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Old 16-04-2007, 04:08 PM posted to
Lewis Perin Lewis Perin is offline
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Join Date: Jan 2006
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Default Tea and caffeine

(Scott Dorsey) writes:

Actually, I mentioned this to a co-worker who pointed me at:

which is an article about a home caffeine test that the Wash U
medical school folks are developing.

The standard old-fashioned test is to mix with an oxidizing agent,
then ammonia is added until a color change is seen. In the case
of tea, you have to clear the tannins out by adding a little bit of
portland cement first... the cement adsorbs the tannins and gives
you a cup of clear liquid.

Ugh! I don't mind a touch of ammonia in my cup any more than the next
guy, but portland cement ... !

Lew Perin /