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Bachmann S.,Institute for Radiochemistry | Bakry R.,Institute for Radiochemistry | Huck C.W.,Institute for Radiochemistry | Polato F.,Institute for Radiochemistry | And 2 more authors.

This article reports the results of a study carried out to evaluate the offline hyphenation of capillary zone electrophoresis with matrix-assisted lased desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) for the analysis of low-abundant complex samples, represented by the tryptic phosphorylated peptides of phosphoproteins, such as α-casein, β-casein, and fetuin. The proposed method employs a latex-coated capillary and consists in the online preconcentration of the tryptic peptides by a pH-mediated stacking method, their separation by capillary zone electrophoresis, and subsequent deposition of the separated analytes onto a MALDI target for their MS analysis. The online preconcentration method allows loading a large sample volume (~150nL), which is introduced into the capillary after the hydrodynamic injection of a short plug of 1.0M ammonium hydroxide solution and is sandwiched between two plugs of the acidic background electrolyte solution (BGE) filling the capillary. The sample spotting of the separated analytes onto the MALDI target is performed either during or postseparation using an automatic spotting device connected to the exit of the separation capillary. The proposed method allows the separation and identification of multiphosphorylated peptides from other peptides and enables their identification at femtomole level with improved efficiency compared with LC approaches hyphenated to MS. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Cataldo F.,Actinium Chemical Research | Cataldo F.,Institute of Chemical Methodologies | Angelini G.,Institute of Chemical Methodologies | Revay Z.,TU Munich | And 2 more authors.
Fullerenes Nanotubes and Carbon Nanostructures

Commercial detonation nanodiamond samples were exposed to neutron bombardment in the dose range between 1.1 and 3.3 × 1016 n cm-2. Differential scanning calorimetry revealed that this nanodiamond material allows up to 237 J/g of Wigner energy to build up until released as an exothermic peak above 300°C. At comparable neutron dose the Wigner energy of graphite flakes is only 9.5 J/g. The same nanodiamond processed with γ radiation to dose levels of 1MGy and 2 MGy did not show any accumulation of Wigner energy but even a reduction of the internal defects in the pristine nanodiamond. Copyright © 2014 Taylor & Francis Group, LLC. Source

Cataldo F.,Istituto di Astrofisica Spaziale e Fisica Cosmica | Cataldo F.,Lupi Chemical Research | Ursini O.,Institute of Chemical Methodologies | Angelini G.,Institute of Chemical Methodologies | Iglesias-Groth S.,Institute of Astrophysics of Canarias
Fullerenes Nanotubes and Carbon Nanostructures

The Scholl reaction was adopted to synthesize the very large polycyclic aromatic hydrocarbons (VLPAHs) hexabenzocoronene (HBC), quaterrylene and dicoronylene as well as their nonalternant isomers. These molecules can be considered subsections of a graphene sheet since the radial diameter of HBC is 13.5 and the length of both quaterrylene and dicoronylene is about 17.9 . Improved synthetic procedures of synthesis are presented, and the resulting VLPAHs were isolated and recognized from their characteristic electronic absorption spectra. The precursor PAHs used in the Scholl's synthesis where studied by differential scanning calorimetry (DSC), and the thermal behavior of the resulting VLPAHs was studied by thermogravimetric analysis and differential thermal analysis (TGA-DTA). The VLPAHs hexabenzocoronene (HBC), quaterrylene and dicoronylene show a trend to carbonization (growth of the laminar molecules into stacked and large graphene sheets) when heated slowly to high temperature in a nitrogen atmosphere. © Taylor & Francis Group, LLC. Source

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