Once the sample has been digested and a the liquid slurry has been filtered, the sample is ready for analyzation. To analyze for Lead, Copper, Chromium, and Nickel, standard solutions and a matrix modifier are mixed. An appropriate matrix modifier is also pipetted into the autosampler to increase peak height at the appropriate wavelength and to decrease background noise in the sample as well as the standards. NIST Pine Needle standard powder samples were the first samples I ran, to verify my extraction procedure and assure method optimization. I am also analyzing soil samples from each site to verify the use of Thuidium delicatulum as an ectohydric moss and as a useful bioaccumulator.
Extraction is slightly different, using HCl as a digesting organic solvent.
Trends in metal levels and correlation with moss data is suggesting that the organism does not seem to maintain enough contact with its substrate to eliminate use of the moss as a monitor. One problem has been that I can only run one sample at a time, each taking at least 8 hours to run. The acquisition of another digestion bomb after the 39th sample cut my hours of remaining extraction in half. TWNF is a non-profit organization dedicated to studying the natural history of the Blue Ridge. I will be the first research intern to be funded under a new research grant from the Stemmler Fund for Research in the Natural Sciences.