Hamilton polystyrene-divinylbenzene (PS-DVB) columns are stable from pH 1 to 13, so they survive aggressive mobile phases and NaOH cleaning that dissolve silica. PRP-1 and PRP-3 are reversed-phase polymer columns for peptides, proteins and small molecules; PRP-X100, PRP-X200 and PRP-X300 are anion, cation and ion-exclusion columns for inorganic ions and organic acids; RCX-10 and RCX-30 serve carbohydrate analysis; HC-75 handles sugars and organic acids by ion exclusion. HxSil C8 and C18 are conventional silica columns for routine reversed phase. Match the guard cartridge and holder to the column family and dimensions.