Previous studies by the authors have used thin-layer chromatography to demonstrate the ability of chiral low molecular weight carboxylic acids to undergo spontaneous oscillatory chiral conversion in abiotic (aqueous and nonaqueous) solutions. General mechanisms of this conversion were proposed, taking into account the enol/enolate anion intermediary species. This study provides the first experimental evidence of the spontaneous oscillatory chiral conversion of phenylglycine (Phg) with use of the chiral high-performance liquid chromatography with diode array detection. Moreover, this study provides the results of an auxiliary non-chromatographic experiment that might serve as evidence of the accumulation and relatively long lifetime of the enol/enolate anion species derived from Phg.