Quantitative determination of caffeine, formic acid, trigonelline and 5-(hydroxymethyl)furfural in soluble coffees by 1H NMR spectrometry

Analytical methods applied for the characterization and the determination of bioactive compounds in coffee

“…Besides chromatographic techniques, the proton nuclear magnetic resonance technique ( 1 H NMR) was applied [78][79][80]. 1 H NMR spectrum at the 7.5-10.0 ppm range for the quantitative and simultaneous determination of caffeine, formic acid, trigonelline and 5-(hydroxymethyl)-2-furaldehyde was obtained [80].…”

“…1 H NMR spectrum at the 7.5-10.0 ppm range for the quantitative and simultaneous determination of caffeine, formic acid, trigonelline and 5-(hydroxymethyl)-2-furaldehyde was obtained [80]. The time of analysis was 20 min with no need of any previous derivatization or treatment.…”

Nuclear magnetic resonance-based metabolomics of exhaled breath condensate: methodological aspects

“…the operating magnetic field, the number of acquisitions, the possible use of a cryoprobe, and the detection limit), it is difficult to conclude that NMR spectroscopy cannot be used to analyse EBC samples because it does not have the sensitivity required to observe the endogenous metabolites in the EBC [7]. With our spectrometer set-up, we have estimated a detection limit that is notably low for NMR-based metabolomics [10].…”

Correlation between caffeine contents of green coffee beans and altitudes of the coffee plants grown in southwest Ethiopia

“…Therefore, choosing the right analytical method is essential for the accurate determination of caffeine in test samples. There have been numerous reports on the determination of caffeine in coffee samples following different analytical methods: gas chromatography [15,17,18], electrochemical methods such as voltammetry [19], and spectroscopic techniques including nuclear magnetic resonance spectroscopy [20], near infrared [21], high performance liquid chromatography [5,8,22,23], UV-Vis spectroscopy [4,7,24,25] and fluorescence spectroscopy [26]. However, there are only limited reports available on the comparative study of caffeine determination by different analytical methods for a given set of samples [5,23].…”