Hi,
I'm measuring FTIR spectra of samples made with KBr pellets. I take a background of the air, then measure the spectrum of a KBr pellet, and I'm seeing a set of peaks around 3500 cm^-1 and a doublet centered at 1630 cm^-1. The procedure is to grind 0.4 g in a mortar and pestle, load it into a dye, then compact it at 1 ton. The pellet is about 1 mm thick.
So I try drying the KBr by heating under air and get the same results.
I try heating the KBr under vacuum and get the same results.
I try the same experiment with NaCl and get the same results, and the same experiment with NaCl + yellow prussiate, a drying agent, and get the same results.
I try cleaning my pellet press thoroughly with a few different solvents and get the same results.
I assume this is water, maybe in the form of a hydrate since im getting resolved peaks rather than bands. But it's just not going away when I try to dry it.
Does anyone know how to address this? My KBr should be transparent in the 400-4000 cm^-1 range if I dry it perfectly.
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