Intro to UV-Vis Molecular
Download
1 / 14

Intro to UV-Vis Molecular Absorption Spectrometry Chap 13 - PowerPoint PPT Presentation


  • 79 Views
  • Uploaded on

Intro to UV-Vis Molecular Absorption Spectrometry Chap 13. Beer's Law A = ε bc = -logT = -log(P/P o ) Absorbance is additive: A total = A 1 + A 2 ...= ε 1 bc 1 + ε 2 bc 2 ... Only if species do not react chemically!. Limitations of Beer's Law (pp 338 - 348). Real limitations:

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Intro to UV-Vis Molecular Absorption Spectrometry Chap 13' - aria


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Intro to UV-Vis Molecular

Absorption Spectrometry

Chap 13


  • Absorbance is additive:

    • Atotal = A1 + A2 ...= ε1bc1 + ε2bc2...

  • Only if species do not react chemically!


  • Limitations of Beer's Law

    (pp 338 - 348)

    • Real limitations:

      • Interactions at c > 0.01 M

      • Refractive index change at high c


    (2) Chemical effects - analyte associates, dissociates or reacts to give molecule with different ε


    (3) Instrumental effects - stray light, polychromatic radiation or noise  non-linear calibration curve (Fig 13-4)



    Fig. 7-2 (a) p 166 radiation or noise


    Typical UV-Vis Spectrophotometers radiation or noise

    Single-beam

    Fig 13-13 (a)


    Typical UV-Vis Spectrophotometers radiation or noise

    Double-beam in Space

    Fig 13-13 (b)


    Typical UV-Vis Spectrophotometers radiation or noise

    Double-beam in Time

    Fig 13-13 (c)


    Multichannel Spectrophotometer: radiation or noise

    No monochromator, but disperses transmitted light and measures "all wavelengths at once" (Fig 13-14)


    Fig. 10-8 radiation or noise

    Used in ICP


    ad