title: Novel diffusive gradients in thin films technique to assess labile sulfate in soil.
abstract: A novel diffusive gradients in thin films (DGT) technique for sampling labile soil sulfate was developed, based on a strong basic anion exchange resin (Amberlite IRA-400) for sulfate immobilization on the binding gel. For reducing the sulfate background on the resin gels, photopolymerization was applied instead of ammonium persulfate-induced polymerization. Agarose cross-linked polyacrylamide (APA) hydrogels were used as diffusive layer. The sulfate diffusion coefficient in APA gel was determined as 9.83 × 10(-6) ± 0.35 × 10(-6) cm(2) s(-1) at 25 °C. The accumulated sulfate was eluted in 1 mol L(-1) HNO3 with a recovery of 90.9 ± 1.6 %. The developed method was tested against two standard extraction methods for soil sulfate measurement. The obtained low correlation coefficients indicate that DGT and conventional soil test methods assess differential soil sulfate pools, rendering DGT a potentially important tool for measuring labile soil sulfate.
authors.affiliation: Department of Chemistry - VIRIS Laboratory, University of Natural Resources and Life Sciences Vienna, Konrad-Lorenz-Strasse 24, 3430, Tulln, Austria.|Institute of Forest Ecology, University of Natural Resources and Life Sciences Vienna, Peter-Jordan-Strasse 82, 1190, Vienna, Austria.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Hanousek
authors.affiliation: School of Agriculture, Food and Wine, University of Adelaide and the Waite Research Institute, Adelaide, South Australia, 5064, Australia.
authors.forename: Sean
authors.initials: S
authors.lastname: Mason
authors.affiliation: Division of Agronomy, University of Natural Resources and Life Sciences Vienna, Konrad-Lorenz-Strasse 24, 3430, Tulln, Austria. jakob.santner@boku.ac.at.
authors.forename: Jakob
authors.identifier: http://orcid.org/0000-0003-2540-539X
authors.initials: J
authors.lastname: Santner
authors.affiliation: School of Agriculture, Food and Wine, University of Adelaide and the Waite Research Institute, Adelaide, South Australia, 5064, Australia.
authors.forename: Md Mobaroqul Ahsan
authors.initials: MM
authors.lastname: Chowdhury
authors.affiliation: Institute of Forest Ecology, University of Natural Resources and Life Sciences Vienna, Peter-Jordan-Strasse 82, 1190, Vienna, Austria.
authors.forename: Torsten W
authors.initials: TW
authors.lastname: Berger
authors.affiliation: Department of Chemistry - VIRIS Laboratory, University of Natural Resources and Life Sciences Vienna, Konrad-Lorenz-Strasse 24, 3430, Tulln, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Prohaska
keywords: Diffusive gradients in thin films (DGT); ICP-MS; Soil; Sulfate; Sulfur