HPLC guard column (analytical), NUCLEODEX ALPHA-PM, length:

Cyclodextrin-modified silica phases for HPLC enantiomer separation Features Base material NUCLEOSIL® silica Particle size 5 μm Pore size 100 Å Modified cyclodextrins as chiral selectors NUCLEODEX β-OH : β-cyclodextrin (R = H; n = 2) · USP L45 Separation based on hydrogen bonds and dipole interactions between functional groups of the analyte and hydroxyl groups of the cyclodextrin Examples for successful enantiomer separations: chlorthalidone and other compounds, which require free hydroxyl groups for enantioselective interactions Eluent in column CH3OH – 0.1 % TEAA pH 4 (55:45) NUCLEODEX α-PM : permethylated α-cyclodextrin (R = CH3; n = 1) For all permethylated phases the ability to form hydrogen bonds is reduced, the hydrophobicity of the phase is increased compared to β-OH, resulting in shorter retention times. Examples for successful enantiomer separations: mecoprop and dichlorprop as free carboxylic acids, trans-stilbene oxide and styrene oxide Eluent in column CH3OH – 50 mM phosphate pH 3 (70:30) NUCLEODEX β-PM : permethylated β-cyclodextrin (R = CH3; n = 2) · USP L45 Examples for successful enantiomer separations: mephobarbital (prominal), pesticides derivatives mecoprop-methyl et fenoxaprop-ethyl Eluent in column CH3OH – 0.1 % TEAA pH 4 (65:35) NUCLEODEX γ-PM : permethylated γ-cyclodextrin (R = CH3; n = 3)