Development of a method for simultaneous analysis of caffeine and taurine in energy drinks by micellar electrokinetic chromatography with diode-array detector

Abstract

The objective of this study was to develop, optimize and validate a fast and reliable method for the simultaneous determination of caffeine and taurine contents by micellar electrokinetic chromatography with diode array detector, using direct and indirect detection concomitantly. Multivariate statistical techniques were used as a central composite design and the simultaneous optimization method of responses of Derringer and Suich were used for optimization. The method was applied in the analysis of 73 samples of energy drinks commercialized in Brazil. The optimized method employed a capillary tube with an extended bulb of 50 µm i.d. x 72 cm total length, an electrolyte containing 16.20 mmol.L-1 of benzoic acid and 39.90 mmol.L-1 of SDS, a pH value of 7.26, + 30 kV voltage, direct detection of caffeine at 274 nm and indirect detection of taurine at 230 nm. Validation parameters have demonstrated the reliability and applicability of this method. Ot was found that more than 50% of the samples were out of the legal limits determined by the Brazilian government regarding the taurine content and 68 % contained caffeine below the value declared on the label. Therefore, the need for greater control concerning the composition of these drinks exists.

Utilization of 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) as a fluorogenic reagent for the development of a spectrofluorometric assay method for taurine in energy drinks

“…8 Notably, the LOQ values of previous high performance liquid chromatography (HPLC) methods with UV, 13 fluorescence 13 and MS detection were lower than that of the current method. For a previous capillary electrophoresis/UV method, 3 a higher level and a wider linear range was obtained from the previous method compared to that was obtained from the current method. Nevertheless, the previous CE/UV method 3 reported a higher LOQ value than that of the current method.…”

“…For a previous capillary electrophoresis/UV method, 3 a higher level and a wider linear range was obtained from the previous method compared to that was obtained from the current method. Nevertheless, the previous CE/UV method 3 reported a higher LOQ value than that of the current method.…”

“…It plays a significant role in fat absorption in the human body and heart protection; besides it is considered an antioxidant. 3 On the other hand, overdoses of taurine result in adverse effects. In extreme cases, death was documented by overdoses of taurine–caffeine combinations.…”

Capillary electromigration methods for food analysis and Foodomics: Advances and applications in the period February 2019–February 2021

“…Caffeine is one of the most common ingredients in energy drinks due to its stimulation effect, whereas taurine is very often added at lower amounts in energy drinks with caffeine, although the ergogenic potential of this combination is not well described. The content of both additives in energetic drinks can be analyzed simultaneously by MEKC with DAD [111]. Benzoic acid was the run electrolyte chosen because it presents a chromophore in its structure, which has a maximum absorptivity of 230 nm, allowing indirect determination of taurine content, but that does not absorb at the 274 nm region, which is the wavelength of caffeine absorption.…”

Capillary electrophoresis method for simultaneous analysis of caffeine, vanillin and ethyl vanillin in beverages

“…A number of analytical procedures have been utilized for the determination of caffeine in beverages, these techniques involve, spectroscopic methods [18][19][20], HPLC [4,6,[21][22][23]] CE [23][24][25], MEKC [26][27][28], laser diode thermal desorption mass spectrometry (LDTD-MS/MS) [29], ion mobility [30], and mass spectrometric detection techniques [31,32]. Electrochemical sensor for the simultaneous estimation of caffeine and vanillin in food and beverages were reported [33][34][35].…”