2015 Volume 22 Issue 3 Pages 170-174
2-(5-Benzyl-3,6-dioxopiperazin-2-yl)acetic acid (DKP) is one of the degradation products of aspartame (APM). The Joint FAO/WHO Expert Committee on Food Additives (JECFA), USA, EU, and Japan has set 1.5 wt% as the maximum level of DKP in APM. In this study, we developed and validated a high-performance liquid chromatography (HPLC) method to determine the content of DKP in APM, based on the approach recommended in the Food Chemical Codex (FCC) from USA. For the separation of analyte, the column was investigated with 5 and 10 μm particle size. In the recovery test, the developed method gave satisfactory recoveries (99.1% and 99.5%) and repeatabilities (0.4%) from APM spiked with two concentrations (viz. 0.15 and 1.5 wt%). The limits of detection and quantification for DKP are estimated to be 0.0005 and 0.002 wt%, respectively. In the analyses of ten commercial APM samples, the DKP contents determined using the developed method are all in good agreement with those obtained using the conventional FCC method. This developed method is therefore applicable for the determination of DKP contents in commercial-grade APM.
