Application of KCl denuder for measuring gas phase mercuric species (Hg2+ ) in atmosphere

KCl denuder technique was meployed in the measurement of Hg(II) species in atmosphere firstly. Intensive lab tests indicate that Hg⁰ can pass through KCl denuder freely, while Hg²⁺ can be trapped in it very efficiently. The efficiencies for adsorbing inorganic Hg²⁺ averaged between 95% to 100% with a gross mean of 98%, and those for absorption of organic Hg²⁺ were around 94%. Mass balance calculation shows that mercury trapped in denuder can be quantitatively extracted by 1 mol/L HCl (super grade) and analysed by the method of SnCl 2 reduction CVAFS determination, thus, demonstrated the feasibility of KCl denuder in measurement of Hg(II) in atmosphere. Preliminary application at two sites Gteborg, Sweden and one site in Ireland, found 0 04—0 15 ng/m³ of Hg(II) species, contributing to 2%—10% of the total mercury.