Lecture 32 11/21/05 2 seminars left
Analysis of a Mixture A = X b[X] + Y b[Y] + Z b[Z] +....
Spectra overlap 1. Constant concentration of both analytes 1. Find of each individual component at different 2.Least squares to find best values of [X] and [Y] 1. A m = X b[X] + Y b[Y] 2. A calc = X b[X] guess + Y b[Y] guess
Spectra not-overlapping A’ = ’ X b[X] + ’ Y b[Y] at ’ A’’ = ’’ X b[X] + ’’ Y b[Y] at ’’
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Example 19-1 Find [X] and [Y] in a solution whose absorbance is at 272 nm and at 327 nm in a cm cell. (M -1 cm -1 ) (nm) [X][Y]
Isosbestic point: X ⇄ Y ε X(465) = ε Y(465)