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Willey, Joan D.; Kieber, Robert J.; Williams, Kelly; Crozier, Jamie S.; Skrabal, Stephen A.; Avery, G. Brooks

doi:10.1023/a:1006421624865

Cited by 49 publications

(53 citation statements)

References 46 publications

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“…Thus, we conclude that stabilizing ligands, present in differing concentrations in each rain sample, protect Cu(I) from rapid oxidation in authentic rainwater. These results are similar to earlier kinetic studies with Fe, which demonstrated that Fe(II) is also effectively protected against oxidation in rainwater by organic complexation (24,44,49).…”

Section: Concentrations Of Cu Species In Rainwatersupporting

confidence: 91%

“…Cr(VI) concentrations were significantly higher in the summer months relative to Cr(III) concentrations, whereas in the winter the reverse was true when significantly more Cr(III) was present. Iron speciation displayed a similar seasonal pattern where rainwater concentrations of Fe(III) were higher in spring and summer relative to autumn and winter (49). Therefore, the concentrations of the more oxidized forms of Cu, Cr, and Fe are all higher during summer at this location, indicating a more oxidizing environment is present in the atmosphere during the warm season.…”

Section: Concentrations Of Cu Species In Rainwatermentioning

confidence: 71%

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Redox Speciation of Copper in Rainwater: Temporal Variability and Atmospheric Deposition

Kieber

Skrabal

Smith

et al. 2004

Environ. Sci. Technol.

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Copper speciation was determined in 68 rainwater samples collected in Wilmington, NC, from August 25, 2000, to September 24, 2002. Volume-weighted average concentrations of Cu(total), dissolved Cu(II), and dissolved Cu(I) were 5.3, 3.2, and 1.4 nM, respectively, with a significantly higher ratio of Cu(II)/Cu(I) in summer relative to winter events. The concentrations of all Cu species were higher in storms of continental origin relative to marine-dominated events, suggesting anthropogenic and/or terrestrial sources are important contributors of Cu in precipitation. Concentrations of strong Cu-complexing ligands were consistently lower than dissolved Cu concentrations, indicating a significant portion, but not all, of the dissolved Cu in rainwater is strongly complexed. A portion of these ligands, in addition to the sulfite and chloride in precipitation, may be Cu(I)-complexing ligands, which may explain the resistance of Cu(I) against oxidation in rainwater. Using our rainwater concentration data along with other published rainwater Cu concentrations and an estimate for total global annual rain, the total global flux of Cu removed from the atmosphere via wet deposition is 150 x 106 kg yr(-1). This represents complete removal of the estimated Cu input into the troposphere and indicates essentially all Cu released into the global atmosphere is removed by rain.

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Section: Concentrations Of Cu Species In Rainwatersupporting

confidence: 91%

Section: Concentrations Of Cu Species In Rainwatermentioning

confidence: 71%

Redox Speciation of Copper in Rainwater: Temporal Variability and Atmospheric Deposition

Kieber

Skrabal

Smith

et al. 2004

Environ. Sci. Technol.

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“…The average ratio of [L t ] to [DFe] of the NWS, ES, and CSS in spring were higher than that in summer ( Table 1). According to Willey's study (Willey et al, 2000) inorganic Fe species were found to dominate in rainwater at pH from 4.0 to 5.0 [free Fe(II) ion, Fe(III)-oxalate and Fe(OH) + 2 ]. There are two main mechanisms governing concentration of DFe, one is the input of industrial and rain wastewater, the other is the uptake by organisms.…”

Section: Variation Of Dfe and L T In The Two Contrasting Periodsmentioning

confidence: 99%

Distribution and Speciation of Dissolved Iron in Jiaozhou Bay (Yellow Sea, China)

Yang

Pižeta

et al. 2016

Front. Mar. Sci.

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The distribution of total dissolved iron (DFe) and its chemical speciation were studied in vertical profiles of the shallow and semi-closed Jiaozhou Bay (JZB, China) during two contrasting periods: summer (July 19 th , 2011) and spring (May 10 th , 2012). Samples collected from the surface, middle and bottom layers were analyzed by competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-aCSV). The mean DFe concentration during the summer period (median 18.8 nM; average 20.7 nM) was higher than in the spring period (median 12.4 nM; average 16.9 nM), whereas the spatio-temporal variation in spring was larger than in summer. The DFe-values showed distinct regional and seasonal differences, ranging from 5.6 to 107 nM in spring period and 13.4 to 43.4 nM in summer period. In spring, the highest DFe-values were observed in the eastern coastal region, especially near an industrial area (up to 107 nM), whereas the DFe distribution in summer was relatively even. Due to a tide influence, the vertical variations in the DFe and L t in both seasons were not significant. On average, the L t concentration (one class of ligand was estimated in all samples), was higher in spring (35.2 ± 23.4 nM) than in summer (31.1 ± 10.3 nM). A statistically significant correlation was found between L t and DFe concentrations, it was higher for the summer period than for the spring period. The conditional stability constants (logK ′ ) of organic complexes with iron were weaker in spring (11.7 ± 0.3) than in summer (12.3 ± 0.3). The concentrations of L t were higher in comparison to DFe in all samples: the average [L t ]/[DFe] ratio in the spring and summer samples was 2.4 and 1.5, respectively. Speciation calculations showed that the DFe in the JZB existed predominantly (over 99.99%) in the form of strong organic complexes in both seasons.

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“…The recognized importance of iron [1,2,3,4,5] in natural systems has resulted in the publication of many methods for its speciation in a variety of environmental systems, e.g. anoxic basins, near bottom waters, seawater, and surface waters [6] where iron is usually present at µg L -1 levels, depending on the water body and on the influence of anthropogenic activity [2,3,6].…”

Section: Introductionmentioning

confidence: 99%

“…anoxic basins, near bottom waters, seawater, and surface waters [6] where iron is usually present at µg L -1 levels, depending on the water body and on the influence of anthropogenic activity [2,3,6]. Several techniques, e.g.…”

Section: Introductionmentioning

confidence: 99%

Speciation of Fe(II) and Fe(III) by the modified ferrozine method, FIA–spectrophotometry, and flame AAS after cloud-point extraction

2002

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A method has been developed for the simultaneous determination of traces of Fe(III) and Fe(II) in water by on-line coupling of spectrophotometry with flame atomic absorption spectrometry (FAAS). The method involves cloud-point extraction (CPE) of both species with ammonium pyrrolidinecarbodithioate (APDC) under standard conditions, which facilitates the in situ complexation and extraction of both species. Differentiation of the oxidation states of iron is achieved by using mathematical equations to overcome the interference of Fe(III) in the spectrophotometric determination of Fe(II) when they are both present in the same solution. In this manner the time-consuming and labor-intensive steps of preoxidation of Fe(II) or reduction of Fe(III) are eliminated. By preconcentrating a 10-mL sample solution detection limits as low as 7 microg L(-1), were obtained after a single-step extraction procedure. The relative standard deviation (n=4, 30 microg L(-1)) was 2.6 % and 1.8 % for spectrophotometry and FAAS, respectively. Recoveries in the range of 96-105 % were obtained by analysis of spiked real samples. The method was further verified by analyzing a certified reference material (IMEP-9); for this the recovery was 98.5 %.

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Untitled

Cited by 49 publications

References 46 publications

Redox Speciation of Copper in Rainwater: Temporal Variability and Atmospheric Deposition

Redox Speciation of Copper in Rainwater: Temporal Variability and Atmospheric Deposition

Distribution and Speciation of Dissolved Iron in Jiaozhou Bay (Yellow Sea, China)

Speciation of Fe(II) and Fe(III) by the modified ferrozine method, FIA–spectrophotometry, and flame AAS after cloud-point extraction

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