Could do with some help (what's new :) )?
1D That's - that was (5) S?E?L [thinking SWELL maybe?]
14A Taramasalata (3,3) [OIL in there somewhere?]
21A Sultanate swig (17) (3) [answer to 17 is ferric]
13D 7 got a problem with loud measurement (8) [answer to 7 is CORBETT]