Prudel M, Davídková E
Nahrung. 1985;29(4):381-9. doi: 10.1002/food.19850290420.
A HPLC method for the determination of Usal (Aspartame hydrochloride, L-aspartyl-L-phenylalanine methyl ester hydrochloride) and its decomposition products was elaborated. Aspartic acid, phenylalanine, phenylalanine methyl ester, aspartyl-phenylalanine, phenylalanyl-aspartic acid, 5-benzyl-3,6-dioxo-2-piperazineacetic acid (DOP) and Usal were separated on Separon SI C-18. The mobile phase was: 0.5 M NaH2PO4 (pH 2.1) and methanol (85:15 v/v). The detection was carried out at 200 nm. The method for DOP determination was tested by the analysis of 10 types of soft drinks to which DOP was added. In two newly developed sorts of soft drinks sweetened with Usal the formation of DOP was followed during storage. The DOP increment after 34 days of storage reached 0.7 and 6 mg/l at 7 and 20 degrees C, resp. The method is also suitable for DOP determination in the sweetener itself.
建立了一种用于测定优赛（盐酸天冬甜素，L-天冬氨酰-L-苯丙氨酸甲酯盐酸盐）及其分解产物的高效液相色谱法。天冬氨酸、苯丙氨酸、苯丙氨酸甲酯、天冬氨酰苯丙氨酸、苯丙氨酰天冬氨酸、5-苄基-3,6-二氧代-2-哌嗪乙酸（DOP）和优赛在Separon SI C-18柱上分离。流动相为：0.5M磷酸二氢钠（pH 2.1）和甲醇（85:15 v/v）。检测波长为200nm。通过对添加了DOP的10种软饮料进行分析，对DOP的测定方法进行了测试。在两种新开发的用优赛增甜的软饮料中，在储存过程中跟踪DOP的形成情况。在7℃和20℃下储存34天后，DOP的增量分别达到0.7mg/L和6mg/L。该方法也适用于测定甜味剂本身中的DOP。
