Tried an excitation sculpted watergate on a sample in H2O with 150 mM salt and I found that it is very hard to suppress the water signal (we have a room temperature H{C,N} gradient probe, and 800 MHz instrument).

Why presense of salt makes it so much more difficult to suppress water?

Thanks.

Tried an excitation sculpted watergate on a sample in H2O with 150 mM salt and I found that it is very hard to suppress the water signal (we have a room temperature H{C,N} gradient probe, and 800 MHz instrument).

Why presense of salt makes it so much more difficult to suppress water?

I understand that 90 degree pulse will be longer due to the RF losses. High power 90 on water increased by ~25% in this particular case, doesn't seem to be a huge increase...

Thanks.