Quantitative determination of caffeine, formic acid, trigonelline and 5-(hydroxymethyl)furfural in soluble coffees by 1H NMR spectrometry
Quantitative determination of caffeine, formic acid, trigonelline and 5-(hydroxymethyl)furfural in soluble coffees by 1H NMR spectrometry
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DOI：
10.1016/j.talanta.2009.12.010
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发表时间：
2010-04-15
期刊：
影响因子：
6.1
通讯作者：
Zuriarrain, Juan
中科院分区：
文献类型：
--
作者：
del Campo, Gloria;Berregi, Inaki;Zuriarrain, Juan
本文提出了一种用质子核磁共振技术（H-1 NMR）测定水溶性咖啡中咖啡因、甲酸、胡芦巴碱和5-羟甲基糠醛（5-HMF）的方法。这些化合物中的每一种在光谱的7.6-9.5 ppm间隔处记录单线态信号，并且其面积用于确定浓度。以精确已知的浓度加入3-（三甲基甲硅烷基）-2，2，3，3-四氘代丙酸作为δ = 0.00 ppm的参比物和作为内标物。该方法应用于市售可溶性咖啡，并与标准方法获得的结果进行了满意的比较。咖啡因、甲酸、胡芦巴碱和5-HMF的检测限和变异系数（N = 10）分别为1.32 mg/g和4.2%、0.45 mg/g和2.6%、0.58 mg/g和2.4%、0.30 mg/g和7.3%。所描述的方法是直接的，并且不需要预先衍生化。(C)2010 Elsevier B. V.保留所有权利。
A quantitative method for the determination of caffeine, formic acid, trigonelline and 5(hydroxymethyl)furfural (5-HMF) in soluble coffees by applying the proton nuclear magnetic resonance technique (H-1 NMR) is proposed. Each of these compounds records a singlet signal at the 7.6-9.5 ppm interval of the spectrum, and its area is used to determine the concentration. 3-(Trimethylsilyl)-2,2,3,3-tetradeuteropropionic acid is added in an exact known concentration as a reference for delta = 0.00 ppm and as an internal standard. The method is applied to commercial soluble coffees and satisfactorily compared with results obtained by standard methods. The limits of detection and the coefficients of variation (N = 10) are, respectively, 1.32 mg/g of solid product and 4.2% for caffeine, 0.45 mg/g and 2.6% for formic acid, 0.58 mg/g and 2.4% for trigonelline, and 0.30 mg/g and 7.3% for 5-HMF. The described method is direct and no previous derivatization is needed. (C) 2010 Elsevier B.V. All rights reserved.