PartiSphere RTF (Reduced Tailing Factor) media characteristics (spherical media): Base-deactivated column employs a unique proprietary process that effectively "deactivates"� the secondary chromatographic effect due to residual silanols. Columns are extremely stable and can be used from pH 2 to pH 8 with no loss in performance. Excellent for separation of basic compounds without the need for amine modified mobile phases. PartiSphere columns require one-time purchase of 4.6 mm ID WVS end fittings, catalog number 479-27634.