title: Influence of dissolved organic matter on dissolved vanadium speciation in the Churchill River estuary (Manitoba, Canada).
abstract: Diffusive gradients in thin films (DGT) devices were used to investigate the temporal and spatial changes in vanadium (V) speciation in the Churchill estuary system (Manitoba). Thirty-six DGT sets and 95 discrete water samples were collected at 8 river and 3 estuary sites during spring freshet and summer base flow. Dissolved V concentration in the Churchill River at summer base flow was approximately 5 times higher than those during the spring high flow (27.3 ± 18.9 nM vs 4.8 ± 3.5 nM). DGT-labile V showed an opposite trend with greater values found during the spring high flow (2.6 ± 1.8 nM vs 1.4 ± 0.3 nM). Parallel factor analysis (PARAFAC) conducted on 95 excitation-emission matrix spectra validated four humic-like (C1C4) and one protein-like (C5) fluorescent components. Significant positive relationship was found between protein-like DOM and DGT-labile V (r = 0.53, p < 0.05), indicating that protein-like DOM possibly affected the DGT-labile V concentration in Churchill River. Sediment leachates were enriched in DGT-labile V and protein-like DOM, which can be readily released when river sediment began to thaw during spring freshet.
authors.affiliation: Environment and Life Sciences Graduate Program, Trent University, Peterborough, ON, Canada.
authors.forename: Yong Xiang
authors.initials: YX
authors.lastname: Shi
authors.affiliation: Environment and Life Sciences Graduate Program, Trent University, Peterborough, ON, Canada.
authors.forename: Vaughn
authors.initials: V
authors.lastname: Mangal
authors.affiliation: Department of Chemistry, Trent University, Peterborough, ON, Canada. Electronic address: celinegueguen@trentu.ca.
authors.forename: Céline
authors.initials: C
authors.lastname: Guéguen
mesh_terms: D002170:Canada; D063366:Estuaries; D005163:Factor Analysis, Statistical; D019015:Geologic Sediments / Q000032:analysis*; D008350:Manitoba; D025341:Principal Component Analysis; D045483:Rivers / Q000737:chemistry*; D012621:Seasons; D014639:Vanadium / Q000032:analysis* / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D014639:Vanadium
keywords: DGT-Labile species; DOM; High resolution mass spectrometry; PARAFAC; Vanadium