Hi Guldana Issabayeva

I of course don't know what you have in your mixture so my answer is tentative.

What you propose is correct in principle, but it will take a long time and unless done under vacuum (close to room temperature) it may lead to thermal degradation of your product. I'll suggest two alternatives.

One possibility is actually to separate the aqueous phase and add more MgSO4 to it, to near saturation, so you "salt out" your product. Then extract it with a low polarity solvent such as diethyl ether or ethyl acetate.

Another possibility is to titrate the aqueous phase slowly with a Ba(OH)2 solution of known concentration. (This assumes you have at least a rough idea how much MgSO4 is in the solution.) The end-point detection can be done conductometrically or thermometrically, and probably there are a couple additional methods that will work. You'll get Mg(OH)2 and BaSO4, both insoluble, and in principle they can be separated out by filtration. Since at least Mg(OH)2 is hard to filter though, it may be more practical to centrifuge the suspension and decant. This will lose some product, but the extraction procedures will lose some too.

Emanuel Cooper , Thank you for your recommendations. I will try to "salt out" the product as you suggested.