First Set of Samples Processed

I have now finished sampling and digesting all the samples from the Lake Matoaka core and have run them all through the ICP. My graph follows the basic pattern of a Pb concentration graph with depth. My professor Jim Kaste and I were very interested in what looks like a double peak in my data around 20cm. If you look closely you can see there are two recorded Pb concentrations for the depth of 20-21cm. This is because I did some duplicates of randomly chosen depths so that I could compare their values to see if there was error with either the ICP or during the digestion processes. The first 20-21cm sample has a Pb concentration of 110 Micrograms of Pb/ gram of sediment and the second of 133 Micrograms of Pb/ gram of sediment. This is a huge margin of error and causes my data to appear to have a double peak. My professor and I discussed reasons for the large error and we believe that the burn step, where the samples go in the furnace for 6hrs, could be the issue. We are now in the processes of resampling a few samples around the peak and alleviating the burn step, and replacing it with an overnight peroxide step to dissolve out the organic matter that way instead. This method could also have a greater return on Pb concentrations as we believe our values are a bit low.

A rough draft of a graph with all my data collected from the Lake Matoaka core.

A rough draft of a graph with all my data collected from the Lake Matoaka core.

 

 

 

Comments

  1. This research is really fascinating, especially because I have never take the time to think about the led concentrations in Lake Matoaka. I hope the resampling process goes well!

  2. tabrandon says:

    I really enjoyed reading up on your research!

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