Sulpha is a related term of sulfur.
As adjectives the difference between sulpha and sulfur
is that
sulpha is (pharmacology) of or containing sulphanilamide while
sulfur is of a yellowish green colour, like that of sulfur.
As a noun sulfur is
(uncountable) a chemical element (
symbol s) with an atomic number of 16.
As a verb sulfur is
to treat with sulfur, or a sulfur compound, especially to preserve or to counter agricultural pests.