Problems and Applications
We expect a linear response to the analyte
concentration in the sample, but:
This assumes that a constant %age of the
analyte can be detected where were looking;
That nothing int
Applications of MS
Basic structural info of pure compounds
Elemental analysis from solution, even more
so from solids
Fancy techniques protein analysis, etc
Generally rely on tandem techniques, MSn systems
that cause s
Robinson chapter 13. Briefly.
Equilibria between ions in solution and
ions of like sign on the surface of the
Stationary phase: Polymeric resins
For cations, typically sulfonic acid groups
(Practical) GC Separations
Robinson Ch. 12
Sample GC System
Officially, there are two types:
Gas-Liquid (GLC): stationary phase is a liquid
immobilized on an inert solid surface inside the
Gas-Solid (GSC): the stat
Robinson, end of chapter 4.
This really deserves a whole week, not just a day.
Yes, Raman is that cool.
1928: Indian physicist C. V. Raman noticed that
Shine a monochromatic light source on a sample: Youll see very
The Science of Chemical Measurement
We want to measure one or more chemicals
that are present in a material.
Measure or analyze: 3 common meanings
1) Detect is chemical X present?
Matches Robinson Chapter 2
Faster Access to Essential Info
In the 1930s, instrumental techniques were
sometimes studied, but most analysis was still done
by wet chemical methods.
Wet analysis methods were familiar and reliable
This is suitable for an absorption experiment.
Note that some instruments put the wavelength selector
after the sample. Whats the impact of that?
Variations on a Theme
Basic luminescence setup the detector only
measures the l
Fourier Transforms for Analytical
Robinson: 2.6 & 4.2. Skoog: 7I, 16B
Consider a wave of pure (monochromatic)
coherent light, and an identical copy of it.
The intensity at any point (in space) will be the
sum of the in
What sort of data did you collect in quant lab?
Typically it was a simple number mass or
Did you ever make an exact measurement?
CHEM 4520 - Fall 2016
Chapter 4 in Robinsons book
UV/vis: Electronic excitation
Including fluorescence, atomic techniques
Infrared: Vibrational transitions
And a little bit of r
Textbook: Mostly Robinson Ch. 2 & 5
The detection limit represents the amount of
analyte whose presence we can just barely
That is, we can be sure that its there.
This might be an exciting new d
Robinson chapter 6; Skoog chapters 8 through 10;
Harris in Ch. 20.
Sometimes all we need to know is the amount of
a specific element.
Solution: Atomic spectroscopy.
Optical: valence electron transitions
Mass spec is the collection of techniques for
analyzing a sample based on detecting ions.
We use the mass-to-charge ratio, m/z, as the
ICP is a good source for atomic ions, not
What is it?
Relaxation of an excited electronic state to a
ground electronic state
Typically also a difference in the vibrational
Total difference between E1 and E0 is less than
the transition E0 to E1.
Robinson Chapter 13
We covered the basic theory already
Solutes partition between the stationary phase and
the mobile phase; this affects the retention time.
Peak width depends on the column efficiency
(number & heig