Kinetex Phenyl Hexyl columns 26 provide separations not achievable on C18 or C8 columns; such as increased retention for polar, aromatic compounds as well as reversals in analyte elution order. Most phenyl phases use a short propyl (3 carbon) linker, which limits phase stability. The Phenyl-Hexyl bonded phase employs a phenyl ring with a hexyl (6 carbon) linker and is densely bonded to Luna silica surface, reducing bonded phase hydrolysis and increasing chemical stability that results in highly reproducible and stable phenyl phase, dual selectivity of both phenyl phase and a short alkyl phase (C5 or C8) gives excellent retention to polar amine compounds. Along with the advantages of the chemistry, Kinetex columns are core shell technology products from Phenomenex that provides increased efficiencies over traditional, fully porous columns. The precise architecture of core-shell particles provide dramatic leaps in the performance in two ways - high particle density that creates optimal bed structure which reduces band broadening effects of Eddy Diffusion and the thin, porous layer, or “shell”, decreases the diffusion path length, thus reducing the time it takes for molecules to diffuse into and out of the particle. Because of all these advantages of kinetex phenyl-hexyl column, excellent peak shape and good resolution has been achieved for Pregabalin.
The result is a shift in the temperature of maximum density to lower temperatures. At high enough pressures the density maximum is shifted to below 0 °C (at just over MPa). Above MPa it cannot be observed above the melting point (now at K), except in supercooled water [ 1860 ], and it cannot be observed at all above about 200 MPa where it encounters the homogeneous nucleation limit. The stronger and more linear hydrogen bonding in D 2 O gives rise to a 25% smaller shift in the temperature of maximum density (from °C at MPa) with respect to increasing pressure [ 726 ].