Abstract
Background: A new rapid, simple, sensitive, accurate and precise method to determine taurine in energy drinks has been developed and validated.
Materials and Methods: The developed method is based on the reaction between the taurine and 4- chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) at alkaline medium (pH 10) to form yellow adduct, exhibiting maximum absorption (λmax) at 474 nm. Different variables affecting the reaction of taurine with NBD-Cl (e.g. pH, temperature, time, and NBD-Cl concentration) have been studied and optimized. Under the optimized reaction conditions, the method was linear in the concentration range of 10-50 µg/mL with a correlation coefficient 0.9993.
Results: The limit of detection (LOD) and limit of quantification (LOQ) were found to be 1.69 and 5.15 µg/mL, respectively. The recoveries in the range of (92.4-102.4 %) and the precision as RSD was in the range of (0.14 – 1.59%) are obtained. The method was successfully applied for determination of taurine in energy drinks. The content of taurine measured compared to the labeled amount in three commercial energy drinks containing taurine was found to be (93.9 – 101.8%). The method can be for analysis of taurine in energy drinks in quality control laboratories.
Keywords: Taurine, Energy drinks, Spectrophotometric analysis, 4-Chloro-7-nitrobenzo-2-oxa-1, 3-diazole (NBD-Cl).
Graphical Abstract
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