SPECTROPHOTOMETRY Flashcards
Defined as method of analysis which deals with the measurement of spectra
SPECTROMETRY
Range of colors, energy, and activity of a drug
SPECTRA
A branch of spectrometry which embraces the measurement of
the absorption by chemical species of radiant energy of definite
and narrow wavelength approximating monochromatic radiation
SPECTROPHOTOMETRY
Complete cycle which pass a given point per second
FREQUENCY
Number of waves per cm
WAVELENGTH
Fxnal grp which absorbs radiant energy in uv/vis region (ethylene, methylene, aldehyde, and ketone)
CHROMOPHORE
The ratio of the radiant power transmitted by the soln to the radiant power transmitted by the blank
TRANSMITTANCE
Also called optical density, absorbancy, extinction coefficient
ABSORBANCE
Expressed in grams of solute per liter of soln
CONCENTRATION
The value obtained by dividing the absorbance by the product of conc (in g/L)
ABSORPTIVITY
The value obtained by dividing the absorbance by the product of conc (in moles/L)
MOLAR ABSORPTIVITY
The complete system of energy propagated in wave form
ELECTROMAGNETIC SPECTRUM
Refers to the energy in UV, Vis, and IR regions of the EM spectrum
RADIANT ENERGY
The graph plotting absorbance versus wavelength
ABSORPTION SPECTRUM
WAVELENGTH—
UV
VISIBLE
NEAR IR
UV=220-380nm
VISIBLE=380-780nm
NEAR IR=780-3000nm
WAVELENGTH—
Medium
Grp Freq Region
Fingerprint Region
Far IR
Medium=3.0-15um
Grp Freq Region=3-8um
Fingerprint Region=8-15um
Far IR=15-300um
Radiation of single wavelength
MONOCHROMATIC RADIATION
Usual spectral region that approximates monochromatic radiation
0.5-10nm
States that the power of a transmitted radiant decreases exponentially as the concentration of the solution containing the
absorbing chemical species increases arithmetically
BEER’S LAW
States that the power of a transmitted radiant beam decreases exponentially as the thickness (turbidity or cloudy) of the solution
containing the absorbing chemical species increases arithmetically
LAMBERT OR BOUGUER’S LAW
A combination of the above law and relates the power of the
incident and the transmitted radiant beam to the thickness and concentration of the solution containing absorbing chemical species
BEER-LAMBERT OR BEER-BOUGER’S LAW
- Associated with the overall motion of electrons around the nuclei
Electronic (UV)
- Associated with the motion of atoms within the molecule
VIBRATIONAL (IR)
Associated with the overall rotation of the molecule
Rotational
(Microwave)