The Tekran Model 1135 Particulate Mercury Module connects seamlessly to the top of the Model 1130 to continuously monitor ambient air particulate bound mercury (HgP), gaseous oxidized mercury (GOM) and gaseous elemental mercury (GEM). The complete Tekran 2537-1130-1135 Atmospheric Mercury Speciation System provides fully automated, unattended operation to determine all three mercury species concurrently. It is the only system available which has this advanced capability to routinely measure part per quadrillion mercury speciation in ambient air. Measurement of Hgp with the Tekran Model 1135 is the important link connecting deposition of air mercury to sensitive aquatic ecosystems.