ATOMIC SPECTROMETRY
1. Flames
2. Electrothermal Atomizers
3. Plasmas
X = laser plasmas
stellar interior
Na
Mg+
Na Spectrum
Combustion zones
in the common
Bunsen Burner
Combustion zones
in a pre-mixed,
elongated, laminar
flame
Temperature
profiles for a
natural gas-air
flame.
Air-Acetylene Flame Fuel-air ratios
How do we
introduce liquid
samples into the
flame?
Direct Insertion…
Total Consumption Burner
Total Consumption Burner
VERY NOISY!!
Total Consumption Burner
Plan B: Use a nebulizer
Concentric nebulizer
Crossed-flow nebulizer
Ball-type Babington
nebulizer for viscous
samples
V-Groove Babington
nebulizer
Pre-mixed flame system with concentric
nebulizer and spray chamber
Perkin-Elmer Burner System
Burner Head Design (Looking down from above)
Emission/Fluorescence
Absorption
Fraction of analyte present as neutral free gaseous
atom in the flame
Background Emission from Flames
Oxygen - Hydrogen
Oxygen - Acetylene
Nitrous oxide - Acetylene
Flame Absorption Profiles vary by element
Signals also vary with sample flow rate
Block Diagram of a Flame Emission
Spectrometer
Schematic Diagram of a single-beam atomic absorption spectrometer
The monochromator in an atomic
absorption experiment simply
isolates the appropriate spectral line
from all of the lines emitted by the
light source
Atomic
Absorption
Spectrometers
Continuum Source
Background
Correction
Continuum Source
Background
Correction
Representative Flame Detection Limits (ng/mL)