Thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS):: Application for total determination of Cd, Pb and Zn in fresh waters, seawater and marine sediments

Thermospray flame furnace Atomic Absorption Spectrometry (TS-FF-AAS) was used for the total determination of Cd, Ph and Zn in fresh water and seawater samples at mug L-1 levels, and in marine sediment samples at mug g(-1) levels. Using a sample loop of 50 muL and a peristaltic pump the samples were transported into the metallic tube placed over an air/acetylene flame, through a ceramic capillary (o.d. = 3.2 mm) containing two parallel internal orifices (i.d = 0.5 unit). The detection limits determined for Cd, Ph and Zn using a synthetic water matrix (2.5% m/v NaCl, 0.5% m/v MgCl2 and 0.8% m/v CaCl2) were 0.32 mug L-1; 2.6 mug L-1 and 0.21 mug L-1 respectively. The methodology by TS-FF-AAS was validated by determination of Cd, Ph and Zn in certified reference materials of water and marine sediment, and the t-test for differences between means was applied. No statistically significant differences were established in fresh water and seawater (p>0.05), whereas differences became apparent in marine sediment (p<0.03).