Analytical Chemistry - Atomic Absorption

Atomic Absorption
Home > Analytical Chemistry > Atomic Absorption

ATOMIC ABSORPTION

 

 

 

 

 

 

 

 

Atomic absorption spectrometry (AAS) is an analytical technique that measures the concentration of an element by measuring the amount of light (intensity of light) that is absorbed - at a characteristic wavelength - when it passes through a cloud of atoms of this element. As the number of atoms in the light path increases, the amount of light absorbed increases in a predictable way. Modern atomic absorption spectrometry was introduced in 1955 as a result of the independent work  of A. Walsh and C.T.J Alkemade. Commercial atomic absorption spectrophotometers were introduced by the early 1960’s, and the importance of atomic absorption as an analytical technique was soon evident.

 

References

  1. (a) A. Walsh, Anal. Chem., 63, 933A–941A, 1991 (b) S.R. Koirtyohann, Anal. Chem., 63, 1024A–1031A, 1991 (c) W. Slavin, Anal. Chem., 63, 1033A–1038A, 1991.

  2. D. Harvey,  “Modern Analytical Chemistry”, McGraw-Hill Companies Inc., 2000

  3. D.A. Skoog, F.J.  Holler, T.A.  Nieman,  “Principles of Instrumental Analysis”. Saunders College Publishing: Philadelphia, 1998.

Comments

Post a Comment

Popular posts from this blog

Carbocations: Factors affecting their Stability

Image
A carbocation is a species where a carbon atom bonds to three carbon atoms and has a positive charge. Carbocations are electron deficient species and therefore very reactive and unstable . Anything which donates electron density to the electron-deficient center will help to stabilize them. Factors that stabilize them are the following:  Neighboring carbon atoms (inductive effect) Neighboring carbon-carbon multiple bonds (resonance effect) Neighboring atoms with lone pairs (resonance effect) How carbocations are stabilized by neighboring carbons atoms? The stability of carbocations decreases as the number of carbons attached to the C+ decreases. That means that tertiary carbocations are more stable than secondary that in turn are more stable than primary (Fig. 1). Fig. 1: Carbocation stability increases as methyl substitution increases around the electron deficient carbon C+. The methyl groups (-CH 3 ) are electron donating and therefore stabilize the positive charge (inductive ...
Read more

Standard Enthalpies of Formation of Organic Compounds

Standard Enthalpies of Formation of selected organic compounds Home > Fundamental Physical Constants - Chemical - Physical - Thermochemical Data > Standard Enthalpies of Formation of Inorganic Compounds > Standard Enthalpies of Formation of Organic Compounds Standard Enthalpies of Formation of Organic Compounds   The standard enthalpy of formation ΔΗ° f of a substance is the change in enthalpy for the reaction that forms 1 mol of the substance from its elements with all reactants and products at 1 atm pressure and usually 298.15 K. For any element in its most stable state at 298 K and 1 atm pressure, ΔΗ° f = 0. Standard enthalpies of formation of inorganic compounds were given in a previous post.   Table 1: Standard Molar Enthalpies of Formation ΔΗ° f at 25 °C (298.15K) Substance Formula ΔΗ° f   Acetylene C 2 ...
Read more

CHEMISTRY NET - INTRODUCTION - LIST OF TOPICS

Chemistry Net - Introduction - Table of Contents CHEMISTRY NET Analytical Chemistry Biological Chemistry Inorganic Chemistry Organic Chemistry Physical & Theoretical Chemistry Chemical News & Interesting / Chem. Data Chemistry is the understanding, the definition and the description of the structure and the behavior of matter, the matter that surrounds us and the matter we are consisting off. It is our history, our life and our future. It is sometimes called the central science because of its role in connecting the other physical sciences (physics, astronomy, earth sciences) with the life sciences (biology, medicine) and engineering. There are many approaches to studying this fascinating science but for convenience and historical reasons has been divided it into five fields: analytical , biological , inorganic , organic and physical chemistry. Chemistry is a challenging subject to teach and even more challenging to learn. This si...
Read more