Methodology optimization and application for measurement of gaseous elemental mercury in the amazon atmosphere

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.