CHEM 524 -- Course Outline (Sect. 1)
I. Introduction -- Optical Spectroscopy in Analytical Chemistry
A. Analytical uses of Spectroscopy
1. Qualitative -- "what is it?"
Property detection
Spectral transitions -- difference in E-levels
Types of transitions -- spectral region studied (Text: Table 1-1)
2. Quantitative -- generally detect concentration -- "how much is it?"
Optical Spectra sensitive and widely useful --flexible and general
Standardize by comparison (linear range)
Simple/inexpensive
B. Spectroscopy -- (Read Chap 1 & 2)
1. Response of system to light as function of frequency -- process is important
2. Needs: Source - Control/sampling - Detection - Analysis/standards/linearity/interference
3. Analyses:
Dispersion of response -- Qualitative
Amount of response -- Quantitative
4. Basic Quantities
Wavelength/frequency -- (Text: Table 1-1)
Intensity: from source and onto detector -- (Text: Table 2-1. 2-2)
Energy: Q,
Flux: F=dQ/dt;
Intensity: I=dF/dW
Source radiance: B(l)=d2F/dWdAscosq
Irradiance on Detector: E=dF/dAdet
5. Methods -- all analyte population dependent
Absorbance/transmittance (figure I-1): T=F/F o A=-log10(T)
Beer Lambert Law: A=ebc
Concentration dependence linear regime
Emission (figure I-2): — emitting states in equilibrium (thermal), nj~nt
Luminescence — specific state excited (cool), nj~nt if low absorption
Scattering -- elastic (ws= wo) and inelastic (ws wo),
