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I love soup, even a thick soup for dinner, yet many soup products have 400 to 1000 mg of sodium in them. Is there a simple chemical procedure any consumer could do to take the sodium out of the product without 'hurting' the flavor?

If one takes some, say, Campbell's soup and heats it to boiling, then freezes it, then heats it again, then freezes it etc., would this extract some sodium?

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Several brands offer low-sodium versions, but maybe you'd like even less salt that they offer? –  Silvio Levy Jul 22 at 21:53
I don't know how practicable it would be with soup, but size exclusion chromatography or dialysis can used to remove salts (although there would be no selectivity for sodium). –  canadianer Jul 24 at 2:24
IF several brands offer low salt versions WHERE do you find them? Shopper's Drug Mart sells a lot of tasty foods in some of their stores but they generally have a salt content over 300 mg. for each product. THEY'RE supposed to be for health I assume. EVEN those Health Check product in Grocery stores have over 400 mg. of salt for one person with one serving. –  user128932 Aug 15 at 6:08

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up vote 6 down vote accepted

Short answer: no, there is no easy (or even moderately hard) procedure, and certainly not boiling and freezing.

The thing is that water dissolves sodium ions better than just about anything else, so almost everything will come out of solution before the sodium does. You're much better off with a product that starts with less salt to begin with.

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Could some safe substance be added to the soup that absorbs the sodium and doesn't spoil the flavor? –  user128932 Jul 22 at 21:53
I've added a 2nd paragraph to my answer addressing that. Sorry to disappoint you. –  Silvio Levy Jul 22 at 21:58
@user128932 To elaborate on Levy's answer, sodium very rarely forms any type of solid compound because of its solubility. There's nothing you can do to "absorb" the sodium because elements can't be lost. Your best bet would be to react something with the sodium ions that produces an insoluble solid, and then to physically remove the solid. But that's virtually impossible with sodium. –  Jeremy Jul 23 at 0:38
In truth it is not inconceivable that some day we will have molecular sieves that can preferentially trap sodium ions while rejecting bigger species. You could then add some of these magic beads to your soup, stir for 10 minutes and scoop them out, carrying the salt (assuming the soup is not too thick). I doubt taste would be unaffected, though. Your soup would taste sour since you'd be replacing $\ce{Na^+}$ with, presumably, $\ce{H^+}$; even if most of these got attached to bases you'd still be lowering the pH. In any case I know of no such technology at present. –  Silvio Levy Jul 23 at 1:07
Great information! It would be nice if more chemists and food chemists could complain to Campbells soup , Knorr soup ,Healthy-choice soup, and a whole lot of other product about the amount of sodium in the product that can't be gotten rid of. Isn't it true if most people cut down their sodium levels from processed food A LOT of money would be saved in healthcare costs? –  user128932 Jul 24 at 2:18

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