In reply to Jones Beene's message of Wed, 3 Dec 2008 18:10:42 -0800 (PST): Hi, >Robin, > >> "There another possibility that keeps nagging at me.... It occurs to me that >> perhaps there is something like CHy, with a strong bond between the Hy and >> the C, which would have a mass of 13, and would pass for C13. > > >Well - the problem is that the (hypothetical) molecular ion 12C(Hy)+ would not >have the identical mass of atomic 13C+, but in fact would be slightly less. >The instrument used - so I am told - should be of a precision to be able to >differentiate the two if it were calibrated to do so, and if the operator was >so instructed to look for it. Apparently two different instruments were used, >and the results with the most precision was done by an outside contractor and >specialist who perhaps should have noticed a variance. This is not clear >however.
Indeed. A resolution (M/delta M) of about 3000 would be needed to tell the difference. [snip] Regards, Robin van Spaandonk <[EMAIL PROTECTED]>
