Thanks for putting me on the track again.
I should visit my own isotope class next semester and a look into a book can also be helpful... :-)
Am 09.07.2010 um 11:35 schrieb Robert Van Hale:
> Easy way round: Enter zeros for the gas into Isodat and the intercept of your normalisation equation is the value of the gas. That's assuming that you using a two/multi point normalisation.
> Otherwise with NBS 19 alone: two steps, raw delta vs gas converts to gas vs raw delta with (1/(d/1000+1)-1)x1000; gas vs raw delta converts to gas vs PDB with da-db+(daxdb)/1000