TY - JOUR

T1 - High-resolution two-dimensional quantitative analysis of phosphorus, vanadium and arsenic, and qualitative analysis of sulphide, in a freshwater sediment.

AU - Stockdale, Anthony

AU - Davison, William

AU - Zhang, Hao

N1 - The final, definitive version of this article has been published in the Journal, Environmental Chemsitry, 5 (2), 2008, © CSIRO 2008

PY - 2008/4/17

Y1 - 2008/4/17

N2 - Recently introduced techniques that can provide two-dimensional images of solution concentrations in sediments for multiple analytes have revealed discrete sites of geochemical behaviour different from the average for that depth (microniches). We have developed a new preparation method for a binding phase, incorporated in a hydrogel, for the diffusive gradients in thin-films (DGT) technique. It allows co-analysis of sulphide and the reactive forms of phosphorus, vanadium and arsenic in the porewaters at the surface of the device. This gel, when dried and analysed using laser ablation mass spectrometry, allows the acquisition of high-resolution, sub-millimetre-scale, data. The binding phase was deployed within a DGT device in a sediment core collected from a productive lake, Esthwaite Water (UK). Localized removal from the porewaters of the sediment for phosphate and vanadium has been demonstrated at a microniche of local sulphide production. The possible removal processes, including bacterial uptake and reduction of vanadate to insoluble VIII by sulphide, are discussed. Understanding processes occurring at this scale may allow improved prediction of pollutant fate and better prediction of past climates where trace metals are used as paleoredox proxies.

AB - Recently introduced techniques that can provide two-dimensional images of solution concentrations in sediments for multiple analytes have revealed discrete sites of geochemical behaviour different from the average for that depth (microniches). We have developed a new preparation method for a binding phase, incorporated in a hydrogel, for the diffusive gradients in thin-films (DGT) technique. It allows co-analysis of sulphide and the reactive forms of phosphorus, vanadium and arsenic in the porewaters at the surface of the device. This gel, when dried and analysed using laser ablation mass spectrometry, allows the acquisition of high-resolution, sub-millimetre-scale, data. The binding phase was deployed within a DGT device in a sediment core collected from a productive lake, Esthwaite Water (UK). Localized removal from the porewaters of the sediment for phosphate and vanadium has been demonstrated at a microniche of local sulphide production. The possible removal processes, including bacterial uptake and reduction of vanadate to insoluble VIII by sulphide, are discussed. Understanding processes occurring at this scale may allow improved prediction of pollutant fate and better prediction of past climates where trace metals are used as paleoredox proxies.

KW - DGT

KW - early diagenesis

KW - laser ablation

KW - microniche

KW - phosphate.

UR - http://www.scopus.com/inward/record.url?scp=42949113970&partnerID=8YFLogxK

U2 - 10.1071/EN07096

DO - 10.1071/EN07096

M3 - Journal article

VL - 5

SP - 143

EP - 149

JO - Environmental Chemistry

JF - Environmental Chemistry

SN - 1448-2517

IS - 2

ER -