We studied how well two widely used methods capture oxidized mercury from the air, a key step for its quantification. Our research showed that denuders can lose a significant amount of mercury during sampling, leading to underestimation, while cation exchange membranes were more reliable in retaining mercury. These results highlight the need for improved measurement techniques to ensure accurate data, which is essential for evaluating mercury pollution and shaping environmental policy.

To demonstrate the robustness and comparability of the novel primary mercury gas standard, the results of comparisons are presented with current calibration methods maintained, using the bell jar in combination with the Dumarey equation or NIST liquid standard reference material. The results show that the primary standard and the NIST reference material are comparable, whereas a difference of −8 % exists between results traceable to the primary standard and the Dumarey equation.