What's the standard amount or concentration for using Cr(acac) in a Quantitative Carbon? I read 30mg per ml but that is A LOT more than appears to be in some of the doped stardards. It is VERY difficult to shim with that much in the tube. What do you generally go with?
asked Aug 17 '12 at 09:02
I used to use around 6mg per 0.7mL of sample within the tube. This is around 0.025M. Using this concentration, I had no problems shimming the sample and line-broadening was barely noticeable. For my samples, the T1-times were reduced to considerably less than the half of the values you get for the case of not adding a relaxation agent.
answered Aug 18 '12 at 10:17