Re: A test that can give the concentration of aspartame after hydrolysis?

     The best method for determining the concentration of methanol (MeOH) 
would be via Gas Chromatography/Flame Ionization Detector (GC/FID) 
Headspace Analysis.  The reason that I would consider this the optimal 
analytical technique, in this instance, is that the temperature of the 
liquid below the headspace would not need to be elevated above 55C to 
drive the MeOH into the headspace.  The low temperature is critical 
because I have read that free MeOH will form in aspartame containing 
liquids at 62C.  Please see http://dorway.com/goldnote.html.  I realize 
that this website contains anti-aspartame propaganda, however I do not 
have the time to seperate scientific fact from fiction.  The aspartame 
issue has created a stir in the non-scientific community, much the same 
way that alar did with apples (for an excellent book explaining this type 
of hysteria, read "Science Under Seige" by Michael Fumento.)  Limiting the 
temperature to 55C would eliminate this issue.  Heating the liquid to 55C 
will seperate the volatile MeOH fraction from the non-volatile products 
without any side reactions.  I would avoid direct injections due to 
possible breakdown and activity in a hot injection port.
     I don't know what type of analytical instrumentation your school 
owns, but headspace analysis can be performed with a heating block and 
test tubes with septa for sampling the headspace into a gastight syringe.  
The headspace can then be injected into a GC/FID for analysis.  The GC/FID 
is pretty standard for any analytical laboratory.  I hope that this 
information helps you to complete your experiment.  You can contact me at 
dsherman@chr-hansen-us.com if you need any additional information.