Precise selenium isotope measurement in seawater by carbon-containing hydride generation-Desolvation-MC-ICP-MS after thiol resin preconcentration

Chang, Yan; Zhang, Jing; Qu, Jian-Quo; Xue, Yifeng

doi:10.1016/j.chemgeo.2017.09.011

Cited by 23 publications

(13 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…By mass balance, residual dissolved Se (i.e., the marine dissolved Se reservoir) should be isotopically heavier. This is consistent with observations of slightly elevated Se isotope ratios in modern seawater (+0.3 ‰; Chang et al, 2017), FeMn-oxides (+0.3 ‰; Rouxel et al, 2002) and phytoplankton biomass (+0.3 ‰; Mitchell et al, 2012). Oxic sediments are thought to roughly record the isotopic composition of dissolved Se due to removal chiefly via adsorption to FeMn-oxides (which does not substantially fractionate Se isotopes; Figure 2).…”

Section: The Modern Se Cyclesupporting

confidence: 88%

Selenium Isotope Paleobiogeochemistry

Stüeken

Kipp

2020

View full text Add to dashboard Cite

The attraction of selenium isotopes as a paleoenvironmental tracer lies in the high redox potential of selenium oxyanions (Se IV and Se VI ), the two dominant species in the modern ocean. The largest isotopic fractionations occur during oxyanion reduction, which makes selenium isotopes a sensitive proxy for the redox evolution of our planet. As a case study we review existing data from the Neoarchean and Paleoproterozoic, which show that significant isotopic fractionations are absent until 2.5 Ga, and prolonged isotopic deviations only appear around 2.3 Ga. Selenium isotopes have thus begun to reveal complex spatiotemporal redox patterns not reflected in other proxies.

show abstract

Section: The Modern Se Cyclesupporting

confidence: 88%

Selenium Isotope Paleobiogeochemistry

Stüeken

Kipp

2020

View full text Add to dashboard Cite

show abstract

“…Owing to its low concentration (~1-2 nM), there are few direct measurements of Se isotope ratios in seawater. A recently developed method for determining the concentration and isotopic composition of Se in seawater yielded d 82/78 Se values (scaled from d 82/76 Se assuming massdependent fractionation) of +0.27‰ for deep waters of the NW Pacific Ocean (Chang et al, 2017). This closely agrees (within a 1s analytical precision of ±0.1-0.2‰; cf.…”

Section: The Selenium Cyclesupporting

confidence: 55%

“…We report isotopic data as d 82/78 Se values because this isotopic pair is the least affected by isobaric interferences under our analytical protocol. We note that many other studies (e.g., Chang et al, 2017;Mitchell et al, 2012Mitchell et al, , 2016 (Mitchell et al, 2012;Stüeken et al, 2013Stüeken et al, , 2015bKurzawa et al, 2017;Kipp et al, 2017;Pogge von Strandmann et al, 2014Schilling et al, 2011). Uncertainty for Se concentration measurements was ±7% (RSD).…”

Section: Selenium Measurementsmentioning

confidence: 59%

Basinal hydrographic and redox controls on selenium enrichment and isotopic composition in Paleozoic black shales

Kipp

Algeo

Stüeken

et al. 2020

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

Mass-dependent variations in selenium stable isotope ratios have recently been developed as a paleo-redox proxy. Since the reduction of selenium oxyanions occurs at a relatively high redox potential, this system holds promise for probing conditions relevant to the evolution and diversification of eukaryotic and animal life, which required substantial dissolved oxygen levels. Although several studies have identified selenium isotopic variability during oxygenation events in Earth's distant past, we still have only a broad understanding of the mechanisms controlling this isotopic variability. This currently limits the robust interpretation of selenium isotope variability to first-order mechanisms driving large-magnitude changes. Here, we explore selenium isotope variability within and among Paleozoic black shales deposited on the North American craton that have been well-studied using a variety of other paleo-environmental proxies. Using this combined dataset, we attempt to unravel the controls on selenium abundance and isotope ratios in organic-rich ancient marine sedimentary rocks. We find that in the Late Pennsylvanian units, an estuarine nutrient trap on the Midcontinent Shelf enabled vigorous selenium recycling, leading to very high concentrations in sediments and enrichment of heavy isotopes in the aqueous selenium reservoir. In contrast, we find that among the Late Devonian units, differences in local basinal hydrography led to a gradient in selenium abundance and isotopic fractionation, with the more restricted basins depleting their selenium reservoirs and causing enrichment of heavy isotopes in the residual aqueous reservoir. In both of these case studies, the additional context provided by complementary paleo-environmental proxies was critical for distinguishing between possible drivers of selenium isotopic variability. When extending such studies to other paleo-environmental settings, we suggest that the continued use of complementary datasets will enable the most robust use of the selenium paleo-redox proxy. Moreover, further development of techniques for high-precision and phase-specific selenium isotope measurements will greatly improve the ability to deduce subtle redox fluctuations with this proxy.

show abstract

“…The Se(IV), dissolved inorganic Se (DISe) and total dissolved Se (TDSe) concentrations were determined in carboncontaining plasma using a hydride generation (HG) system (Hydride FAST, ESI) combined with a sector field inductively coupled plasma-mass spectrometry (ICP-MS) instrument, as outlined in the operationally defined hydride generation-based speciation analysis methods described by Chang et al (2014Chang et al ( , 2017. Selenium was measured at mz −1 = 82 with low resolution.…”

Section: Methodsmentioning

confidence: 99%

Distribution and behaviour of dissolved selenium in tropical peatland-draining rivers and estuaries of Malaysia

Chang

Müller

et al. 2020

Biogeosciences

Self Cite

View full text Add to dashboard Cite

Selenium (Se) is an essential micronutrient for aquatic organisms. Despite its importance, our current knowledge of the biogeochemical cycling of dissolved Se in tropical estuaries is limited, especially in Southeast Asia. To gain insights into Se cycling in tropical peat-draining rivers and estuaries, samples were collected from the Rajang, Maludam, Sebuyau, Simunjan, Sematan, Samunsam and Lunda rivers and estuaries in western Sarawak, Malaysia, in March and September 2017 and analysed for various forms of Se (dissolved inorganic and organic). Mean total dissolved Se (TDSe), dissolved inorganic Se (DISe) and dissolved organic Se concentrations (DOSe) were 2.2 nmol L −1 (range: 0.7 to 5.7 nmol L −1 ), 0.18 nmol L −1 (range: less than the detection limit to 0.47 nmol L −1 ) and 2.0 nmol L −1 (range: 0.42 to 5.7 nmol L −1 ), respectively. In acidic, low-oxygen, organicrich blackwater (peatland-draining) rivers, the concentrations of DISe were extremely low (near or below the detection limit, i.e. 0.0063 nmol L −1 ), whereas those of DOSe were high. In rivers and estuaries that drained peatland, DOSe / TDSe ratios ranged from 0.67 to 0.99, showing that DOSe dominated. The positive relationship between DISe and salinity and the negative relationship between DOSe and salinity indicate marine and terrestrial origins of DISe and DOSe, respectively. The positive correlations of DOSe with the humification index and humic-like chromophoric dissolved organic matter components in freshwater river reaches suggest that peat soils are probably the main source of DOSe.The DOSe fractions may be associated with high molecular weight peatland-derived aromatic and black carbon compounds and may photodegrade to more bioavailable forms once transported to coastal waters. The TDSe flux delivered by the peat-draining rivers exceeded those reported for other small rivers and is quantitatively more significant than previously thought.

show abstract

Precise selenium isotope measurement in seawater by carbon-containing hydride generation-Desolvation-MC-ICP-MS after thiol resin preconcentration

Cited by 23 publications

References 33 publications

Selenium Isotope Paleobiogeochemistry

Selenium Isotope Paleobiogeochemistry

Basinal hydrographic and redox controls on selenium enrichment and isotopic composition in Paleozoic black shales

Distribution and behaviour of dissolved selenium in tropical peatland-draining rivers and estuaries of Malaysia

Contact Info

Product

Resources

About