What is the purpose of a graphite furnace?
Graphite furnaces are used for atomic absorbance measurements. Radiation from the source shines through the tube to the detector. A small volume of sample (typically 0.5 to 10μl) is introduced through the hole into the tube either through the use of a micropipette or a spray system.
Why graphite furnace AAS is more sensitive than flame AAS?
The entire volume injected into the graphite tube remains inside the sealed cavity till atomization and light absorption by the analyte atoms produced is over. This means that sensitivity improvement takes place due to the increased residence time required to complete the temperature program steps (around 1-2 minutes).
What are the two 2 advantages of graphite furnace AAS over flame AAS?
The practical advantages derived include (a) the ability to use an autosampler for unattended operation; (b) that to process several replicates from a single aliquot and hence to better establish the precision of the method; (c) that to handle increased masses of sample to improve representativeness; (d) that to alter …
How does flame emission spectroscopy work?
In the flame emission spectroscope, the coloured light from a vaporised sample can be split to produce an emission spectrum . The different lines in an emission spectrum look like a coloured barcode. Each metal ion produces a unique emission spectrum.
How does flame atomic absorption spectroscopy work?
The flame converts samples into free ground state atoms that can be excited. A lamp emitting light at a wavelength specific to the atoms is passed through the flame, and as the light energy is absorbed, the electrons in the atoms are elevated to an excited state.
Is graphite flammable?
Natural Graphite is not flammable under normal conditions.
What is the atomic number of graphite?
Graphite is the crystalline allotropic form of carbon occurs in free state in nature. It can be prepared artificially by heating a mixture of sand and coke in electrical furnace about 3300 K. In graphite, the carbon atoms are sp 2 hybridized. Each carbon atoms are linked by covalent bonds. 2.
What is list of atomic absorption spectroscopy applications?
Atomic Absorption Spectroscopy applications: 1. Atomic spectroscopy is used for quantitative analysis of metal elements in water, soil, plant material, and ceramics. 2. In health care, it is used to analyze ionic metal elements in blood, saliva, urine samples. The elements analyzed routinely include sodium, potassium, magnesium, calcium, and zinc.
What is the principle of atomic absorption spectroscopy?
Quantitative metal concentrations in solution
What can atomic absorption spectroscopy be used for?
Atomic absorption spectroscopy is based on absorption of light by free metallic ions. In analytical chemistry the technique is used for determining the concentration of a particular element (the analyte) in a sample to be analyzed.