The aim of this study was to optimize a semi-automatic methodology using commercial pure gold cartridges (Tekran Inc.) to quantify gaseous elemental mercury (GEM) in the Amazon atmosphere. The detection limit was 0.020 ± 0.006 ng Hg. This corresponds to detection limits varying from 0.2 to 0.4 ng Hg m-3, for field sample volumes ranging between 0.1 and 0.05 m³. The similarity between the 9 tested cartridges was evaluated. Under sampling flow rates varying between 0.4 and 2.0 L min-1 no difference among cartridges was observed. The maximum retention capacity of the cartridge (breakthrough) was not reached in experiments with flow rates of 1 or 2 L min-1, and with Hg concentration of 25 ng m-3 and maximum air volume of 150 L. Water condensation on the gold surface showed to be a problem, but that was solved by heating the sample cartridge at 60 ºC during sampling.
gaseous elemental mercury (GEM); atmospheric mercury; Amazon atmosphere; methodology optimization
