Celine Gueguen

Celine Gueguen
Université de Sherbrooke | UdeS · Department of Chemistry

PhD

About

122
Publications
19,335
Reads
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3,268
Citations
Citations since 2017
48 Research Items
1762 Citations
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20172018201920202021202220230100200300
20172018201920202021202220230100200300
20172018201920202021202220230100200300
Additional affiliations
June 2019 - November 2019
Université de Sherbrooke
Position
  • Professor (Full)
January 2019 - May 2019
Université de Sherbrooke
Position
  • Professor (Associate)
July 2007 - December 2018
Trent University
Position
  • Professor (Associate)

Publications

Publications (122)
Article
Full-text available
Background The Arctic Ocean receives massive freshwater input and a correspondingly large amount of humic-rich organic matter of terrestrial origin. Global warming, permafrost melt, and a changing hydrological cycle will contribute to an intensification of terrestrial organic matter release to the Arctic Ocean. Although considered recalcitrant to d...
Article
Hudson Bay and James Bay are fed by numerous rivers, which also deliver large amounts of dissolved organic matter (DOM). The objective of this study is to assess Hudson Bay wide DOM spatial distribution using ultraviolet-visible light absorption and excitation-emission matrix fluorescence spectroscopies. Overall, a five-component PARAFAC model was...
Preprint
Full-text available
Background The Arctic Ocean receives massive freshwater input and a correspondingly large amount of humic-rich organic matter of terrestrial origin. Global warming, permafrost melt, and a changing hydrological cycle will contribute to an intensification of terrestrial organic matter release to the Arctic Ocean. Although considered recalcitrant to d...
Article
Full-text available
The critical rare earth element dysprosium (Dy) is integral for sustainable technologies. What is concerning is that Dy is in imminent short supply and no current replacements yet exist, coupled with increasing environmental Dy levels influenced by anthropogenic activities. This study applies chemometric methods such as response surface methodology...
Chapter
This chapter provides a concise overview of the entire monograph by assembling summaries of 10 individual chapters starting with a global review of large-scale, persistent nutrient fronts of the World Ocean followed by regional chapters on the Arctic Ocean, North Atlantic, Baltic Sea, Kuroshio Current, and the Yellow Sea, a global review of CDOM dy...
Article
Full-text available
Industrial development and urbanization has led to the diverse presence of metals in wastewater that are often improperly treated. The microalgae Euglena gracilis can tolerate high concentrations of metal via the excretion of organic metabolites, including phenolics. This study aims to evaluate how carbon amendment stimulates phenolic compound prod...
Article
Full-text available
The molecular mass distribution (MMD) and fluorescence properties of dissolved organic matter (DOM) are important characteristics for tracing and predicting its pathways, processes, and fate in aquatic systems. For the first time, asymmetrical flow field-flow fractionation (AF4) with coupled absorbance and fluorescence detectors was used to determi...
Article
Full-text available
Mercury contamination in aquatic systems poses a serious environmental stress to phototrophic plankton. We used Euglena gracilis to gain an understanding of the physiochemical changes resulting from mercury stress across the transcriptome and metabolome. Using a combination of Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS)...
Article
The Conditional Affinity Spectrum (CAS) is essential for describing the binding site heterogeneity of natural organic matter. A numerical method called ‘Fully Optimized ContinUouS’ (FOCUS) is described and employed to determine the CAS of H and Pb binding to Suwannee River Humic Acid (SRHA). The FOCUS-CAS is compared with the analytical solution of...
Article
Full-text available
During a research expedition in Hudson Bay in June 2018, vast areas of thick (>10 m), deformed sediment-laden sea ice were encountered unexpectedly in southern Hudson Bay and presented difficult navigation conditions for the Canadian Coast Guard Ship Amundsen. An aerial survey of one of these floes revealed a maximum ridge height of 4.6 m and an av...
Article
Full-text available
Estimating sea–air CO2 fluxes in coastal seas remains a source of uncertainty in global carbon budgets because processes like primary production, upwelling, water mixing, and freshwater inputs produce high spatial and temporal variability of CO2 partial pressure (pCO2). As a result, improving our pCO2 baseline observations in these regions is impor...
Article
Full-text available
Absorbance and fluorescence properties of dissolved organic matter (DOM) were measured in the upper and lower polar mixed layer (UPML and LPML, respectively) over an 11‐year period (2007–2017) to assess for yearly changes in the quality and quantity of colored and fluorescent DOM (CDOM and FDOM, respectively) in relation with sea ice concentration...
Patent
A method of binding a target metal in solution. The method of binding a target metal comprises contacting a solution containing i) a target metal with ii) an encapsulated exudate of a culture of algal flagellate, or a fraction thereof; or an encapsulated dried Euglena biomass or a fraction thereof, to form a complex between the target metal, and th...
Article
Cadmium (Cd) is a widespread contaminant in aquatic systems and has a variety of toxicological implications on freshwater microorganisms. In this study, the green algae Scenedesmus obliquus was exposed to increasing Cd concentrations that inhibited growth by 20% (12.6 μmol L⁻¹), 30% (39.8 μmol L⁻¹) and 40% (83.2 μmol L⁻¹) and the metabolite profile...
Article
Asymmetrical flow field-flow fractionation (AF4) and high-resolution Orbitrap mass spectrometry (HRMS) were used to separate and characterize cellular fractions of the dark- and light-grown Euglena gracilis cellular material. Biological replicates analyzed by HRMS shared 21–73% of commonly detected m/z values. Greater variability in shared features...
Article
Full-text available
In this study, we estimated extracellular concentrations of algal-derived sulfur species in response to changing photoperiods. Cultures from three algal species (Chlorella vulgaris, Chlamydomonas reinhardtii, Scenedesmus obliquus) were subjected to five different light:dark cycles (12:12, 14:10, 16:8, 18:6, 20:4 h) for a period of 3 days. Sulfur co...
Article
Full-text available
Recent research has focused on the changing ability of oceans to absorb atmospheric CO2 and the consequences for ocean acidification, with Arctic shelf seas being among the most sensitive regions. Hudson Bay is a large shelf sea in northern Canada whose location at the margin of the cryosphere places it in the vanguard of global climate change. Her...
Article
Full-text available
This study aims to assess the influence of growth and culture conditions of the Euglena gracilis protist on the cellular chemical composition. Fourier transform infrared spectroscopy (FT-IR) and direct infusion Orbitrap electrospray ionization mass spectrometry (ESI-MS) were used in tandem for confirmation of functional groups, and to decipher the...
Article
Dissolved organic matter (DOM) plays a crucial role in terrestrial and aquatic carbon and biogeochemical cycles; however, molecular transformations between aquatic and terrestrial systems remain poorly understood due to the complexity and heterogeneity of DOM. In this study, we investigated the molecular diversity of aquatic DOM and adjacent soil d...
Patent
The present application discloses a method of binding a metal ion in water. The method comprises contacting the water with a fraction of dissolved organic material (DOM) to form a complex between the DOM fraction and the metal ion; and optionally separating the complex from the water. The present application also discloses a use of DOM for binding...
Article
Full-text available
Dissolved organic matter (DOM) absorption and fluorescence properties were investigated for seawater samples collected from the polar mixed layer (0–30 m) of the Canada Basin in 2010–2012. Sea ice concentration as well as fractions of meteoric and sea ice meltwater (fMW and fSIM) calculated from oxygen isotope ratio (δ¹⁸O) were applied to assess th...
Article
Full-text available
Interactions between algal derived dissolved organic matter (DOM) and mercury (Hg) are crucial for understanding the fate, transport, and bioavailability of Hg to methylating microorganisms. For the first time, high resolution mass spectrometry (Q-Exactive Orbitrap) was used to examine Hg binding ligands released by Chlorella vulgaris, Chlamydomona...
Article
The biological mobilization of mercury (Hg) into microbes capable of Hg methylation is one of the limiting steps in the formation of the neurotoxin methylmercury (MeHg). Although algal dissolved organic matter (DOM) has been associated with increased MeHg production, the relationship between bacterial Hg uptake and algal DOM remains unexplored. In...
Article
Full-text available
The Arctic Ocean currently receives a large supply of global river discharge and terrestrial dissolved organic matter. Moreover, an increase in freshwater runoff and riverine transport of organic matter to the Arctic Ocean is a predicted consequence of thawing permafrost and increased precipitation. The fate of the terrestrial humic-rich organic ma...
Preprint
Full-text available
The Arctic Ocean currently receives a large supply of global river discharge and terrestrial dissolved organic matter. Moreover, an increase in freshwater runoff and riverine transport of organic matter to the Arctic Ocean is a predicted consequence of thawing permafrost and increased precipitation. The fate of the terrestrial humic-rich organic ma...
Article
Organic sulfur and humics play a key role in the biogeochemistry of metals in natural waters but their distribution is not well understood. In this study, we measured the concentrations of thiol-like, humic substance (HS) -like and fluorescent dissolved organic matter (FDOM) during the 2015 Canadian Arctic GEOTRACES cruises in the Canada Basin and...
Article
Full-text available
This study evaluated the influence of dissolved organic matter (DOM) properties on the speciation of Pb, Zn and Cd. Six DOM samples were categorized into autochthonous and allochthonous source based on their absorbance and fluorescence properties. The concentration of free metal ions (CM2+) measured by titration using Absence of Gradient and Nernst...
Article
Rivers contribute a substantial amount of trace metals including molybdenum (Mo) into the oceans. The driving forces controlling the riverine fluxes of dissolved metals still remain not fully understood. Our study then investigated the spatial variations of dissolved metals including molybdenum in a typically human perturbed river, the Jiulong Rive...
Article
Full-text available
The spring flood season in Northern aquatic systems is characterized by rapid changes in river discharge and fluxes of organic and inorganic species, yet remains under sampled. In this study, we examine the molecular characteristics and transformations of dissolved organic matter (DOM) during the Arctic spring season at three locations in the lower...
Article
Full-text available
Vanadium has the potential to be released as a by-product of the combustion of fossil fuels such as oil and coal in the aquatic system. Presence of tailing ponds and other mining operations may pose the largest threat to downstream users and to the long-term aquatic health of the Mackenzie River Basin (MRB, Canada). The need for developing a solid...
Article
Full-text available
Biosorption and bioaccumulation involve the decrease in concentration or removal of metals from aqueous solution through the sequestering of ions by active or metabolically inert biomass. In this study, the potential use of Euglena gracilis, a free-floating, flagellated unicellular species of protist, to remove Cu and Ni ions at environmentally rel...
Article
Full-text available
Sediments from an arsenic (As) contaminated groundwater vent site were used to investigate As(III) binding, transformation and redistribution in native and iron oxide amended lake sediments using aging spiked batch reactions and a sequential extraction procedure that maintains As(V) and As(III) speciation. In the native sediments, fractionation ana...
Article
The effects of pH, metal ions (i.e. Cu²⁺, Cd²⁺, Pb²⁺ and Zn²⁺) and natural organic matter (i.e. Suwannee River natural organic matter standard [SRNOM]) on determination of thiol (i.e. reduced glutathione [GSH]) by cathodic stripping voltammetry were evaluated. pH was the most critical parameter to influence GSH voltammogram (i.e. peak shape, positi...
Code
Matlab algorithm package for applying self-organizing maps to raw 3D fluorescence EEMs and PARAFAC-modelled EEMs, CORRECTED to include SOM_fmax_data.xls file that was missing from original version.
Article
The molecular weight (MW) of dissolved organic matter (DOM) is considered as an important factor affecting the bioavailability of organic matter and associated chemical species. Colored DOM (CDOM) MW distribution was determined, for the first time, in the Beaufort Sea (Canada Basin) by asymmetrical flow field-flow fractionation (AF4) coupled with o...
Article
The Athabasca's oil sands exploitation is controversial due to its potential risks to water quality but little is known about the temporal changes in the most bioavailable fraction of metal, the free/labile species. In this study, diffusive gradient in thin films (DGT) and the Windermere Humic Aqueous Model (WHAM VII) equilibrium model were used to...
Data
Full-text available
Article
Full-text available
Parallel factor analysis (PARAFAC) has facilitated an explosion in research connecting the fluorescence properties of dissolved organic matter (DOM) to its functions and biogeochemical cycling in natural and engineered systems. However, the validation of robust PARAFAC models using split-half analysis requires an oft unrealistically large number (h...
Article
Full-text available
Orbitrap high resolution mass spectrometry (HRMS) with electrospray ionization in both positive and negative polarity was conducted on Suwannee River fulvic acid (SRFA), Pony Lake fulvic acid (PLFA) standards, and dissolved organic matter (DOM) released by freshwater phytoplankton (Scenedesmus obliquus, Euglena mutabilis, and Euglena gracilis). Thr...
Conference Paper
Full-text available
Acknowledgements A special thanks goes to Dr. Joel Heath who urged researchers to take a closer look at the winter sea dynamics in southeast Hudson Bay and around the Belcher Islands. We have greatly appreciated the opportunity to work alongside members of the Arctic Eider Society and look forward to continue working with Lucassie Arragutainaq and...
Article
Surface absorption and fluorescence measurements of Dissolved Organic Matter (DOM) were conducted along with hydrographic parameters in the Amerasian and Makarov Basins. Parallel factor analysis of DOM fluorescence identified four humic-like and one protein-like component in all 107 surface samples. Based on strong negative trends observed between...
Article
Full-text available
Surface absorption and fluorescence measurements of Dissolved Organic Matter (DOM) were conducted along with hydrographic parameters in the Amerasian and Makarov Basins. Parallel factor analysis of DOM fluorescence identified four humic-like and one protein-like component in all 107 surface samples. Based on strong negative trends observed between...
Chapter
Full-text available
Leaves are an integral component of the worldwide C cycle. Leaching is the process through which soluble substances of varying character are removed from leaves in the early period following exposure to water. The dissolved organic matter leached from leaves, or leaf leachate dissolved organic matter (LLDOM), contributes substantial nutrients and e...
Article
Fluorescent dissolved organic matter (FDOM) samples collected from water masses of Beaufort Sea (n = 12) and the North Atlantic Subtropical Gyre (NASG; n = 6) were assessed based on susceptibilities of its parallel factor analysis (PARAFAC) modeled fluorescent components to photobleaching over 72 hours of simulated solar irradiation. 315 excitation...
Article
Full-text available
In this study, molecular weights of thiols from four laboratory cultures (Scenedesmus obliquus, Chlorella vulgaris, Euglena gracilis, and Attheya septentrionalis) and the Churchill River (Manitoba) were assessed using a fluorescent-labeling method such as monobromotrimethylammoniobimane (qBBr) and asymmetrical flow field-flow fractionation (AF4) co...
Article
Full-text available
Relationships between the molecular weight (MW) and fluorescence properties of dissolved organic matter (DOM) are important considerations for studies seeking to connect these properties to water treatment processes. Relationships between the size and fluorescence properties of nine allochthonous DOM sources (i.e. leaf leachates, grass, and headwat...
Article
Full-text available
Diffusion coefficients (D) and the molecular weight distribution (MW) of 18 dissolved organic matter (DOM) samples collected in the Churchill River estuary system (Manitoba, Canada) were determined using a diffusive cell apparatus. NaN3 addition has been shown to preserve the DOM MW distribution within 5 weeks of collection whereas the diffusive pr...
Article
Full-text available
The analysis of dissolved organic matter (DOM) fluorescence has facilitated tracing throughout both natural and engineered aquatic systems, and the connection of DOM quality to its effectiveness as a binding agent, nutrient source, and generator of disinfection byproducts. While methods that deconvolute fluorescence into distinct underlying compone...
Article
Full-text available
Dissolved organic matter is a ubiquitous constituent of natural waters that plays key roles in several important processes. The fluorescence properties of DOM have been linked to its functionality, but these properties may vary with pH. In this study the Kohonen's self-organizing maps (SOM)were applied to EEMs of fresh dissolved organic matter (DOM...