Spectroscopy
Atomic Absorption Spectrophotometer (AAS)
Measures one metal at a time by how much light of that element's own wavelength is absorbed by free atoms in a flame or graphite furnace. Simple, robust and still widely used for metals in pharma QC.
- Pharmaceutical
- Food & beverage
- Environmental
- Mining & metallurgy
- Agriculture
- Clinical
TROUBLESHOOTING
Common problems, causes and fixes
Low absorbance (poor sensitivity)
Likely causes
- • Nebuliser partly blocked
- • Burner not aligned or wrong height
- • Lamp weak or wrong current
- • Wrong fuel/oxidant ratio
What to do
- • Clean or replace the nebuliser
- • Re-optimise burner position with a standard
- • Check lamp energy and replace if needed
- • Re-optimise gas flows
Noisy or drifting signal
Likely causes
- • Lamp not warmed up
- • Salt build-up on burner slot
- • Unstable aspiration rate
What to do
- • Allow full lamp warm-up
- • Clean the burner head
- • Check capillary tubing and nebuliser
Results biased high in a heavy matrix
Likely causes
- • Background absorption not corrected
- • Spectral overlap
What to do
- • Switch on deuterium or Zeeman correction
- • Use an alternative line or matrix-matched standards
Results biased low for Ca or Mg
Likely causes
- • Chemical interference from phosphate or silicate
What to do
- • Add a lanthanum or strontium releasing agent
- • Use a nitrous oxide–acetylene flame
Flame will not ignite
Likely causes
- • Low gas pressure
- • Burner head not seated
- • Drain trap interlock open
- • Exhaust interlock
What to do
- • Check cylinder and regulator
- • Re-seat burner head
- • Fill the drain trap
- • Confirm exhaust is on
In LimsPulse · Calibration Management
Keep every AAS in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.