absorption coefficients

Justin A. Cobb jacobb at students.uiuc.edu
Fri Mar 3 17:07:25 EST 2000

Use Beer's Law to calculate an average absorption coefficient from all of
the data you collected.  This should be accurate enough.  Here is Beer's


A=Absorption (at 450 nm, in this case)
E=Absorption coefficient
c=Concentration of solute
l="length" (outer diameter of cuvette)

This is a pain in the ass compared to looking it up in a book, but it will
be good enough.

Justin Cobb
Sophomore, Biology-General
University of Illinois at Urbana-Champaign
School of Life Sciences
"Kai Schmengler" <schmeng at uni-muenster.de> wrote in message
news:38BEA22B.A78C7107 at uni-muenster.de...
> Dear all!
> I determined Km-values of an enzyme with the substrates guaiacol and
> potassium iodide. Unfortunately I chose wavelengths (near published
> ones) I didn't have the absorption coefficients (extinction
> coefficients) for. Now I'm looking for a table or papers in which those
> coefficients could be published. The wavelenghts were 405 nm for
> potassium iodide and 450 nm for guaiacol.
> Thank you very much.
>           Kai

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