Yes. But the procedures aren't trivial, for a high school student. For one thing, the items pose matrix problems -- it will be harder to analyze for caffeine in the sports bars, as an example. You also don't mention to what level of accuracy you need these numbers. And sugar can mean many things, chemically. You'll have to think harder, and try to find something simpler. Caffeine in a soda, now that you might be able to learn how to do.