Normal Phase HPLC Columns
Normal phase HPLC columns were used in the earliest form of HPLC, and typically use a stationary phase that is more polar than the mobile phase. Modern columns offer excellent efficiency and reliability with a range of stationary phases suitable for the analysis of lipophilic compounds. Normal phase columns are also a powerful tool for resolving challenging isomer separations.
Typical stationary phases used in normal phase HPLC include unbonded silica, diol, cyano, and amino columns. Bare silica columns are suitable for the analysis of non-polar and moderately polar organic compounds and are often used for isomer separations. Diol columns are a versatile alternative to silica and can provide improved reproducibility. Cyano columns have alternative selectivity and offer faster equilibration times making them especially suitable for gradient separations. Amino columns can be used under aqueous normal phase conditions for the retention and separation of carbohydrates.
