Thursday, June 10, 2010
This morning, I analyzed the results from my tests yesterday, and I found some strange results. In general, all of the predicted solution concentrations I got from the spectrometer read-outs were at least 3% larger than the concentration to which I tried to prepare the solutions. In fact, all but one set of data was over the prepared concentration. This is rather a rather disturbing systematic error, and the sources need to be identified. Though the results are not as accurate as we need, the good news is they are very precise, because if you ignore their consistant 3-6% overreading, they are then within 1%. These could be all random errors, but that seems unlikely because of their consistency. They could also being coming from my technique of solution. It could also be a systematic error coming from the pipettes. It could also be an issue with the calibration with the machine. I will investigate the source of the error more tomorrow. I did a few tests at the end of the day, and they showed that the pipettes might be cause a small portion of the error, but nowhere near all of it. I also did more research into the cobalthexamine project that I will be working on throughout the summer.
Posted by jgiannini at 11:32 PM