Atomic Absorption Spectroscopy: Instrument Components

Nebulizer

FLAME

Hollow Cathode Lamp

Monochromator

Air/oxidiser in

Fuel mixture in

Detector

Sample sucked in through small tube

Slot burner

ATOMIC ABSORBANCE SPECTROSCOPY

- Metal atom formed in flame

-Analysing metals

- Concentration measured by absorbance

Flame: CREATES ATOMS

Solution is burnt in flame and vaporates liquid and matrix

Remaining solid atomised in flame & converts to neutral metal atoms

Rich ratio (more fuel to oxidant)

- excess carbon which reduces formation of metal oxides/hydroxides

Lean ratio (more oxidant than fuel)

-Hotter flame (early transition metals and metalloids)

Hollow cathode Lamp:

Lamp of same metal

Radiation selectively absorbed by analyte metal

Organic molecules- H, C, N, O, F, S, Cl, Br, I + nobles

Sample

Nebuliser:

Sucks up liquid sample at a controlled rate, creates a fine aerosol for intro into flame, mix the aerosol, fuel and oxidant thoroughly

Monochromator:

ISOLATES PHOTONS

removes scattered light