MULTI-ELEMENT INORGANIC WATER CHEMISTRY OF ADIRONDACK LAKES

Water from thirty-five Adirondack lakes from the Lowlands to the Central Highlands have been analyzed by multi-element ICP-MS and yield chemical trends indicative of the geological and environmental conditions of their respective watersheds. Nearly all lakes have relatively low amounts of total dissolved solids (3.1 mg/L – 74.6 mg/L) and are dominated by Ca, Cl, S, Na, Si, Mg, Fe, K, and Al (in general descending order). Other elements detectable at lower concentrations, in nearly all the lakes, include Ba, Cu, Mn, Nd, Rb, Sr, Y, and Zn. A subset of water samples from nine Central Adirondack lakes were analyzed without, and with, filtration though a 0.45 μm filter. The filter removed substantial amounts of particulate bound elements including Al (-20%), Ce (-19%), Fe (-33%), Mn (-14%), Nd (-16%), Rb (-76%), Si (-4%), and Y (-11%). More surprisingly, filtration also added substantial amounts of Ba (1518%), Ca (6%), Cu (184%), K (5%), Li (24%), Mg (5%), S (50%), and Sr (5%). These same nine lakes were analyzed for total mercury by cold vapor atomic fluorescence (Tekran) and yielded 1.15-5.42 ng/L total mercury and had between 4.3-18.3 mg/L dissolved organic carbon. Mercury concentrations were positively correlated (r²) with insoluble elements including Al (0.75), Be (0.91), REEs (~0.70), Si (0.78), Y (0.72), and dissolved organic carbon (0.79). These data document the importance of small (<0.45 μm) organic particles and/or colloids in lake water trace element geochemistry.