Connect the TSKgel NH2-100 DC column directly into a TSKgel reversed column to provide sufficient retention for the hydrophilic counter ion on the amino column and its API (active pharmaceutical ingredient) on the reversed phase column without the loss of column efficiency normally experienced when connecting two columns with capillary tubing. TSKgel VMpak-25 columns are specialty columns for the analysis of basic drugs that are often difficult to retain with good peak shape on alkyl-bonded reversed phase columns. Depending on the mobile phase composition, compounds will be retained by a combination of reverse phase and cation exchange on residual carboxylic acid groups. TSKgel OApak-A columns contain weak cation exchange groups for the analysis of organic acids by an ion-exclusion mechanism. Applications include organic acids in fruit juices, wine, beer, coffee, and salt solutions. Separate free amino acids in food products with the TSKgel Aminopak cation exchange column and detect them by post-column reaction with ninhydrin or o-phthalaldehyde. TSKgel Sugar AXI and AXG columns are packed with 8 and 10μm porous spherical polymer beads which are modified with strong anion exchange groups. Use the TSKgel Sugar AXI column for the isocratic separation of carbohydrates and the TSKgel Sugar AXG column for the separation of monosaccharides, disaccharides, and sugar alcohols by gradient elution. TSKgel SAX columns contain 5μm porous spherical PS/DVB particles which are surface modified with a strong anion exchange groups for the separation of isomerized sugars, alcohols, and low molecular weight organic acids. TSKgel SCX (Na+) columns are packed with 5μm porous spherical PS/DVB particles which are modified with strong cation exchange groups in the sodium form. The column is optimized for the separation and analysis of organic acids, saccharides and alcohols. TSKgel SCX (H+) columns are mainly applied to the analysis of isomerized sugars, alcohols and lower organic acids. The TSKgel IC-Cation SW column is a high performance ion chromatography column used without a suppression system. Typical applications include the analysis of transition metal ions and the analysis of amine compounds which have a strong hydrophobic group and long chain aliphetic amines.