The determination of total magnesium by atomic absorption spectrometry (AAS) is found to be convenient but some matrix interferences have to be taken account. Elimination of interference effects of some ions on magnesium determination was reported in earlier studies of AAS [15–17]. Generally, interference effects were eliminated by adding
releasing agents, such as lanthanum or strontium salts. A halocarbon-loaded air–acetylene flame was found to be suitable
for determination of magnesium by preventing interference effects from sample matrix [18]. Direct determination of magnesium after digestion as described below is not difficult using AAS. Microwave digestion at high pressure has some advantages: short analysis time, lower acid consumption, working at high temperature and preventing escape of
volatile constituents