Instrumental Chemical Analysis
     Atomic Spectroscopy
     Dr. Ahmad Najjar 
     Philadelphia University
     Faculty of Pharmacy
     Department of Pharmaceutical Sciences
     1st semester,  2020/2021
  Atomic Spectroscopy
   • It is  used for qualitative and quantitative 
    determination of perhaps 70 elements. 
   • Sensitivities of atomic methods in the ppm to ppb 
    range. 
   • Methods are speed, convenience, unusually high 
    selectivity, and moderate instrument costs 
   Difference between molecular spectroscopy 
   and atomic spectroscopy in basic principles
     • Molecular spectroscopy is conducted for molecular species at 
       room temperature 
     • Atomic spectroscopy can only be performed on a gaseous 
       medium in which the individual atoms (or sometimes, 
                          +  +    +
       elementary ions, such as Fe , Mg , or Al ) are well separated 
       from one another. 
     • Consequently, the first step in all atomic spectroscopic 
       procedures is atomization. How?
     • The sample is volatilized and decomposed in such a way as to 
       produce an atomic gas.
     • Atomization is the most critical step in atomic spectroscopy.
     • The efficiency and reproducibility of atomization determines 
       the method's sensitivity, precision, and accuracy.
  Atomization methods
   • Flame: AAS, AFS, AES
   • Electro thermal: AAS
   • Inductively coupled plasma: AES
   • Direct Current plasma: AES