- A method of analysis that deals with the measurement of spectra
SPECTROMETRY
is a system of color bands, it is a continuum of color formed when a beam of light is dispersed, so that its component wavelengths are arranged in order
spectrum
- Types of Spectrum
- Color Spectrum
- Electromagnetic Spectrum
3 most important Spectrum
o UV
o Visible - color spectrum
o Infrared
Shorter wavelength = —— energy= ——— frequency
higher energy = higher frequency
Ex. Shorter wavelength
Gamma ray and X-ray
Longer wavelength = —— energy= ——— frequency
lower
Ex. Longer wavelength
Radio and Microwaves
- Determination of the identity of a certain compound
Significance
- Determination of the quantity of the active ingredient
Significance
- It refers to the length of a complete wave or cycle from the peak of one wave to the peak of the next
Wavelength
- refers to the number of waves per second
Wavelength
Units of Wavelength
- Micrometer (um) = 10-4 cm
- Nanometer (nm) = 10-7 cm
- Angstrom (Å) = 10-8 cm
Ranges of Wavelength Used in Spectrometry
- Far UV - <180nm
- Near UV - 200 to 380 nm
- Visible - 380 to 780 nm
- Near IR - 780 to 3000 nm
- Mid IR - 3 to 15 um
- Far IR - 15 to 300 um
- The symbol is “v”
Frequency
- It refers to the number of complete cycles which pass a given point per second (cps)
Frequency
- It is expressed in cps and hertz (1 cps = 1 Hz)
Frequency
- It refers to the number of waves per centimeter
Wavenumber
- Units of Wavenumber
- 1 um- = 10’4 cm-
- 1 nm- = 10’7 cm-
- It is a functional group which absorbs radiant energy in the UV and visible regions of the spectrum
Chromophore
- It refers to the energy in the electromagnetic spectrum that is propagated in waveform
Radiant Energy
First theory states that radiant energy occurs in bundles called “——-” or “——–”
photon or quanta
- h=
Plank’s constant = 6.62x10-27 ergs . s
- v=
frequency = cps or Hz
