Determination of mercury in seawater by cold vapour atomic absorption spectrophotometry

Abstract

     This paper describes a closed aeration technique coupled with a double amalgamation stage on a gold absorber, which is used for the determination of mercury in seawater samples from some different parts of the open and coastal Adriatic Sea.

     Mercury analysis was conducted using a LDC-UV monitor (model 1225) equipped with a Hewlett Packard integrator (HP 3390A).

     The double-amalgamation stage offers more advantages: the elimination of interferences due to organics or Cl₂ and measurement from the same gold trap which is well characterized. The precision of the method was investigated by determination of total mercury in surface water samples from some different parts of the Adriatic.

      The reproducibility was tested by 10 fold measurements of 2 ng Hg²⁺ spikes. The mean value was 1.9 ± 0.4 ng l^-1. The detection limit was found to be 0.5 ng l^-1.