Pickling solution (5)
I believe the answer is:
brine
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pickling solution</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for brine that I've seen before include "preservative" , "Salty water" , "pickle" , "Seawater" , "Strong salt-water solution" .)