A 100 g (fresh weight) of minced fish was
placed into a 500 ml flask and spiked with 13C-labeled standard
mixture.
150 ml of acetone was added, and mixture
was homogenized for 5 min.
150 ml of hexane was added into the mix and
homogenized after 5 min followed by addition of 60 g of ammonium sulfate.
The final sample was mixed by a homogenizer
for 30 minutes and let settle.
After 1-2 hours the top fraction was
decanted and filtered. The residue was washed twice by 30-50 ml of hexane.
Canned fishes samples (without sauce) were
extracted by the same procedure.