Publications by authors named "Warren T Corns"

Article Synopsis
  • Exposure to mercury from fish consumption poses serious health risks, especially as aquaculture grows and the demand for sustainable aquafeeds increases.
  • Tuna byproducts are rich in protein but contain high levels of mercury, although they also have selenium, which may help counteract mercury's toxic effects.
  • The study examines how mercury and selenium interact in juvenile rainbow trout, revealing potential detoxification mechanisms and highlighting opportunities for safer, sustainable aquafeed production.
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  • This study is the first to report selenium (Se) isotopes in marine top predators, specifically focusing on giant petrels, and provides extensive characterization of Se isotopes in animals.
  • A new methodology was developed using hydride generation and mass spectrometry to analyze various internal organs of the seabirds, revealing different Se isotopic signatures among tissues.
  • The findings show that the liver has higher concentrations of heavier Se isotopes and indicate a strong correlation between the presence of selenoneine and shifts in Se isotopic composition, suggesting a promising avenue for further understanding Se dynamics in animals.
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  • This study investigates how different forms of selenium (Se) affect mercury (Hg) accumulation in rainbow trout (Oncorhynchus mykiss) during a 6-month feeding trial.
  • The research tested twelve dietary conditions, including both plant-based diets and tuna byproduct diets, finding that the tuna byproduct diet led to lower Hg levels in fish compared to the plant-based options.
  • The results suggest that using specific Se compounds from tuna-based aquafeed can significantly reduce Hg bioaccumulation, promoting the use of fisheries byproducts in sustainable fish feeds.
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Article Synopsis
  • Arsenic is a serious environmental pollutant that contaminates the food chain and poses cancer risks, mainly through contaminated water and food.
  • Various costly chemical methods exist for removing arsenic from soil and water, but phytoremediation offers a more sustainable alternative by using plants to absorb and remove arsenic from contaminated areas.
  • Ongoing research into plants and microbes that can bioaccumulate arsenic holds promise for future large-scale solutions to manage this contamination effectively.
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Arsenic is one of the regulated hazard materials in the environment and a persistent pollutant creating environmental, agricultural and health issues and posing a serious risk to humans. In the present review, sources and mobility of As in various compartments of the environment (air, water, soil and sediment) around the World are comprehensively investigated, along with measures of health hazards. Multiple atomic spectrometric approaches have been applied for total and speciation analysis of As chemical species.

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Knowledge of the uptake and fate of mercury (Hg) compounds in biota is important in understanding the global cycling of Hg and its transfer pathways through food chains. In this study, we analysed total mercury (T-Hg) and methylmercury (MeHg) concentrations in 117 livers of Scottish birds of prey that were found across Scotland and submitted for post-mortem examination through the Raptor Health Scotland project between 2009 and 2019. Statistical comparisons focussed on six species (barn owl, Tyto alba; Eurasian common buzzard, Buteo buteo; golden eagle, Aquila chrysaetos; hen harrier, Circus cyaneus; Eurasian sparrowhawk, Accipiter nisus; and tawny owl, Strix aluco) and showed that golden eagles had a statistically lower fraction of MeHg compared to other raptor species.

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Birds are principally exposed to selenium (Se) through their diet. In long-lived and top predator seabirds, such as the giant petrel, extremely high concentrations of Se are found. Selenium speciation in biota has aroused great interest in recent years; however, there is a lack of information about the chemical form of Se in (sea)birds.

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Tiemannite (HgSe) is considered the end-product of methylmercury (MeHg) demethylation in vertebrates. The biomineralization of HgSe nanoparticles (NPs) is understood to be an efficient MeHg detoxification mechanism; however, the process has not yet been fully elucidated. In order to contribute to the understanding of complex Hg metabolism and HgSe NPs formation, the Hg isotopic signatures of 40 samples of 11 giant petrels were measured.

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Correct handling and preservation of water samples is crucial to ensure their integrity for arsenic speciation measurements. ISO TS 19620:2018 is a method for the determination of arsenic(iii) and arsenic(v) species in waters by liquid chromatography (LC) coupled to inductively coupled plasma mass spectrometry (ICP-MS) or hydride generation atomic fluorescence spectrometry (HG-AFS). During the development of this method, a study was performed to establish the best practices for storage and preservation of samples to maintain the integrity of the arsenic speciation and stability.

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The accumulation and transformation of arsenic species have been studied in the context of hydroponic cultivation of strawberry plants. Cultivation experiments have been performed by adding inorganic arsenic at concentrations of 10, 100 and 1000 µg L via root irrigation. The total arsenic content was determined by Hydride Generation-Atomic Fluorescence Spectrometry (HG-AFS).

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Rice is known to accumulate methylmercury (MeHg) in the rice grains. MeHg as a neurotoxin impacts on the human central nervous systems and especially on the developing brain. In this exploratory study, 87 commercial rice products sold in Europe, including nine baby-rice products, were analyzed for total Hg and MeHg content.

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Mercury (Hg) is a global pollutant which occurs in different species, with methylmercury (MeHg) being the critical compound due to its neurotoxicity and bioaccumulation through the food chain. Methods for trace speciation of MeHg are therefore needed for a vast range of sample matrices, such as biological tissues, fluids, soils or sediments. We have previously developed an ultra-trace speciation method for methylmercury in water, based on a preconcentration HPLC cold vapour atomic fluorescence spectrometry (HPLC-CV-AFS) method.

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Two novel methods based on hydride generation atomic fluorescence spectrometry for the accurate screening of total and inorganic arsenic (As) in rice grain digests in 5 and 2 minutes, respectively, are proposed here. Total As determination was achieved using online UV photolysis aided by alkaline potassium persulphate oxidation, which converted all organic As to arsenate and thus allowed quantitative hydride generation. Determination of inorganic As in rice grains was accomplished by selective hydride generation at high acidity (4.

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In this work, a device based on diffusive gradients in thin films (DGT) was evaluated for the determination of Hg(II) in river water. The DGT device was assembled with a cellulose phosphate ion exchange membrane (P81 Whatman) as a binding phase and agarose gel 1.5% (m/v) as a diffusive layer.

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The manual and semi-automatic methods for the measurement of total gaseous mercury in ambient air have been compared in a field trial for the first time. The comparison results have shown that whilst the expected random scatter is present, there was no significant systematic bias between the two methods, whose operational differences have also been outlined and analysed in this work. Furthermore it has been observed that because variation in instrument sensitivity is largely random in nature there is little effect on the results of the comparison if the period between instrument calibrations is altered.

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The majority of measurements of mercury vapour, for example those to determine mass concentration in air, are currently ultimately traceable to the vapour pressure of mercury, usually via a bell-jar calibration apparatus. This allows a saturated concentration of mercury vapour in air to develop in a confined space in equilibrium with ambient conditions, from which a known mass of mercury can be removed for calibration purposes. Several empirical equations are available to describe the vapour pressure of mercury at a given temperature, but the agreement between them is not good, with data from different equations sometimes differing by 5% or more.

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