not yet been set, but is expected to be released in 2002. Perchlorate is measured in environmental samples primarily by ion chromatography. It can be removed by anion exchange or membrane filtration. It is destroyed by some biological and chemical processes. The environmental occurrence, toxicity, analytical chemistry, and remediative approaches are discussed.

Liquid chromatographic determination of histamine in fish, sauerkraut, and wine: interlaboratory study.

PubMed

Beljaars, P R; Van Dijk, R; Jonker, K M; Schout, L J

1998-01-01

An interlaboratory study of the liquid chromatographic (LC) determination of histamine in fish, sauerkraut, and wine was conducted. Diminuted and homogenized samples were suspended in water followed by clarification of extracts with perchloric acid, filtration, and dilution with water. After LC separation on a reversed-phase C18 column with phosphate buffer (pH 3.0)--acetonitrile (875 + 125, v/v) as mobile phase, histamine was measured fluorometrically (excitation, 340 nm; emission, 455 nm) in samples and standards after postcolumn derivatization with o-phthaldialdehyde (OPA). Fourteen samples (including 6 blind duplicates and 1 split level) containing histamine at about 10-400 mg/kg or mg/L were analyzed singly according to the proposed procedure by 11 laboratories. Results from one participant were excluded from statistical analysis. For all samples analyzed, repeatability relative standard deviations varied from 2.1 to 5.6%, and reproducibility relative standard deviations ranged from 2.2 to 7.1%. Averaged recoveries of histamine for this concentration range varied from 94 to 100%.

Quantification of Hydroxychloroquine in Blood Using Turbulent Flow Liquid Chromatography-Tandem Mass Spectrometry (TFLC-MS/MS).

PubMed

Chambliss, Allison B; Füzéry, Anna K; Clarke, William A

2016-01-01

Hydroxychloroquine (HQ) is used routinely in the treatment of autoimmune disorders such as rheumatoid arthritis and lupus erythematosus. Issues such as marked pharmacokinetic variability and patient non-compliance make therapeutic drug monitoring of HQ a useful tool for management of patients taking this drug. Quantitative measurements of HQ may aid in identifying poor efficacy as well as provide reliable information to distinguish patient non-compliance from refractory disease. We describe a rapid 7-min assay for the accurate and precise measurement of HQ concentrations in 100 μL samples of human blood using turbulent flow liquid chromatography coupled to tandem mass spectrometry. HQ is isolated from EDTA whole blood after a simple extraction with its deuterated analog, hydroxychloroquine-d4, in 0.33 M perchloric acid. Samples are then centrifuged and injected onto the TFLC-MS/MS system. Quantification is performed using a nine-point calibration curve that is linear over a wide range (15.7-4000 ng/mL) with precisions of <5 %.

Using 31P NMR spectroscopy at 14.1 Tesla to investigate PARP-1 associated energy failure and metabolic rescue in cerebrocortical slices.

PubMed

Zeng, Jianying; Hirai, Kiyoshi; Yang, Guo-Yuan; Ying, Weihai; Swanson, Raymond A; Kelly, Mark; Mayer, Moriz; James, Thomas L; Litt, Lawrence

2004-08-01

PARP-1 activation by H(2)O(2) in an acute preparation of superfused, respiring, neonatal cerebrocortical slices was assessed from PAR-polymer formation detected with immunohistochemistry and Western blotting. (31)P NMR spectroscopy at 14.1 Tesla of perchloric acid slice extracts was used to assess energy failure in a 1-h H(2)O(2) exposure as well as in a subsequent 4-h recovery period where the superfusate had no H(2)O(2) and specifically chosen metabolic substrates. Although more data are needed to fully characterize different bioenergetic responses, a high NMR spectral resolution (PCr full-width at half-max approximately.01 ppm) and narrow widths for most metabolites (<.2 ppm) permitted accurate quantifications of spectrally resolved resonances for ADP, ATP, NAD(+)/NADH, and other high energy phosphates. It appears possible to use brain slices to quantitatively study PARP-related, NAD-associated energy failure, and rescue with TCA metabolites.

Evaluation of the risk of perchlorate exposure in a population of late-gestation pregnant women in the United States: Application of probabilistic biologically-based dose response modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lumen, A, E-mail: Annie.Lumen@fda.hhs.gov

The risk of ubiquitous perchlorate exposure and the dose-response on thyroid hormone levels in pregnant women in the United States (U.S.) have yet to be characterized. In the current work, we integrated a previously developed perchlorate submodel into a recently developed population-based pregnancy model to predict reductions in maternal serum free thyroxine (fT4) levels for late-gestation pregnant women in the U.S. Our findings indicated no significant difference in geometric mean estimates of fT4 when perchlorate exposure from food only was compared to no perchlorate exposure. The reduction in maternal fT4 levels reached statistical significance when an added contribution from drinkingmore » water (i.e., 15 μg/L, 20 μg/L, or 24.5 μg/L) was assumed in addition to the 90th percentile of food intake for pregnant women (0.198 μg/kg/day). We determined that a daily intake of 0.45 to 0.50 μg/kg/day of perchlorate was necessary to produce results that were significantly different than those obtained from no perchlorate exposure. Adjusting for this food intake dose, the relative source contribution of perchlorate from drinking water (or other non-dietary sources) was estimated to range from 0.25–0.3 μg/kg/day. Assuming a drinking water intake rate of 0.033 L/kg/day, the drinking water concentration allowance for perchlorate equates to 7.6–9.2 μg/L. In summary, we have demonstrated the utility of a probabilistic biologically-based dose-response model for perchlorate risk assessment in a sensitive life-stage at a population level; however, there is a need for continued monitoring in regions of the U.S. where perchlorate exposure may be higher. - Highlights: • Probabilistic risk assessment for perchlorate in U.S. pregnant women was conducted. • No significant change in maternal fT4 predicted due to perchlorate from food alone. • Drinking water concentration allowance for perchlorate estimated as 7.6–9.2 μg/L.« less

Thyroid hormones and thyroid disease in relation to perchlorate dose and residence near a superfund site.

PubMed

Gold, Ellen B; Blount, Benjamin C; O'Neill Rasor, Marianne; Lee, Jennifer S; Alwis, Udeni; Srivastav, Anup; Kim, Kyoungmi

2013-07-01

Perchlorate is a widely occurring contaminant, which can competitively inhibit iodide uptake and thus thyroid hormone production. The health effects of chronic low dose perchlorate exposure are largely unknown. In a community-based study, we compared thyroid function and disease in women with differing likelihoods of prior and current perchlorate exposure. Residential blocks were randomly selected from areas: (1) with potential perchlorate exposure via drinking water; (2) with potential exposure to environmental contaminants; and (3) neighboring but without such exposures. Eligibility included having lived in the area for ≥6 months and aged 20-50 years during 1988-1996 (during documented drinking water well contamination). We interviewed 814 women and collected blood samples (assayed for thyroid stimulating hormone and free thyroxine) from 431 interviewed women. Daily urine samples were assayed for perchlorate and iodide for 178 premenopausal women with blood samples. We performed multivariable regression analyses comparing thyroid function and disease by residential area and by urinary perchlorate dose adjusted for urinary iodide levels. Residential location and current perchlorate dose were not associated with thyroid function or disease. No persistent effect of perchlorate on thyroid function or disease was found several years after contaminated wells were capped.

Urinary perchlorate exposure and risk in women of reproductive age in a fireworks production area of China.

PubMed

Li, Qin; Yu, Yun-jiang; Wang, Fei-fei; Chen, Shi-wu; Yin, Yan; Lin, Hai-peng; Che, Fei; Sun, Peng; Qin, Juan; Liu, Jie; Wang, Hong-mei

2014-07-01

Perchlorate is used widely in fireworks, and, if ingested, it has the potential to disrupt thyroid function. The concentrations of perchlorate in water and soil samples and in urine samples of women of reproductive age from Liuyang, the largest fireworks production area in China, were investigated. The results showed that the average perchlorate concentrations in groundwater, surface water, farmland soil, and urine samples of women from the fireworks production area were significantly greater than those from the control area. The health risk of perchlorate ingested through drinking water was assessed based on the mode recommended by the United States Environmental Protection Agency. The values of hazard quotient of river water and groundwater in the fireworks production area were much greater than the safe level (=1), which indicates that adverse health effects may result from perchlorate when these sources of water are used as drinking water. These results indicated that the environment of the fireworks production area has been polluted by perchlorate and that residents were and are facing greater exposure doses of perchlorate. Fireworks production enterprises may be a major source of perchlorate contamination.

Isotopic Discrimination of Perchlorate Sources in Ground Water

NASA Astrophysics Data System (ADS)

Bohlke, J.; Hatzinger, P. B.; Sturchio, N. C.; Gu, B.; Jackson, W. A.; Abbene, I. J.

2007-12-01

Perchlorate has been detected in ground water and drinking water in many areas of the U.S. during the past decade. Sources of potential perchlorate enrichment in ground water include releases from past military activities, fireworks manufacture and display, fertilizer applications, discarded road flares, and local atmospheric deposition. Here we present analyses of stable isotopes (δ37Cl, δ18O, and Δ17O) of dissolved perchlorate, along with other supporting environmental tracer data, from selected occurrences in ground water in the U.S. The isotope data indicate that both synthetic and natural perchlorate are present in ground water, and that multiple sources are present locally in some areas. The sampled ground waters generally were oxic and the perchlorate isotopes generally were not affected substantially by biodegradation. In some areas, natural perchlorate, with Δ17O = +7 to +10 ‰, can be attributed to agricultural applications of atmospherically derived natural nitrate fertilizer imported from South America (Atacama Desert, Chile). In at least one agricultural area in New York, concentrations of perchlorate increase with depth and ground-water age, possibly because of decreasing application rates of Atacama nitrate fertilizer and(or) decreasing perchlorate concentrations in the imported fertilizer products in recent years.

Perchlorate Exposure Through Water and Milk in Istanbul.

PubMed

Can, Ozge; Blount, Ben; Valentin-Blasini, Liza; Erdemgil, Yigit; Uzunoglu, Deniz; Aksoy, Murat; Coskun, Abdurrahman; Serteser, Mustafa; Unsal, Ibrahim; Ozpinar, Aysel

2016-09-01

Perchlorate is a chemical pollutant that inhibits iodide uptake and may possibly impair thyroid function. Our previous study found widespread perchlorate exposure in non-pregnant, non-lactating, healthy women residing in Istanbul. The aim of this study is to assess the relative amounts of perchlorate exposure attributable to consumption of municipal water, bottled water and boxed milk available in Istanbul. Only trace levels of perchlorate were found in treated municipal water (58 % detectable, mean = 0.13 µg/L, maximum = 0.75 µg/L) and bottled water (7.4 % detectable, mean = 

Evidence of Influence of Human Activities and Volcanic Eruptions on Environmental Perchlorate from a 300-Year Greenland Ice Core Record.

PubMed

Cole-Dai, Jihong; Peterson, Kari Marie; Kennedy, Joshua Andrew; Cox, Thomas S; Ferris, David G

2018-06-26

A 300-year (1700-2007) chronological record of environmental perchlorate, reconstructed from high-resolution analysis of a central Greenland ice core, shows that perchlorate levels in the post-1980 atmosphere were two-to-three times those of the pre-1980 environment. While this confirms recent reports of increased perchlorate in Arctic snow since 1980 compared with the levels for the prior decades (1930-1980), the longer Greenland record demonstrates that the Industrial Revolution and other human activities, which emitted large quantities of pollutants and contaminants, did not significantly impact environmental perchlorate, as perchlorate levels remained stable throughout the eighteenth, nineteenth, and much of the twentieth centuries. The increased levels since 1980 likely result from enhanced atmospheric perchlorate production, rather than from direct release from perchlorate manufacturing and applications. The enhancement is probably influenced by the emission of organic chlorine compounds in the last several decades. Prior to 1980, no significant long-term temporal trends in perchlorate concentration are observed. Brief (a few years) high concentration episodes appear frequently over an apparently stable and low background (~1 ng kg‒1). Several such episodes coincide in time with large explosive volcanic eruptions including the 1912 Novarupta/Katmai eruption in Alaska. It appears that atmospheric perchlorate production is impacted by large eruptions in both high and low latitudes, but not by small eruptions and non-explosive degassing.

77 FR 52633 - Notice of a Public Meeting: Stakeholder Meeting Concerning EPA's Intent To Regulate Perchlorate...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-30

...: Stakeholder Meeting Concerning EPA's Intent To Regulate Perchlorate Levels in Drinking Water AGENCY... a proposed National Primary Drinking Water Regulation for Perchlorate. DATES: The public meeting and... to obtain access to the building. FOR FURTHER INFORMATION CONTACT: More information on Perchlorate is...

77 FR 64335 - Notification of a Public Teleconference of the Science Advisory Board; Perchlorate Advisory Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-19

... Science Advisory Board; Perchlorate Advisory Panel AGENCY: Environmental Protection Agency (EPA). ACTION... announces two public teleconferences of the SAB Perchlorate Advisory Panel to discuss its revised draft... Epidemiological Evidence to Develop a Maximum Contaminant Level Goal (MCLG) for Perchlorate. DATES: The public...

THE REDUCTIVE TRANSFORMATION OF PERCHLORATE IN A FRESH WATER SEDIMENT: LABORATORY BATCH STUDIES

EPA Science Inventory

Perchlorate is widely used as a propellant in solid rocket fuel, and has recently been found in ground, surface, and drinking water, in many cases above the interim action level of 18 ppb. Perchlorate is recalcitrant to chemical reduction, however, studies of perchlorate in pure ...

THE REDUCTIVE TRANSFORMATION OF PERCHLORATE IN A FRESH WATER SEDIMENT: LABORATORY BATCH STUDIES.

EPA Science Inventory

Perchlorate is widely used as a propellant in solid rocket fuel, and has recently been found in ground, surface, and drinking water, in many cases above the interim action level of 18 ppb. Perchlorate is recalcitrant to chemical reduction, however, studies of perchlorate in pure ...

Using a physiologically based pharmacokinetic model to link urinary biomarker concentrations to dietary exposure of perchlorate

EPA Science Inventory

Exposure to perchlorate is widespread in the United States and many studies have attempted to character the perchlorate exposure by estimating the average daily intakes of perchlorate. These approaches provided population-based estimates, but did not provide individual-level exp...

Determination of carbonate carbon in geological materials by coulometric titration

USGS Publications Warehouse

Engleman, E.E.; Jackson, L.L.; Norton, D.R.

1985-01-01

A coulometric titration is used for the determination of carbonate carbon in geological materials. Carbon dioxide is evolved from the sample by the addition of 2 M perchloric acid, with heating, and is determined by automated coulometric titration. The coulometric titration showed improved speed and precision with comparable accuracy to gravimetric and gasometric techniques. ?? 1985.

An unprecedented Fe(36) phosphonate cage.

PubMed

Beavers, Christine M; Prosvirin, Andrey V; Prosverin, Andrey V; Cashion, John D; Dunbar, Kim R; Richards, Anne F

2013-02-18

The reaction of 2-pyridylphosphonic acid (LH(2)) with iron(II) perchlorate and iron(III) nitrate afforded an interconnected, double-layered, cationic iron cage, [{Fe(36)L(44)(H(2)O)(48)}](20+) (1a), the largest interconnected, polynuclear ferric cage reported to date. Magnetic studies on 1a revealed antiferromagnetic coupling between the spins on adjacent Fe(III) ions.

49 CFR 173.127 - Class 5, Division 5.1-Definition and assignment of packing groups.

Code of Federal Regulations, 2013 CFR

2013-10-01

... pressure rise time of a 1:1 perchloric acid (50 percent)/cellulose mixture. (ii) Packing Group II, any... not met. (iii) Packing Group III, any material which exhibits a mean pressure rise time less than or... packing groups. 173.127 Section 173.127 Transportation Other Regulations Relating to Transportation...

Containerized Wetland Bioreactor Evaluated for Perchlorate and Nitrate Degradation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dibley, V R; Krauter, P W

2004-12-02

The U.S. Department of Energy (DOE) and Lawrence Livermore Laboratory (LLNL) designed and constructed an innovative containerized wetlands (bioreactor) system that began operation in November 2000 to biologically degrade perchlorate and nitrate under relatively low-flow conditions at a remote location at Site 300 known as Building 854. Since initial start-up, the system has processed over 3,463,000 liters of ground water and treated over 38 grams of perchlorate and 148 kilograms of nitrate. Site 300 is operated by the University of California as a high-explosives and materials testing facility supporting nuclear weapons research. The 11-square mile site located in northern Californiamore » was added to the NPL in 1990 primarily due to the presence of elevated concentrations of volatile organic compounds (VOCs) in ground water. At the urging of the regulatory agencies, perchlorate was looked for and detected in the ground water in 1999. VOCs, nitrate and perchlorate were released into the soil and ground water in the Building 854 area as the result of accidental leaks during stability testing of weapons or from waste discharge practices that are no longer permitted at Site 300. Design of the wetland bioreactors was based on earlier studies showing that indigenous chlorate-respiring bacteria could effectively degrade perchlorate into nontoxic concentrations of chlorate, chlorite, oxygen, and chloride. Studies also showed that the addition of organic carbon would enhance microbial denitrification. Early onsite testing showed acetic acid to be a more effective carbon source than dried leaf matter, dried algae, or milk replacement starter; a nutrient and carbon source used in a Department of Defense phytoremediation demonstration. No inocula were added to the system. Groundwater was allowed to circulate through the bioreactor for three weeks to acclimate the wetland plants and to build a biofilm from indigenous flora. Using solar energy, ground water is pumped into granular activated carbon canisters to remove VOCs (Figure x). Following solar treatment, ground water containing approximately 46 mg/L of nitrate and 13 {micro}g/L of perchlorate is gravity-fed continuously into two parallel series of two-1,900 liter tank bioreactors. Each bioreactor contains coarse, aquarium-grade gravel and locally-obtained plant species such as cattails (Typha spp.), sedges (Cyperus spp.), and indigenous denitrifying microorganisms. No inocula were added to the system. Groundwater was allowed to circulate through the bioreactor for three weeks to acclimate the wetland plants and to build a biofilm from indigenous flora. Sodium acetate is added to the first bioreactor in each of the two series to promote growth and metabolic activity of rhizome microorganisms. The split flow from each series is combined, and flows through two back-up ion exchange columns to assure complete perchlorate removal. Effluent from the ground water treatment system is monitored and discharged an infiltration trench in accordance with the Substantive Requirements for Waste Discharge issued by the California Regional Water Quality Control Board.« less

Mesophilic, Circumneutral Anaerobic Iron Oxidation as a Remediation Mechanism for Radionuclides, Nitrate and Perchlorate

NASA Astrophysics Data System (ADS)

Bose, S.; Thrash, J. C.; Coates, J. D.

2008-12-01

Iron oxidation is a novel anaerobic metabolism where microorganisms obtain reducing equivalents from the oxidization of Fe(II) and assimilate carbon from organic carbon compounds or CO2. Recent evidence indicates that in combination with the activity of dissimilatory Fe(III)-reducing bacteria, anaerobic microbial Fe(II) oxidation can also contribute to the global iron redox cycle. Studies have also proved that Fe(II)- oxidation is ubiquitous in diverse environments and produce a broad range of insoluble iron forms as end products. These biogenic Fe(III)-oxides and mixed valence Fe minerals have a very high adsorption capacity of heavy metals and radionuclides. Adsorption and immobilization by these biogenic Fe phases produced at circumneutral pH, is now considered a very effective mode of remediation of radionuclides like Uranium, especially under variable redox conditions. By coupling soluble and insoluble Fe(II) oxidation with nitrate and perchlorate as terminal electron acceptors in-situ, anaerobic Fe-oxidation can also be used for environmental cleanup of Fe through Fe-mineral precipitation, as well as nitrate and perchlorate through reduction. Coupling of Fe as the sole electron and energy source to the reduction of perchlorate or nitrate boosts the metabolism without building up biomass hence also taking care of biofouling. To understand the mechanisms by which microorganisms can grow at circumneutral pH by mesophilic, anaerobic iron oxidation and the ability of microorganisms to reduce nitrate and perchlorate coupled to iron oxidation recent work in our lab involved the physiological characterization of Dechlorospirillum strain VDY which was capable of anaerobic iron-oxidation with either nitrate or perchlorate serving as terminal electron acceptor. Under non-growth conditions, VDY oxidized 3mM Fe(II) coupled to nitrate reduction, and 2mM Fe(II) coupled to perchlorate reduction, in 24 hours. It contained a copy of the RuBisCO cbbM subunit gene which was differentially regulated. With perchlorate as the sole terminal electron acceptor, cbbM was expressed under autotrophic growth with hydrogen as the electron donor but not during heterotrophic growth on acetate, indicating a putative carbon-fixation pathway. Similarly, Ferrutens uranioxidens strain 2002 was also capable of autotrophic growth during nitrate-dependent iron oxidation, although the carbon fixation pathway has yet to be identified. Anoxic XPRD analysis of the biogenic end products of nitrate-dependent Fe(II) oxidation by Diaphorobacter sp. strain TPSY and strain 2002 indicated the gradual appearance of green rust (GR II) with cacoxenite and lepidocrocite from the precursor vivianite over 81 days. SEM and TEM showed the presence of hexagonal plate like crystals surrounding the bacterial cells whose morphology closely resembled GR II, indicating a very low redox potential and a weakly acidic to weakly basic pH. Mixotrophic growth incubations of strain TPSY with 1, 5 and 10 mM Fe(II) showed markedly different end products. The identity of the mineral phases and the reason behind this difference is currently under investigation.

Aquifer susceptibility to perchlorate contamination in a highly urbanized environment

USGS Publications Warehouse

Woolfenden, Linda R.; Trefly, Michael G.

2007-01-01

Perchlorate contamination from anthropogenic sources has been released into the Rialto-Colton, California, USA, groundwater flow system since the 1940s during its production, distribution, storage, and use. Preliminary analysis of lithological, geophysical, and water-chemistry data provided new understanding of the pathways of perchlorate migration that aid in assessing the susceptibility of drinking-water supplies to contamination within the Rialto-Colton basin. Vertical migration of perchlorate into the main water-producing aquifers is restricted by an areally extensive old soil surface; however, perchlorate data indicate contamination below this soil surface. Possible pathways for the downward migration of the contaminated water include wellbore flow and discontinuities in the old soil surface. Horizontal migration of perchlorate is influenced by lithology and faults within the basin. The basin fill is a heterogeneous mixture of boulders, gravel, sand, silt, and clay, and internal faults may restrict perchlorate migration in some areas.

76 FR 78256 - Request for Nominations of Experts for the Review of Approaches To Derive a Maximum Contaminant...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-16

... Approaches To Derive a Maximum Contaminant Level Goal for Perchlorate AGENCY: Environmental Protection Agency... maximum contaminant level goal (MCLG) for perchlorate. DATES: Nominations should be submitted by January... perchlorate. In 2011, EPA announced its decision (76 FR 7762-7767) to regulate perchlorate under the Safe...

Reports of the second All-Union conference on the chemistry of transplutonium elements (Dmitrovgrad, June 21-23, 1963)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1987-05-01

The nine papers presented at this conference cover the following topics: the systematization, condensed description, and prediction of sets of anion exchange extraction constants on the basis of their statistical computer treatment; characteristics and uses of solid extractants containing D2EHPA and TBP for separating the transplutonium elements; enrichment of americium 242m and americium 242 by the Szilard-Chalmers method; an x-ray diffraction pattern analysis for transplutonium compounds; the radiation chemistry of americium; and the effects of alpha irradiation on the behavior of americium in perchlorate solutions.

Occurrence of perchlorate in groundwater, paired farmland soil, lettuce, and rhizosphere soil from Chengdu, China.

PubMed

Tang, Yulu; Zhong, Bifeng; Qu, Bing; Feng, Shujin; Ding, Sanglan; Su, Shijun; Li, Zhi; Gan, Zhiwei

2017-05-24

A total of 28 groundwater, paired farmland soil, lettuce, and its rhizosphere soil samples were collected from Chengdu, China to detect perchlorate levels and to evaluate the relationships of perchlorate concentrations among these matrices. The perchlorate concentrations in the groundwater, farmland soil, lettuce, and rhizosphere soil samples ranged from below detection limit to 60.2 μg L -1 , from below detection limit to 249 μg kg -1 dry weight (dw), from 2.07 to 1010 μg kg -1 wet weight, and from below detection limit to 314 μg kg -1 dw, respectively. Significant correlation was found in the perchlorate levels among the farmland soil, lettuce, and rhizosphere soil, suggesting that they have common pollution sources, or perchlorate might transfer from farmland soil-rhizosphere soil-plant. However, there is no significant correlation between groundwater and the other three matrices, indicating that infiltration from perchlorate contaminated farmland soil was not the predominant source for groundwater pollution in Chengdu. The perchlorate concentrations in the farmland soil and lettuce samples were significantly higher than those in the rhizosphere soil, primarily due to uptake of perchlorate through the rhizosphere micro-environment by lettuce, or accelerated degradation by rhizospheric microorganisms, which contributed more needs further investigation.

Thyroid Hormones and Thyroid Disease in Relation to Perchlorate Dose and Residence Near a Superfund Site

PubMed Central

Gold, Ellen B.; Blount, Benjamin C.; Rasor, Marianne O’Neill; Lee, Jennifer S.; Alwis, Udeni; Srivastav, Anup; Kim, Kyoungmi

2013-01-01

Background Perchlorate is a widely occurring contaminant, which can competitively inhibit iodide uptake and thus thyroid hormone production. The health effects of chronic low dose perchlorate exposure are largely unknown. Objectives In a community-based study, we compared thyroid function and disease in women with differing likelihoods of prior and current perchlorate exposure. Methods Residential blocks were randomly selected from areas: 1) with potential perchlorate exposure via drinking water; 2) with potential exposure to environmental contaminants; and 3) neighboring but without such exposures. Eligibility included having lived in the area for ≥6 months and aged 20–50 years during 1988–1996 (during documented drinking water well contamination). We interviewed 814 women and collected blood samples (assayed for thyroid stimulating hormone [TSH] and free thyroxine [fT4]) from 431 interviewed women. Daily urine samples were assayed for perchlorate and iodide for 178 premenopausal women with blood samples. We performed multivariable regression analyses comparing thyroid function and disease by residential area and by urinary perchlorate dose adjusted for urinary iodide levels. Results Residential location and current perchlorate dose were not associated with thyroid function or disease. Conclusions No persistent effect of perchlorate on thyroid function or disease was found several years after contaminated wells were capped. PMID:22968349

Effects of larval-juvenile treatment with perchlorate and co-treatment with thyroxine on zebrafish sex ratios

USGS Publications Warehouse

Mukhi, S.; Torres, L.; Patino, R.

2007-01-01

The objective of this study was to determine the effect of larval-juvenile exposure to perchlorate, a thyroid hormone synthesis inhibitor, on the establishment of gonadal sex ratios in zebrafish. Zebrafish were exposed to untreated water or water containing perchlorate at 100 or 250 ppm for a period of 30 days starting at 3 days postfertilization (dpf). Recovery treatments consisted of a combination of perchlorate and exogenous thyroxine (T4; 10 nM). Thyroid histology was assessed at the end of the treatment period (33 dpf), and gonadal histology and sex ratios were determined in fish that were allowed an additional 10-day period of growth in untreated water. As expected, exposure to perchlorate caused changes in thyroid histology consistent with hypothyroidism and these effects were reversed by co-treatment with exogenous T4. Perchlorate did not affect fish survival but co-treatment with T4 induced higher mortality. However, relative to the corresponding perchlorate concentration, co-treatment with T4 caused increased mortality only at a perchlorate concentration of 100 ppm. Perchlorate alone or in the presence of T4 suppressed body length at 43 dpf relative to control values. Perchlorate exposure skewed the sex ratio toward female in a concentration-dependent manner, and co-treatment with T4 not only blocked the feminizing effect of perchlorate but also overcompensated by skewing the sex ratio towards male. Moreover, co-treatment with T4 advanced the onset of spermatogenesis in males. There was no clear association between sex ratios and larval survival or growth. We conclude that endogenous thyroid hormone plays a role in the establishment of gonadal sex phenotype during early development in zebrafish. ?? 2006 Elsevier Inc. All rights reserved.

Novel biomarkers of perchlorate exposure in zebrafish

USGS Publications Warehouse

Mukhi, S.; Carr, J.A.; Anderson, T.A.; Patino, R.

2005-01-01

Perchlorate inhibits iodide uptake by thyroid follicles and lowers thyroid hormone production. Although several effects of perchlorate on the thyroid system have been reported, the utility of these pathologies as markers of environmental perchlorate exposures has not been adequately assessed. The present study examined time-course and concentration-dependent effects of perchlorate on thyroid follicle hypertrophy, colloid depletion, and angiogenesis; alterations in whole-body thyroxine (T4) levels; and somatic growth and condition factor of subadult and adult zebrafish. Changes in the intensity of the colloidal T4 ring previously observed in zebrafish also were examined immunohistochemically. Three-month-old zebrafish were exposed to ammonium perchlorate at measured perchlorate concentrations of 0, 11, 90, 1,131, and 11,480 ppb for 12 weeks and allowed to recover in clean water for 12 weeks. At two weeks of exposure, the lowest-observed-effective concentrations (LOECs) of perchlorate that induced angiogenesis and depressed the intensity of colloidal T4 ring were 90 and 1,131 ppb, respectively; other parameters were not affected (whole-body T4 was not determined at this time). At 12 weeks of exposure, LOECs for colloid depletion, hypertrophy, angiogenesis, and colloidal T4 ring were 11,480, 1,131, 90, and 11 ppb, respectively. All changes were reversible, but residual effects on angiogenesis and colloidal T4 ring intensity were still present after 12 weeks of recovery (LOEC, 11,480 ppb). Whole-body T 4 concentration, body growth (length and weight), and condition factor were not affected by perchlorate. The sensitivity and longevity of changes in colloidal T4 ring intensity and angiogenesis suggest their usefulness as novel markers of perchlorate exposure. The 12-week LOEC for colloidal T4 ring is the lowest reported for any perchlorate biomarker in aquatic vertebrates. ?? 2005 SETAC.

Perchlorate Clinical Pharmacology and Human Health: A Review

PubMed Central

Soldin, Offie Porat; Braverman, Lewis E.; Lamm, Steven H.

2013-01-01

Summary Potassium perchlorate has been used at various times during the last 50 years to treat hyperthyroidism. Since World War II ammonium perchlorate has been used as a propellant for rockets. In 1997, the assay sensitivity for perchlorate in water was improved from 0.4 mg/L (ppm) to 4 µg/L (ppb). As a result, public water supplies in Southern California were found to contain perchlorate ions in the range of 5 to 8 ppb, and those in Southern Nevada were found to contain 5 to 24 ppb. Research programs have been developed to assess the safety or risk from these exposures and to assist state and regulatory agencies in setting a reasonable safe level for perchlorate in drinking water. This report reviews the evidence on the human health effects of perchlorate exposure. Perchlorate is a competitive inhibitor of iodine uptake. All of its pharmacologic effects at current therapeutic levels or lower are associated with inhibition of the sodium-iodide symporter (NIS) on the thyroid follicular cell membrane. A review of the medical and occupational studies has been undertaken to identify perchlorate exposure levels at which thyroid hormone levels may be reduced or thyrotropin levels increased. This exposure level may begin in the 35 to 100 mg/d range. Volunteer studies have been designed to determine the exposure levels at which perchlorate begins to affect iodine uptake in humans. Such effects may begin at levels of approximately 1 mg/d. Environmental studies have assessed the thyroidal health of newborns and adults at current environmental exposures to perchlorate and have concluded that the present levels appear to be safe. Whereas additional studies are underway both in laboratory animals and in the field, it appears that a safe level can be established for perchlorate in water and that regulatory agencies and others are now trying to determine that level. PMID:11477312

Jarosite dissolution rates in perchlorate brine

NASA Astrophysics Data System (ADS)

Legett, Carey; Pritchett, Brittany N.; Elwood Madden, Andrew S.; Phillips-Lander, Charity M.; Elwood Madden, Megan E.

2018-02-01

Perchlorate salts and the ferric sulfate mineral jarosite have been detected at multiple locations on Mars by both landed instruments and orbiting spectrometers. Many perchlorate brines have eutectic temperatures <250 K, and may exist as metastable or stable liquids for extended time periods, even under current Mars surface conditions. Therefore, jarosite-bearing rocks and sediments may have been altered by perchlorate brines. Here we measured jarosite dissolution rates in 2 M sodium perchlorate brine as well as dilute water at 298 K to determine the effects of perchlorate anions on jarosite dissolution rates and potential reaction products. We developed a simple method for determining aqueous iron concentrations in high salinity perchlorate solutions using ultraviolet-visible spectrophotometry that eliminates the risk of rapid oxidation reactions during analyses. Jarosite dissolution rates in 2 M perchlorate brine determined by iron release rate (2.87 × 10-12 ±0.85 × 10-12 mol m-2 s-1) were slightly slower than the jarosite dissolution rate measured in ultrapure (18.2 MΩ cm-1) water (5.06 × 10-12 mol m-2 s-1) using identical methods. No additional secondary phases were observed in XRD analyses of the reaction products. The observed decrease in dissolution rate may be due to lower activity of water (ɑH2O = 0.9) in the 2 M NaClO4 brine compared with ultrapure water (ɑH2O = 1). This suggests that the perchlorate anion does not facilitate iron release, unlike chloride anions which accelerated Fe release rates in previously reported jarosite and hematite dissolution experiments. Since dissolution rates are slower in perchlorate-rich solutions, jarosite is expected to persist longer in perchlorate brines than in dilute waters or chloride-rich brines. Therefore, if perchlorate brines dominate aqueous fluids on the surface of Mars, jarosite may remain preserved over extended periods of time, despite active aqueous processes.

Thyroid Hormones and Moderate Exposure to Perchlorate during Pregnancy in Women in Southern California.

PubMed

Steinmaus, Craig; Pearl, Michelle; Kharrazi, Martin; Blount, Benjamin C; Miller, Mark D; Pearce, Elizabeth N; Valentin-Blasini, Liza; DeLorenze, Gerald; Hoofnagle, Andrew N; Liaw, Jane

2016-06-01

Findings from national surveys suggest that everyone in the United States is exposed to perchlorate. At high doses, perchlorate, thiocyanate, and nitrate inhibit iodide uptake into the thyroid and decrease thyroid hormone production. Small changes in thyroid hormones during pregnancy, including changes within normal reference ranges, have been linked to cognitive function declines in the offspring. We evaluated the potential effects of low environmental exposures to perchlorate on thyroid function. Serum thyroid hormones and anti-thyroid antibodies and urinary perchlorate, thiocyanate, nitrate, and iodide concentrations were measured in 1,880 pregnant women from San Diego County, California, during 2000-2003, a period when much of the area's water supply was contaminated from an industrial plant with perchlorate at levels near the 2007 California regulatory standard of 6 μg/L. Linear regression was used to evaluate associations between urinary perchlorate and serum thyroid hormone concentrations in models adjusted for urinary creatinine and thiocyanate, maternal age and education, ethnicity, and gestational age at serum collection. The median urinary perchlorate concentration was 6.5 μg/L, about two times higher than in the general U.S. Adjusted associations were identified between increasing log10 perchlorate and decreasing total thyroxine (T4) [regression coefficient (β) = -0.70; 95% CI: -1.06, -0.34], decreasing free thyroxine (fT4) (β = -0.053; 95% CI: -0.092, -0.013), and increasing log10 thyroid-stimulating hormone (β = 0.071; 95% CI: 0.008, 0.133). These results suggest that environmental perchlorate exposures may affect thyroid hormone production during pregnancy. This could have implications for public health given widespread perchlorate exposure and the importance of thyroid hormone in fetal neurodevelopment. Steinmaus C, Pearl M, Kharrazi M, Blount BC, Miller MD, Pearce EN, Valentin-Blasini L, DeLorenze G, Hoofnagle AN, Liaw J. 2016. Thyroid hormones and moderate exposure to perchlorate during pregnancy in women in Southern California. Environ Health Perspect 124:861-867; http://dx.doi.org/10.1289/ehp.1409614.

High-nitrogen-based pyrotechnics: development of perchlorate-free green-light illuminants for military and civilian applications.

PubMed

Sabatini, Jesse J; Raab, James M; Hann, Ronald K; Damavarapu, Reddy; Klapötke, Thomas M

2012-06-01

The development of perchlorate-free hand-held signal illuminants for the US Army's M195 green star parachute is described. Compared with the perchlorate-containing control, the optimized perchlorate-free illuminants were less sensitive toward various ignition stimuli while offering comparable burn times and visible-light outputs. The results were also important from the perspective of civilian fireworks because the development of perchlorate-free illuminants remains an important objective of the commercial fireworks industry. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solvent Effects on the Kinetics of Simple Electrochemical Reactions. I. Comparison of the Behavior of Co(III)/(II) Trisethylenediamine and Ammine Couples with the Predictions of Dielectric Continuum Theory.

DTIC Science & Technology

1981-01-08

lithium perchlorate was dried at -180°C for several days. Tetraethylammonium perchlorate was recrystallized from water and dried in a vacuum oven at...cases the electrolyte composition p, was chosen to be 0.1 M lithium perchlorate or 0.1 M tetraethyl ammonium perchlorate (TEAP). These electrolytes...perchlorate specific adsorption is quite noticeable. Hexafluorophosphate adsorption is sufficiently weak so that small positive values of the potential across

Widespread natural perchlorate in unsaturated zones of the southwest United States

USGS Publications Warehouse

Rao, Balaji; Anderson, Todd A.; Orris, Greta J.; Rainwater, Ken A.; Rajagopalan, Srinath; Sandvig, Renee M.; Scanlon, Bridget R.; Stonestrom, David A.; Walvoord, Michelle Ann; Jackson, W Andrew

2007-01-01

A substantial reservoir (up to 1 kg ha-1) of natural perchlorate is present in diverse unsaturated zones of the arid and semi-arid southwestern United States. The perchlorate co-occurs with meteoric chloride that has accumulated in these soils throughout the Holocene [0 to 10−15 ka (thousand years ago)] and possibly longer periods. Previously, natural perchlorate widely believed to be limited to the Atacama Desert, now appears widespread in steppe-to-desert ecoregions. The perchlorate reservoir becomes sufficiently large to affect groundwater when recharge from irrigation or climate change flushes accumulated salts from the unsaturated zone. This new source may help explain increasing reports of perchlorate in dry region agricultural products and should be considered when evaluating overall source contributions.

Determination of inorganic arsenic in algae using bromine halogenation and on-line nonpolar solid phase extraction followed by hydride generation atomic fluorescence spectrometry.

PubMed

Zhang, Weihong; Qi, Yuehan; Qin, Deyuan; Liu, Jixin; Mao, Xuefei; Chen, Guoying; Wei, Chao; Qian, Yongzhong

2017-08-01

Accurate, stable and fast analysis of toxic inorganic arsenic (iAs) in complicated and arsenosugar-rich algae matrix is always a challenge. Herein, a novel analytical method for iAs in algae was reported, using bromine halogenation and on-line nonpolar solid phase extraction (SPE) followed by hydride generation atomic fluorescence spectrometry (HG-AFS). The separation of iAs from algae was first performed by nonpolar SPE sorbent using Br - for arsenic halogenation. Algae samples were extracted with 1% perchloric acid. Then, 1.5mL extract was reduced by 1% thiourea, and simultaneously reacted (for 30min) with 50μL of 10% KBr for converting iAs to AsBr 3 after adding 3.5mL of 70% HCl to 5mL. A polystyrene (PS) resin cartridge was employed to retain arsenicals, which were hydrolyzed, eluted from the PS resin with H 2 O, and categorized as iAs. The total iAs was quantified by HG-AFS. Under optimum conditions, the spiked recoveries of iAs in real algae samples were in the 82-96% range, and the method achieved a desirable limit of detection of 3μgkg -1 . The inter-day relative standard deviations were 4.5% and 4.1% for spiked 100 and 500μgkg -1 respectively, which proved acceptable for this method. For real algae samples analysis, the highest presence of iAs was found in sargassum fusiforme, followed by kelp, seaweed and laver. Copyright © 2017 Elsevier B.V. All rights reserved.

Seasonal Variation and Exposure Risks of Perchlorate in Soil, Indoor Dust, and Outdoor Dust in China.

PubMed

Li, Yiwen; Liao, Ruoying; Gan, Zhiwei; Qu, Bing; Wang, Rong; Chen, Mengqin; Ding, Sanglan; Su, Shijun

2018-04-25

A total of 97 paired soil, outdoor dust, and indoor dust samples were collected in the national scale of China in summer, and the perchlorate levels were compared with those in soil and outdoor dust samples collected in winter in our previous study. The median perchlorate concentrations in the outdoor dust, indoor dust, and soil samples were 8.10, 11.4, and 0.05 mg/kg, respectively, which were significantly lower than those in the winter samples due to the natural factors and human activities. No significant differences in perchlorate concentrations were found between Northern and Southern China in the dust samples, whereas the difference was obtained in the soil samples. In the terms of possible source, the perchlorate levels in the outdoor dust exhibited strong correlation with SO 4 2- (r 2  = 0.458**) and NO 3 - (r 2  = 0.389**), indicating part of perchlorate in outdoor environment was likely from atmospheric oxidative process in summer. The perchlorate, SO 4 2- , and Cl - levels in the indoor dust were significantly related to those in the outdoor dust, suggesting that outdoor contaminants might be an important source for indoor environment. Furthermore, the human exposure to perchlorate was under relatively safe state in China except for special sites or periods with high perchlorate levels. Dust made an unexpected contribution of 41.3% to the total daily perchlorate intake for children, whereas 2.46% for adults in China based on biomonitoring, which deserves more attention.

Transport and degradation of perchlorate in deep vadose zone: implications from direct observations during bioremediation treatment

NASA Astrophysics Data System (ADS)

Dahan, Ofer; Katz, Idan; Avishai, Lior; Ronen, Zeev

2017-08-01

An in situ bioremediation experiment of a deep vadose zone ( ˜ 40 m) contaminated with a high concentration of perchlorate (> 25 000 mg L-1) was conducted through a full-scale field operation. Favourable environmental conditions for microbiological reduction of perchlorate were sought by infiltrating an electron donor-enriched water solution using drip irrigation underlying an airtight sealing liner. A vadose zone monitoring system (VMS) was used for real-time tracking of the percolation process, the penetration depth of dissolved organic carbon (DOC), and the variation in perchlorate concentration across the entire soil depth. The experimental conditions for each infiltration event were adjusted according to insight gained from data obtained by the VMS in previous stages. Continuous monitoring of the vadose zone indicated that in the top 13 m of the cross section, perchlorate concentration is dramatically reduced from thousands of milligrams per litre to near-detection limits with a concurrent increase in chloride concentration. Nevertheless, in the deeper parts of the vadose zone (< 17 m), perchlorate concentration increased, suggesting its mobilization down through the cross section. Breakthrough of DOC and bromide at different depths across the unsaturated zone showed limited migration capacity of biologically consumable carbon and energy sources due to their enhanced biodegradation in the upper soil layers. Nevertheless, the increased DOC concentration with concurrent reduction in perchlorate and increase in the chloride-to-perchlorate ratio in the top 13 m indicate partial degradation of perchlorate in this zone. There was no evidence of improved degradation conditions in the deeper parts where the initial concentrations of perchlorate were significantly higher.

Genetic Factors That Might Lead to Different Responses in Individuals Exposed to Perchlorate

PubMed Central

Scinicariello, Franco; Murray, H. Edward; Smith, Lester; Wilbur, Sharon; Fowler, Bruce A.

2005-01-01

Perchlorate has been detected in groundwater in many parts of the United States, and recent detection in vegetable and dairy food products indicates that contamination by perchlorate is more widespread than previously thought. Perchlorate is a competitive inhibitor of the sodium iodide symporter, the thyroid cell–surface protein responsible for transporting iodide from the plasma into the thyroid. An estimated 4.3% of the U.S. population is subclinically hypothyroid, and 6.9% of pregnant women may have low iodine intake. Congenital hypothyroidism affects 1 in 3,000 to 1 in 4,000 infants, and 15% of these cases have been attributed to genetic defects. Our objective in this review is to identify genetic biomarkers that would help define subpopulations sensitive to environmental perchlorate exposure. We review the literature to identify genetic defects involved in the iodination process of the thyroid hormone synthesis, particularly defects in iodide transport from circulation into the thyroid cell, defects in iodide transport from the thyroid cell to the follicular lumen (Pendred syndrome), and defects of iodide organification. Furthermore, we summarize relevant studies of perchlorate in humans. Because of perchlorate inhibition of iodide uptake, it is biologically plausible that chronic ingestion of perchlorate through contaminated sources may cause some degree of iodine discharge in populations that are genetically susceptible to defects in the iodination process of the thyroid hormone synthesis, thus deteriorating their conditions. We conclude that future studies linking human disease and environmental perchlorate exposure should consider the genetic makeup of the participants, actual perchlorate exposure levels, and individual iodine intake/excretion levels. PMID:16263499

Effects of ammonium perchlorate on the reproductive performance and thyroid follicle histology of zebrafish

USGS Publications Warehouse

Patino, R.; Wainscott, M.R.; Cruz-Li, E. I.; Balakrishnan, S.; McMurry, C.; Blazer, V.S.; Anderson, T.A.

2003-01-01

Adult zebrafish were reared up to eight weeks in control water or in water containing ammonium perchlorate (AP) at measured perchlorate concentrations of 18 (environmentally relevant, high) and 677 ppm. Groups of eight females were paired with four males on a weekly basis to assess AP effects on spawned egg volume, an index of reproductive performance. All treatments were applied to four to five spawning replicates. At 677 ppm, spawn volume was reduced within one week and became negligible after four weeks. At 18 ppm, spawn volume was unaffected even after eight weeks. Also, perchlorate at 18 ppm did not affect percentage egg fertilization. Fish were collected at the end of the exposures (677 ppm, four weeks; control and 18 ppm, eight weeks) for whole-body perchlorate content and thyroid histopathological analysis. Fish perchlorate levels were about one-hundredth of those of treatment water levels, indicating that waterborne perchlorate does not accumulate in whole fish. At 677 ppm for four weeks, perchlorate caused thyroid follicle cell (nuclear) hypertrophy and angiogenesis, whereas at 18 ppm for eight weeks, its effects were more pronounced and included hypertrophy, angiogenesis, hyperplasia, and colloid depletion. In conclusion, an eight-week exposure of adult zebrafish to 18 ppm perchlorate (high environmentally relevant concentrations) affected the histological condition of their thyroid follicles but not their reproductive performance. The effect of 677 ppm perchlorate on reproduction may be due to extrathyroidal toxicity. Further research is needed to determine if AP at lower environmentally relevant concentrations also affects the thyroid follicles of zebrafish.

Oxychlorine and Chloride/Ferrian Saponite Mixtures as a Possible Source of Hydrochloric Acid Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater, Mars

NASA Astrophysics Data System (ADS)

Hogancamp, J. V.; Sutter, B.; Archer, D., Jr.; Ming, D. W.; Mahaffy, P. R.

2017-12-01

The Sample Analysis at Mars (SAM) instrument on board the Curiosity Rover has detected HCl gas releases from several analyzed Gale Crater sediments, which are attributed to the presence of perchlorates, chlorates, and/or chlorides in martian sediment. Previous SAM analog laboratory analyses found that most pure perchlorates and chlorates produced HCl at different temperatures than those observed in the SAM data. Subsequent studies examined the effects of perchlorate and chlorate mixtures with Gale Crater analog iron phases, which are known to catalyze oxychlorine decomposition. Several mixtures produced characteristic O2 releases at similar temperatures as Gale Crater materials, but most of these mixtures did not produce HCl releases comparable to those detected by the SAM instrument. Perchlorates, chlorates, and chlorides were mixed with Gale Crater analog ferrian saponite to understand evolved HCl detected by SAM. Evolved water from thermally decomposing saponite is hypothesized to react with residual chloride phases from oxychlorine decomposition to produce high temperature (>700°C) HCl. Mixtures of chlorates, perchlorates, or chlorides with ferrian saponite were heated to 1000 °C in a laboratory analog SAM instrument. Results demonstrated that all chlorate and perchlorate mixtures produce HCl releases below 1000 °C when mixed with ferrian saponite. Mixtures of chlorides with ferrian saponite produced no oxygen releases but did produce HCl releases with peaks below 1000 °C. Ferrian saponite/Mg-chlorate mixtures produced two HCl releases (347 and 820 °C) similar to the Cumberland drilled sample. Additionally, sodium chloride mixed with ferrian saponite produced no oxygen releases and an HCl release (767 °C) similar to the Quela drilled sample. The Marimba drilled sample, which also produced no oxychlorine-derived oxygen, produced a high temperature HCl release that may be the result of chloride(s) reacting with evolved water from thermally decomposing ferrian saponite. Results of this work demonstrated that chlorides in the presence of evolved water from thermally decomposing saponite can explain the high temperature evolved HCl detected by SAM. Chlorides may either be native to the sample or be produced by perchlorate/chlorate thermal decomposition in order to yield Cl for high temperature (>700 °C) HCl production. Mg bearing Cl phases tend to produce two HCl releases (347-496 and 820 °C) while Ca and Na bearing phases produced one high temperature (>700 °C) HCl release. HCl release temperatures can be used to indicate the cation-type of the oxychlorine phase or chloride which is critical to understanding past geochemical conditions in Gale Crater.

Monitoring of perchlorate in diverse foods and its estimated dietary exposure for Korea populations.

PubMed

Lee, Ji-Woo; Oh, Sung-Hee; Oh, Jeong-Eun

2012-12-01

The perchlorate concentrations in various Korean food samples were monitored, and 663 samples belonging to 39 kinds of food were analyzed. The analysis results revealed that dairy products contain the highest average concentration of 6.34 μg/kg and high detection frequency of over 85%. Fruit and vegetables showed the next highest perchlorate concentration with an average of 6.17 μg/kg. Especially, with its average concentration of 39.9 μg/kg, spinach showed the highest perchlorate level among all target food samples studied. Tomato was followed by spinach, which showed a high perchlorate average concentration of 19.8 μg/kg, and over 7 μg/kg was detected in ham and sausage (avg. 7.31 μg/kg) and in instant noodles (avg. 7.58 μg/kg). Less than 2 μg/kg was detected in fishes, meats and beverages. The exposure dose of perchlorate in Korean by food intake was calculated on the basis of the analyzed perchlorate levels in this study. The daily perchlorate dose to which Korean adults are exposed is 0.04 μg/kg bw/day, which is lower than the RfD (0.7 μg/kg bw/day) value suggested by US NAS. This result indicates that Korean people's current exposure to perchlorate from domestic food consumption is evaluated as safe. Copyright © 2012 Elsevier B.V. All rights reserved.

Dissimilatory perchlorate reduction: a review.

PubMed

Bardiya, Nirmala; Bae, Jae-Ho

2011-05-20

In the United States anthropogenic activities are mainly responsible for the wide spread perchlorate contamination of drinking water, surface water, groundwater, and soil. Even at microgram levels, perchlorate causes toxicity to flora and fauna and affects growth, metabolism and reproduction in humans and animals. Reports of antithyroid effects of perchlorate and its detection in common food items have raised serious public health concerns, leading to extensive decontamination efforts in recent years. Several physico-chemical removal and biological decontamination processes are being developed. Although promising, ion exchange is a non-selective and incomplete process as it merely transfers perchlorate from water to the resin. The perchlorate-laden spent resins (perchlorate 200-500 mg L(-1)) require regeneration resulting in production of concentrated brine (6-12% NaCl) or caustic waste streams. On the contrary, biological reduction completely degrades perchlorate into O(2) and innocuous Cl(-). High reduction potential of ClO(4)(-)/Cl(-) (E° =∼ 1.28 V) and ClO(3)(-)/Cl(-) pairs (E° =1.03 V) makes these contaminants thermodynamically ideal e(-) acceptors for microbial reduction. In recent years unique dissimilatory perchlorate reducing bacteria have been isolated and detailed studies pertaining to their microbiological, biochemical, genetics and phylogenetic aspects have been undertaken which is the subject of this review article while the various physico-chemical removal and biological reduction processes have been reviewed by others. Copyright © 2010 Elsevier GmbH. All rights reserved.

Simultaneous removal of perchlorate and energetic compounds in munitions wastewater by zero-valent iron and perchlorate-respiring bacteria.

PubMed

Ahn, Se Chang; Hubbard, Brian; Cha, Daniel K; Kim, Byung J

2014-01-01

Ammonium perchlorate is one of the main constituents in Army's insensitive melt-pour explosive, PAX-21 in addition to RDX and 2,4-dinitroanisole (DNAN). The objective of this study is to develop an innovative treatment process to remove both perchlorate and energetic compounds simultaneously from PAX-21 production wastewater. It was hypothesized that the pretreatment of PAX-21 wastewater with zero-valent iron (ZVI) would convert energetic compounds to products that are more amenable for biological oxidation and that these products serve as electron donors for perchlorate-reducing bacteria. Results of batch ZVI reduction experiments showed that DNAN was completely reduced to 2,4-diaminoanisole and RDX was completely reduced to formaldehyde. Anaerobic batch biodegradation experiments showed that perchlorate (30 mg L(-1)) in ZVI-treated PAX-21 wastewater was decreased to an undetectable level after 5 days. Batch biodegradation experiments also confirmed that formaldehyde in ZVI-treated wastewater was the primary electron donor for perchlorate-respiring bacteria. The integrated iron-anaerobic bioreactor system was effective in completely removing energetic compounds and perchlorate from the PAX-21 wastewater without adding an exogenous electron donor. This study demonstrated that ZVI pretreatment not only removed energetic compounds, but also transformed energetic compounds to products that can serve as the source of electrons for perchlorate-respiring bacteria.

High-temperature solid-phase microextraction procedure for the detection of drugs by gas chromatography-mass spectrometry.

PubMed

Staerk, U; Külpmann, W R

2000-08-18

High-temperature headspace solid-phase microextraction (SPME) with simultaneous ("in situ") derivatisation (acetylation or silylation) is a new sample preparation technique for the screening of illicit drugs in urine and for the confirmation analysis in serum by GC-MS. After extraction of urine with a small portion of an organic solvent mixture (e.g., 2 ml of hexane-ethyl acetate) at pH 9, the organic layer is separated and evaporated to dryness in a small headspace vial. A SPME-fiber (e.g., polyacrylate) doped with acetic anhydride-pyridine (for acetylation) is exposed to the vapour phase for 10 min at 200 degrees C in a blockheater. The SPME fiber is then injected into the GC-MS for thermal desorption and analysis. After addition of perchloric acid and extraction with n-hexane to remove lipids, the serum can be analysed after adjusting to pH 9 as described for urine. Very clean extracts are obtained. The various drugs investigated could be detected and identified in urine by the total ion current technique at the following concentrations: amphetamines (200 microg/l), barbiturates (500 microg/l), benzodiazepines (100 microg/l), benzoylecgonine (150 microg/l), methadone (100 microg/l) and opiates (200 microg/l). In serum all drugs could be detected by the selected ion monitoring technique within their therapeutic range. As compared to liquid-liquid extraction only small amounts of organic solvent are needed and larger amounts of the pertinent analytes could be transferred to the GC column. In contrast to solid-phase extraction (SPE), the SPME-fiber is reusable several times (as there is no contamination by endogenous compounds). The method is time-saving and can be mechanised by the use of a dedicated autosampler.

Structure-Based Design, Synthesis and Testing of Non-Peptide, Cell-Permeable, Potent Small Molecule Smac Mimetics as a New Therapy for Prostate Cancer. Revision

DTIC Science & Technology

2007-02-01

from pyroglutamic acid 7 in eight steps according to a reported method.32 Hydrogenation of the double bond in 8 catalyzed by 10% Pd-C, followed by...with 70% perchloric acid and concentrated hydrochloric acid . RCH2PPh3Br + O O OMe OMe a,b O O OMe OMe R c,d O O OH OH R CHO 21a-1h 3a-3h 4a-4h Scheme...Smac to XIAP BIR3 is mediated by AVPI four amino acid residues in Smac and a well-defined surface binding groove in XIAP BIR3. While the alanine residue

Photooxidation of chloride by oxide minerals: implications for perchlorate on Mars.

PubMed

Schuttlefield, Jennifer D; Sambur, Justin B; Gelwicks, Melissa; Eggleston, Carrick M; Parkinson, B A

2011-11-09

We show that highly oxidizing valence band holes, produced by ultraviolet (UV) illumination of naturally occurring semiconducting minerals, are capable of oxidizing chloride ion to perchlorate in aqueous solutions at higher rates than other known natural perchlorate production processes. Our results support an alternative to atmospheric reactions leading to the formation of high concentrations of perchlorate on Mars.

Potential mechanisms for bioregeneration of perchlorate-containing ion-exchange resin.

PubMed

Sharbatmaleki, Mohamadali; Unz, Richard F; Batista, Jacimaria R

2015-05-15

Ion-exchange (IX) is the most feasible technology for perchlorate removal from drinking water. Reuse of resins present challenges, however. Selective resins are non-regenerable, and are incinerated after one time use, while non-selective resins, when regenerable, produce a waste stream that contains high concentration of perchlorate that must be disposed of. A process to bioregenerate spent resin containing perchlorate with perchlorate-reducing bacteria (PRB) has been recently developed. In this research, potential mechanisms for bioregeneration of resin-attached perchlorate (RAP) were investigated. Batch bioregeneration experiments were performed using gel-type and macroporous-type resins. Various initial chloride concentrations and various resin bead sizes were used. The results of the bioregeneration experiments suggested that chloride, i.e. the product of perchlorate biodegradation, is more likely the desorbing agent of RAP; and increasing the concentration of chloride enhances the bioregeneration process. Both film and pore diffusion were found to be relevant with respect to the rate of perchlorate mass-transfer to the bulk liquid. Bioregeneration was found to be more effective for macroporous than for gel-type resins, especially in the case of macroporous resins with relatively small bead size in the presence of higher chloride concentration. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biotechnological Applications of Microbial (Per)chlorate Reduction.

PubMed

Wang, Ouwei; Coates, John D

2017-11-24

While the microbial degradation of a chloroxyanion-based herbicide was first observed nearly ninety years ago, only recently have researchers elucidated the underlying mechanisms of perchlorate and chlorate [collectively, (per)chlorate] respiration. Although the obvious application of these metabolisms lies in the bioremediation and attenuation of (per)chlorate in contaminated environments, a diversity of alternative and innovative biotechnological applications has been proposed based on the unique metabolic abilities of dissimilatory (per)chlorate-reducing bacteria (DPRB). This is fueled in part by the unique ability of these organisms to generate molecular oxygen as a transient intermediate of the central pathway of (per)chlorate respiration. This ability, along with other novel aspects of the metabolism, have resulted in a wide and disparate range of potential biotechnological applications being proposed, including enzymatic perchlorate detection; gas gangrene therapy; enhanced xenobiotic bioremediation; oil reservoir bio-souring control; chemostat hygiene control; aeration enhancement in industrial bioreactors; and, biogenic oxygen production for planetary exploration. While previous reviews focus on the fundamental science of microbial (per)chlorate reduction (for example see Youngblut et al., 2016), here, we provide an overview of the emerging biotechnological applications of (per)chlorate respiration and the underlying organisms and enzymes to environmental and biotechnological industries.

The colloidal thyroxine (T4) ring as a novel biomarker of perchlorate exposure in the African clawed frog Xenopus laevis

USGS Publications Warehouse

Hu, F.; Sharma, Bibek; Mukhi, S.; Patino, R.; Carr, J.A.

2006-01-01

The purpose of this study was to determine if changes in colloidal thyroxine (T4) immunoreactivity can be used as a biomarker of perchlorate exposure in amphibian thyroid tissue. Larval African clawed frogs (Xenopus laevis) were exposed to 0, 1, 8, 93, and 1131 ??g perchlorate/l for 38 and 69 days to cover the normal period of larval development and metamorphosis. The results of this study confirmed the presence of an immunoreactive colloidal T4 ring in thyroid follicles of X. laevis and demonstrated that the intensity of this ring is reduced in a concentration-dependent manner by perchlorate exposure. The smallest effective concentration of perchlorate capable of significantly reducing colloidal T4 ring intensity was 8 ??g perchlorate/l. The intensity of the immunoreactive colloidal T4 ring is a more sensitive biomarker of perchlorate exposure than changes in hind limb length, forelimb emergence, tail resorption, thyrocyte hypertrophy, or colloid depletion. We conclude that the colloidal T4 ring can be used as a sensitive biomarker of perchlorate-induced thyroid disruption in amphibians. ?? Copyright 2006 Oxford University Press.

Chlorate origin and fate in shallow groundwater below agricultural landscapes.

PubMed

Mastrocicco, Micòl; Di Giuseppe, Dario; Vincenzi, Fabio; Colombani, Nicolò; Castaldelli, Giuseppe

2017-12-01

In agricultural lowland landscapes, intensive agricultural is accompanied by a wide use of agrochemical application, like pesticides and fertilizers. The latter often causes serious environmental threats such as N compounds leaching and surface water eutrophication; additionally, since perchlorate can be present as impurities in many fertilizers, the potential presence of perchlorates and their by-products like chlorates and chlorites in shallow groundwater could be a reason of concern. In this light, the present manuscript reports the first temporal and spatial variation of chlorates, chlorites and major anions concentrations in the shallow unconfined aquifer belonging to Ferrara province (in the Po River plain). The study was made in 56 different locations to obtain insight on groundwater chemical composition and its sediment matrix interactions. During the monitoring period from 2010 to 2011, in June 2011 a nonpoint pollution of chlorates was found in the shallow unconfined aquifer belonging to Ferrara province. Detected chlorates concentrations ranged between 0.01 and 38 mg/l with an average value of 2.9 mg/l. Chlorates were found in 49 wells out of 56 and in all types of lithology constituting the shallow aquifer. Chlorates concentrations appeared to be linked to NO 3 - , volatile fatty acids (VFA) and oxygen reduction potential (ORP) variations. Chlorates behaviour was related to the biodegradation of perchlorates, since perchlorates are favourable electron acceptors for the oxidation of labile dissolved organic carbon (DOC) in groundwater. Further studies must take into consideration to monitor ClO 4 - in pore waters and groundwater to better elucidate the mass flux of ClO 4 - in shallow aquifers belonging to agricultural landscapes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Thermal Reactivity Of Organic Molecules With Perchlorates And The Detection Of Organics In Mars Samples With SAM Onboard Curiosity Rover

NASA Astrophysics Data System (ADS)

Szopa, C.; Millan, M.; Buch, A.; Freissinet, C.; Guzman, M.; Glavin, D. P.; Mahaffy, P. R.; Navarro-Gonzalez, R.

2017-12-01

The search for organic molecules at the Mars surface is a key objective to assess the potential for habitability of the planet and to find biomarkers. Both the past Viking landers and the Curiosity rover of today carry onboard instruments based on gas chromatography coupled to mass spectrometry with the aim to analyze the content of organics present in soil or rock samples. These instruments analyze the volatile compounds released from the samples submitted to thermal or chemical treatments. Even though these sample preparation processes are commonly used on Earth for their efficient extraction of organic materials from mineral matrixes, the presence of oxychlorines recently discovered in the Mars soil [1, 2] makes the process for space applications more complex and the results more difficult to interpret. Indeed, the release of volatile inorganic reactive molecules from oxychlorines during the sample heating process induces reactions of chlorination and oxidation of the organic molecules. For this reason, in an effort to contribute to the interpretation of the results obtained with the Viking/GCMS, and the MSL/SAM experiment our team currently operates on Mars, we started to study systematically the thermal reactivity of a series of organic molecules, of interest for Mars and life purposes, mixed with oxychlorines either detected or potentially present in the soil of Mars [3]. In this presentation, we will mainly focus on two sets of results that were obtained while studying the reactivity of calcium perchlorates with polyaromatic hydrocarbons, amino acids and carboxylic acids under pyrolytic conditions similar to those used in the SAM experiment. First of all, we will show the dependence of reactivity on the temperature of sublimation and decomposition of the individual components in the mixture and, secondly, we will discuss the detection of aromatic chlorinated species by SAM in samples collected at the Cumberland site from the results obtained in this study. [1] Kounaves et al. (2010), JGR 115; [2] Glavin et al. (2013), JGR 181; [3] Sutter et al., JGR (in press);

(Per)chlorate in Biology on Earth and Beyond.

PubMed

Youngblut, Matthew D; Wang, Ouwei; Barnum, Tyler P; Coates, John D

2016-09-08

Respiration of perchlorate and chlorate [collectively, (per)chlorate] was only recognized in the last 20 years, yet substantial advances have been made in our understanding of the underlying metabolisms. Although it was once considered solely anthropogenic, pervasive natural sources, both terrestrial and extraterrestrial, indicate an ancient (per)chlorate presence across our solar system. These discoveries stimulated interest in (per)chlorate microbiology, and the application of advanced approaches highlights exciting new facets. Forward and reverse genetics revealed new information regarding underlying molecular biology and associated regulatory mechanisms. Structural and functional analysis characterized core enzymes and identified novel reaction sequences. Comparative genomics elucidated evolutionary aspects, and stress analysis identified novel response mechanisms to reactive chlorine species. Finally, systems biology identified unique metabolic versatility and novel mechanisms of (per)chlorate respiration, including symbiosis and a hybrid enzymatic-abiotic metabolism. While many published studies focus on (per)chlorate and their basic metabolism, this review highlights seminal advances made over the last decade and identifies new directions and potential novel applications.

49 CFR 173.127 - Class 5, Division 5.1-Definition and assignment of packing groups.

Code of Federal Regulations, 2011 CFR

2011-10-01

... the UN Manual of Tests and Criteria, it spontaneously ignites or its mean time for a pressure rise... ignites when mixed with cellulose in a 1:1 ratio; or (B) Any material which exhibits a mean pressure rise time less than the pressure rise time of a 1:1 perchloric acid (50 percent)/cellulose mixture. (ii...

49 CFR 173.127 - Class 5, Division 5.1-Definition and assignment of packing groups.

Code of Federal Regulations, 2010 CFR

2010-10-01

... the UN Manual of Tests and Criteria, it spontaneously ignites or its mean time for a pressure rise... ignites when mixed with cellulose in a 1:1 ratio; or (B) Any material which exhibits a mean pressure rise time less than the pressure rise time of a 1:1 perchloric acid (50 percent)/cellulose mixture. (ii...

Kinetics and mechanism of permanganate oxidation of iota- and lambda-carrageenan polysaccharides as sulfated carbohydrates in acid perchlorate solutions.

PubMed

Hassan, Refat M; Fawzy, Ahmed; Ahmed, Gamal A; Zaafarany, Ishaq A; Asghar, Basim H; Takagi, Hideo D; Ikeda, Yasuhisa

2011-10-18

The kinetics of oxidation of iota- and lambda-carrageenan as sulfated carbohydrates by permanganate ion in aqueous perchlorate solutions at a constant ionic strength of 2.0 mol dm(-3) have been investigated spectrophotometrically. The pseudo-first-order plots were found to be of inverted S-shape throughout the entire courses of reactions. The initial rates were found to be relatively slow in the early stages, followed by an increase in the oxidation rates over longer time periods. The experimental observations showed first-order dependences in permanganate and fractional first-order kinetics with respect to both carrageenans concentration for both the induction and autoacceleration periods. The results obtained at various hydrogen ion concentrations showed that the oxidation processes in these redox systems are acid-catalyzed throughout the two stages of oxidation reactions. The added salts lead to the prediction that Mn(III) is the reactive species throughout the autoacceleration periods. Kinetic evidence for the formation of 1:1 intermediate complexes was revealed. The kinetic parameters have been evaluated and tentative reaction mechanisms in good agreement with the kinetic results are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Thermal and Evolved Gas Analysis of Magnesium Perchlorate: Implications for Perchlorates in Soils at the Mars Phoenix Landing Site

NASA Technical Reports Server (NTRS)

Ming, Douglas W.; Morris, R.V.; Lauer, H. V.; Sutter, B.; Golden, D.C.; Boynton, W.V.

2009-01-01

Perchlorate salts were discovered in the soils around the Phoenix landing site on the northern plains of Mars [1]. Perchlorate was detected by an ion selective electrode that is part of the MECA Wet Chemistry Laboratory (WCL). The discovery of a mass 32 fragment (likely 02) by the Thermal and Evolved-Gas Analyzer (TEGA) provided additional confirmation of a strong oxidizer in the soils around the landing site. The purpose of this paper is to evaluate the thermal and evolved gas behavior of perchlorate salts using TEGA-like laboratory testbed instruments. TEGA ovens were fabricated from high purity Ni. Hence, an additional objective of this paper is to determine the effects that Ni might have on the evolved gas behavior of perchlorate salts.

Perchlorate as a Ground-Water Tracer Along the Lower Colorado River

NASA Astrophysics Data System (ADS)

Justet, L.; Lico, M. S.

2008-12-01

Anthropogenic perchlorate was first observed in the lower Colorado River (NV and AZ) in 1997. The perchlorate source was traced upstream from Hoover Dam and Lake Mead to Las Vegas Wash. Perchlorate migrated through the local surface- and ground-water systems to the Wash from nearby manufacturing facilities in Henderson, NV, which had been operating since the 1940s. The Nevada Division of Environmental Protection (NDEP) began monitoring perchlorate in the lower Colorado River at Willow Beach, located about 18 km south of the Dam, in 1997. A 3 μg/L reduction was observed at Willow Beach in 2003-2004, coincident with remediation at the Henderson site in 1999-2004. This observed decrease indicates that the effects of remediation rapidly propagated through the surface-water system below the Dam. In July 2008 water samples were collected and analyzed for perchlorate from eight springs along the lower Colorado River below Hoover Dam, from a discharge tunnel in the country rock at Hoover Dam, and from Lake Mead (above and below the thermocline). Lake Mead water collected above the thermocline east of Sentinel Island contained 3.9 μg/L perchlorate, while water below the thermocline contained 1.8 μg/L. Perchlorate concentrations were lower than the 2 to 4 μg/L quantitation limit for the six springs located more than 2 km south of the Dam. Samples from Pupfish Springs, about 0.9 km south of the Dam, contained 6.4-6.8 μg/L perchlorate. Water collected from the discharge tunnel in the Dam contained 8.2 μg/L perchlorate. Perchlorate concentrations observed at Pupfish Springs and the discharge tunnel in the Dam in 2008 are similar to those reported downstream at Willow Beach prior to 2003-2004 by NDEP indicating that the ground water travel time from the Dam to Pupfish Springs is between 4 and 70 years and the maximum flow velocities are between about 13-200 m/y. These rapid velocity estimates suggest that faults and fractures in the area are an important control on discharge points in the vicinity of the Dam. The presence of perchlorate at two sites and absence or background concentrations at the other sites indicates the presence of multiple flow paths between the perchlorate source and the springs near the Dam or that the flow paths are more complex than previously thought.

Nitrated graphene oxide and its catalytic activity in thermal decomposition of ammonium perchlorate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Wenwen; Luo, Qingping; Duan, Xiaohui

2014-02-01

Highlights: • The NGO was synthesized by nitrifying homemade GO. • The N content of resulted NGO is up to 1.45 wt.%. • The NGO can facilitate the decomposition of AP and release much heat. - Abstract: Nitrated graphene oxide (NGO) was synthesized by nitrifying homemade GO with nitro-sulfuric acid. Fourier transform infrared spectroscopy (FTIR), laser Raman spectroscopy, CP/MAS {sup 13}C NMR spectra and X-ray photoelectron spectroscopy (XPS) were used to characterize the structure of NGO. The thickness and the compositions of GO and NGO were analyzed by atomic force microscopy (AFM) and elemental analysis (EA), respectively. The catalytic effectmore » of the NGO for the thermal decomposition of ammonium perchlorate (AP) was investigated by differential scanning calorimetry (DSC). Adding 10% of NGO to AP decreases the decomposition temperature by 106 °C and increases the apparent decomposition heat from 875 to 3236 J/g.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Funke, L.A.; Espenson, J.H.

Reactions of chromium(II) perchlorate with acidified solutions of hydrogen peroxide in water containing modest concentrations of an organic nitrile (RCN) give rise to the cationic organochromium complexes CrCH/sub 2/CN/sup 2 +/ (RCN = acetonitrile), CrCH/sub 2/CH/sub 2/CN/sup 2 +/ (propionitrile), and CrCH/sub 2/CH(CH/sub 3/)CN/sup 2 +/ (isobutyronitrile). These cyanoalkyl complexes are quite resistant to decomposition in aqueous perchloric acid and can be separated by ion-exchange chromatography. Their composition was established by identification of the organic bromide formed by reaction with aqueous bromine. The complexes react with Hg/sup 2 +/ first to form the corresponding HgR/sup +/ and then (if excessmore » organochromium is present) HgR/sub 2/. Kinetic studies for the first stage of this reaction were carried out. The data are consistent with a bimolecular electrophilic substitution process (S/sub E/2 mechanism).« less

An Investigation into Palladium-Catalyzed Reduction of Perchlorate in Water

DTIC Science & Technology

2005-03-01

phytoremediation may help “naturally” reduce the spread of perchlorate in the environment. Rhizodegradation may be particularly effective for reducing...depth beyond the plant root zone, phytoremediation would be not affect the transport of perchlorate. Also, once perchlorate is dispersed in a large... Germany . At Spangdahlem, he led the Environmental Protection Element of the Bioenvironmental Engineering Flight and also led the 52nd Medical

Application of microwave digestion to the analysis of peat

USGS Publications Warehouse

Papp, C.S.E.; Fischer, L.B.

1987-01-01

A microwave digestion technique for the dissolution of peat is described and compared with a dry ashing method and a nitric - perchloric - hydrofluoric acid wet digestion. Peat samples with different organic matter contents were used and Ca, Mg, Fe, AI, Na, K, Mn, Zn, Cu and Li were determined by atomic absoprtion spectrometry. The results obtained using the three dissolution techniques were in good agreement. The microwave method has the advantage of digesting the samples in less than 2 h and uses less acid than the conventional wet digestion method. Keeping the volume of the acid mixture as small as possible minimises contamination and leads to lower blank values.

Combined effects of perchlorate, thiocyanate, and iodine on thyroid function in the National Health and Nutrition Examination Survey 2007–08

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steinmaus, Craig, E-mail: craigs@berkeley.edu; Miller, Mark D., E-mail: ucsfpehsumiller@gmail.com; Cushing, Lara, E-mail: lara.cushing@berkeley.edu

Perchlorate, thiocyanate, and low iodine intake can all decrease iodide intake into the thyroid gland. This can reduce thyroid hormone production since iodide is a key component of thyroid hormone. Previous research has suggested that each of these factors alone may decrease thyroid hormone levels, but effect sizes are small. We hypothesized that people who have all three factors at the same time have substantially lower thyroid hormone levels than people who do not, and the effect of this combined exposure is substantially larger than the effects seen in analyses focused on only one factor at a time. Using datamore » from the 2007–2008 National Health and Nutrition Examination Survey, subjects were categorized into exposure groups based on their urinary perchlorate, iodine, and thiocyanate concentrations, and mean serum thyroxine concentrations were compared between groups. Subjects with high perchlorate (n=1939) had thyroxine concentrations that were 5.0% lower (mean difference=0.40 μg/dl, 95% confidence interval=0.14–0.65) than subjects with low perchlorate (n=2084). The individual effects of iodine and thiocyanate were even smaller. Subjects with high perchlorate, high thiocyanate, and low iodine combined (n=62) had thyroxine concentrations 12.9% lower (mean difference=1.07 μg/dl, 95% confidence interval=0.55–1.59) than subjects with low perchlorate, low thiocyanate, and adequate iodine (n=376). Potential confounders had little impact on results. Overall, these results suggest that concomitant exposure to perchlorate, thiocyanate, and low iodine markedly reduces thyroxine production. This highlights the potential importance of examining the combined effects of multiple agents when evaluating the toxicity of thyroid-disrupting agents. -- Highlights: ► Recent data suggest that essentially everyone in the US is exposed to perchlorate. ► Perchlorate exposure may be associated with lower thyroid hormone levels. ► Some groups may be more susceptible to perchlorate than others.« less

Selenium content and oxidation states in fly ashes from western U.S. coals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mattigod, Shas V; Quinn, Thomas R

2003-08-01

A selective extraction scheme was developed for the determination of the oxidation states of Se species in coal ashes. As compared to HF dissolution, extractions with 70% HC1O4 mobilized 90 to 100% of all compound and redox forms of Se from four of the five fly ashes. Extractions with 16M HNO3 did not mobilize all forms of Se as effectively as perchloric acid. Both oxidized forms of Se (IV and VI) were completely mobilized by 12M HCl extraction. Deionized-distilled water was not an effective extractant for mobilizing all compound forms of Se(IV) from fly ashes. Extraction data (70% HClO4, 16Mmore » HNO3, 12M HCl, DI water) indicated that the solid:solution ratio is a critical factor in Se extractability from fly ashes. Maximum extractions in all cases were obtained only with very high (1:500) solid:solution ratios. Extraction times from 1.5 to 25 hours did not significantly change Se extractability with any of the extractants except with 12M HCl, which required a minimum reaction time of 48 hours to attain maximum Se extractability. Reaction times shorter than the critical time and low solid:solution ratios significantly affected Se extractability from these fly ashes. Measurements of Se content and redox state in particle size and density fractions five western United States coal ashes indicated that typically, the Se content increased with decreasing particle size.. However, no consistent trend in Se concentration between the light and heavy density fractions of <2.7-m size fraction was observed. Selenium redox state data indicated that only Se(0) and Se(IV) forms were present in these five coal ashes. The presence of Se(IV) is significant since it is much more easily mobilized than the elemental form. Examination of fly ashes by the proposed scheme to determine Se redox species could permit better estimation of the Se content of plants grown on fly ash amended soils.« less

Stability of low levels of perchlorate in drinking water and natural water samples

USGS Publications Warehouse

Stetson, S.J.; Wanty, R.B.; Helsel, D.R.; Kalkhoff, S.J.; Macalady, D.L.

2006-01-01

Perchlorate ion (ClO4-) is an environmental contaminant of growing concern due to its potential human health effects, impact on aquatic and land animals, and widespread occurrence throughout the United States. The determination of perchlorate cannot normally be carried out in the field. As such, water samples for perchlorate analysis are often shipped to a central laboratory, where they may be stored for a significant period before analysis. The stability of perchlorate ion in various types of commonly encountered water samples has not been generally examined-the effect of such storage is thus not known. In the present study, the long-term stability of perchlorate ion in deionized water, tap water, ground water, and surface water was examined. Sample sets containing approximately 1000, 100, 1.0, and 0.5 ??g l-1 perchlorate ion in deionized water and also in local tap water were formulated. These samples were analyzed by ion chromatography for perchlorate ion concentration against freshly prepared standards every 24 h for the first 7 days, biweekly for the next 4 weeks, and periodically after that for a total of 400 or 610 days for the two lowest concentrations and a total of 428 or 638 days for the high concentrations. Ground and surface water samples containing perchlorate were collected, held and analyzed for perchlorate concentration periodically over at least 360 days. All samples except for the surface water samples were found to be stable for the duration of the study, allowing for holding times of at least 300 days for ground water samples and at least 90 days for surface water samples. ?? 2006 Elsevier B.V. All rights reserved.

Mechanisms of direct inhibition of the respiratory sulfate-reduction pathway by (per)chlorate and nitrate.

PubMed

Carlson, Hans K; Kuehl, Jennifer V; Hazra, Amrita B; Justice, Nicholas B; Stoeva, Magdalena K; Sczesnak, Andrew; Mullan, Mark R; Iavarone, Anthony T; Engelbrektson, Anna; Price, Morgan N; Deutschbauer, Adam M; Arkin, Adam P; Coates, John D

2015-06-01

We investigated perchlorate (ClO(4)(-)) and chlorate (ClO(3)(-)) (collectively (per)chlorate) in comparison with nitrate as potential inhibitors of sulfide (H(2)S) production by mesophilic sulfate-reducing microorganisms (SRMs). We demonstrate the specificity and potency of (per)chlorate as direct SRM inhibitors in both pure cultures and undefined sulfidogenic communities. We demonstrate that (per)chlorate and nitrate are antagonistic inhibitors and resistance is cross-inducible implying that these compounds share at least one common mechanism of resistance. Using tagged-transposon pools we identified genes responsible for sensitivity and resistance in Desulfovibrio alaskensis G20. We found that mutants in Dde_2702 (Rex), a repressor of the central sulfate-reduction pathway were resistant to both (per)chlorate and nitrate. In general, Rex derepresses its regulon in response to increasing intracellular NADH:NAD(+) ratios. In cells in which respiratory sulfate reduction is inhibited, NADH:NAD(+) ratios should increase leading to derepression of the sulfate-reduction pathway. In support of this, in (per)chlorate or nitrate-stressed wild-type G20 we observed higher NADH:NAD(+) ratios, increased transcripts and increased peptide counts for genes in the core Rex regulon. We conclude that one mode of (per)chlorate and nitrate toxicity is as direct inhibitors of the central sulfate-reduction pathway. Our results demonstrate that (per)chlorate are more potent inhibitors than nitrate in both pure cultures and communities, implying that they represent an attractive alternative for controlling sulfidogenesis in industrial ecosystems. Of these, perchlorate offers better application logistics because of its inhibitory potency, solubility, relative chemical stability, low affinity for mineral cations and high mobility in environmental systems.

CHRONIC PERCHLORATE EXPOSURE CAUSES MORPHOLOGICAL ABNORMALITIES IN DEVELOPING STICKLEBACK

PubMed Central

Bernhardt, Richard R.; Von Hippel, Frank A.; O’Hara, Todd M.

2011-01-01

Few studies have examined the effects of chronic perchlorate exposure during growth and development, and fewer still have analyzed the effects of perchlorate over multiple generations. We describe morphological and developmental characteristics for threespine stickleback (Gasterosteus aculeatus) that were spawned and raised to sexual maturity in perchlorate-treated water (G1,2003) and for their offspring (G2,2004) that were not directly treated with perchlorate. The G1,2003 displayed a variety of abnormalities, including impaired formation of calcified traits, slower growth rates, aberrant sexual development, poor survivorship, and reduced pigmentation that allowed internal organs to be visible. Yet these conditions were absent when the offspring of contaminated fish (G2,2004) were raised in untreated water, suggesting a lack of transgenerational effects and that surviving populations may be able to recover following remediation of perchlorate-contaminated sites PMID:21465539

Supercooling and Ice Formation of Perchlorate Brines under Mars-relevant Conditions

NASA Astrophysics Data System (ADS)

Primm, K.; Gough, R. V.; Tolbert, M. A.

2015-12-01

Perchlorate salts, discovered in the Martian regolith at multiple landing sites, may provide pathways for liquid water stability on current Mars. It has previously been assumed that if perchlorate brines form in the Martian regolith via melting or deliquescence, they would be present only briefly because efflorescence into a crystal or freezing to ice would soon occur. Here, we used a Raman microscope to study the temperature and relative humidity (RH) conditions at which magnesium perchlorate brine will form ice. Although ice is thermodynamically predicted to form whenever the saturation with respect to ice (Sice) is greater than or equal to 1, ice formation by perchlorate brines did not occur until elevated Sice values were reached: Sice= 1.17, 1.29, and 1.25 at temperatures of 218 K, 230.5 K, and 244 K, respectively. If a magnesium perchlorate particle was allowed to deliquesce completely prior to experiencing ice supersaturation, the extent of supercooling was increased even further. These high supersaturation values imply perchlorate brines can exist over a wider range of conditions than previously believed. From these experiments it has been found that magnesium perchlorate exhibits supercooling well into the previous theoretical ice region of the stability diagram and that liquid brines on Mars could potentially exist for up to two additional hours per sol. This supercooling of magnesium perchlorate will help with the exploration of Mars by the Mars 2020 spacecraft by helping to understand the phase and duration of water existing in the Martian subsurface.

Assessment of Mexican Arnica (Heterotheca inuloides Cass) and Rosemary (Rosmarinus officinalis) Extracts on Dopamine and Selected Biomarkers of Oxidative Stress in Stomach and Brain of Salmonella typhimurium Infected rats.

PubMed

Guzmàn, David Calderón; Herrera, Maribel Ortiz; Brizuela, Norma Osnaya; Mejía, Gerardo Barragàn; García, Ernestina Hernàndez; Olguín, Hugo Juàrez; Peraza, Armando Valenzuela; Ruíz, Norma Labra; Del Angel, Daniel Santamaría

2017-01-01

The effects of some natural products on dopamine (DA) and 5-hydroxyindole acetic acid (5-HIAA) in brain of infected models are still unclear. The purpose of this study was to measure the effect of Mexican arnica/rosemary (MAR) water extract and oseltamivir on both biogenic amines and some oxidative biomarkers in the brain and stomach of young rats under infection condition. Female Wistar rats (weight 80 g) in the presence of MAR or absence (no-MAR) were treated as follows: group 1, buffer solution (controls); oseltamivir (100 mg/kg), group 2; culture of Salmonella typhimurium ( S.Typh ) (1 × 10 6 colony-forming units/rat) group 3; oseltamivir (100 mg/kg) + S.Typh (same dose) group 4. Drug and extracts were administered intraperitoneally every 24 h for 5 days, and S.Typh was given orally on days 1 and 3. On the fifth day, blood was collected to measure glucose and hemoglobin. The brains and stomachs were obtained to measure levels of DA, 5-HIAA, glutathione (GSH), TBARS, H 2 O 2 , and total ATPase activity using validated methods. DA levels increased in MAR group treated with oseltamivir alone but decreased in no-MAR group treated with oseltamivir plus S.Typh . 5-HIAA, GSH, and H 2 O 2 decreased in this last group, and ATPase activity increased in MAR group treated with oseltamivir plus S.Typh . TBARS (lipid peroxidation) increased in MAR group that received oseltamivir alone. Most of the biomarkers were not altered significantly in the stomach. MAR extract alters DA and metabolism of 5-HIAA in the brain of young animals infected. Antioxidant capacity may be involved in these effects. The purpose of this study was to measure the effect of Mexican arnica/rosemary water extract and oseltamivir on both biogenic amines and some oxidative biomarkers in the brain and stomach of young rats under infection condition. Results: Mexican arnica and rosemary extract alter dopamine and metabolism of 5-HIAA in the brain of young animals infected. Antioxidant capacity may be involved in these effects. Abbreviations used: AS: Automated system, ATP: Adenosine triphosphate, CNS: Central nervous system, CFU: Colony-forming unit, DA: Dopamine EDTA: Ethylenediaminetetraacetic acid, 5-HIAA: Äcido 5-hidroxindolacético (serotonina), GABA: γ-aminobutyric acid, GSH: Glutathione, H2O2: Hidrogen peroxide, HCLO4: Perchloric acid, iNOS: Inducible nitric oxide synthase, LPS: Lipopolysaccharides, MAR: Arnica/Rosemary, NaCl: Sodium Chloride, NOGSH: nitrosoglutathione, NOS: Nitric oxide, OPT: Ortho-phtaldialdehyde, Pbs: Phosphate buffered saline, pH: potential of Hydrogen, Pi: Inorganic phosphate, ROS: Reactive oxygen species, RNSs: Reactive nitrogen species Tba: Thiobarbaturic acid, TBARS: Thiobarbituric aid reactive, Tca: Trichloroacetic, Tris-HCL: Tris hydrochloride, TSA: Trypticasein Soya Agar.

Assessment of Mexican Arnica (Heterotheca inuloides Cass) and Rosemary (Rosmarinus officinalis) Extracts on Dopamine and Selected Biomarkers of Oxidative Stress in Stomach and Brain of Salmonella typhimurium Infected rats

PubMed Central

Guzmàn, David Calderón; Herrera, Maribel Ortiz; Brizuela, Norma Osnaya; Mejía, Gerardo Barragàn; García, Ernestina Hernàndez; Olguín, Hugo Juàrez; Peraza, Armando Valenzuela; Ruíz, Norma Labra; Del Angel, Daniel Santamaría

2017-01-01

Background: The effects of some natural products on dopamine (DA) and 5-hydroxyindole acetic acid (5-HIAA) in brain of infected models are still unclear. Objective: The purpose of this study was to measure the effect of Mexican arnica/rosemary (MAR) water extract and oseltamivir on both biogenic amines and some oxidative biomarkers in the brain and stomach of young rats under infection condition. Methods: Female Wistar rats (weight 80 g) in the presence of MAR or absence (no-MAR) were treated as follows: group 1, buffer solution (controls); oseltamivir (100 mg/kg), group 2; culture of Salmonella typhimurium (S.Typh) (1 × 106 colony-forming units/rat) group 3; oseltamivir (100 mg/kg) + S.Typh (same dose) group 4. Drug and extracts were administered intraperitoneally every 24 h for 5 days, and S.Typh was given orally on days 1 and 3. On the fifth day, blood was collected to measure glucose and hemoglobin. The brains and stomachs were obtained to measure levels of DA, 5-HIAA, glutathione (GSH), TBARS, H2O2, and total ATPase activity using validated methods. Results: DA levels increased in MAR group treated with oseltamivir alone but decreased in no-MAR group treated with oseltamivir plus S.Typh. 5-HIAA, GSH, and H2O2 decreased in this last group, and ATPase activity increased in MAR group treated with oseltamivir plus S.Typh. TBARS (lipid peroxidation) increased in MAR group that received oseltamivir alone. Most of the biomarkers were not altered significantly in the stomach. Conclusion: MAR extract alters DA and metabolism of 5-HIAA in the brain of young animals infected. Antioxidant capacity may be involved in these effects. SUMMARY The purpose of this study was to measure the effect of Mexican arnica/rosemary water extract and oseltamivir on both biogenic amines and some oxidative biomarkers in the brain and stomach of young rats under infection condition. Results: Mexican arnica and rosemary extract alter dopamine and metabolism of 5-HIAA in the brain of young animals infected. Antioxidant capacity may be involved in these effects. Abbreviations used: AS: Automated system, ATP: Adenosine triphosphate, CNS: Central nervous system, CFU: Colony-forming unit, DA: Dopamine EDTA: Ethylenediaminetetraacetic acid, 5-HIAA: Äcido 5-hidroxindolacético (serotonina), GABA: γ-aminobutyric acid, GSH: Glutathione, H2O2: Hidrogen peroxide, HCLO4: Perchloric acid, iNOS: Inducible nitric oxide synthase, LPS: Lipopolysaccharides, MAR: Arnica/Rosemary, NaCl: Sodium Chloride, NOGSH: nitrosoglutathione, NOS: Nitric oxide, OPT: Ortho-phtaldialdehyde, Pbs: Phosphate buffered saline, pH: potential of Hydrogen, Pi: Inorganic phosphate, ROS: Reactive oxygen species, RNSs: Reactive nitrogen species Tba: Thiobarbaturic acid, TBARS: Thiobarbituric aid reactive, Tca: Trichloroacetic, Tris-HCL: Tris hydrochloride, TSA: Trypticasein Soya Agar PMID:28539708

Perchlorate and nitrate treatment by ion exchange integrated with biological brine treatment.

PubMed

Lehman, S Geno; Badruzzaman, Mohammad; Adham, Samer; Roberts, Deborah J; Clifford, Dennis A

2008-02-01

Groundwater contaminated with perchlorate and nitrate was treated in a pilot plant using a commercially available ion exchange (IX) resin. Regenerant brine concentrate from the IX process, containing high perchlorate and nitrate, was treated biologically and the treated brine was reused in IX resin regeneration. The nitrate concentration of the feed water determined the exhaustion lifetime (i.e., regeneration frequency) of the resin; and the regeneration condition was determined by the perchlorate elution profile from the exhausted resin. The biological brine treatment system, using a salt-tolerant perchlorate- and nitrate-reducing culture, was housed in a sequencing batch reactor (SBR). The biological process consistently reduced perchlorate and nitrate concentrations in the spent brine to below the treatment goals of 500 microg ClO4(-)/L and 0.5mg NO3(-)-N/L determined by equilibrium multicomponent IX modeling. During 20 cycles of regeneration, the system consistently treated the drinking water to below the MCL of nitrate (10 mgNO3(-)-N/L) and the California Department of Health Services (CDHS) notification level of perchlorate (i.e., 6 microg/L). A conceptual cost analysis of the IX process estimated that perchlorate and nitrate treatment using the IX process with biological brine treatment to be approximately 20% less expensive than using the conventional IX with brine disposal.

Thermal Decomposition of Calcium Perchlorate/Iron-Mineral Mixtures: Implications of the Evolved Oxygen from the Rocknest Eolian Deposit in Gale Crater, Mars

NASA Technical Reports Server (NTRS)

Bruck, A. M.; Sutter, B.; Ming, D. W.; Mahaffy, P.

2014-01-01

A major oxygen release between 300 and 500 C was detected by the Mars Curiosity Rover Sample Analysis at Mars (SAM) instrument at the Rocknest eolian deposit. Thermal decomposition of perchlorate (ClO4-) salts in the Rocknest samples are a possible explanation for this evolved oxygen release. Releative to Na-, K-, Mg-, and Fe-perchlorate, the thermal decomposition of Ca-perchlorate in laboratory experiments released O2 in the temperature range (400-500degC) closest to the O2 release temperatures observed for the Rocknest material. Furthermore, calcium perchlorate could have been the source of Cl in the chlorinated-hydrocarbons species that were detected by SAM. Different components in the Martian soil could affect the decomposition temperature of calcium per-chlorate or another oxychlorine species. This interaction of the two components in the soil could result in O2 release temperatures consistent with those detected by SAM in the Rocknest materials. The decomposition temperatures of various alkali metal perchlorates are known to decrease in the presence of a catalyst. The objective of this work is to investigate catalytic interactions on calcium perchlorate from various iron-bearing minerals known to be present in the Rocknest material

A review of perchlorate (ClO4-) occurrence in fruits and vegetables.

PubMed

Calderón, R; Godoy, F; Escudey, M; Palma, P

2017-02-01

Since the 1990s, a large number of studies around the world have reported the presence of perchlorate in different types of environmental matrices. In view of their inherent characteristics, such as high solubility, mobility, persistence, and low affinity for the surface of soil, perchlorates are mobilized through the water-soil system and accumulate in edible plant species of high human consumption. However, the ingestion of food products containing perchlorate represents a potential health risk to people due to their adverse effects on thyroid, hormone, and neuronal development, mainly in infants and fetuses. At present, research has been centered on determining sources, fates, and remediation methods and not on its real extension in vegetables under farming conditions. This review presents a comprehensive overview and update of the frequent detection of perchlorate in fruits and vegetables produced and marketed around the world. Additionally, the impact of fertilizer on the potential addition of perchlorate to soil and its mobility in the water-soil-plant system is discussed. This review is organized into the following sections: sources of perchlorate, mobility in the water-soil system, presence in fruits and vegetables in different countries, international regulations, and toxicological studies. Finally, recommendations for future studies concerning perchlorate in fruits and vegetables are presented.

Preliminary analyses for perchlorate in selected natural materials and their derivative products

USGS Publications Warehouse

Orris, G.J.; Harvey, G.J.; Tsui, D.T.; Eldrige, J.E.

2003-01-01

Increasing concern about sources of perchlorate contamination in ground and surface waters has led to interest in identifying potential sources of natural perchlorate and products derived from these natural sources. To date, most perchlorate found in ground and surface waters has been attributed to its major uses as an oxidizer in solid propellants for rockets, in fireworks and other explosives, and a variety of other uses of man-made perchlorate salts. However, perchlorate found in the soils, surface water, and ground water of some locations cannot be linked to an anthropogenic source. This paper contains preliminary data on the detection and non-detection of perchlorate in a variety of natural materials and their products, including some fertilizer materials. These data were previously presented at two conferences; once in poster session and once orally (Harvey and others, 1999; Orris and others, 2000). Although the results presented here are included in a journal article awaiting publication, the lack of public information on this topic has led to repeated requests for the data used as the basis for our presentations in 1999 and 2000.

Potentiometric perchlorate determination at nanomolar concentrations in vegetables.

PubMed

Leoterio, Dilmo M S; Paim, Ana Paula S; Belian, Mônica F; Galembeck, André; Lavorante, André F; Pinto, Edgar; Amorim, Célia G; Araújo, Alberto N; Montenegro, Maria C B S M

2017-07-15

In this work, an expeditious method based on the multi-commutated flow-analysis concept with potentiometric detection is proposed to perform determinations of the emergent contaminant perchlorate in vegetable matrices down to nanomolar concentration. To accomplish the task, a tubular shaped potentiometric sensor selective to perchlorate ion was constructed with a PVC membrane containing 12mmol/kg of the polyamine bisnaphthalimidopropyl-4,4'-diaminodiphenylmethane and 2-nitrophenyl phenyl ether 68% (w/w) as plasticizer casted on a conductive epoxy resin. Under optimal flow conditions, the sensor responded linearly in the concentration range of 6.3×10 -7 -1.0×10 -3 mol/L perchlorate. In order to extend the determinations to lower concentrations (4.6(±1.3)×10 -10 mol/L perchlorate), a column packed with 70mg of sodium 2,5,8,11,14-pentaoxa-1-silacyclotetradecane-polymer was coupled to the flow-system thus enabling prior pre-concentration of the perchlorate. The proposed procedure provides a simpler alternative for the determination of perchlorate in foods, nowadays only allowed by sophisticated and expensive equipment and laborious methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

Perchlorate bioreduction linked to methane oxidation in a membrane biofilm reactor: Performance and microbial community structure.

PubMed

Xie, Ting; Yang, Qi; Winkler, Mari K H; Wang, Dongbo; Zhong, Yu; An, Hongxue; Chen, Fei; Yao, Fubin; Wang, Xiaolin; Wu, Jiawei; Li, Xiaoming

2018-06-05

Perchlorate bioreduction coupled to methane oxidation was successfully achieved without the addition of nitrate or nitrite in a membrane biofilm reactor (MBfR) inoculated with a mixture of freshwater sediments and anaerobic digester sludge as well as return activated sludge. The reactor was operated at different methane pressures (60, 40 and 20 Kpa) and influent perchlorate concentrations (1, 5 and 10 mg/L) to evaluate the biochemical process of perchlorate bioreduction coupled to methane oxidation. Perchlorate was completely reduced with a higher removal flux of 92.75 mg/m 2 ·d using methane as the sole carbon source and electron donor, other than hydrogen or other limiting organics. Quantitative real-time PCR showed that bacteria prevailed over archaea and the abundances of mcrA, pMMO, pcrA, and nirS genes were correlated with the influent perchlorate flux. High-throughput sequencing of 16S rRNA genes demonstrated that the functional community consisted of methanotrophs, methylotrophs, perchlorate-reducing bacteria, as well as various denitrifiers. Copyright © 2018 Elsevier B.V. All rights reserved.

PHYTOREMEDIATION OF PERCHLORATE AND N-NITROSODIMETHYLAMINE AS SINGLE AND CO-CONTAMINANTS

EPA Science Inventory

Although potential plant species suitable for phytoremediation of perchlorate and the phytoprocesses involved (rhizodegradation and phytodegradation) have been identified in previous research, regulators and some critics argue that plants recycle the perchlorate fract...

The Effects of Perchlorate on Methane Production of Methanogens

NASA Astrophysics Data System (ADS)

Goodhart, T.; Kral, T. A.

2010-04-01

In May 2008, the Phoenix space craft analyzed the martian soil, detecting perchlorate, which is a highly oxidizing compound and potentially harmful to organic matter. This presentation discusses the effects that perchlorate has on methanogen growth.

PERCHLORATE AS AN ENVIRONMENTAL CONTAMINANT

EPA Science Inventory

Perchlorate anion (C104) has been found in drinking water supplies throughout the southwestern United States. I t is primarily associated with releases of ammonium perdhlorate by defense contractors, military operations, and aerospace programs. Ammonium perchlorate is used as ...

Isolation and characterization of autotrophic, hydrogen-utilizing, perchlorate-reducing bacteria.

PubMed

Shrout, Joshua D; Scheetz, Todd E; Casavant, Thomas L; Parkin, Gene F

2005-04-01

Recent studies have shown that perchlorate (ClO(4) (-)) can be degraded by some pure-culture and mixed-culture bacteria with the addition of hydrogen. This paper describes the isolation of two hydrogen-utilizing perchlorate-degrading bacteria capable of using inorganic carbon for growth. These autotrophic bacteria are within the genus Dechloromonas and are the first Dechloromonas species that are microaerophilic and incapable of growth at atmospheric oxygen concentrations. Dechloromonas sp. JDS5 and Dechloromonas sp. JDS6 are the first perchlorate-degrading autotrophs isolated from a perchlorate-contaminated site. Measured hydrogen thresholds were higher than for other environmentally significant, hydrogen-utilizing, anaerobic bacteria (e.g., halorespirers). The chlorite dismutase activity of these bacteria was greater for autotrophically grown cells than for cells grown heterotrophically on lactate. These bacteria used fumarate as an alternate electron acceptor, which is the first report of growth on an organic electron acceptor by perchlorate-reducing bacteria.

37Cl/35Cl isotope ratio analysis in perchlorate by ion chromatography/multi collector -ICPMS: Analytical performance and implication for biodegradation studies.

PubMed

Zakon, Yevgeni; Ronen, Zeev; Halicz, Ludwik; Gelman, Faina

2017-10-01

In the present study we propose a new analytical method for 37 Cl/ 35 Cl analysis in perchlorate by Ion Chromatography(IC) coupled to Multicollector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS). The accuracy of the analytical method was validated by analysis of international perchlorate standard materials USGS-37 and USGS -38; analytical precision better than ±0.4‰ was achieved. 37 Cl/ 35 Cl isotope ratio analysis in perchlorate during laboratory biodegradation experiment with microbial cultures enriched from the contaminated soil in Israel resulted in isotope enrichment factor ε 37 Cl = -13.3 ± 1‰, which falls in the range reported previously for perchlorate biodegradation by pure microbial cultures. The proposed analytical method may significantly simplify the procedure for isotope analysis of perchlorate which is currently applied in environmental studies. Copyright © 2017. Published by Elsevier Ltd.

Influence of nitrate, sulfate and operational parameters on the bioreduction of perchlorate using an up-flow packed bed reactor at high salinity.

PubMed

Chung, J; Shin, S; Oh, J

2010-05-01

In this study we have investigated whether electron acceptors, such as nitrate or sulphate ions, competitively inhibit the reduction of perchlorate in brine in continuous up-flow packed bed bioreactors. The effect of pH and hydraulic retention time (HRT) on the reduction of perchlorate at high salinity has also been examined. Reduction of perchlorate was found to be only moderately influenced by nitrate (under 163 mg N L-'), implying that there was no significant microbial competition for electron acceptors. As a result of microbial diversity, there were few differences between microbial communities fed with a variety of media, suggesting that most nitrate-reducing bacteria are able to reduce perchlorate at high salinity. Reduction of perchlorate was almost complete at relatively high sulfate levels (1000 mg L(-1)), neutral pH (6-8) and relatively long HRTs (> 10 h).

Determination of rhenium in molybdenite by X-ray fluorescence: A combined chemical-spectrometric technique.

PubMed

Solt, M W; Wahlberg, J S; Myers, A T

1969-01-01

Rhenium in molybdenite is separated from molybdenum by distillation of rhenium heptoxide from a perchloric-sulphuric acid mixture. It is concentrated by precipitation of the sulphide and then determined by X-ray fluorescence. From 3 to 1000 microg of rhenium can be measured with a precision generally within 2%. The procedure tolerates larger amounts of molybdenum than the usual colorimetric methods.

Influence of a Boron Precursor on the Growth and Optoelectronic Properties of Electrodeposited Zinc Oxide Thin Film.

PubMed

Tsin, Fabien; Thomere, Angélica; Bris, Arthur Le; Collin, Stéphane; Lincot, Daniel; Rousset, Jean

2016-05-18

Highly transparent and conductive materials are required for many industrial applications. One of the interesting features of ZnO is the possibility to dope it using different elements, hence improving its conductivity. Results concerning the zinc oxide thin films electrodeposited in a zinc perchlorate medium containing a boron precursor are presented in this study. The addition of boron to the electrolyte leads to significant effects on the morphology and crystalline structure as well as an evolution of the optical properties of the material. Varying the concentration of boric acid from 0 to 15 mM strongly improves the compactness of the deposit and increases the band gap from 3.33 to 3.45 eV. Investigations were also conducted to estimate and determine the influence of boric acid on the electrical properties of the ZnO layers. As a result, no doping effect effect by boron was demonstrated. However, the role of boric acid on the material quality has also been proven and discussed. Boric acid strongly contributes to the growth of high quality electrodeposited zinc oxide. The high doping level of the film can be attributed to the perchlorate ions introduced in the bath. Finally, a ZnO layer electrodeposited in a boron rich electrolyte was tested as front contact of a Cu(In, Ga)(S, Se)2 based solar cell. An efficiency of 12.5% was measured with a quite high fill factor (>70%) which confirms the high conductivity of the ZnO thin film.

Effects of Ammonium Perchlorate on Thyroid Function in Developing Fathead Minnows, Pimephales promelas

PubMed Central

Crane, Helen M.; Pickford, Daniel B.; Hutchinson, Thomas H.; Brown, J. Anne

2005-01-01

Perchlorate is a known environmental contaminant, largely due to widespread military use as a propellant. Perchlorate acts pharmacologically as a competitive inhibitor of thyroidal iodide uptake in mammals, but the impacts of perchlorate contamination in aquatic ecosystems and, in particular, the effects on fish are unclear. Our studies aimed to investigate the effects of concentrations of ammonium perchlorate that can occur in the environment (1, 10, and 100 mg/L) on the development of fathead minnows, Pimephales promelas. For these studies, exposures started with embryos of < 24-hr postfertilization and were terminated after 28 days. Serial sectioning of thyroid follicles showed thyroid hyperplasia with increased follicular epithelial cell height and reduced colloid in all groups of fish that had been exposed to perchlorate for 28 days, compared with control fish. Whole-body thyroxine (T4) content (a measure of total circulating T4) in fish exposed to 100 mg/L perchlorate was elevated compared with the T4 content of control fish, but 3,5,3′-triiodothyronine (T3) content was not significantly affected in any exposure group. Despite the apparent regulation of T3, after 28 days of exposure to ammonium perchlorate, fish exposed to the two higher levels (10 and 100 mg/L) were developmentally retarded, with a lack of scales and poor pigmentation, and significantly lower wet weight and standard length than were control fish. Our study indicates that environmental levels of ammonium perchlorate affect thyroid function in fish and that in the early life stages these effects may be associated with developmental retardation. PMID:15811828

PHYTOREMEDIATION OF PERCHLORATE BY TOBACCO PLANTS

EPA Science Inventory

Previous studies have shown that tobacco plants are tolerant of perchlorate and will accumulate perchlorate in the plant tissues. The objective of this research was to determine the effectiveness of tobacco plants in phytoremediation, a technology that employs plants to degrade,...

PERCHLORATE IDENTIFICATION IN FERTILIZERS

EPA Science Inventory

Perchlorate has contaminated groundwater, drinking water, and soils at several locations in the United States. The primary source of contamination at sites that have been investigated to date seems to be from industrial and military operations that use perchlorate as an oxidizing...

Spectrofluorimetric and Potentiometric Determination of Acidity Constants of 4-(4'-Acetyloxy-3'-Methoxybenzylidene)-5-Oxazolone Derivatives.

PubMed

Taskiran, Derya Topkaya; Urut, Gulsiye Ozturk; Ayata, Sevda; Alp, Serap

2017-03-01

4-(4'-acetyloxy-3'-methoxybenzylidene)-5-oxazolone fluorescent molecules bearing four different aryl groups attached to the 2-position of 5-oxazolone ring have been investigated by spectrophotometric and potentiometric techniques in solution media. The acidity constants (pKa) of the fluorescent molecules were precisely determined in acetone, acetonitrile, dimethylformamide and in 1:1 mixture of toluene-isopropanol. The studied derivatives were titrated with tetrabutylammonium hydroxide and non-aqueous perchloric acid by scanning the basic and acidic region of the pH scale. A computerizable derivative method was used in order to descript precisely the end point and pKa values. The molecules investigated performed well-shaped and stoichiometric potentiometric titration curves.

Development of a Screening Tool to Facilitate Technology Transfer of an Innovative Technology to Treat Perchlorate-Contaminated Water

DTIC Science & Technology

2008-03-01

foods such as fruits, vegetables, and beverages (U.S. FDA, 2004). If the U.S. EPA ultimately establishes a drinking water standard for perchlorate...TREAT PERCHLORATE-CONTAMINATED WATER THESIS Daniel A. Craig, Captain, USAF AFIT/GEM/ENV/08-M06 DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY...OF AN INNOVATIVE TECHNOLOGY TO TREAT PERCHLORATE- CONTAMINATED WATER THESIS Presented to the Faculty Department of Systems and Engineering

Stable Isotope Systematics of Martian Perchlorate

NASA Astrophysics Data System (ADS)

Martin, P.; Farley, K. A.; Archer, D., Jr.; Atreya, S. K.; Conrad, P. G.; Eigenbrode, J. L.; Fairen, A.; Franz, H. B.; Freissinet, C.; Glavin, D. P.; Mahaffy, P. R.; Malespin, C.; Ming, D. W.; Navarro-Gonzalez, R.; Sutter, B.

2015-12-01

Chlorine isotopic compositions in HCl released during evolved gas analysis (EGA) runs have been detected by the Sample Analysis at Mars (SAM) instrument on the Curiosity rover ranging from approximately -9‰ to -50‰ δ37Cl, with two spatially and isotopically separated groups of samples averaging -15‰ and -45‰. These extremely low values are the first such detection of any known natural material; common terrestrial values very rarely exceed ±5‰, and the most extreme isotopic signature yet detected elsewhere in the solar system are values of around +24‰ on the Moon. The only other known location in the solar system with large negative chlorine isotopes is the Atacama Desert, where perchlorate with -14‰ δ37Cl has been detected. The Atacama perchlorate has unusual Δ17O signatures associated with it, indicating a formation mechanism involving O3, which suggests an atmospheric origin of the perchlorate and associated large isotopic anomalies. Identification of non-zero positive Δ17O signatures in the O2 released during EGA runs would allow definitive evidence for a similar process having occurred on Mars. Perchlorate is thought to be the most likely source of HCl in EGA runs due to the simultaneous onset of O2 release. If perchlorate is indeed the HCl source, atmospheric chemistry could be responsible for the observed isotopic anomalies, with variable extents of perchlorate production producing the isotopic variability. However, chloride salts have also been observed to release HCl upon heating; if the timing of O2 release is merely coincidental, observed HCl could be coming from chlorides. At thermodynamic equilibrium, the fractionation factor of perchlorate reduction is 0.93, meaning that differing amounts of post-deposition reduction of isotopically normal perchlorate to chloride could account for the highly variable Cl isotopes. Additionally, post-deposition reduction could account for the difference between the two Cl isotopic groups if perchlorate is the HCl source, as the residual perchlorate after reduction will be isotopically heavy. Therefore, conclusive determination of the origin of HCl released during EGA is vital to understanding the origin of this large δ37Cl anomaly.

The Investigation of Magnesium Perchlorate/Iron Phase-mineral Mixtures as a Possible Source of Oxygen and Chlorine Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater, Mars

NASA Technical Reports Server (NTRS)

Sutter, B.; Heil, E.; Archer, P. D.; Ming, D. W.; Eigenbrode, J. L.; Franz, H. B.; Glavin, D. P.; McAdam, A. C.; Mahaffy, P. R.; Niles, P. B.;

Abundances and implications of volatile-bearing species from evolved gas analysis of the Rocknest aeolian deposit, Gale Crater, Mars

NASA Astrophysics Data System (ADS)

Archer, Paul Douglas; Franz, Heather B.; Sutter, Brad; Arevalo, Ricardo D.; Coll, Patrice; Eigenbrode, Jennifer L.; Glavin, Daniel P.; Jones, John J.; Leshin, Laurie A.; Mahaffy, Paul R.; McAdam, Amy C.; McKay, Christopher P.; Ming, Douglas W.; Morris, Richard V.; Navarro-González, Rafael; Niles, Paul B.; Pavlov, Alex; Squyres, Steven W.; Stern, Jennifer C.; Steele, Andrew; Wray, James J.

2014-01-01

The Sample Analysis at Mars (SAM) instrument on the Mars Science Laboratory (MSL) rover Curiosity detected evolved gases during thermal analysis of soil samples from the Rocknest aeolian deposit in Gale Crater. Major species detected (in order of decreasing molar abundance) were H2O, SO2, CO2, and O2, all at the µmol level, with HCl, H2S, NH3, NO, and HCN present at the tens to hundreds of nmol level. We compute weight % numbers for the major gases evolved by assuming a likely source and calculate abundances between 0.5 and 3 wt.%. The evolution of these gases implies the presence of both oxidized (perchlorates) and reduced (sulfides or H-bearing) species as well as minerals formed under alkaline (carbonates) and possibly acidic (sulfates) conditions. Possible source phases in the Rocknest material are hydrated amorphous material, minor clay minerals, and hydrated perchlorate salts (all potential H2O sources), carbonates (CO2), perchlorates (O2 and HCl), and potential N-bearing materials (e.g., Martian nitrates, terrestrial or Martian nitrogenated organics, ammonium salts) that evolve NH3, NO, and/or HCN. We conclude that Rocknest materials are a physical mixture in chemical disequilibrium, consistent with aeolian mixing, and that although weathering is not extensive, it may be ongoing even under current Martian surface conditions.

ADSORPTION CHARACTERISTICS OF PERCHLORATE IN SOILS

EPA Science Inventory

Perchlorate(CI04) is an oxyanion that originates as a contaminant in ground and surface waters from the dissolution of ammonium, potassium, magnesium or sodium salts. Perchlorate is mainly used in solid rocket fuels, explosives, and military batteries. Because of its potential ha...

INVESTIGATION OF AGRICULTURAL FERTILIZERS AND RELATED MATERIALS FOR PERCHLORATE

EPA Science Inventory

The most comprehensive survey of fertilizers and other raw materials for perchlorate to date has been conducted to determine whether these could be significant contributors to environmental perchlorate contamination. Although the data span a large range of commercial products, th...

SURVEY OF FERTILIZERS AND RELATED MATERIALS FOR PERCHLORATE

EPA Science Inventory

The most comprehensive survey of fertilizers and other raw materials for perchlorate to date has been conducted to determine whether these could be significant contributors to environmental perchlorate contamination. Although the data span a large range of commercial products, th...

MARGINAL IODINE DEFICIENCY EXACERBATES PERCHLORATE THYROID TOXICITY.

EPA Science Inventory

The environmental contaminant perchlorate disrupts thyroid homeostasis via inhibition of iodine uptake into the thyroid. This work tested whether iodine deficiency exacerbates the effects of perchlorate. Female 27 day-old LE rats were fed a custom iodine deficient diet with 0, 50...

PERCHLORATE ACCUMULATION FROM FERTILIZER IN LEAFY VEGETATION

EPA Science Inventory

Perchlorate contaminated water and soil has been identified in many areas of the United States. Previous studies indicated that the primary source of contamination was from industry and military operations that use perchlorate as an oxidzing agent. However, recent studies have fo...

Rapid analysis of perchlorate in drinking water at parts per billion levels using microchip electrophoresis.

PubMed

Gertsch, Jana C; Noblitt, Scott D; Cropek, Donald M; Henry, Charles S

2010-05-01

A microchip capillary electrophoresis (MCE) system has been developed for the determination of perchlorate in drinking water. The United States Environmental Protection Agency (USEPA) recently proposed a health advisory limit for perchlorate in drinking water of 15 parts per billion (ppb), a level requiring large, sophisticated instrumentation, such as ion chromatography coupled with mass spectrometry (IC-MS), for detection. An inexpensive, portable system is desired for routine online monitoring applications of perchlorate in drinking water. Here, we present an MCE method using contact conductivity detection for perchlorate determination. The method has several advantages, including reduced analysis times relative to IC, inherent portability, high selectivity, and minimal sample pretreatment. Resolution of perchlorate from more abundant ions was achieved using zwitterionic, sulfobetaine surfactants, N-hexadecyl-N,N-dimethyl-3-ammonio-1-propane sulfonate (HDAPS) and N-tetradecyl-N,N-dimethyl-3-ammonio-1-propane sulfonate (TDAPS). The system performance and the optimization of the separation chemistry, including the use of these surfactants to resolve perchlorate from other anions, are discussed in this work. The system is capable of detection limits of 3.4 +/- 1.8 ppb (n = 6) in standards and 5.6 +/- 1.7 ppb (n = 6) in drinking water.

PERCHLORATE IN FERTILIZERS?: ANALYSIS BY RAMAN SPECTROSCOPY

EPA Science Inventory

Recently, we and others found perchlorate at high levels (approximately 500 - 8000 mg/kg) in 90+% of 25+ fertilizers (primarily lawn-and-garden products) that are not identified as containing components derived from mined Chile saltpeter, which is known to contain perchlorate as ...

ASSOCIATION OF URINARY PERCHLORATE WITH INDIRECT MEASURES OFTHYROID DYSFUNCTION BASED ON NHANES 2001-2002

EPA Science Inventory

Background/Aims: Perchlorate is a widespread environmental pollutant. Previous population studies based on the National Health and Nutrition Examination Survey (NHANES) 2001-2002, showed that urinary perchlorate concentrations were associated with increased levels of thyroid stim...

ALTERNATIVE TECHNIQUES FOR MEASUREMENT OF PERCHLORATE IN FERTILIZER AND ENVIRONMENTAL SAMPLES

EPA Science Inventory

The Perchlorate anion has been implicated as a potentially serious environmental pollutant, being found in drinking water and irrigated crops. Commercial fertilizers have recently been shown to contain high levels of Perchlorate impurities and thus be potentially important source...

Removal of Perchlorate and Chlorate in Aquatic SystemsUsing Integrated Technologies

EPA Science Inventory

Because of its extremely low concentrations and strong resistance to most treatment technologies, perchlorate has become one of the biggest challenges currently being faced by the drinking water industry. Few studies have looked at electrochemical reduction of aqueous perchlorate...

High-Nitrogen-Based Pyrotechnics: Development of Perchlorate-Free Green-Light Illuminants for Military and Civilian Applications

DTIC Science & Technology

2012-01-01

Table 1. Magnesium served as the main fuel in the formulation, barium nitrate and potassium per- chlorate served as the oxidizers, and dechlorane plus...course of the investigation needed to be changed. Although the initial investigation set out to remove potassium per- chlorate oxidizer from the M195 HHS...become a concern of the US Department of Defense is the “perchlorate issue.” Potassium perchlorate and ammonium perchlorate oxidizers, once believed to be

Dracorhodin perchlorate regulates fibroblast proliferation to promote rat's wound healing.

PubMed

Jiang, Xiaowen; Liu, Lin; Qiao, Lu; Zhang, Binqing; Wang, Xuewei; Han, Yuwen; Yu, Wenhui

2018-02-01

In recent years, plant-derived extracts are increasing interest from researchers worldwide due to good efficacy and lower side effects. Among the different plant extracts, Dracorhodin perchlorate (DP) is originated from Dragon's blood which has long been used as a natural medicine with various pharmacological activities. In the present study, we have explored the potential regulation of DP on fibroblast proliferation which promotes wound healing both in vitro and in vivo. DP at treatment of 12-24 h significantly induced fibroblast proliferation which is associated with increasing level of phosphorylated-extracellular signal-regulated kinase (ERK). Moreover, if ERK is halted with siRNA, DP cannot induce fibroblast proliferation. In vivo, DP ointment treatment at low- (2.5 μg/mL), medium- (5 μg/mL) and high-(10 μg/mL) doses, rat wounds healed more rapidly compared with the control group. After DP treatment for 7 days, Serpin family H member 1 (SERPINH1) staining confirmed enhanced fibroblast proliferation in the wound tissue. Finally, phosphorylated-ERK in the wound tissue remarkably increased with DP ointment treatment. Therefore, DP may be developed into a potential lead compounds for the treatment of wounds in clinical trials in the near future. Copyright © 2018 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Dealing With Perchlorate in the Santa Clarita Valley, CA

NASA Astrophysics Data System (ADS)

Boulos, L.; Min, J.; Juby, G.; McLean, S.; Prasifka, D.; Brown, J.

2004-05-01

Castaic Lake Water Agency was faced with a dilemma: how to support the increasing water needs of a growing population in the Santa Clarita Valley with three to five wells in the area shut-down due to the presence of perchlorate. Carollo Engineers was hired to design a treatment program for the removal of perchlorate from Saugus Aquifer. Several unknowns challenged the project including an uncertainty in a regulatory MCL for perchlorate, lack of brine line in the area, and low chloride limits in LACSD sewer lines. The preliminary phase of the project was to identify and recommend perchlorate treatment processes for further bench and/or pilot-scale testing. Two alternatives were selected: 1) Three NSF certified perchlorate-selective ion exchange resins and 2) Two types of biological treatment systems. Selection criteria included: cost, minimal formation of wastes and full-scale demonstration of the processes. This paper will focus on the basis, design, and findings from three perchlorate-selective ion-exchange resins. Bench-scale testing of the ion-exchange resins was conducted over a period of 3 months. NDMA formation following chlorination and chloramination was investigated. The spent resins were further characterized for metals and uranium. Results: Adsorption cycles of two of the resins lasted more than 70,000 bed volumes before perchlorate was detected in the effluent of the columns (approximately 200,000- 550,000 gal/cu-ft resin). No NDMA was formed as a result of post-chlorination with free and combined chlorine, or as a result of prechlorination with free chlorine. The metals measured in the spent results were well below the TTLC and STLC limits, despite the long run times. Ion-exchange is therefore a feasible technology for treatment perchlorate in the Santa Clarita Valley.

Determination of perchlorate in drinking water by ion chromatography using macrocycle-based concentration and separation methods.

PubMed

Lamb, John D; Simpson, David; Jensen, Bryce D; Gardner, Joseph S; Peterson, Quinn P

2006-06-16

Macrocycle-based ion chromatography provides a convenient, reliable method for the determination of perchlorate ion, which is currently of great interest to the environmental community. This study shows that effective perchlorate determinations can be made using standard conductimetric detection by combining an 18-crown-6-based mobile phase with an underivatized reversed-phase mobile phase ion chromatography (MPIC) column. One unique feature of this method is the flexibility in column capacity that is achieved through simple variations in eluent concentrations of 18-crown-6 and KOH, facilitating the separation of target analyte anions such as perchlorate. Using a standard anion exchange column as concentrator makes possible the determination of perchlorate as low as 0.2 ug/L in low ionic strength matrices. Determination of perchlorate at the sub-ug/L level in pure water and in spiked local city hard water samples with high background ion concentrations can be achieved this way. However, like other IC techniques, this method is challenged to achieve analyses at the ug/L level in the demanding high ionic strength matrix described by the United States Environmental Protection Agency (EPA) (1,000 mg/L chloride, sulfate and carbonate). We approached this challenge by use of the Cryptand C1 concentrator column, provided by Dionex Corporation, to effectively preconcentrate perchlorate while reducing background ion concentrations in the high ionic strength matrix. The retention characteristics of the concentrator column were studied in order to maximize its effectiveness for perchlorate determinations. The method makes possible the determination of perchlorate at the 5 ug/L level in the highest ionic strength matrix described by the EPA.

Perchlorate: Health Effects and Technologies for Its Removal from Water Resources

PubMed Central

Srinivasan, Asha; Viraraghavan, Thiruvenkatachari

2009-01-01

Perchlorate has been found in drinking water and surface waters in the United States and Canada. It is primarily associated with release from defense and military operations. Natural sources include certain fertilizers and potash ores. Although it is a strong oxidant, perchlorate is very persistent in the environment. At high concentrations perchlorate can affect the thyroid gland by inhibiting the uptake of iodine. A maximum contaminant level has not been set, while a guidance value of 6 ppb has been suggested by Health Canada. Perchlorate is measured in environmental samples primarily by ion chromatography. It can be removed from water by anion exchange or membrane filtration. Biological and chemical processes are also effective in removing this species from water. PMID:19440526

Development and Evaluation of Cefadroxil Drug Loaded Biopolymeric Films Based on Chitosan-Furfural Schiff Base

PubMed Central

Dixit, Ritu B.; Uplana, Rahul A.; Patel, Vishnu A.; Dixit, Bharat C.; Patel, Tarosh S.

2010-01-01

Cefadroxil drug loaded biopolymeric films of chitosan-furfural schiff base were prepared by reacting chitosan with furfural in presence of acetic acid and perchloric acid respectively for the external use. Prepared films were evaluated for their strength, swelling index, thickness, drug content, uniformity, tensile strength, percent elongation, FTIR spectral analysis and SEM. The results of in vitro diffusion studies revealed that the films exhibited enhanced drug diffusion as compared to the films prepared using untreated chitosan. The films also demonstrated good to moderate antibacterial activities against selective gram positive and gram negative bacteria. PMID:21179325

RAMAN SPECTRAL ANALYSIS OF PERCHLORATE CONTAMINATION IN COMMONLY-USED FERTILIZERS

EPA Science Inventory

Raman spectroscopy (RS) was used for qualitative and quantitative analysis of perchlorate (ClO4-1) in 30+ commonly-used fertilizers. Perchlorate contamination is emerging as an important environmental issue since its discovery in water resources that are widely used for drinking...

PHYTOTRANSFORMATION OF PERCHLORATE USING PARROT-FEATHER

EPA Science Inventory

Perchlorate is an oxvanion that has been extensively is a strong oxidizing
agent in solid rocket fuel. Contamination of groundwater has occurred as the result of Perchlorate use. Standard disposal practices during the 1950s through the 1970s did not reflect the current knowled...

DEVELOPMENT OF AN ELECTROSPRAY MASS SPECTROMETRIC METHOD FOR DETERMINING PERCHLORATE IN FERTILIZERS

EPA Science Inventory

An electrospray mass spectrometric method has been developed for application to agricultural and horticultural fertilizers to determine perchlorate. After fertilizers are leached or dissolved in water, the method relies on the formation of stable ion pair complex of the perchlor...

ELECTROCHEMICAL TREATMENT AND RECYCLING OF SPENT PERCHLORATE-CONTAMINATED ION-EXCHANGE REGENERATION BRINE - PHASE I

EPA Science Inventory

Eltron Research & Development, Inc. (Eltron) proposes to develop an ion-selective, polymer membrane electrode capable of detecting perchlorate in water at low parts per billion (ppb) concentrations. With the discovery of perchlorate contamination in an increasing number of...

PERCHLORATE IDENTIFICATION IN FERTILIZERS AND ACCUMULATION IN LETTUCE SEEDLINGS

EPA Science Inventory

Perchlorate has contaminated groundwater, drinking water and soils at several locations in the U.S. The primary source of contamination at sites that have been investigated to date seems to be from industrial and military operations that use Perchlorate as an oxidizing agent. How...

Toxic Byproduct Formation during Electrochemical Treatment of Latrine Wastewater

PubMed Central

2017-01-01

Electrochemical systems are an attractive option for onsite latrine wastewater treatment due to their high efficiency and small footprint. While concerns remain over formation of toxic byproducts during treatment, rigorous studies examining byproduct formation are lacking. Experiments treating authentic latrine wastewater over variable treatment times, current densities, chloride concentrations, and anode materials were conducted to characterize byproducts and identify conditions that minimize their formation. Production of inorganic byproducts (chlorate and perchlorate) and indicator organic byproducts (haloacetic acids and trihalomethanes) during electrolysis dramatically exceeded recommendations for drinking water after one treatment cycle (∼10–30 000 times), raising concerns for contamination of downstream water supplies. Stopping the reaction after ammonium was removed (i.e., the chlorination breakpoint) was a promising method to minimize byproduct formation without compromising disinfection and nutrient removal. Though treatment was accelerated at increased chloride concentrations and current densities, byproduct concentrations remained similar near the breakpoint. On TiO2/IrO2 anodes, haloacetic acids (up to ∼50 μM) and chlorate (up to ∼2 μM) were of most concern. Although boron-doped diamond anodes mineralized haloacetic acids after formation, high production rates of chlorate and perchlorate (up to ∼4 and 25 μM) made them inferior to TiO2/IrO2 anodes in terms of toxic byproduct formation. Organic byproduct formation was similar during chemical chlorination and electrolysis of wastewater, suggesting that organic byproducts are formed by similar pathways in both cases (i.e., reactions with chloramines and free chlorine). PMID:28538093

Toxic Byproduct Formation during Electrochemical Treatment of Latrine Wastewater.

PubMed

Jasper, Justin T; Yang, Yang; Hoffmann, Michael R

2017-06-20

Electrochemical systems are an attractive option for onsite latrine wastewater treatment due to their high efficiency and small footprint. While concerns remain over formation of toxic byproducts during treatment, rigorous studies examining byproduct formation are lacking. Experiments treating authentic latrine wastewater over variable treatment times, current densities, chloride concentrations, and anode materials were conducted to characterize byproducts and identify conditions that minimize their formation. Production of inorganic byproducts (chlorate and perchlorate) and indicator organic byproducts (haloacetic acids and trihalomethanes) during electrolysis dramatically exceeded recommendations for drinking water after one treatment cycle (∼10-30 000 times), raising concerns for contamination of downstream water supplies. Stopping the reaction after ammonium was removed (i.e., the chlorination breakpoint) was a promising method to minimize byproduct formation without compromising disinfection and nutrient removal. Though treatment was accelerated at increased chloride concentrations and current densities, byproduct concentrations remained similar near the breakpoint. On TiO 2 /IrO 2 anodes, haloacetic acids (up to ∼50 μM) and chlorate (up to ∼2 μM) were of most concern. Although boron-doped diamond anodes mineralized haloacetic acids after formation, high production rates of chlorate and perchlorate (up to ∼4 and 25 μM) made them inferior to TiO 2 /IrO 2 anodes in terms of toxic byproduct formation. Organic byproduct formation was similar during chemical chlorination and electrolysis of wastewater, suggesting that organic byproducts are formed by similar pathways in both cases (i.e., reactions with chloramines and free chlorine).

The thyroid endocrine disruptor perchlorate affects reproduction, growth, and survival of mosquitofish.

PubMed

Park, June-Woo; Rinchard, Jacques; Liu, Fujun; Anderson, Todd A; Kendall, Ronald J; Theodorakis, Christopher W

2006-03-01

The perchlorate anion--an oxidizer found in rockets, missiles, some ammunition, flares, airbags, and fireworks--occurs as a contaminant in ground and surface water in many parts of the United States. Its toxic effects include inhibition of thyroid hormone synthesis. To investigate its chronic toxicity, mosquitofish (Gambusia holbrooki) adults and fry were exposed to aqueous sodium perchlorate at 1, 10, and 100mg/L, and growth and reproductive performance (fecundity, eggs/embryos mass, and gonadosomatic index [GSI]) were determined. Five-day acute toxicity tests were also performed. Perchlorate had a stimulatory effect on fecundity, GSI, and egg/embryo mass, at least for some treatments. The LC50 of sodium perchlorate was 404 mg/L. Growth was enhanced at 1mg/L but inhibited at 10mg/L. These results suggest that, at environmentally relevant concentrations, perchlorate does not induce acutely toxic effects but may have mild stimulatory or hormetic effects on fitness parameters in this species.

A Systematic Approach to In Situ Bioremediation in Groundwater Including Decision Trees on In Situ Bioremediation for Nitrates, Carbon Tetrachloride, and Perchlorate

DTIC Science & Technology

2002-08-01

and Disease Registry (ATSDR). When conducting risk assessments , primary and secondary contaminants must be incorporated into the exposure...industry; acid production; textile bleaching; petroleum refining; refrigeration; production of pulp , paper , and rubber; as a catalytic agent in...memorandum from Michael Honeycutt, Ph.D., Toxicology and Risk Assessment Section, Office of Permitting, Remediation and Registration, Texas Natural Resource

Process for the synthesis of iron powder

DOEpatents

Not Available

1982-03-06

A process for preparing iron powder suitable for use in preparing the iron-potassium perchlorate heat-powder fuel mixture used in thermal batteries, comprises preparing a homogeneous, dense iron oxide hydroxide precipitate by homogeneous precipitation from an aqueous mixture of a ferric salt, formic or sulfuric acid, ammonium hydroxide and urea as precipitating agent; and then reducing the dense iron oxide hydroxide by treatment with hydrogen to prepare the iron powder.

Process for the synthesis of iron powder

DOEpatents

Welbon, William W.

1983-01-01

A process for preparing iron powder suitable for use in preparing the iron-potassium perchlorate heat-powder fuel mixture used in thermal batteries, comprises preparing a homogeneous, dense iron oxide hydroxide precipitate by homogeneous precipitation from an aqueous mixture of a ferric salt, formic or sulfuric acid, ammonium hydroxide and urea as precipitating agent; and then reducing the dense iron oxide hydroxide by treatment with hydrogen to prepare the iron powder.

Eighth Mendeleyev Congress on General and Applied Chemistry - USSR -

DTIC Science & Technology

1960-07-18

A. Nazarova and V. S. Orlova (Moscow) succeeded in forming sulfates , nitrates and carbonates of platinum iodopentamine by ammonia substitution of...of ruthenium; S. I. Ginsburg, N. K. Pshenitsyn and L. G. Sal’skaya (moscow) studied the nature of colored iridum compounds formed in sulfuric ...phosphoric and perchloric acids ; Ye. V. Shenderet- skaya and I. I. Chernyayev (Moscow) studied formates of mono- valent rhodium; E. P. Deichman (Moscow

Direct Catalytic Anti-Markovnikov Hydroetherification of Alkenols

PubMed Central

Hamilton, David S.; Nicewicz, David A.

2012-01-01

A direct intramolecular anti-Markovnikov hydroetherification reaction of alkenols is described. By employing catalytic quantities of commercially-available 9-mesityl-10-methylacridinium perchlorate and 2-phenylmalononitrile as a redox-cycling source of a hydrogen atom, we report the anti-Markovnikov hydroetherification of alkenes with complete regioselectivity. In addition, we present results demonstrating that this novel catalytic system can be applied to the anti-Markovnikov hydrolactonization of alkenoic acids. PMID:23113557

Determination of rhenium in molybdenite by X-ray fluorescence. A combined chemical-spectrometric technique

USGS Publications Warehouse

Solt, M.W.; Wahlberg, J.S.; Myers, A.T.

1969-01-01

Rhenium in molybdenite is separated from molybdenum by distillation of rhenium heptoxide from a perchloric-sulphuric acid mixture. It is concentrated by precipitation of the sulphide and then determined by X-ray fluorescence. From 3 to 1000 ??g of rhenium can be measured with a precision generally within 2%. The procedure tolerates larger amounts of molybdenum than the usual colorimetric methods. ?? 1969.

Probability of detecting perchlorate under natural conditions in deep groundwater in California and the Southwestern United States

USGS Publications Warehouse

Fram, Miranda S.; Belitz, Kenneth

2011-01-01

We use data from 1626 groundwater samples collected in California, primarily from public drinking water supply wells, to investigate the distribution of perchlorate in deep groundwater under natural conditions. The wells were sampled for the California Groundwater Ambient Monitoring and Assessment Priority Basin Project. We develop a logistic regression model for predicting probabilities of detecting perchlorate at concentrations greater than multiple threshold concentrations as a function of climate (represented by an aridity index) and potential anthropogenic contributions of perchlorate (quantified as an anthropogenic score, AS). AS is a composite categorical variable including terms for nitrate, pesticides, and volatile organic compounds. Incorporating water-quality parameters in AS permits identification of perturbation of natural occurrence patterns by flushing of natural perchlorate salts from unsaturated zones by irrigation recharge as well as addition of perchlorate from industrial and agricultural sources. The data and model results indicate low concentrations (0.1-0.5 μg/L) of perchlorate occur under natural conditions in groundwater across a wide range of climates, beyond the arid to semiarid climates in which they mostly have been previously reported. The probability of detecting perchlorate at concentrations greater than 0.1 μg/L under natural conditions ranges from 50-70% in semiarid to arid regions of California and the Southwestern United States to 5-15% in the wettest regions sampled (the Northern California coast). The probability of concentrations above 1 μg/L under natural conditions is low (generally <3%).

Perchlorate-Coupled Carbon Monoxide (CO) Oxidation: Evidence for a Plausible Microbe-Mediated Reaction in Martian Brines.

PubMed

Myers, Marisa R; King, Gary M

2017-01-01

The presence of hydrated salts on Mars indicates that some regions of its surface might be habitable if suitable metabolizable substrates are available. However, several lines of evidence have shown that Mars' regolith contains only trace levels of the organic matter needed to support heterotrophic microbes. Due to the scarcity of organic carbon, carbon monoxide (CO) at a concentration of about 700 parts per million (about 0.4 Pa) might be the single most abundant readily available substrate that could support near-surface bacterial activity. Although a variety of electron acceptors can be coupled to CO oxidation, perchlorate is likely the most abundant potential oxidant in Mars' brines. Whether perchlorate, a potent chaotrope, can support microbial CO oxidation has not been previously documented. We report here the first evidence for perchlorate-coupled CO oxidation based on assays with two distinct euryarchaeal extreme halophiles. CO oxidation occurred readily in 3.8 M NaCl brines with perchlorate concentrations from 0.01 to 1 M. Both isolates were able to couple CO with perchlorate or chlorate under anaerobic conditions with or without nitrate as an inducer for nitrate reductase, which serves as a perchlorate reductase in extreme halophiles. In the presence of perchlorate, CO concentrations were reduced to levels well below those found in Mars' atmosphere. This indicates that CO could contribute to the survival of microbial populations in hydrated salt formations or brines if water activities are suitably permissive.

Bacterial growth tolerance to concentrations of chlorate and perchlorate salts relevant to Mars

NASA Astrophysics Data System (ADS)

Al Soudi, Amer F.; Farhat, Omar; Chen, Fei; Clark, Benton C.; Schneegurt, Mark A.

2017-07-01

The Phoenix lander at Mars polar cap found appreciable levels of (per)chlorate salts, a mixture of perchlorate and chlorate salts of Ca, Fe, Mg and Na at levels of ~0.6% in regolith. These salts are highly hygroscopic and can form saturated brines through deliquescence, likely producing aqueous solutions with very low freezing points on Mars. To support planetary protection efforts, we have measured bacterial growth tolerance to (per)chlorate salts. Existing bacterial isolates from the Great Salt Plains of Oklahoma (NaCl-rich) and Hot Lake in Washington (MgSO4-rich) were tested in high concentrations of Mg, K and Na salts of chlorate and perchlorate. Strong growth was observed with nearly all of these salinotolerant isolates at 1% (~0.1 M) (per)chlorate salts, similar to concentrations observed in bulk soils on Mars. Growth in perchlorate salts was observed at concentrations of at least 10% (~1.0 M). Greater tolerance was observed for chlorate salts, where growth was observed to 2.75 M (>25%). Tolerance to K salts was greatest, followed by Mg salts and then Na salts. Tolerances varied among isolates, even among those within the same phylogenetic clade. Tolerant bacteria included genera that also are found in spacecraft assembly facilities. Substantial microbial tolerance to (per)chlorate salts is a concern for planetary protection since tolerant microbes contaminating spacecraft would have a greater chance for survival and proliferation, despite the harsh chemical conditions found near the surface of Mars.

Optimization of a Three-Component Green Corrosion Inhibitor Mixture for Using in Cooling Water by Experimental Design

NASA Astrophysics Data System (ADS)

Asghari, E.; Ashassi-Sorkhabi, H.; Ahangari, M.; Bagheri, R.

2016-04-01

Factors such as inhibitor concentration, solution hydrodynamics, and temperature influence the performance of corrosion inhibitor mixtures. The simultaneous studying of the impact of different factors is a time- and cost-consuming process. The use of experimental design methods can be useful in minimizing the number of experiments and finding local optimized conditions for factors under the investigation. In the present work, the inhibition performance of a three-component inhibitor mixture against corrosion of St37 steel rotating disk electrode, RDE, was studied. The mixture was composed of citric acid, lanthanum(III) nitrate, and tetrabutylammonium perchlorate. In order to decrease the number of experiments, the L16 Taguchi orthogonal array was used. The "control factors" were the concentration of each component and the rotation rate of RDE and the "response factor" was the inhibition efficiency. The scanning electron microscopy and energy dispersive x-ray spectroscopy techniques verified the formation of islands of adsorbed citrate complexes with lanthanum ions and insoluble lanthanum(III) hydroxide. From the Taguchi analysis results the mixture of 0.50 mM lanthanum(III) nitrate, 0.50 mM citric acid, and 2.0 mM tetrabutylammonium perchlorate under the electrode rotation rate of 1000 rpm was found as optimum conditions.

COMMENT ON "PERCHLORATE IDENTIFICATION IN FERTILIZERS" AND THE SUBSEQUENT ADDITION/CORRECTION [LETTER TO EDITOR

EPA Science Inventory

Perchlorate contamination has been reported in several fertilizer materials and not just in mined Chile saltpeter, where it is a welo-known natural impurity. To survey fertilizers for perchlorate, two analytical techniques have been applied to 45 products that span agricultural, ...

Developmental exposure to perchlorate alters synaptic transmission in hippocampus of the adult rat: in vivo studies.

EPA Science Inventory

Perchlorate, a contaminant found in food and water supplies throughout the USA, blocks iodine uptake into the thyroid gland to reduce circulating levels of thyroid hormone. Neurological function accompanying developmental exposure to perchlorate was evaluated in the present study...

PERCHLORATE UPTAKE BY SALT CEDAR (TAMARIX RAMOSISSIMA) IN THE LAS VEGAS WASH RIPARIAN ECOSYSTEM

EPA Science Inventory

Perchlorate ion (CIO4-) has been identified in samples of dormant salt cedar (Tamarix ramosissima) growing in the Las vegas Wash. Perchlorate is an oxidenat, but its reduction is kineticaly hindered. CXoncern over thyrpoid effects caused the Environmental Protection Agency (EPA...

Thyroid antagonists and thyroid indicators in U.S. pregnant women in the Vanguard Study of the National Children's Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mortensen, Mary E., E-mail: MMortensen@cdc.gov; Birch, Rebecca; Wong, Lee-Yang

The sodium iodide-symporter (NIS) mediates uptake of iodide into thyroid follicular cells. This key step in thyroid hormone synthesis is inhibited by perchlorate, thiocyanate (SCN) and nitrate (NO{sub 3}) anions. When these exposures occur during pregnancy the resulting decreases in thyroid hormones may adversely affect neurodevelopment of the human fetus. Our objectives were to describe and examine the relationship of these anions to the serum thyroid indicators, thyroid stimulating hormone (TSH) and free thyroxine (FT4), in third trimester women from the initial Vanguard Study of the National Children's Study (NCS); and to compare urine perchlorate results with those in pregnantmore » women from the National Health and Nutritional Examination Survey (NHANES). Urinary perchlorate, SCN, NO{sub 3}, and iodine, serum TSH, FT4, and cotinine were measured and a food frequency questionnaire (FFQ) was administered to pregnant women enrolled in the initial Vanguard Study. We used multiple regression models of FT4 and TSH that included perchlorate equivalent concentration (PEC, which estimates combined inhibitory effects of the anions perchlorate, SCN, and NO{sub 3} on the NIS). We used multiple regression to model predictors of each urinary anion, using FFQ results, drinking water source, season of year, smoking status, and demographic characteristics. Descriptive statistics were calculated for pregnant women in NHANES 2001–2012. The geometric mean (GM) for urinary perchlorate was 4.04 µg/L, for TSH 1.46 mIU/L, and the arithmetic mean for FT4 1.11 ng/dL in 359 NCS women. In 330 women with completed FFQs, consumption of leafy greens, winter season, and Hispanic ethnicity were significant predictors of higher urinary perchlorate, which differed significantly by study site and primary drinking water source, and bottled water was associated with higher urinary perchlorate compared to filtered tap water. Leafy greens consumption was associated with higher urinary NO{sub 3} and higher urinary SCN. There was no association between urinary perchlorate or PEC and TSH or FT4, even for women with urinary iodine <100 µg/L. GM urinary perchlorate concentrations in the full sample (n=494) of third trimester NCS women (4.03 µg/L) were similar to pregnant women in NHANES (3.58 µg/L). - Highlights: • Limited biomonitoring data are available in pregnant women. • We found no effect of perchlorate and related anions on thyroid indicators in third trimester women. • Leafy green vegetables were a dietary source for perchlorate, nitrate, and thiocyanate.« less

76 FR 8674 - Notice of a Public Meeting: Environmental Justice Considerations for Drinking Water Regulatory...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-15

... perchlorate and carcinogenic volatile organic compounds (VOCs). While the Agency is in the very preliminary stages of developing the regulatory efforts for perchlorate and carcinogenic VOCs, EPA plans to discuss..., Regulatory Determinations 3, perchlorate, and carcinogenic VOCs rulemaking efforts. Date and Location: The...

PERFORMANCE OF POLYVINYL ALCOHOL GEL COLUMNS ON THE ION CHROMATOGRAPHIC DETERMINATION OF PERCHLORATE IN FERTILIZERS

EPA Science Inventory

Interest in possible sources of perchlorate (ClO4-) that could lead to environmental release has been heightened since the EPA placed this anion on its Contaminant Candidate List (CCL) for drinking water. Besides its association with defense and aerospace activities, perchlorate ...

METHOD DEVELOPMENT FOR THE LOW-LEVEL DETERMINATION OF PERCHLORATE IN DRINKING WATER

EPA Science Inventory

Perchlorate anion has been found in numerous drinking water supplies at concentrations that recent studies indicate may adversely affect human health. In order to measure perchlorate at levels of health concern in drinking water, there is a need to be able to quantify perchlorat...

NOVEL ASSOCIATIONS BETWEEN URINARY PERCHLORATE AND POTENTIALLY RELEVANT EFFECTS ON RISK FACTORS FOR HEART DISEASE BASED ON NHANES 2001-2002

EPA Science Inventory

Perchlorate is a widespread environmental pollutant, and is a thyroid hormone disruptor. A previous population study based on the National Health and Nutrition Examination Survey (NHANES) 2001-2002 database showed that urinary perchlorate concentrations were associated with signi...

REPORT ON THE PEER REVIEW OF THE U.S. EPA'S "Perchlorate ENVIRONMENTAL CONTAMINATION: TOXICOLOGICAL REVIEW AND RISK CHARACTERIZATION (External Review Draft)" 2002

EPA Science Inventory

This report summarizes the comments made at a two-day independent scientific peer review meeting on the Agency's draft assessment of health and ecotoxicological effects of perchlorate, entitled Perchlorate Environmental Contamination: Toxicological Review and Risk Characteriza...