TY - JOUR A1 - Knappe, Patrick A1 - Bienert, Ralf A1 - Weidner, Steffen A1 - Thünemann, Andreas T1 - Poly(acrylic acid): A combined analysis with field-flow fractionation and SAXS N2 - Polyelectrolytes such as PAA and its salts are widely used, but are notoriously difficult to characterize due to their polyelectrolyte properties and broad molecular mass distributions. In this paper, we report on a new PAA analysis by combining asymmetrical flow field-flow fractionation and an advanced SAXS technique using an acoustic levitator to minimize background scattering. The proof-of-principle is demonstrated with a mixture of three standard PAAs with different molecular masses. Detailed information on the PAA fractions is available on radii of gyration, polymer contour lengths, and coil conformation. Our method is expected to be applicable for a wide range of water-soluble synthetic and natural polymers and ideal for molecular masses of 5 × 103–2 × 105 g · mol-1. KW - Fractionation of polymers KW - Molar mass distribution KW - Polyelectrolytes KW - Small-angle X-ray scattering KW - Water-soluble polymers PY - 2010 U6 - https://doi.org/10.1002/macp.201000163 SN - 1022-1352 SN - 1521-3935 VL - 211 IS - 19 SP - 2148 EP - 2153 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-22005 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knappe, Patrick A1 - Weidner, Steffen A1 - Thünemann, Andreas T1 - A4F-SAXS Online Coupling in-situ Nanoparticles Analysis T2 - BfR-Seminar zum Thema Nanotoxikologie, Bundesinstitut für Risikobewertung CY - Berlin, Germany DA - 2010-08-04 PY - 2010 AN - OPUS4-21795 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knappe, Patrick A1 - Weidner, Steffen A1 - Thünemann, Andreas T1 - A4F-SAXS Online Coupling - In-situ Nanoparticle Analysis T2 - BfR-Seminar zum Thema Nanotoxikologie CY - Berlin, Germany DA - 2010-08-04 PY - 2010 AN - OPUS4-21937 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Knappe, Patrick A1 - Boehmert, L. A1 - Bienert, Ralf A1 - Karmutzki, S. A1 - Niemann, B. A1 - Lampen, A. A1 - Thünemann, Andreas T1 - Processing nanoparticles with A4F-SAXS for toxicological studies: Iron oxide in cell-based assays N2 - Nanoparticles are not typically ready-to-use for in vitro cell culture assays. Prior to their use in assays, powder samples containing nanoparticles must be dispersed, de-agglomerated, fractionated by size, and characterized with respect to size and size distribution. For this purpose we report exemplarily on polyphosphate-stabilized iron oxide nanoparticles in aqueous suspension. Fractionation and online particle size analysis was performed in a time-saving procedure lasting 50 min by combining asymmetrical flow field-flow fractionation (A4F) and small-angle X-ray scattering (SAXS). Narrowly distributed nanoparticle fractions with radii of gyration (Rg) from 7 to 21 nm were obtained from polydisperse samples. The A4F-SAXS combination is introduced for the preparation of well-characterized sample fractions originating from a highly polydisperse system as typically found in engineered nanoparticles. A4F-SAXS processed particles are ready-to-use for toxicological studies. The results of preliminary tests of the effects of fractionated iron oxide nanoparticles with a Rg of 15 nm on a human colon model cell line are reported. KW - Field-flow-fractionation KW - Small-angle X-ray scattering KW - Nanoparticle PY - 2011 U6 - https://doi.org/10.1016/j.chroma.2010.11.012 SN - 0021-9673 VL - 1218 IS - 27 SP - 4160 EP - 4166 PB - Elsevier CY - Amsterdam AN - OPUS4-23951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knappe, Patrick A1 - Boehmert, L. A1 - Karmutzki, S. A1 - Niemann, B. A1 - Bienert, Ralf A1 - Weidner, Steffen A1 - Thünemann, Andreas A1 - Lampen, A. T1 - Fractionation and Analysis of Iron Oxide Nanoparticles by A4F-SAXS Coupling and Testing their Cytotoxicity on Caco-2-Cells T2 - Golm International Symposium on Bioactive Surfaces CY - Potsdam, Germany DA - 2010-05-20 PY - 2010 AN - OPUS4-21279 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knappe, Patrick A1 - Boehmert, L. A1 - Karmutzki, S. A1 - Niemann, B. A1 - Lampen, A. A1 - Bienert, Ralf A1 - Weidner, Steffen A1 - Thünemann, Andreas T1 - Fraktionierung und Charakterisierung von Eisenoxid-Nanopartikeln mittels A4F-SAXS Online-Kopplung und Untersuchung der Zytotoxizität an Caco-2 Zellen T2 - 48. Wiss. Kongress der Deutschen Gesellschaft für Ernährung (DGE), Uni Potsdam CY - Potsdam, Germany DA - 2011-03-16 PY - 2011 AN - OPUS4-23597 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knappe, Patrick A1 - Bienert, Ralf A1 - Weidner, Steffen A1 - Rolf, Simone A1 - Thünemann, Andreas T1 - Nanoparticle and Polymer Analysis using Synchrotron Radiation: Coupling Small-Angle Scattering and Field-Flow Fractionation T2 - 2nd Joint BERII and BESSY II Users Meeting CY - Berlin, Germany DA - 2010-12-09 PY - 2010 AN - OPUS4-22830 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -