See Hamilton's Qualifying USP "L" Columns Below

USPPacking MaterialsStationary Phase
L1 Octadecyl silane chemically bonded to porous silica or ceramic micro-particles, 1.5 to 10 µm in diameter, or a monolithic silica rod
L7 Octylsilane chemically bonded to totally porous silica particles, 1.5 to 10 µm in diameter, or a monolithic silica rod
L17 Strong cation-exchange resin consisting of sulfonated cross-linked styrene-divinylbenzene copolymer in the hydrogen form, 7 to 11 µm in diameter
L19 Strong cation-exchange resin consisting of sulfonated cross-linked styrene-divinylbenzene copolymer in the calcium form, about 9 µm in diameter
L21 A rigid, spherical styrene-divinylbenzene copolymer, 3 to 10 µm in diameter
L22 A cation-exchange resin made of porous polystyrene gel with sulfonic acid groups, about 10 µm in size
L23 An anion-exchange resin made of porous polymethacrylate or polyacrylate gel with quaternary ammonium groups, about 10 µm in size
L34 Strong cation-exchange resin consisting of sulfonated cross-linked styrene-divinylbenzene copolymer in the lead form, about 9 µm in diameter
L47 High capacity anion-exchange microporous substrate, fully functionalized with trimethylamine groups, 8 µm in diameter