This is an interesting prospect. 64Ni and 64Zn are not separable by even high resolution ICP-MS. HR-ICP-MS can have resolving powers up to about 10k, but separating 64Ni and 64Zn would require a resolving power of about 55k. It is also relatively difficult to separate Ni and Zn chemically. HOWEVER, if the Zn were present, you would also see peaks for stable 66Zn and 68Zn for which there would be no corresponding peaks of Ni. The amount of total Zn would be inferred from the amounts of the 66Zn and 68Zn extrapolated back to the amount of 64Zn. I find it hard to believe that a competent lab would miss this.
On Fri, Mar 25, 2016 at 9:15 PM, Eric Walker <eric.wal...@gmail.com> wrote: > > > On Mar 25, 2016, at 8:33, "Jones Beene" <jone...@pacbell.net> wrote: > > > > However ... it should be noted that there is one other possibility to > > consider. Zinc-64 is the most common isotope of zinc, and it is slightly > > radioactive ! > > I like this suggestion a lot. As 64Zn comprises nearly half of natural > zinc, it strikes me as more likely there would have been zinc impurity than > that there should be a surprisingly high relative fraction of 64Ni. If this > is what happened, I'm further surprised that Parkhamov didn't catch > something so obvious (with hindsight and/or skill). > > I'm going to further wager that there was a high degree of measurement > uncertainty, obscuring a change that was minor or not at all in this case. > > Eric >
