The cyanopropyl-containing Rtx-225 phase is slightly less polar than bonded polyethylene glycol (PEG) phases, but it can be used for many of the same applications.
Improvements to the Rtx-225 polymer have increased thermal stability, reduced bleed, and improved inertness. The Rtx-225 column provides a 20 °C thermal stability advantage over other "225" columns because of our unique polymer synthesis technology and proprietary siloxane deactivation. In most similar columns, the Carbowax deactivation layer is not fully compatible with the cyanopropyl siloxane polymer, which can cause adsorption, tailing of active compounds, and lower efficiency.
Agilent: CP-Sil 43 CB, DB-225ms