In: Chemistry
Describe the physical effects and interferences that the method of standard additions would correct or compensate for in AAS.
this question came straight from the textbook... no other explanation was given
Type of Interferences in the AAS
2) Scattering : This occurs due to the scattering of radiation source due to matrix impurities
3) Background Absorbtion : Due to absorption of radiation by the solvent
4) Matrix Interference : the Molecular absorption due to the matrix causes this type of interference
This can be overcome with the standard addition
The above are the common interference that occurs in atomic absorption spectroscopy but the major interference that is overcome by standard addition is the matrix effect. Matrix is basically the different components present in the sample of intrest. Due to absorption by this components the absorption of sample may increase or decrease causing error in spectra
To overcome this , the method of standard addition is used in this first the measurement is done of the unknown without any standard and then unknown alongwith various concentration of standard is done to nullify the matri effect