What are the three main techniques of atomic spectroscopy?
The science of atomic spectroscopy has yielded three techniques for analytical use: Atomic Absorption. Atomic Emission. Atomic Fluorescence. The process of excitation and decay to the ground state is involved in all three fields of atomic spectroscopy.
Where is AAS used?
This led to an invention that has since been labelled as one of the most significant achievements in chemical analysis last century. AAS allows the measurement of extremely small amounts of elements and is routinely used in medicine, manufacturing, mining, environmental monitoring and laboratories throughout the world.
What are the atomic spectroscopy techniques?
Atomic spectroscopy includes the techniques of atomic absorption spectroscopy (AAS), atomic emission spectroscopy (AES), atomic fluorescence spectroscopy (AFS), X-ray fluorescence (XRF), and inorganic mass spectroscopy (MS).
What are the components of atomic absorption spectroscopy?
The standard AAS instrument consists of four components: the sample introduction area, the light (radiation) source, the monochromator or polychromator, and the detector (figure 1).
What is flame atomizer?
In a flame atomizer, a solution of the sample is nebulized by a flow of gaseous oxidant, mixed with a gaseous fuel, and carried into a flame where atomization occurs. As shown in Figure, a complex set of interconnected processes then occur in the flame.
What is the importance of atomic absorption spectroscopy?
Using an atomic absorption spectrometer, you can determine the concentration of many different elements in a sample. The spectrometer identifies the amount of metal in liquids and measures the quality of metal in a sample as well.
What is the difference between atomic absorption and emission spectra?
The main difference between emission and absorption spectra is that an emission spectrum has different coloured lines in the spectrum, whereas an absorption spectrum has dark-coloured lines in the spectrum.
How do you prepare a sample for AAS?
After dilution of the digested solutions, samples can be directly injected into flame AAS as well as graphite furnace AAS….FAAS and GFAAS sample preparation.
| Sample preparation techniques | Hot plate, microwave digestion, acid digestion, high-pressure digestion |
|---|---|
| Acid | HNO3, HCl, H2SO4, HF, H2O2 |
How many elements can AAS measure?
AAS can be used to determine over 70 different elements in solution, or directly in solid samples via electrothermal vaporization, and is used in pharmacology, biophysics, archaeology and toxicology research.
What is a nebuliser in AAS?
A nebulizer is a device that introduces a liquid sample into the AAS. Here, we will discuss the most common types: pneumatic and ultrasonic nebulizers. Pneumatic Nebulizers. A pneumatic nebulizer converts a sample solution into an aerosol of tiny droplets using a jet of compressed gas.
Why acetylene gas is used in AAS?
Because it gives a very high temperature: 2200-2400 ∘C. This is due to its high heat of combustion, around 1300 kJ/ mol. If still higher temperatures are required, as for Al, Si, Ti, etc., a combination of acetylene and N2O is used, which reaches 2600-2800 ∘C.
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