Mathematical Description of Waves
With time as a variable a wave can be described by
the equation for a sine wave:
y = A sin ( t + )
Where y is the electric field, A is the amplitude of
the wave, t is time and is the phase
Fundamentals of Spectrophotometry
The measurement of the absorption and emission of light
by materials is known as spectrophotometry, often
shortened as spectrometry.
Absorption = take up, emission = give off.
Light (visible light) is
Molecular excitation is brought about by the absorption of
Fluorescence: No change in electronic spin, short-lived with
luminescence ceasing almost immediately (<10-5 s).
Optical Atomic Spectroscopy
What is it?
spetroscopic determination of WELL SEPARATED
-a sample is volatilized and
-decomposed to produce gas phase atoms and ions
The efciency of the atomization step controls the
Fourier Transform Infrared Spectrometer
Based on the Fabrey-Perot Michelson Interferometer
which replaced the older dispersive design.
Development of fast computers
Radiation from a conventional IR source is split into 2
paths by a beam splitt
Infra Red Spectroscopy
Absorption of Infrared Radiation
IR radiation is not energetic enough to cause
IR can cause vibrational and rotational transitions
resulting in closely spaced absorption bands.
Rotation is often h
UV Spectroscopy of Organic
Analytically useful UV region of the spectrum: 200-380 nm
The wavelength at which an organic compound absorbs
radiation is dependent on how tightly its electrons are held.
Quality Assurance and Calibration
How and Why
Part of Good Laboratory Practice (GLP) regulations,
proposed in 1976 as part of the CFR (Code of
GALP or Good Automated Laboratory Practice an
extension of GLP specifi
+/- t= (xbar-u)sqrt(n)/s
The value of t is calculated by the following
equation where all terms have the usual meaning:
TINV function on calculator
If a good estimate of is available then the above
equation can be used to decide if the v
How is an analytical method selected?
Define the problem by answering the following
1. What accuracy and precision are required?
2. How much sample is available?
3. What is the concentration range of the sample?
4. What components ca
An Introduction to Instrumental
What does Analytical Chemistry tell
Four questions about any sample can be
answered by the use of analytical chemistry:
What arrangement, structure or form?
Definitions to k