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Atomic Absorption SpectroscopyAn Overview
Central Laboratory
Faculty of Postgraduate Studies for Advanced ScienceBeni-Suef University
Chemist/ Ahmed HashemDirector of Lab
Assoc. Prof. Ali Selim
By/Ahmed Abdelmohsen
Bachelor of Science (Chemistry) - Excellent with first class honor
The prize of the best presenter & best graduation project in faculty of science – Scientific conference
Pre-Master in Materials Science and Nanotechnology - Grade Excellent (Top GPA = A-)
Pre-Master Physical Chemistry
Erasmus Mundus Scholarship – FAME program 2015/2017
Chemist at Central Laboratory, PSAS ,Beni-Suef University
An Introduction
What is Spectroscopy ??
Interaction of Radiation and Matter
Spectroscopic Analytical Methods are based on….
Measuring amount of radiation…….
1- Produced by molecular or atomic species
2- Absorbed by molecular or atomic species
Spectroscopic methods are classified according to region of the electromagnetic spectrum
1- General Principles
Introduction for flame, graphite furnace spectroscopy and hydride system.
Interferences (Determination and elimination).
How to decide best way for analysis.
Data analysis, and complete analysis for selected elements
2- Sample Preparation
3- Optimization of Instrument
4- Background Correction
Training
1- General Principles
Na, Li, K
1- Atomization Chamber
Nebulizer
Nebulizer and Flame
http://www.chem.agilent.com/en-US/products-services/Parts-Supplies/Spectroscopy/Atomic-Absorption/Mark-7-Spray-Chamber-Supplies/Pages/explodedview.aspx
Glass Bead
2- Hollow-cathode lamp
HCL usually consists of a glass tube containing a cathode, an anode, and a buffer gas (usually a noble gas). A large voltage across the anode and cathode will cause the buffer gas to ionize, creating a plasma. The buffer gas ions will then be accelerated into the cathode, sputtering off atoms from the cathode. Both the buffer gas and the sputtered cathode atoms will in turn be excited by collisions with other atoms/particles in the plasma. As these excited atoms decay to lower states, they will emit photons, which can then be detected and a spectrum can be determined. Either the spectrum from the buffer gas or the sputtered cathode material itself, or both, may be of interest.
Cathode
Anode
The anode of the hollow cathode lamp is made of zirconium.During processing, we subject the anode to ion bombardmentthat vaporizes a small amount of zirconium and deposits it onthe lamp envelope near the anode. This film of zirconium is highly reactive and acts as a very efficient scavenger of traces of oxygen and other molecular gases that might otherwise reduce the lifetime of the lamp. It is called a "getter". Look for the dark smudge behind the anode. It is there to help prolong the useful life of the lamp.
Flame ( Burner AAS)
Air/Acetylene Air/Acetylene & Nitrous/Acetylene
Flame Temperature
Sample Preparation
Digestion of Different types of Samples:
Please Visit this link for more information:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532003000200004
50 mL of Sample 5 mL Nitric Acid
Acid Digestion
To extract all cations from suspended matters and particulates
+
Accuracy in measuring samples
Nitric Acid5 mL
Sample 50 mL
Magnetic Stirring
Heating for 1 hours at 100 degree Celsius
Deionized Water
Graphite Furnace Spectroscopy
Graphite Tubes
Hydride Unit Separating the analyte from the matrix can improve the sensitivity of the atomic absorption technique and avoids physical, matrix and spectral interferences.
Metalloid Oxyanions
Hydride generation (HG) is a very effective analytical technique developed to separate hydride forming metals, such as Se and As, from a range of matrices and varying acid concentrations. The heated quartz tube atomizer is particularly useful for the determination of arsenic and selenium because the absorption wavelengths for these elements are below 200 nm in an area subject to intense interference from flame radicals that can significantly affect detection limits. Mercury can be easily reduced in solution to generate elemental mercury, otherwise known as cold vapor (CV). This technique is also effective at separating mercury from a range of matrices. These analytical techniques can improve detection limits by a factor of approximately 3000 times that of flame detection limits and typically have less interference than graphite furnace techniques.
Advanced Approaches
Background Correction In AAS, GFAAS
AAS Team - BSU
Nashaat Ahmed Ahmed Hashem
Ahmed Hashem Baioumy AbdelmohsenMaster Candidate at Material Science and Nanotechnology
DepartmentFaculty of Postgraduate Studies for Advanced Science
Beni-Seuf [email protected]
[email protected]@gmail.com
https://www.facebook.com/Ahmed.BaioumyAlfazary
