Lecture 31 11/18/05 2 seminars left

Recap Absorbance  Specific wavelengths of light electronic transition  UV/Vis: electronic transition Vibrations  IR: Vibrations Beer’s Law  For Quantitation  Monochromatic light  Additive  Dilute solutions

IC: Internal conversionISC: Intersystem crossing F: fluorescenceP: phosphorescence

Luminescence Fluorescence  Emission of photon during transition between S 1  S 0 Phosphorescence  Emission of photon during transition between T 1  S 0

Luminescence More sensitive than absorption Lower energy (higher wavelength) than the energy absorbed

I = kP 0 c

Analysis of a Mixture A =  X b[X] +  Y b[Y] +  Z b[Z] +....

Spectra overlap 1. Constant concentration of both analytes 1. Find  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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Spectra not-overlapping A’ =  ’ X b[X] +  ’ Y b[Y] at ’ A’’ =  ’’ X b[X] +  ’’ Y b[Y] at ’’

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