sample digestion Flashcards
what are the real samples subjected to
several pre-treatment steps to make them fit for analysis
what is washing used for
to remove dirt and any exogenous contamination
what does the washing treatment involve
several steps using buffers, deionised water and/or organic solvents
what might the washing process be conducted under
mechanical or ultrasonic agitation
what is the digestion process
conversion of
a solid matrix into a liquid matrix, i.e. the solid
sample is decomposed.
what is the most common approach to digestion
use of mineral acids and heat
alternatively dry washing and fusion can be employed
acid digestion involves what
the use of mineral or oxidising acids and an external heat source
how is the acid chosen
depends upon
the nature of the matrix to be
decomposed.
what three things can contamination arise from
the grade reagents
the vessels
human involvement
give 5 ways to minimise the risk of contamination
use highest purity reagents and acids including water
use sample blanks in the analytical procedures
soak overnight sample vessels in an acid leaching bath
store clean glassware (protected from dust)
use clean and all necessary laboratory wearing.
