The simplest solution would be to buy a new bottle of DMSO. If you want to recover the d6-DMSO, then If you have a mixture of DMSO and water, try distillation, it should work. If you have several % of water, use whatever procedure to dry DMSO.
Separation: DMSO and water can be separated through a process called fractional distillation. This method takes advantage of the different boiling points of DMSO and water. DMSO has a boiling point of 189 °C (372 °F), while water boils at 100 °C (212 °F). By heating the mixture, you can vaporize the DMSO, which can then be condensed and collected separately.
Distillation setup: Set up a distillation apparatus, which typically consists of a round-bottom flask, a distillation column or fractionating column, a condenser, and a collection flask. Ensure that the apparatus is clean and free of contaminants.
Heat and condense: Apply heat to the mixture, gradually raising the temperature. As the temperature increases, Water will vaporize and rise up the column. The vapor will then condense on the cooler surface of the condenser and drip into the collection flask. The DMSO will remain in the original flask.
Collection: Collect the condensed DMSO in the collection flask. The purity of the DMSO will depend on the efficiency of the distillation process. Repeat the distillation process if higher purity is desired.
It's important to note that DMSO has a relatively high boiling point, so you'll need to use appropriate equipment capable of handling the necessary temperatures. Additionally, proper safety precautions should be followed when working with heat and volatile substances.
If there is not much water, inorganic salts can be added to saturate the water layer, which can be layered. Alternatively, molecular sieves can be used. But if there is too much water, it is recommended to purchase dmso again.