Atomic Absorption spectroscopy is extensively used in analysis of trace metals in ppm to sub ppm levels using absorption of element specific wavelengths by atoms in ground state. It has found applications in water analysis, foods & beverages, agricultural products,geological samples and body fluids.
- R&D Scientists
- QA Managers & Practicing Chemists
- Students in disciplines of Chemistry, Pharmacy, Food & Nutrition and Agricultural Sciences.
- Geological and Mining scientists
- Clinical researchers
- Govt Regulatory Bodies
- Environmental Scientists
Click the links below to access the free e-course on AAS
Introduction to Atomic Absorption Spectroscopy course
The overwhelming response to the free e-learning HPLC and GC courses has encouraged me to move ahead with the free AAS course which was announced earlier. I understand that everyone has busy work schedules and today’s hectic life style leaves you little or no time to refer to voluminous books to learn any technique. However, for sustained growth learning has to be adopted as a lifelong habit….
Module 1 : Scope of Spectroscopic Analysis
Spectroscopic analysis is based on an atom or compound’s interaction with electromagnetic radiation of specific wavelength. Spectroscopy provides information on chemical identity of a compound, quantity present and structure based on the technique selected and the wavelength of electromagnetic spectrum. Commonly used spectroscopic techniques in any laboratory are UV –VIS spectroscopy, FT – IR spectroscopy, Atomic Absorption spectroscopy and ICP/ ICP – MS spectroscopy….
Module 2 : Evolution of Atomic Absorption Spectroscopy
Trace metal studies on composition of materials has been the oldest branch of analytical chemistry. Traditional gravimetric techniques still constitute the backbone of most undergraduate educational laboratories but instrumental methods are fast replacing them due to advantages of speed and precision….
Module 3 : Introduction to AAS component parts
Atomic absorption occurs when a ground state atom absorbs light of a specific wavelength.The amount of light absorbed is governed by Beer Lambert’s law and will increase as the number of atoms of the element in the light path increases. The component parts of Atomic Absorption Spectrometer are similar to a UV -Vis spectrophotometer as both operate on same principle….
Module 4 : Types of Light Sources in AAS
Light sources are generally of two types. You’d be familiar with ‘continuum light sources’ such as Sun or a light bulb which emit electromagnetic radiation in the wavelength range from about 250 to 700 nm in the visible region which we see as normal white light. The white light comprises of several different wavelengths which constitute the colours of the rainbow…
Module 5 : Flame Atomic Absorption Spectroscopy
Sample atomisation produces ground state atoms that are necessary for atomic absorption to take place. This involves application of thermal energy to break the bonds that hold the atoms together.
The complete atomisation assembly comprises of:
- Spray chamber
- Burner Head….
Module 6 : Graphite Furnace Atomic Absorption Spectroscopy
Flame atomic absorption spectroscopy is a well established and precise method for elemental analysis giving concentration results in mg/L (ppm) levels. However, better sensitivity is achievable using electro- thermal atomisation with a graphite furnace.
Limitations of flame AAS
- Burner – nebuliser is a rather inefficient sampling device. Majority of the sample gets drained and the small fraction reaching the flame has a short residence in the light path
- High sample consumption of the order of 3-5ml/min
- Matrix interferences limit applications particularly in analysis of biological and geological samples…..
Module 7 : Dispersion and Resolution of Light in Atomic Absorption Spectroscopy
A monochromator is a device that isolates and transmits a band of wavelength from a wider range of wavelengths available at the inlet slit. The dispersion of light can be obtained by means of a prism or diffraction grating. The Czerny- Turner monochromator using a pair of concave mirrors and a plane grating is most widely used in atomic absorption spectroscopy…..
Module 8 : Interferences in Atomic Absorption Spectroscopy
Interference is a phenomena that leads to changes in intensity of the analyte signal in spectroscopy. Interferences in atomic absorption spectroscopy fall into two basic categories, namely, non-spectral and spectral.
Non-spectral interferences affect the formation of analyte items and spectral interferences result in higher light absorption due to presence of absorbing species other than the analyte element….
Module 9 : Background correction in Atomic Absorption Spectroscopy
Before you move to background correction it is necessary to understand what is background absorption. The main reason for background absorption is presence of undissociated molecules of matrix that have broadband absorption spectra and tiny solid particles in the flame which may scatter light over a wide wavelength region. When this type of non-specific adsorption overlaps the atomic absorption wavelength of the analyte the ground state absorption is cut…..
Module 10 : 10 Interview questions in Atomic Absorption Spectroscopy
In this module I have posed before you some typical questions which you could come across during interview sessions when you apply for a job involving use of atomic absorption spectrometers. I have deliberately not provided you with tailored made answers and the objective is to motivate you to look for the answers. I’m sure that if you review the earlier modules on the topic you’ll find all your answers. This exercise will encourage you to search for solutions that you are faced with not only in atomic absorption spectroscopy but in other areas of your activity as well…