A Fast and Effective Method for Packing Nano-LC Columns with Solid-Core Nano Particles Based on the Synergic Effect of Temperature, Slurry Composition, Sonication and Pressure

Nano-LC columns of different lengths (14–35 cm), 75 μm i.d., were packed with solid-core C18 particles using a conventional HPLC system at low pressure (375 bar) and without expensive tools and fittings. Solid-core particles consist of a solid, non-porous core surrounded with a shell of a porous layer with a very narrow particle size distribution. This geometry allows a faster diffusion of the analytes compared to porous particles, reducing the C term of the Knox plot. Different slurries of packing material were evaluated and tested. The packing procedure was carried out at room temperature and at 70 °C to evaluate the influence of this parameter on the overall process. The synergic action of pressure, temperature and sonication contributed to columns of various lengths in the packing process. The columns were tested at room temperature taking into account the following parameters: Knox plots, specific permeability and peak capacity. Reduced heights of theoretical plates, h, ranged between 3.8 and 5.1 at ν between 2 and 6. An LC-MS test was carried out with a Direct-EI LC-MS instrument.     

Decay and other estimates for a semi-infinite magnetoelastic cylinder: Saint-Venant''s principle

An analogue of the well known Toupin's version of Saint-Venant's principle is proved for a semi-infinite magnetoelastic cylinder under very mild assumptions on the asymptotic behaviour of the Dirichlet integral of the magnetic field and of the elastic energy. With regard to the elastic fields, we assign on the base either the stress or the displacement vector while we assume that the lateral surface is either traction free or held fixed at zero displacement. We make use of the first Korn inequality and estimate the total energy of the conductor in terms of the data for all the problems considered.     

Iodine(III)-promoted ring contraction of 1,2-dihydronaphthalenes: a diastereoselective total synthesis of (+/-)-indatraline

[reaction: see text] A new approach for the synthesis of (+/-)-indatraline, which is a 3-phenyl-1-indanamine that displays several biological activities, is described. The strategy features as the key step a diastereoselective ring contraction of a 1,2-dihydronaphthalene promoted by PhI(OTs)OH, to construct the indan ring system. The oxidative rearrangement of other 1,2-dihydronaphthalenes was also investigated, generalizing this method to obtain indans.