Flashcards in Interferences in atomic spectroscopy Deck (7):
what is an interference
any effect that changes the signal while analyte concentration remains unchanged
how can interference be corrected by
by removing the source of interference or by preparing standards that exhibit the same interference
what is spectral interference
- Unwanted signals overlapping analyte signal
example of spectral interference
e.g. A Cd line at 228.802 nm causes spectral interference with the As line at 228.812 nm in most spectrometers.
With sufficient high resolution (monochromator with resolution of 0.005 nm), the two peaks are separated and there is no interference.
look on ppt for image.
what is chemical interference
- Chemical reactions decreasing the concentration of analyte atoms
example of chemical interference
e.g. Chemical interference is causes by any component of the sample that decreases
the extent of atomoization of analyte.
♦ For example, SO42- and PO43- hinder the atomization of Ca2+ (by forming nonvolatile salts).
♦ Releasing agents (as EDTA) are chemicals that are added to a sample
to decrease chemical interference.