Half Life of ATP, PPADs and Suramin - (Feb/25/2009 )

I am about to do some physiology experiments but cannot find that half live values for ATP, PPADs and Suramin does anyone know them? I have tried the net but I cannot find much! Cheers.

hope it's not too late for the answer!
I don't know about suramin or PPADS, but ATP is very short lived in cell culture or slices. it's metabolized in minutes by extracellular nucleotidases present in the cell surface.