Zorbax 300Extend-C18

Zorbax 300Extend-C18 Guard Columns from Agilent Technologies

Choosing to use guard columns can help reduce operating expenses, by reducing the frequency of analytical column replacement. The guard column prevents damage caused by particulate matter and strongly adsorbed material. To maintain an adequate capacity for sample impurities, choose a guard column with an internal diameter similar to the column internal diameter.

Ideally, the packing of the guard column should be the same as the analytical column so that the chromatography of the analytical column is not altered. Guard columns contribute to the separation, so you should include a guard column inline during method development. Agilent UHPLC guards provide protection for high-efficiency Poroshell 120 and ZORBAX RRHD and RRHT columns, without reducing performance.

Extend-C18 columns incorporate a unique patented bidentate silane, combined with a double-endcapping process that protects the silica from dissolution at high pH - up to pH 11.5. Columns are best applied for separations of compounds that are either (1) basic and have little or no retention at low or intermediate pHs, (2) more stable or more soluble at high pH, or (3) basic and show poor peak shape at low or intermediate pH.