AAS Flashcards
It is an analytical technique that measures the concentrations of
elements. It makes use of the absorption of light by these elements in order to measure their
concentration.
ATOMIC ABSORPTION SPECTROSCOPY (AAS)
It quantifies the absorption of ground state atoms in the gaseous state.
ATOMIC ABSORPTION SPECTROSCOPY (AAS)
These are usually determined from a working curve after calibrating the instrument with standards of known concentration.
Concentration measurements
They absorb ultraviolet or visible light and make transitions to higher electronic energy levels.
atoms
It is determined from the amount of absorption.
Analyte Concentration
It is a very common technique for detecting metals and metalloids in environmental samples.
Atomic absorption
4 principal components of Atomic absorption spectrometers
1- A light source ( usually a hollow cathode lamp)
2 - An atom cell (atomizer )
3 - A monochromator
4 - A detector, and read out device.
The usual light source of the element that is being measured
hollow cathode lamp
It contains a tungsten anode and a hollow cylindrical cathode made of the element to be determined. These are sealed in a glass tube filled with an inert gas (neon or argon).
Hollow cathode lamp
Elements to be analyzed needs to be in ___
atomic sate
It is the separation of particles into individual molecules and breaking molecules into atoms.
- This is done by exposing the analyte to high temperatures in a flame or graphite furnace.
Atomization
two types of atomization:
Flame and Graphite Furnace Atomization
Gas/Air
1700-1900
Gas/O2
2700-2800
H2/Air
2000-2100