Isocratic micellar liquid chromatography using mixed anionic and non-ionic surfactants as mobile phase additives for separation of 17 free amino acids

Abstract

In this work, an isocratic micellar chromatographic method for separation of 17 free amino acids was first established. Mixed anionic and non-ionic surfactants were used as mobile phase additives. Besides, a chromatographic environment was simulated and the possible mechanism was discussed. Pre-column derivatization with 9-fluorenylmethyl chloroformate was used before chromatographic analysis. The optimized chromatographic conditions were the mobile phase A (0.075\xa0M sodium dodecyl sulfate solutions and 0.010\xa0M polyoxyethylene lauryl ether containing 20\xa0mM ammonium acetate at pH 3.5) and B (100% acetonitrile) (85:15, v/v) running at 1.2\xa0mL/min by a Venusil XBP\xa0C18 column (5\xa0µm, 250\u2009×\u20094.6\xa0mm) at 35.0\xa0°C. Compared with the conventional reversed phase liquid chromatography, the consumption of organic solvent in the method is lower which reduces the analysis cost and being environment-friendly. In addition, complex gradient elution is not required. This provides an alternative way for the separation of amino acids.