SPECTROPHOTOMETRY PART 1 Flashcards
- monochromator used is either a prism or a diffraction gratig
spectro
- wavelength selector
monochromator
- filter
photometer
Electrons are excited when subjected to the heat of a flame. as they return to a ground state, they emit radiation of a characteristic wavelength
FLAME PHOTOMETRY
FLAME PHOTOMETRY
Component parts
Atomizer, flame air and gas supply, monochromator, detector, readout device
FLAME PHOTOMETRY
Use
Na+, K+, Li+
Sodium =
yellow
Rubidium =
red
Potassium =
violet
Magnesium =
blue
Lithium =
red
mixture of Hydrogen and Oxygen gas
Gases for Flame Photometry
Oxygen gas
Natural gas
Acetylene
Propane
- for Na and K determination
Propane
Burner Assembly
aspirator
atomizer/nebulizer
flame
breaks the chemical bonds to produce atoms
Burner Assembly
cause excitation of the electrons of an atom
Burner Assembly
Internal standard:
Lithium or Cesium
Burner Assembly Advantages:
[?] intensity
absent from [?]
emits wavelength different from [?]
(?) as radiation buffer
high emision
biological fluid/ trace element
Na and K
Li
Burner Assembly Importance:
to achieve stability
TWO TYPES OF BURNERS OF A FLAME PHOTOTMETER
TOTAL CONSUMPTION BURNER
LAMINAR FLOW BURNER OR PRE-MIX BURNER
Gases are passed at high velocity over the end of a capillary suspended in the solution, causing liquid to be drawn up through the capillary into the flame
TOTAL CONSUMPTION BURNER
Gravitational feeding of solution through a restricting capillary into an area of high velocity gas flow where small droplets are produced and passed into the flame
LAMINAR FLOW BURNER OR PRE-MIX BURNER
ESSENTIAL PARTS OF THE FLAME PHOTOMETER
MONOCHROMATOR
Interference filter
MONOCHROMATOR
Maximum amount of the line emission to pass through the detector
narrowest band path
: giving-off of various wavelengths by non-ionic materials
Continuous emission
Measures light absorbed by ground state atoms.
ATOMIC ABSORPTION SPECTROPHOTOMETRY
ATOMIC ABSORPTION SPECTROPHOTOMETRY
Band path width:
0.001 to 0.01 nm
ATOMIC ABSORPTION SPECTROPHOTOMETRY
Component parts
Hollow cathode lamp (with argon or neon gas), atomizer, burner, monochromator, detector, readout device
ATOMIC ABSORPTION SPECTROPHOTOMETRY
Use
Calcium
Magnesium
Copper
Zinc
Lead
