Chemisches und Veterinäruntersuchungsamt-CVUA Karlsruhe, Weissenburger Strasse 3, D-76187 Karlsruhe, Germany.
J Agric Food Chem. 2012 Mar 21;60(11):2778-84. doi: 10.1021/jf204777m. Epub 2012 Mar 13.
¹H Nuclear magnetic resonance (NMR) spectroscopy (400 MHz) was used in the context of food surveillance to develop a reliable analytical tool to differentiate brands of cola beverages and to quantify selected constituents of the soft drinks. The preparation of the samples required only degassing and addition of 0.1% of TSP in D₂O for locking and referencing followed by adjustment of pH to 4.5. The NMR spectra obtained can be considered as "fingerprints" and were analyzed by principal component analysis (PCA). Clusters from colas of the same brand were observed, and significant differences between premium and discount brands were found. The quantification of caffeine, acesulfame-K, aspartame, cyclamate, benzoate, hydroxymethylfurfural (HMF), sulfite ammonia caramel (E 150D), and vanillin was simultaneously possible using external calibration curves and applying TSP as internal standard. Limits of detection for caffeine, aspartame, acesulfame-K, and benzoate were 1.7, 3.5, 0.8, and 1.0 mg/L, respectively. Hence, NMR spectroscopy combined with chemometrics is an efficient tool for simultaneous identification of soft drinks and quantification of selected constituents.
¹H 核磁共振（NMR）光谱（400 MHz）在食品监测中被用于开发一种可靠的分析工具，以区分可乐饮料的品牌，并定量分析软饮料中的选定成分。样品的制备仅需脱气，并在 D₂O 中添加 0.1%的 TSP 用于锁定和参考，然后将 pH 值调节至 4.5。获得的 NMR 光谱可以被视为“指纹”，并通过主成分分析（PCA）进行分析。观察到来自同一品牌的可乐的聚类，并且发现优质品牌和折扣品牌之间存在显著差异。使用外部校准曲线和将 TSP 用作内标，可以同时定量咖啡因、乙酰磺胺酸钾、阿斯巴甜、环己胺、苯甲酸、羟甲基糠醛（HMF）、亚硫酸氨焦糖（E 150D）和香草醛。咖啡因、阿斯巴甜、乙酰磺胺酸钾和苯甲酸的检测限分别为 1.7、3.5、0.8 和 1.0 mg/L。因此，NMR 光谱结合化学计量学是一种用于同时识别软饮料和定量选定成分的有效工具。
