A new method for preconcentration and determination of mercury in fish, shellfish and saliva by cold vapour atomic absorption spectrometry

Abstract

The development of a method using solid phase extraction for preconcentration and determination of mercury by cold vapour atomic absorption spectrometry is described. Hg (II) ions are sorbed on a minicolumn packed with Amberlite XAD-4 sorbent functionalised with 2-(2′-benzothiazolylazo)-p-cresol (BTAC). Then, a reducing solution was used for desorption and the transport of the analyte for subsequent detection. The assay presented a limit of detection of 0.011μgL−1 (0.011μgg−1, for solid samples), a limit of quantification of 0.038μgL−1 (0.038μgg−1, for solid samples), a precision of 0.50% (1.000μgL−1 Hg solution) and an enrichment factor of 46. The proposed method was applied to the determination of mercury in human saliva (0.055–0.200μgL−1). The following seafood collected in Todos os Santos Bay, Brazil was also analysed: bass (0.169–0.195μgg−1), mullet (0.043–0.361μgg−1), shrimp (0.075–0.374μgg−1) and mussel (0.206–0.397μgg−1).