PDF(Pubmed)
Abstract：
Aspartame (APM), a dipeptide of aspartic acid (ASP) and phenylalanine (PHE), is a widely used artificial sweetener in beverages. It is unclear whether residual chlorine in tap water can react with APM to form disinfection byproducts (DBPs). Therefore, we investigated the formation of DBPs from the reaction of APM with residual chlorine in authentic tap water. APM and a commercial sweetener (CS) packet containing APM were studied under authentic and simulated tap water conditions. Eight chlorinated products of APM were detected using solid-phase extraction (SPE) and high performance liquid chromatography quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS). These new chloro-products were tentatively identified based on accurate masses, isotopic patterns of 35,37Cl, and MS/MS spectra. Furthermore, we identified APM as a precursor to 2,6-dichloro-1,4-benzoquinone (DCBQ). DCBQ significantly increased to 2.3-12 ng/L with the addition of APM or CS in tap waters collected from different locations compared to 1.4-1.8 ng/L in the same tap water samples without sweetener. DCBQ and two of the chlorinated transformation products were identified in cold prepared tea containing APM. DCBQ formation was eliminated when the residual chlorine in tap water was reduced by ascorbic acid or boiling prior to the addition of APM or CS. This study found that eight new DBPs and DCBQ were produced by the reactions of residual chlorine with APM and CS. These findings show an unintended exposure source of emerging DBPs via APM sweetened beverages.
摘要：
阿斯巴甜(APM),天冬氨酸（ASP）和苯丙氨酸（PHE）的二肽，是饮料中广泛使用的人造甜味剂。尚不清楚自来水中的残留氯是否会与APM反应形成消毒副产物（DBPs）。因此,我们研究了APM与真实自来水中残留氯的反应形成DBPs。在真实和模拟自来水条件下研究了APM和含有APM的商业甜味剂（CS）包。使用固相萃取（SPE）和高效液相色谱四极杆飞行时间质谱（HPLC-QTOF-MS）检测了8种APM的氯化产物。这些新的氯产品是根据准确的质量初步确定的，同位素模式为35,37Cl,和MS/MS光谱。此外，我们确定APM是2,6-二氯-1,4-苯醌(DCBQ)的前体。在从不同位置收集的自来水中添加APM或CS，DCBQ显着增加到2.3-12ng/L，而在不含甜味剂的相同自来水样品中添加了1.4-1.8ng/L。在含有APM的冷制茶中鉴定出DCBQ和两种氯化转化产物。当在添加APM或CS之前通过抗坏血酸或沸腾减少自来水中的残余氯时,消除了DCBQ的形成。这项研究发现，余氯与APM和CS的反应产生了八个新的DBPs和DCBQ。这些发现显示了通过APM加糖饮料出现的DBPs的意外暴露源。
