The structure of a C-18 phase based on titania (C-18-A), synthesized by the
method of solution polymerization, is investigated by diffuse reflectance
infrared Fourier transform (DRIFT) and solid-state nuclear magnetic resonan
ce (NMR) spectroscopy. The findings are compared with the results of a seco
nd C-18 phase based on titania (C-18-B) which was synthesized by the method
of surface hydrosilation. The dynamic behavior of both phases is examined
by H-1 NIAS NMR detection of spin-lattice relaxation times in the rotating
frame (T-1pH) and conventional spin-lattice relaxation times (T-1). Due toe
smaller ligand density, phase C-18-A appears to be a somewhat mure mobile
than phase C-18-B.
The chromatographic capability of the phase C-18-A is demonstrated by the s
eparation of samples containing benzene derivates or anilines. The elution
order is analogous to the phase C-18-B, but for both test mixtures the pola
rity of the mobile phase has to be increased. Phase C-18-A is classified as
being polymeric by the Sander and Wise test, whereas phase C-18-B shows in
termediate retention behavior.