Tosoh, 0021969, TSKgel NH2-100

TSKgel NH2-100 amino-bonded columns stand out by providing much improved chemical stability, a prerequisite for achieving reproducible and reliable results. These columns are packed with 3 μm silica particles containing 10 nm pores. A novel bonding strategy was adopted to improve chemical stability of the bonded phase. First, the silica is reacted with a trimethylsilane endcapping reagent at a low stoichiometric ratio before reacting residual and accessible silanol groups with trifunctional alkylaminosilane reagent. The resulting bonded phase provides a better safeguard against hydrolysis of the underlying silica. TSKgel NH2-100 columns are unique in that the bonded phase ligand not only has a terminal primary amino group as expected, but that the spacer also incorporates secondary as well as tertiary amino groups. Anionic compounds are retained on the column by ionic interaction. This allows for the use of gradients in salt concentration in addition to gradient elutions with acetonitrile. Since the TSKgel NH2-100 columns have cationic sites, the columns can be used as mixed mode columns under some conditions. TSKgel NH2-100 columns are well suited for the analysis of all types of hydrophilic compounds, including carbohydrates and peptides.