So the obvious question to me is: is there no other physical property that can be used to separate the hydration shell + ion molecule combinations from the just

So the obvious question to me is: is there no other physical property that can be used to separate the hydration shell + ion molecule combinations from the just-water molecules? Different magnetic charge? Different mass? Different chemical reactivity? ¯\_(ツ)_/¯ I know the answer must be 'no' since if there were a better answer, none of what I'm thinking of requires more than high-school-level chemistry to discover/exploit.