A5107411479- Mercury impact and mitigation studies
- Arsenic contamination and mitigation
- Heavy metals in environment
- Analytical chemistry methods development
- Heavy Metal Exposure and Toxicity
- Toxic Organic Pollutants Impact
- Selenium in Biological Systems
- Environmental Toxicology and Ecotoxicology
- Per- and polyfluoroalkyl substances research
- Atmospheric chemistry and aerosols
- Air Quality and Health Impacts
- Isotope Analysis in Ecology
- Fluoride Effects and Removal
- Marine animal studies overview
- Electrochemical Analysis and Applications
- Heavy Metals in Plants
- Radioactive element chemistry and processing
- Chemical Analysis and Environmental Impact
- Melamine detection and toxicity
- Cultural Heritage Materials Analysis
- Marine Biology and Environmental Chemistry
- Trace Elements in Health
- Field-Flow Fractionation Techniques
- Mine drainage and remediation techniques
- Metabolomics and Mass Spectrometry Studies
University of Aberdeen
2014-2025
Kettering University
2023
Winston-Salem State University
2010
Bangladesh Agricultural University
2009
Université de Pau et des Pays de l'Adour
2001-2005
Centre National de la Recherche Scientifique
2001-2004
Essen University Hospital
1999
University of Duisburg-Essen
1998
The biogeochemical cycle of arsenic (As) has been extensively studied over the past decades because As is an environmentally ubiquitous, nonthreshold carcinogen, which often elevated in drinking water and food. It known for a century that micro-organisms can volatilize inorganic salts to arsines (arsine AsH3, mono-, di-, trimethylarsines, MeAsH2, Me2AsH, TMAs, respectively), but this part cycle, with exception geothermal environs, almost entirely neglected lack suited field measurement...
Abstract To understand the biochemistry of methylmercury (MeHg) that leads to formation mercury-selenium (Hg-Se) clusters is a long outstanding challenge promises deepen our knowledge MeHg detoxification and role Se plays in this process. Here, we show mercury selenide (HgSe) nanoparticles liver brain long-finned pilot whales are attached Se-rich structures possibly act as nucleation point for large Se-Hg clusters, which can grow with age over 5 μm size. The mechanism fully developed from...
Arsenic volatilization in the environment is thought to be an important pathway for transfer from terrestrial pools atmosphere. However, this phenomenon not well characterized due inherent sampling issues trapping, quantifying and qualifying these arsine gases; including (AsH(3)), monomethyl (MeAsH(2)), dimethyl (Me(2)AsH) trimethyl (TMAs). To quantify qualify arsines air we developed a novel technique based on silver nitrate impregnated silica gel filled tubes. The method was by measuring...
Although it has been known for decades that arsenic forms fat-soluble compounds, only recent attempts to identify the compounds have successful by using a combination of fractionation and elemental molecular mass spectrometry. Here we show arsenolipids can directly be identified quantified in biological extracts reversed-phase high-performance liquid chromatography (RP-HPLC) simultaneously online-coupled high-resolution inductively coupled plasma spectrometry (ICPMS) electrospray (ES-MS)...
The molecular structure of a variety novel mercury-phytochelatin complexes was evidenced in rice plants exposed to inorganic mercury (Hg2+) using RP-HPLC with simultaneous detection via ICP-MS and ES-MS.
Because of the toxicity inorganic arsenic (iAs), only iAs needs to be monitored in food and feedstuff. This demands development easy quick analytical methods screen large number samples. work focuses on hydride generation (HG) coupled with an ICPMS as detector where HG is added a selective step determine gaseous phase while organically bound As remains solution. forms volatile arsine species high efficiency when treated NaBH4 at acidic conditions, whereas most other organoarsenic compounds...
Mercury in plants or animal tissue is supposed to occur the form of complexes formed with biologically relevant thiols (biothiols), rather than as free cation. We describe a technique for separation and molecular identification mercury methylmercury derived from their reactions cysteine (Cys) glutathione (GS): Hg(Cys)(2), Hg(GS)(2), MeHgCys, MeHgGS. Complexes were characterised by electrospray mass spectrometry (MS) equipped an ion trap fragmentation pattern MeHgCys was explained using MP2...
The identification of molecular structures an arsenolipid is pivotal for its toxicological assessment and in understanding the arsenic cycling environment. However, analysis these compounds a lipid matrix ongoing challenge. So far, only few arsenolipids have been reported, including fatty acids (AsFAs) hydrocarbons (AsHCs). By means RP-HPLC-ICPMS/ESMS, we investigated Capelin oil ( Mallotus villosus ) possible new species arsenolipids. Twelve were identified fish three AsFAs seven AsHCs....
Abstract Whales accumulate mercury (Hg), but do not seem to show immediate evidence of toxic effects. Analysis different tissues (liver, kidney, muscle) and biofluids (blood, milk) from a pod stranded long-finned pilot whales ( Globicephala melas ) showed accumulation Hg as function age, with significant decrease in the MeHg fraction. Isotopic analysis revealed remarkable differences between juvenile adult whales. During first period life, liver became isotopically lighter (δ 202 decreased)...
Per- and polyfluoroalkyl substances (PFAS) are emerging organic pollutants can occur in surface groundwater. To identify the degree of pollution water with PFAS, often targeted HPLC-ESI-MS/MS has been employed which commonly 30-40 compounds analyzed. However, other PFAS organofluorines remain undetected. We sampled river Spree Teltow Canal Berlin, Germany, affected by effluent discharge wastewater treatment plants. Here, we high-resolution continuum source graphite furnace molecular...
An isotope dilution (ID) procedure for the determination of methylmercury (MMHg) in biological samples using an inductively coupled plasma mass spectrometer as detector after capillary gas chromatographic separation (CGC/ICPMS) has been developed. For first time, open-focused-microwave pretreatment used conjunction with ID. Optimum conditions measurement ratios on fast transient peaks have established. Mass bias was found to be about 1.5%/mass unit and corrected by simultaneously measured...
Driven by increasing demand for the monitoring of industrial perfluorinated compounds (PFCs), identification novel fluorine containing (FOCs) and tracking organofluorine drugs their degradation products, there is a clear need sensitive, fluorine-specific detection unknown FOCs. Here we report first ever direct (speciation) method; capable individually detecting untargeted FOCs in environmental biological samples through application continuum source molecular absorption spectrometry (CS-MAS)...
The first study which shows that total fluorine determination and speciation analysis are possible with a conventional ICPMS/MS by creating BaF<sup>+</sup>ions in the plasma limiting polyatomic interfering barium oxide/hydroxide ions at ppb level.
Abstract Nucleocidin is one of the very few natural products known to contain fluorine. Mysteriously, nucleocidin producer Streptomyces calvus ATCC 13382 has not been observed synthesize compound since its discovery in 1956. Here, we report that complementation S. with a functional bldA ‐encoded Leu‐tRNA UUA molecule restores production nucleocidin. was detected culture extracts by 19 F NMR spectroscopy, HPLC‐ESI‐MS, and HPLC‐continuum source molecular absorption spectroscopy for...
Speciated isotope-dilution mass spectrometry (SID-MS) is claimed to be an absolute method; however, it has been found affected by artifact monomethylmercury (MMHg) formation in sediments. The determination of MMHg sediments was carried out SID-MS after open-focused microwave extraction. extracted mercury species were then ethylated and separated capillary gas chromatography (CGC). Isotope ratios (peak area at different masses) measured on-line ICP-MS detection the CGC-separated compounds....
Biovolatilisation of arsenic as their arsines in the form AsH(3), and mono-, di trimethylarsine has often been determined under laboratory conditions. Although environmental point sources such landfill sites or hot springs have characterised, only limited knowledge is available on how widespread formation volatile methylated compounds are environment. Here we studied atmospheric stability different quantified oxidation products particulate matter (PM(10)) two locations Argentina. The...