Agilent, 851725-911, AdvanceBio Peptide Mapping 120Å, 2.1 x 5 mm, 2.7 µm, guard, 3/pk

Agilent AdvanceBio Peptide Mapping guard columns protect a compatible reversed-phase peptide-mapping analytical column by intercepting strongly retained contaminants before they reach the primary separation bed. Each guard is 2.1 mm in internal diameter and 5 mm in length, with 2.7 µm superficially porous C18 particles and a 120 Å pore size. Matching stationary-phase chemistry reduces the risk of introducing a different retention mechanism upstream of the analytical column. These short cartridges are useful when digest samples contain salts, preparation residues or matrix components that could shorten main-column life. Install the guard in the appropriate holder and flow direction, then check system pressure and chromatographic performance after replacement. Change the guard if increased pressure or degraded peak shape persists after other causes are excluded. The supplied three-pack is intended for routine preventive replacement; it is not a substitute for the full-length analytical separation column.