Nowadays, the most widespread method for Hg determination is cold vapor atomic absorption spectrometry (CVAAS). The CVAAS was adopted as a standard method for analysis of Hg in foodstuffs. This technique is based on the chemical
reduction of Hg, usually by Sn2+ or BH4 ions to elemental Hg which is swept from the solution by a carrier gas to a quartz cell placed in the optical path of an atomic absorption spectrophotometer where the absorption of Hg is measured