Interferences in AAS can impact the accuracy and reliability of measurements. They are categorized into three types:
1) Spectral Interferences:
Cause: Occur when another species absorbs light at the same or nearby wavelength as the analyte.
Examples: Overlapping absorption lines or stray light from the source.
2) Chemical Interferences:
Cause: Changes in the analyte's chemical form, preventing atomization, or reactions with other species in the sample.
Examples:
Matrix elements causing precipitation or complexation of the analyte.
Flame characteristics (oxidizing/reducing) affecting analyte atomization.
3) Physical Interferences of AAS:
Cause: Sample matrix properties affecting atomization efficiency or light transmission.
Examples:
Viscosity, refractive index, and surface tension impacting nebulization or mist formation.
Dust or particulates scattering light.
Proper strategies to address these interferences are essential to ensure accurate analysis.