Dataset: Lake Tahoe TSP Metals

TSP samples were collected between 2005 and 2010. Weekly integrated samples were collected on acid washed quartz fiber filters (10"x8", Whatman®) using a Graseby Andersen TSP High Volume Sampler. Between November 2005 and May 2007, the sampler was located near the lake at the UC Davis Field Station (Hatchery) away from any local source of disturbance. After May 2007, the sampler was relocated about 300 meters south to reduce local impacts due to remodeling at the Hatchery. The TSP sampler was placed 3.2 meters above the ground and protected by trees from direct road dust inputs. TSP samples were collected at an airflow rate of 85 cubic meters per hour. All filters were kept frozen until further analyses. To extract the soluble fraction of nutrients and trace metals in TSP samples, a 47 mm circular subsample of each filter was placed on an acid-washed filter tower, and 100 mL of MilliQ water was passed through the sample under gentle vacuum pressure exposing the sample for about 10 s to the water (Buck et al., 2006). A 100 μL of concentrated nitric acid was added to 5 mL of the MilliQ water for trace metal analysis.

TSP total and soluble trace metal concentrations of Al, V, Cr, Mn, Fe, Co, Ni, Cu, Cd, and Pb were analyzed by a High Resolution Inductively Coupled Plasma Mass Spectrometry (Element XR) with triple detector mode. Na, Mg, Ca, P, Zn, Sr, Ti, and U were also measured in bulk TSP and in the TSP soluble fraction samples, while total concentration of Ba was determined only in bulk TSP samples. Low resolution mode was used for Cd, Ba, Pb and U and medium resolution for the rest of the elements. Instrument calibration was done using gravimetrically prepared multi-element standards in the range of concentrations represented by our samples.