Quick and simultaneous determination of caffeine and taurine in beverages using UPLC-ESI-MS

Abstract

A rapid UPLC-ESI-MS method was developed for simultaneous determination of caffeine and taurine in beverages (energy drinks and soft drinks). The molecular ions of caffeine and taurine were identified in single ion recording mode at m/z 194.98 and 125.86, respectively. The mass spectrometer parameters were optimized as: capillary voltage 3.0 kV, cone voltage 35 V, extractor 3 V, RF Lens 0.1 V, source temperature 150 °C, desolvation temperature 350 °C, nitrogen 600 L/h, LMR1 7.9, HMR1 15.2, IE1 0.30. The mobile phase comprising methanol (0.1% formic acid) (A) and water (5 mM ammonium acetate) (B) was used in gradient mode. The mobile phase components A and B were pumped in 80:20 (v:v) ratio from 0-0.44 min, and then 100% of component A was pumped between 0.45-0.68 min, and at 0.69 min the composition was returned to 80:20 (v:v) ratio of A and B till 2.0 min. Caffeine and taurine were eluted at 0.46 and 0.43 min, respectively. The samples of energy drinks and soft drinks were diluted in a solvent system comprising methanol and water in 80:20 (v:v) ratio. Our investigations showed that soft drinks SD1 and SD2 have 88.8±4.2% and 110.7±3.6% (w:w) caffeine of their labeled claim. The caffeine content in energy drink brands ED1, ED2, ED3, and ED4 was 76.9±2.5, 65.6±3.4, 88.1±12.6, and 89.1±2.8% (w:w) of labeled claims, respectively. While taurine content in ED1, ED2, ED3, and ED4 was 86.5±8.4, 81.3±27.5, 101.9±4.8, and 97.1±0.3% (w:w) of labeled claim, respectively.

Development of thin-layer chromatographic method for determination of caffeine in black, green, and white tea

“…In the period of 1 hour and 30 minutes is expected the main content of the tea samples to pass from the samples through the Green tea from the grocery store for health nutrition (1) and green market (2), white tea from local market (3), black tea from the green market (4) from 2010 and (5) from 2020. 2 Mean value (n=3) ± Standard deviation (SD); Relative standard deviation (RSD). laboratory beakers where hot water is present.…”

“…Caffeine is also present in a large number of products which are used as the counter pain relievers, headache remedies, and antihistamines. In recent years, caffeine has received increasing attention in the food and pharmaceutical industries, due to its pharmacological properties which comprise stimulation of the central nervous system [2] and muscle relaxant properties, for heart, renal, gastrointestinal and respiratory systems [3][4][5][6].…”

“…Green tea from the grocery store for health nutrition (1) and green market (2), white tea from local market (3), black tea from the green market (4) from 2010 and (5) from 2020 2. Mean value (n=3) ± Standard deviation (SD); Relative standard deviation (RSD).…”