Agilent HPLC Column Selection Guide

HPLC Column Selection GuidelinesColumn and Mobile Phase Guidelines:Reversed PhaseHPLC columns consist of two parts, the column chemistry and hardware. For the propercolumn chemistry, consult the catalog section for each type of bonded phase. For choosingcolumn hardware and particle sizes, consult the section on column sizes and rapidseparations, including Agilent ZORBAX Rapid Resolution and Rapid Resolution HTcolumns, as well as Solvent Saver and Capillary columns and PrepHT columns.For more information aboutcolumn selection, visitwww.zorbaxmethod.comPore Size SelectionChoose a column packing with small pore (60-120Å) if the solute molecular weight is lessthan about 5000. Otherwise, use column packing with the 300Å pore size.Particle Size SelectionThe standard particle size for HPLC columns is 5 µm with 3.5 µm now dominant for methoddevelopment. If high-speed analyses or higher resolution analyses are required, packing with1.8 µm and 3.5 µm particles can be used. Shorter columns with these particles can producefaster high-resolution separations, with the 1.8 µm particle size in Rapid Resolution HTcolumns, providing the highest efficiency. The 3.5 µm particle size operates at a routineoperating pressure and can be used on all LC's. Short (50 mm and shorter) 1.8 µm RRHTcolumns can be used on optimized standard LC's, while the longer columns may requirea higher pressure LC (one supporting pressures greater than 400 bar).Column ConfigurationThe column sizes most often recommended for analytical method development are4.6 x 150 mm or 4.6 x 75 mm. If more resolution is needed, use a longer column,4.6 x 250 mm or the same size column with a smaller particle size. During methoddevelopment, choose the column internal diameter (e.g., 2.1, 3.0 mm) to accommodateadditional application objectives (e.g., sensitivity, solvent usage) or compatibility with certaininstrument types (capillary, nano, or prep).8 Order online at www.agilent.com/chem/store