A method has been developed for the simultaneous determination of taurine and caffeine using a laboratory-made instrument enabling separation analysis in a short 10.5 cm capillary. The substances are detected using a contactless conductometry/ultraviolet (UV) photometry detector that enables recording both signals at one place in the capillary. The separation of caffeine and taurine was performed using the MEKC technique in a BGE with the composition 40 mM CHES, 15 mM NaOH, and 50 mM SDS, pH 9.36. Under these conditions, the migration time of caffeine is 43 s and of taurine 60 s; LOD for caffeine is 4 mg/L using photometric detection and LOD for taurine is 24 mg/L using contactless conductometric detection. The standard addition method was used for determination in Red Bull energy drink of caffeine 317 mg/L and taurine 3860 mg/L; the contents in Kamikaze drink were 468 mg/L caffeine and 4110 mg/L taurine. The determined values are in good agreement with the declared contents of these substances. RSD does not exceed 3%.
- Klíčová slova
- Caffeine, Dual detection, Energy drinks, Micellar electrokinetic chromatography, Short capillary separation, Taurine,
- MeSH
- chromatografie micelární elektrokinetická kapilární ekonomika přístrojové vybavení MeSH
- design vybavení MeSH
- elektrická vodivost MeSH
- energetické nápoje analýza MeSH
- fotometrie ekonomika přístrojové vybavení MeSH
- kofein analýza MeSH
- konduktometrie ekonomika přístrojové vybavení MeSH
- limita detekce MeSH
- taurin analýza MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- Názvy látek
- kofein MeSH
- taurin MeSH
The methodology for separations of saccharides in standard electrophoretic systems has been transferred to the short-capillary electrophoresis format. The laboratory-designed apparatus used employs a quartz capillary with an internal diameter of 10 μm, a total length of 10 cm, and an effective length of 4 cm, in combination with contactless conductivity detection. It has been applied to separations of neutral mono- and disaccharides. The saccharides are separated in the anionic form, in solutions of alkali hydroxides, namely, KOH, NaOH, and LiOH. The separation of a model mixture of five saccharides (sucrose, lactose, glucose, fructose, and ribose) takes less than 1 min, the LOD equaling 15, 35, 19, 17, and 24 mg L(-1) and the LOQ equaling 52, 117, 63, 53, and 79 mg L(-1) for sucrose, lactose, glucose, fructose, and ribose, respectively. The technique developed has been used to determine sucrose, glucose and fructose in high-energy drinks. The separation is finished within less than 50 s; the saccharide contents determined are identical with the declared values within the reliability interval in most cases, the RSD value being mostly less than 2%. In general, the separation system developed is very convenient for rapid analyses of large sets of similar samples, e.g., in product quality control or environmental monitoring.
- MeSH
- časové faktory MeSH
- design vybavení MeSH
- elektrická vodivost MeSH
- elektroforéza kapilární ekonomika přístrojové vybavení MeSH
- energetické nápoje analýza MeSH
- limita detekce MeSH
- monosacharidy analýza izolace a purifikace MeSH
- sacharosa analýza izolace a purifikace MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- Názvy látek
- monosacharidy MeSH
- sacharosa MeSH
