You did not tell me the two papers. Am I guilty?
In LIMS for Light Stable Isotopes, I aid users in "adjusting"
their isotopic data using the "normalization" equation:
Final Delta = a * Penultimate delta + b
I call call coefficient a the "expansion factor" and
coefficient b the "additive correction factor." Together they
make up the normalization equation coefficients. It seems to
me that you are concerned about the case where a is 1. Then this
equation reduces to:
Final Delta = Penultimate delta + b
Now if I understand your concern, you would say that performing
this operation is not "normalization," but rather data adjustment,
or call it something else. I do not have strong feelings on this
topic, but it seems to me that this can be called normalization.
Does it matter that the expansion factor is 1 or not?
I think we are slowly moving to the position where the carbon and the
sulfur scales will be constrained by more than a single reference
material. When this happens, I suppose we would both call the process
of adjusting isotopic data using two reference materials (standards)
>Confusion of terms
>There have been two international papers recently, which have
>misused or abused the term 'normalization'. At least since
>Gonfiantini (1978) in NATURE 271, 534-536, there are two modes of
>adjustment of a stable isotope delta scale. One is the exact
>setting of zero (zero shift) and the other, scale normalization.
>Scale normalization involves two isotopically very different
>reference materials and effectively sets or normalizes the size
>of the delta permil unit. The zero shift is more trivial, but no
>less important. Clearly the Oxford or Webster Dictionary will not
>tell us the difference, but confusing these terms will begin to
>undo the tremendous progress made in the last few years with the
>reporting of stable isotope data.
>Thanks, and cheers from New Zealand.
>([log in to unmask])