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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: kwroyer on October 31, 2005, 04:56:21 PM

Title: Simple test for the level of caffeine coffee
Post by: kwroyer on October 31, 2005, 04:56:21 PM

I want to be  able to determine the amount of caffeine I am getting in a cup of coffee. Simple that can be done at the time of consumption. A need would be to verify if a coffee is decafinatied.
I have searched many sites including very technical ones but they only discuss the effects of caffeine on various human and animal conditions.

Title: Re:Simple test for the level of caffeine coffee
Post by: lemonoman on November 01, 2005, 12:38:42 AM

I don't think you're going to find one.  Coffee is a HUGE matrix, with thousands of chemicals in it.  A single test that can instantaneously determine the caffeine content of a beverage doesn't exist (to my knowledge).  Chromatographic methods are currently one of the best ways to get this value.

Wanna find out how complex a coffee matrix REALLY is?  Go to Analysis of roasted coffee bean volatiles by using comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry - Journal of Chromatography A, Volume 1054, Issues 1-2, 29 October 2004, Pages 57-65 by Danielle Ryan, Robert Shellie, Peter Tranchida, Alessandro Casilli, Luigi Mondello and Philip Marriott (http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6TG8-4DBJVVJ-D-5&_cdi=5248&_user=1067412&_orig=search&_coverDate=10%2F29%2F2004&_sk=989459998&view=c&wchp=dGLbVlb-zSkzS&md5=64b36047b5d80fb3c974caa96be205e7&ie=/sdarticle.pdf)

Want a pile of articles about caffeine (including one about, "Caffeine effects on resting-state arousal"  :D) ? Try This page from Elsevier (http://www.sciencedirect.com/science?_ob=QuickSearchListURL&_method=list&_aset=V-WA-A-W-AUUU-MsSAYZA-UUA-U-AABBVACABD-AABUEECEBD-VVBAVYDCD-VECB-U&_sort=d&view=c&_st=13&_acct=C000051246&_version=1&_userid=1067412&md5=94d956974d9d7226f6f25b3d8041fa95)

Good luck!

Title: Re:Simple test for the level of caffeine coffee
Post by: constant thinker on November 01, 2005, 09:05:39 PM

I have an idea.

Just drink the coffee. If you feel perkier later then you got caffeine in it. :P

lemonoman does have a point thought. I looked up what was in coffee other than caffeine once. I got a huge list of molecules.