This document describes a method for the sampling and determining mercury species in flue gas passing through ducts or chimney stacks. Mercury generally exists in gaseous elemental form, gaseous oxidized form and particulate-bound form. This method applies to the sampling and determination of gaseous elemental mercury (Hg0), gaseous oxidized mercury (Hg2+), particulate-bound mercury (HgP) and total mercury (HgT) in the flue gas from stationary sources.
This method is suitable at locations with high dust content, including locations upstream of the dust removal device with high particulate loadings in flue gas up to 120 g/m3.
This method is applicable to locations with sulfur dioxide (SO2) concentration up to 0,25 % when the sampling volume is 0,5 m3 (on a dry basis as corrected to standard conditions).
The limit of detection and the limit of determination depend on the instrumental limit of detection, reagent blank, field blank, measurement technique and volume of sampled gas. When the sampling volume is 1,5 m3 (on a dry basis as corrected to standard conditions), the expected limits of detection for Hg0, HgP, Hg2+ and HgT are 0,103 μg/m3, 0,011 μg/m3, 0,035 μg/m3 and 0,127 μg/m3, respectively. The expected limits of determination for Hg0, HgP, Hg2+ and HgT are 0,229 μg/m3, 0,025 μg/m3, 0,082 μg/m3 and 0,263 μg/m3, respectively.
