Subject: How can you measure electrolytes in sport drinks or other drinks?

How can you measure electrolytes in sport drinks or other drinks? I can't find 
any science fair projects on this topic. For my project I would like to 
measure the electrolytes in drinks to see if the expensive energy drinks such 
as,Red bull, have the same amout or more electrolytes than say pineapple juice 
or water.I want to see if the fancy expensive enrgy drinks actually give you 
that extra energy.

So far I have done this, I took a battery tester and put the two wires into a 
glass of pineapple jus. The measure was 24 on the scale. For water the measure 
was 46 on the scale. What is this measuruing? electrolytes? energy in the 
drink? and what are these measures on the scale?

If you can answer these questions or if you have any other ideas it would be 
greatly appreciated.

Thank You,
Dave

Re: How can you measure electrolytes in sport drinks or other drinks?