A liquid chromatography method for identifying an analyte of interest utilizing as retention index standards a homologous series of neutrally charged compounds having at least one functional group bearing a positive charge and at least one functional group bearing a negative charge. The method is especially useful for liquid chromatography-mass spectrometry (LC-MS) methods, more especially for LC-MS methods employing electrospray (ESI) or atmospheric pressure chemical ionization (APCI) ionization systems.