(iii) Afterwards, the mixture was cooled
and filtered by membrane filter of 0.45 lm. (iv) pH of the digested
sample was adjusted to 7.0 by using diluted NaOH (1.5 mol L1).
(v) The separated solution was diluted with deionized water to
the final volume of 50 mL. Then, the present method was applied
by taking 5 mL of all of the samples including CRMs. Also, two different
CRMs were analyzed in order to test the accuracy and precision
of the method. The CRMs were chosen: ERM-BCO84a (tin in
tomato paste, ERM-LGC) and SRM 1548a (typical diet, proximities
and trace elements, NIST). They were used as bottled, without further
grinding and sieving.