The mercury analyser was calibrated by using aqueous Hg
standards. In order to measure low and high levels of Hg
concentrations, two analytical calibration curves were constructed.
The combined use of two cuvettes in series allowed
the measurement in the two ranges (typically 0–20 and
20–1000 ng of Hg). During the analysis, the same amount of Hg
was measured twice, at the two different sensitivity levels
resulting in two instrumental dynamic ranges