- 日本食品化学学会誌 (ISSN:13412094)
- vol.17, no.2, pp.130-135, 2010
A simple and rapid method has been developed for determining of L,L-aspartame (APM), its epimer (L,D-APM), diketopiperazine (DKP), L-phenylalanine (Phe) and D-Phe in various foods by high performance liquid chromatography (HPLC) and liquid chromatography/mass spectrometry (LC/MS). These compounds in foods were extracted with 0.01mol/L hydrochloric acid in ultrasonic bath, and the extract was loaded onto a strata-X-C, cation-exchange and reverse-phase cartridge. The HPLC separation was performed on a SUMICHIRAL OA-5000 (monolithic-type, 4.6mm i.d.×10cm) with ultraviolet detection, using 2mmol/L CuSO<sub>4</sub> solution-acetonitrile-isopropyl alcohol (85:10:5) as a mobile phase. The LC/MS separation was performed on a CHIROBIOTIC TAG (2.1mm i.d.×25cm, 5μm) with a mobile phase of 0.01% ammonium acetate-0.005% acetic acid-ethanol (1:1:2). The recoveries of 5 compounds from foods added at the level of 0.2g/kg in HPLC and LC/MS were 93.9-102.9% and 82.1-102.4%, respectively. In HPLC, the detection limits of APM, DKP and Phe were 0.02g/kg. In LC/MS, the detection limits of APM was 0.01g/kg, and DKP and Phe were 0.02g/kg.