Given a list of Uniprot ids that are linked to a Esemble ID is there a way to systematically determine which is the _primary_ accession number with no other information? 

[According to ExPasy](http://web.expasy.org/docs/userman.html#AC_line)
> Researchers who wish to cite entries in their publications should
> always cite the first accession number. This is commonly referred to
> as the 'primary accession number'. 'Secondary accession numbers' are
> sorted alphanumerically.

But what if the order has been jumbled or compiled from a different source and resorted.

For example:

Ensembl:

ENSMUSG00000035642

Uniprot: 

Q8R0P4, Q8CF11, D6RJK8, D6RJJ4, D3Z442, D3Z1Q3, D3YZD8, D3YY39, D3YX09, D3YWY5