A microchip method to reliably determine taurine levels in energy drinks has been developed by scientists in the Netherlands.

The team, led by Uwe Karst at the University of Twente, used very simple and fast sample preparation methods with a combination of microchip electrophoresis and fluorescence detection to determine taurine levels in the drinks. Because taurine itself is not fluorescent, a labelling reagent was added to the samples.

Microchip electrophoresis, a method of separating substances on a miniature chip, can achieve much shorter analysis times than more conventional electrophoretic techniques - in this case the separation times were as low as twelve seconds. However, this on-chip method suffers from bad reproducibility according to Karst. 'There are very few validated applications for the analysis of real samples,' he claimed. Karst said the work shows that, if some precautions are taken, quantitative analysis with excellent reproducibility is possible using this technique.

Eleven energy drinks were purchased and analysed by the scientists, and to validate their results the team also used performed the experiments on a commercial HPLC system.

Taurine is a semi-essential amino acid and is a common ingredient in many commercial energy and sports drinks. The popularity of these drinks means that the normal daily consumption of taurine may easily be exceeded by up to 100 times, according to Karst. With possible health implications associated with this intake, a rapid way to assess the levels of taurine in food and beverages is needed for quality assurance and product control, Karst added.

'There should be a very bright future for quantitative microchip electrophoresis,' said Karst. The major challenge now is the automation of these systems. 'Without autosamplers, no routine work in industry will be carried out on these systems,' Karst said. 'The introduction of an automated platform for routine analysis would be extremely helpful to spread these technologies.'

Caroline Moore