Interferences in atomic spectroscopy

Question 1

what is an interference

Answer 1

any effect that changes the signal while analyte concentration remains unchanged

Question 2

how can interference be corrected by

Answer 2

by removing the source of interference or by preparing standards that exhibit the same interference

Question 3

what is spectral interference

Answer 3

• Unwanted signals overlapping analyte signal

Question 4

example of spectral interference

Answer 4

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.

Question 5

what is chemical interference

Answer 5

• Chemical reactions decreasing the concentration of analyte atoms

Question 6

example of chemical interference

Answer 6

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.

Question 7

what is ionisation interference

Answer 7

Ionization interference

- Ionization of analyte atoms decreasing the concentration of neutral atoms