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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: DutchGirl13 on September 28, 2010, 05:42:20 PM

Title: What accounts for the discrepancy in peak heights on UV-Vis spectroscopy?
Post by: DutchGirl13 on September 28, 2010, 05:42:20 PM

I am looking at graphs made by a UV-Vis spectrophotometer of a HoCl3 solution. At a slit width of 0.04 nm, the peaks are sharp and high. When the same solution was analyzed with a slit width of 5.00 nm, the peaks were wider and shorter. In one case, the 5-nm peak was about five-eighths the size of the 0.04-nm peak. I am sure it has something to do the slit opening size, but i am not sure how to connect it. I think it goes something like this: the broader slit width allows in more light, so it seems the light comes from a larger range of wavelengths and is not concentrated as much at one wavelength. Is this close to reality?