TY - JOUR A1 - Schwarz, W. A1 - Wilsch, Gerd A1 - Katsumi, N. A1 - Ebell, Gino A1 - Völker, Tobias T1 - Ion distribution in concrete overlay, mapped by laser induced breakdown spectroscopy (LIBS), modified by an embedded zinc anode JF - MATEC web of conferences N2 - Galvanic corrosion protection by embedded zinc anodes is an accepted technique for the corrosion protection of reinforcing steel in concrete. Galvanic currents flow between the zinc anode and the steel reinforcement due to the potential difference that is in the range of a few hundred mV. The ion distribution was studied on two steel reinforced concrete specimens admixed with 3 wt.% chloride/wt. cement and galvanically protected by a surface applied EZ-anode. On both specimens, a zinc anode was embedded and glued to the concrete surface by a geo-polymer-based chloride-free binder. At one specimen, the EZ-anode was operated for 2,5 years, the EZ-anode at the other specimen was not electrically connected to the reinforcement, this specimen serves as a reference. Both specimens have been stored under identical conditions. The ion distribution between the anode (EZ-ANODE) and cathode (steel reinforcement) was studied by laser-induced breakdown spectroscopy (LIBS) after 7 months, 12 months, and 2,5 years. Results of the LIBS studies on the specimen with activated EZ-anode after 7 months, 12 months, and 2,5 years and of the reference specimen after 2,5 years are reported. Results show that diffusion of ions contributes to the changes in the ion distribution but migration, especially of chlorides towards the EZ-anode is significant despite the weak electric field – several hundred millivolts - generated by the galvanic current. Results show that chloride ions accumulate near the zinc-anode as in water-insoluble zinc-hydroxy chlorides - Simonkollite. T2 - ICCRRR 2022 CY - Capetown, South Africa KW - Corrosion KW - LIBS KW - Zinc KW - Anode PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-560576 DO - https://doi.org/10.1051/matecconf/202236404023 SN - 2261-236X VL - 364 SP - 1 EP - 7 PB - EDP Sciences CY - Les Ulis AN - OPUS4-56057 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schwarz, W. A1 - Wilsch, Gerd A1 - Katsumi, N. A1 - Ebell, Gino A1 - Völker, Tobias T1 - Ion distribution in concrete overlay, mapped by laser induced breakdown spectroscopy (LIBS), modified by an embedded zinc anode N2 - Galvanic corrosion protection by embedded zinc anodes is an accepted technique for the corrosion protection of reinforcing steel in concrete. Galvanic currents flow between the zinc anode and the steel reinforcement due to the potential difference that is in the range of a few hundred mV. The ion distribution was studied on two steel reinforced concrete specimens admixed with 3 wt.% chloride/wt. cement and galvanically protected by a surface applied EZ-anode. On both specimens, a zinc anode was embedded and glued to the concrete surface by a geo-polymer-based chloride-free binder. At one specimen, the EZ-anode was operated for 2,5 years, the EZ-anode at the other specimen was not electrically connected to the reinforcement, this specimen serves as a reference. Both specimens have been stored under identical conditions. The ion distribution between the anode (EZ-anode) and cathode (steel reinforcement) was studied by laser-induced breakdown spectroscopy (LIBS) after 7 months, 12 months, and 2,5 years. Results of the LIBS studies on the specimen with activated EZ-anode after 7 months, 12 months, and 2,5 years and of the reference specimen after 2,5 years are reported. Results show that diffusion of ions contributes to the changes in the ion distribution but migration, especially of chlorides towards the EZ-anode is significant despite the weak electric field – several hundred millivolts - generated by the galvanic current. Results show that chloride ions accumulate near the zinc-anode as in water-insoluble zinc-hydroxy chlorides - Simonkolleit. T2 - ICCRRR 2022 CY - Capetown, South Africa DA - 03.10.2022 KW - Korrosion KW - Corrosion KW - LIBS KW - Zinc PY - 2022 AN - OPUS4-55948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schwarz, W. A1 - Wilsch, Gerd A1 - Pichelhöfer, A. A1 - Ebell, Gino A1 - Völker, Tobias T1 - Galvanic chloride extraction by an embedded zinc anode: Ion distribution mapped by laser induced breakdown spectroscopy (LIBS) T2 - Concrete Solutions 2019 N2 - An important aspect with regard to the service life of zinc based galvanic anodes and the durability of the corrosion protection of steel in concrete is the “galvanic chloride extraction”. Chloride ions move in the electric field generated by the current, flowing between the galvanic anode and the cathodic steel. Migration leads to an accumulation of anions, e.g. chloride ions, at the anode and depletion of chlorides near the steel rebar surface. The ion migration was studied on steel reinforced concrete specimens admixed with 3 wt.% chloride/wt. cement and galvanically protected by a surface applied embedded zinc anode (EZA). The zinc anode was embedded and glued to the concrete surface by a geo-polymer based chloride free binder. The EZA was operated over a period of 1 year and the ion distribution between anode (EZA) and cathode (steel reinforcement) was studied by laser induced breakdown spectroscopy (LIBS) after 5 months, 7 months and 12 months. The results show that chloride ions efficiently migrate in the direction of the zinc-anode and accumulate there. Chloride distribution in the EZA correlates with the distribution of zinc ions generated by the anodic dissolution of the zinc anode in the binder matrix. The microstructure of the binder matrix and its interface to the zinc-anode are studied by REM/EDX – preliminary results will be reported. T2 - Concrete Solutions 2019 CY - Cluj Napoca, Romania DA - 30.09.2019 KW - Galvanic corrosion KW - Corrosion KW - Chloride extraction PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-488189 DO - https://doi.org/10.1051/matecconf/201928903010 VL - 289 SP - 03010, 1 EP - 5 PB - MATEC Web of Conferences AN - OPUS4-48818 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schwarz, G. A1 - Müller, Larissa A1 - Beck, S. A1 - Linscheid, M.W. T1 - DOTA based metal labels for protein quantification: a review JF - Journal of analytical atomic spectrometry N2 - Today, quantitative data play a pivotal role in the understanding of biological processes. This is particularly true for the proteome: protein quantification always follows protein identification. To obtain useful and reliable quantitative data, rather sophisticated strategies using electrospray and MALDI mass spectrometry have been developed, which allow relative and sometimes even absolute quantification. All of those strategies have merits and limitations. In order to overcome some of these limits, methods based on the reliable and sensitive detection and quantification of heavy metals present in proteins using inductively coupled plasma (ICP)-MS have been reported. With specific labels carrying heavy metals, the applicability of ICP-MS has been extended to almost every protein. One of such covalently bound metal tags, allowing the quantification of low abundant proteins, uses 1,4,7,10-tetraazacyclododecane N,N',N'',N''-tetraacetic acid (DOTA) chelate complexes carrying lanthanides as the metal core. In this review the scope and limitations of peptide and protein quantification will be addressed. The metal tags do not only provide low detection limits, but also due to the large number of different lanthanides and lanthanide isotopes, multiplexing capabilities and previously unknown accuracy based on inherently possible isotope dilution methods came into reach. The developed workflows, including electrophoretic and chromatographic separation and preconcentration techniques, will be addressed to allow a comparison with already established procedures. KW - Protein quantification KW - ICP-MS KW - DOTA KW - Labeling PY - 2014 DO - https://doi.org/10.1039/c3ja50277e SN - 0267-9477 SN - 1364-5544 VL - 29 IS - 2 SP - 221 EP - 233 PB - Royal Society of Chemistry CY - London AN - OPUS4-30730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schwarz, Gunnar A1 - Beck, S. A1 - Weller, Michael G. A1 - Linscheid, M.W. T1 - MeCAT - new iodoacetamide reagents for metal labeling of proteins and peptides JF - Analytical and bioanalytical chemistry N2 - Besides protein identification via mass spectrometric methods, protein and peptide quantification has become more and more important in order to tackle biological questions. Methods like differential gel electrophoresis or enzyme-linked immunosorbent assays have been used to assess protein concentrations, while stable isotope labeling methods are also well established in quantitative proteomics. Recently, we developed metalcoded affinity tagging (MeCAT) as an alternative for accurate and sensitive quantification of peptides and proteins. In addition to absolute quantification via inductively coupled plasma mass spectrometry, MeCAT also enables sequence analysis via electrospray ionization tandem mass spectrometry. In the current study, we developed a new labeling approach utilizing an iodoacetamide MeCAT reagent (MeCAT-IA). The MeCAT-IA approach shows distinct advantages over the previously used MeCAT with maleinimide reactivity such as higher labelling efficiency and the lack of diastereomer formation during labeling. Here, we present a careful characterization of this new method focusing on the labeling process, which yields complete tagging with an excess of reagent of 1.6 to 1, less complex chromatographic behavior, and fragmentation characteristics of the tagged peptides using the iodoacetamide MeCAT reagent. KW - Quantitative proteomics KW - Mass spectrometry KW - Metal labeling KW - Stable isotope labeling KW - Lanthanide DOTA KW - Metall-Markierung KW - Reagenzien KW - Protein-Quantifizierung KW - Lanthaniden KW - Multiplexing PY - 2011 DO - https://doi.org/10.1007/s00216-011-5189-7 SN - 1618-2642 SN - 1618-2650 VL - 401 IS - 4 SP - 1203 EP - 1209 PB - Springer CY - Berlin AN - OPUS4-23949 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schwarz, G. A1 - Beck, S. A1 - Weller, Michael G. A1 - Linscheid, M.W. T1 - Comparison of the fragmentation behavior of differentially metal-coded affinity tag (MeCAT)-labeled peptides JF - Journal of mass spectrometry PY - 2012 DO - https://doi.org/10.1002/jms.3036 SN - 1076-5174 SN - 1096-9888 VL - 47 IS - 7 SP - 885 EP - 889 PB - Wiley CY - Chichester AN - OPUS4-27436 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -