@article{WehePieperHoltkampetal.2014,
  author    = {Wehe, Christoph A. and Pieper, Imke and Holtkamp, Michael and Thyssen, Georgina M. and Sperling, Michael and Schwerdtle, Tanja and Karst, Uwe},
  title     = {On-line species-unspecific isotope dilution analysis in the picomolar range reveals the time- and species-depending mercury uptake in human astrocytes},
  series = {Analytical \& bioanalytical chemistry},
  volume    = {406},
  journal   = {Analytical \& bioanalytical chemistry},
  number    = {7},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {1618-2642},
  doi       = {10.1007/s00216-013-7608-4},
  pages     = {1909 -- 1916},
  year      = {2014},
  abstract  = {In order to reveal the time-depending mercury species uptake by human astrocytes, a novel approach for total mercury analysis is presented, which uses an accelerated sample introduction system combined on-line with an inductively coupled plasma mass spectrometer equipped with a collision/reaction cell. Human astrocyte samples were incubated with inorganic mercury (HgCl2), methylmercury chloride (MeHgCl), and thimerosal. After 1-h incubation with Hg2+, cellular concentrations of 3 mu M were obtained, whereas for organic species, concentrations of 14-18 mu M could be found. After 24 h, a cellular accumulation factor of 0.3 was observed for the cells incubated with Hg2+, whereas the organic species both showed values of about 5. Due to the obtained steady-state signals, reliable results with relative standard deviations of well below 5 \% and limits of detection in the concentration range of 1 ng L-1 were obtained using external calibration and species-unspecific isotope dilution analysis approaches. The results were further validated using atomic fluorescence spectrometry.},
  language  = {en}
}
@article{NiehoffSchulzSoltwischetal.2016,
  author    = {Niehoff, Ann-Christin and Schulz, Jacqueline and Soltwisch, Jens and Meyer, Soren and Kettling, Hans and Sperling, Michael and Jeibmann, Astrid and Dreisewerd, Klaus and Francesconi, Kevin A. and Schwerdtle, Tanja and Karst, Uwe},
  title     = {Imaging by Elemental and Molecular Mass Spectrometry Reveals the Uptake of an Arsenolipid in the Brain of Drosophila melanogaster},
  series = {Analytical chemistry},
  volume    = {88},
  journal   = {Analytical chemistry},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0003-2700},
  doi       = {10.1021/acs.analchem.6b00333},
  pages     = {5258 -- 5263},
  year      = {2016},
  abstract  = {Arsenic-containing lipids (arsenolipids) are natural products of marine organisms such as fish, invertebrates, and algae, many of which are important seafoods. A major group of arsenolipids, namely, the arsenic-containing hydrocarbons (AsHC), have recently been shown to be cytotoxic to human liver and bladder cells, a result that has stimulated interest in the chemistry and toxicology of these compounds. In this study, elemental laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) and molecular matrix-assisted laser desorption/ionization (MALDI-)MS were used to image and quantify the uptake of an AsHC in the model organism Drosophila melanogaster. Using these two complementary methods, both an enrichment of arsenic and the presence of the AsHC in the brain were revealed, indicating that the intact arsenolipid had crossed the blood-brain barrier. Simultaneous acquisition of quantitative elemental concentrations and molecular distributions could allow new insight into organ-specific enrichment and possible transportation processes of arsenic-containing bioactive compounds in living organisms.},
  language  = {en}
}
@article{NiehoffBauerKroegeretal.2015,
  author    = {Niehoff, Ann-Christin and Bauer, Oliver Bolle and Kr{\"o}ger, Sabrina and Fingerhut, Stefanie and Schulz, Jacqueline and Meyer, S{\"o}ren and Sperling, Michael and Jeibmann, Astrid and Schwerdtle, Tanja and Karst, Uwe},
  title     = {Quantitative Bioimaging to Investigate the Uptake of Mercury Species in Drosophila melanogaster},
  series = {Analytical chemistry},
  volume    = {87},
  journal   = {Analytical chemistry},
  number    = {20},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0003-2700},
  doi       = {10.1021/acs.analchem.5b02500},
  pages     = {10392 -- 10396},
  year      = {2015},
  abstract  = {The uptake of mercury species in the model organism Drosophila melanogaster was investigated by elemental bioimaging using laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS). The mercury distribution in Drosophila melanogaster was analyzed for the three species mercury(II) chloride, methylmercury chloride, and thimerosal after intoxication. A respective analytical method was developed and applied to the analysis of the entire Drosophila melanogaster first, before a particular focus was directed to the cerebral areas of larvae and adult flies. For quantification of mercury, matrix-matched standards based on gelatin were prepared. Challenges of spatially dissolved mercury determination, namely, strong evaporation issues of the analytes and an inhomogeneous distribution of mercury in the standards due to interactions with cysteine containing proteins of the gelatin were successfully addressed by complexation with meso-2,3-dimercaptosuccinic acid (DMSA). No mercury was detected in the cerebral region for mercury(II) chloride, whereas both organic species showed the ability to cross the blood brain barrier. Quantitatively, the mercury level in the brain exceeded the fed concentration indicating mercury enrichment, which was approximately 3 times higher for methylmercury chloride than for thimerosal.},
  language  = {en}
}
@misc{AschnerPalinskiSperlingetal.2017,
  author    = {Aschner, Michael A. and Palinski, Catherine and Sperling, Michael and Karst, U. and Schwerdtle, Tanja and Bornhorst, Julia},
  title     = {Imaging metals in Caenorhabditis elegans},
  series = {Metallomics : integrated biometal science},
  volume    = {9},
  journal   = {Metallomics : integrated biometal science},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1756-5901},
  doi       = {10.1039/c6mt00265j},
  pages     = {357 -- 364},
  year      = {2017},
  abstract  = {Systemic trafficking and storage of essential metal ions play fundamental roles in living organisms by serving as essential cofactors in various cellular processes. Thereby metal quantification and localization are critical steps in understanding metal homeostasis, and how their dyshomeostasis might contribute to disease etiology and the ensuing pathologies. Furthermore, the amount and distribution of metals in organisms can provide insight into their underlying mechanisms of toxicity and toxicokinetics. While in vivo studies on metal imaging in mammalian experimental animals are complex, time- and resource-consuming, the nematode Caenorhabditis elegans (C. elegans) provides a suitable comparative and complementary model system. Expressing homologous genes to those inherent to mammals, including those that regulate metal homeostasis and transport, C. elegans has become a powerful tool to study metal homeostasis and toxicity. A number of recent technical advances have been made in the development and application of analytical methods to visualize metal ions in C. elegans. Here, we briefly summarize key findings and challenges of the three main techniques and their application to the nematode, namely sensing fluorophores, microbeam synchrotron radiation X-ray fluorescence as well as laser ablation ( LA) coupled to inductively coupled plasma-mass spectrometry (ICP-MS).},
  language  = {en}
}