L1 /
10
CH3041
SOLIDS SEPARATION
II
• A strong oxidising acid such as HNO3 is
used to digest organic material. This is then
diluted to prepare the analytical sample.
used to digest organic material. This is then
diluted to prepare the analytical sample.
• Silicate
materials are broken down by
hydrofluoric acid N HF N. Digestions must be carried out in Teflon as the HF eats away
glass beakers as it is just another silicate.
hydrofluoric acid N HF N. Digestions must be carried out in Teflon as the HF eats away
glass beakers as it is just another silicate.
• Selective
complexation may be used to separate interfering complexes
pre-analysis.
eg. to analyse
for Ca2+ add EDTA to form [CaEDTA]2- this removes the interference caused by non-volatile CaSO4 in Atomic Absorption analysis.
