Having worked previously in a laboratory setting, and being on good terms with the lab, I would have access to an HPLC machine. The downfall to running an experiment like this would be the hours it would take, and thus the cost of running these tests, only to determine what I believe to be true: there are too many variances between teas, growing seasons, ect. for this information to be of much use. It is important to keep in mind also, that each individual will have different reactions to the combination of caffeine and L-theanine. An avid tea drinking habit has led me to the conclusion that the combination of these two chemicals has quite a different physiological effect than each on their own (ie the difference between the effect of comsuming an espresso vs. tea). The effects of the combination of these chemicals affects me differently on a day to day basis, and probably has something to do with my hydration levels, and interaction with chemicals already in my body.

I think a more useful study would be to measure the physiological effects of these two chemicals on the human body, rather than the amount that is extracted with brewing. When it comes down to it we want to know the amount of each in the brew, because we want to know what it will do to us! Or because we want to control the effects, as mentioned above, trying to eliminate caffeine, but not theanine. Why not just enjoy it as it is? If you want to drink something that won't keep you up all night, there are many herbal teas that are naturally caffeine free. Or wait until the next day, when you can drink the first infusion early in the day. I guess it is human to try to control nature, when it is really nature that controls us!

The hours and cost of a physiological effects study will be astronomical, I am sure. Too much for pursuit by any tea or beverage company, even with the tout of Lipton. By the way, commercial tea in tea bags definitely do not seem to have the same effect as fresh, loose tea, indicating to me a much lower content of active caffeine and theanine. The only feasible way to go about this, would be to get a research company interested in the topic. Any takers?

On a separate note: it is possible to give yourself an overdose of caffeine. It's not fun!!! I have done this once and caution anybody to use care when consuming anything that contains this chemical. Some people seem immune to the effects of caffeine while others, like me, are ultra-sensitive. Also, studies done recently are showing certain pharmaceuticals cause the body to decrease ability to eliminate caffeine. This causes caffeine to "build-up" in the body, and produce a very scary overdose effect. Some of these are in birth control, taken by millions of women. Please see this website, for possible drug interactions with green tea/caffeine:

Possible Interactions with: Green Tea