Jones, >From what I have read, you are correct that some QMS RGA instruments can read negative ions (such as potentially f/D-), but it must have a dual mode ionizer front end. In normal mode the ionizer has fast electrons that will not produce significant negative ions, and in fact the high speed electrons will typically disassociate molecules. To measure negative ions, the front end must be configurable for low speed electrons that will not cause impact ionization and will allow electron attachment. So there is easy and intentional discrimination between normal positive ion mode and optional negative ion mode of the front end. We don't know if Mizuno's RGA has the negative ion capability, but it most certainly has positive ion mode as its main (and perhaps only) mode. What was reported was highly likely the positive ion readout. We should probably presume the positive ion mode and also molecular fragmentation.
Thanks for stimulating me to take a closer look at QMS. Bob Higgins On Sat, Aug 2, 2014 at 3:13 PM, Jones Beene <jone...@pacbell.net> wrote: > *From:* Bob Higgins > > > > The quadrapole mass spec RGA will have a front end ionizer to extract an > ionized sample for measurement. I think this front end is likely to only > extract positive ions and there will be no f/D+ because there is no such > thing. > > > > AFAIK - Mass specs can be run in positive mode or negative mode. > > > > If an f/D- exists, I don't think it would be measured by the RGA. So, > M/e=2 would have to be D+ or H2+. > > > > We need to know if they were running in positive mode before we can go > that far. You could be right, but we do not have enough information. > > > > Robin may weigh in on redundant deuterons. To be honest, I had always > marginalized the possibility of “deuterino deuteride” before Yoshino/Mizuno. > > > > The great allure of it, is that it explains things in a way that is hard > to do otherwise. This is how Physics, or Fizzix, if you are in doubt - > ended up with the “neutrino”. It was invented many years before it was > found, simply to answer questions. Later it was actually found. Sometimes > you can work backward from known results. > > > > There is no doubt that lots of people thought the neutrino was a stretch. > A few still do. Nevertheless it is a case in point for using the best data > fit and then working backwards from that by the process of elimination. > > > > Jones > > >
