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Spectroscopy
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Spectroscopy is the study of the interaction of electromagnetic radiation, such as ultra-violet and visible light, with matter. Ultra-violet and visible light spectroscopy is the measurement of the wavelength and intensity of transmittance or absorption of ultraviolet and visible light of a sample. Ultraviolet and visible light are energetic enough to promote outer electrons to higher energy levels. UV-vis spectroscopy is usually applied to molecules and inorganic ions or complexes in solution. The uv-vis spectra have broad features that are of limited use for sample identification but are very useful for quantitative measurements. The concentration of a sample in solution can be determined by measuring the transmittance at some wavelength and applying the Beer-Lambert Law. Transmittance is the preferred physical measurement as it is linear on the spectrophotometers meter scale and absorbance is logarithmic and harder to read accurately.
A = 2 - log(%T)
Where:
%T = the percent of transmittance of light through a sample.
A = absorbance
A = ecl
Absorbance is directly related to concentration if measurements are made at a fixed wavelength in a cell of constant path length and the sample obeys the Beer-Lambert Law.
Light spectrum of colors visible by unaided human eye.
| visible | visible | visable | visible | visible | visible | visible | |||
| Ultra Violet | Violet | Indigo | Blue | Green | Yellow | Orange | Red | Infra Red | |
| (l Range) | 190-400 | 400-460 | 460-475 | 475-490 | 490-565 | 565-575 | 575-600 | 600-800 | 900-1400 |
| (Avg. l) | 295 | 430 | 467.5 | 482.5 | 527.5 | 570 | 587.5 | 700 | 1150 |
| (Energy) | 10-3 | 4.65 | 4.25 | 4.15 | 3.8 | 3.475 | 3.375 | 2.9 | (10-19 J) |
A
database of spectral lines can be found at this URL:
NIST
Scientific and Technical Databases - Online Scientific
Mass Spectroscopy
A
History of Mass Spectroscopy
FTIR TroubleshootingThe
FTNMR Free Induction Decay Archive
Instrumentation and
Ionization Methods Tutorial
Mass Spectroscopy Tools
Nuclear Magnetic
Resonance (NMR)
Organic Structure
Elucidation – A Workbook of Unknowns
SDBS - Integrated
Spectral Data Base System for Organic Compounds
Secondary Ion Mass
Spectrometry
Secondary Ion Mass
Spectrometry (SIMS) Home Page
Spectroscopic Tools
SPECTRONIC 20 LINKS
Use
of the Spectonic 20 at a fixed wavelength
Use of the Spectronic
Detecting blood Glucose with the Spec 20
Spectronic
20 Spectrophotometer
Spectronic
20 (calibration)
Spectronic
20-D Operation
Spectronic 20
Overview of Spectronic 10 Controls
Chemlab
- Spectronic Instructions - GREAT!
Other Web Links
Spectroscopy
- Home Page
spectroscopyNOW.com
- spectroscopy and spectrometry portalwww.sciencedirect.com/science/journal/09242031
Optics
and Spectroscopy
USGS
Spectroscopy Lab - home page
Year
2: NMR Spectroscopy
WebSpectra
- Problems in NMR and IR Spectroscopy
Society
for Applied Spectroscopy Home Page
Thermal
Emission Spectrometer Project Homepage
The
Science of Spectroscopy (www.scienceofspectroscopy.info)
IR
Spectroscopy Tutorial
JPL
Molecular Spectroscopy
Spectroscopy
Europe: a wealth of information on spectroscopy
Spektroskopische
Tools/Spectroscopic Tools :: Steffen's Science
Mineral
Spectroscopy
SAS
2002 Election Results
Spectroscopy
- Wikipedia, the free encyclopedia
www3.interscience.wiley.com/cgi-bin/jtoc?ID=3420
Chemistry
> Spectroscopy in the Yahoo! Directory
WinTorg
WinTorg
is a Windows simulation program that shows university
and
college students how to use spectroscopy to identify organic
compounds.
There are 100 unknowns available.
Spectroscopy
is emphasized (pmr, cmr, ir, ms, uv) and the
unknowns
can be identified by spectroscopy and/or chemical tests
and/or
derivatives. Extensive context-sensitive help is available
and
the program can be highly customised.
For
more information and to download a free shareware version
with
3 unknowns go to: http://www.chem.utas.edu.au/staff/blackman/shareware/torganal.htm
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