The H adduct works very well for PC. The FA assignments
are more reliable with H adducts than with Na adducts,
even though more FA assignments are possible with Na. The
problem with Na is that the fragments are closer to noise
which may be due to the generally lower intensity of the
precursor. Biological data shows that Na FA assignments
can be used for verification of H assignments, but they
lead to more FPs -> it is not advisable to trust FA assignments
based solely on Na adducts.

Positional assignment is only feasible with the H adducts.

