Katharina Johanna Heilen | Authors


Direct Analysis of Amino Acids by HILIC–ESI-MS

Hydrophilic interaction liquid chromatography coupled to electrospray ionization mass spectrometry (HILIC–ESI-MS) has been established as a method to separate and quantify polar and ionic analytes in a direct way for two decades. HILIC separation is based on the polarity of analytes, so the more polar analytes have stronger retention on a HILIC column.