Plz try this, by the conformation test i think it will be workout. Add Ethanol with trimethyl sulphoxonium iodide and make the solution little warm up 40-60 C for 2 to 3 h. Check any clear solution has seperated out. The solution turn to be a brown when impaigning with the light (uv) source. Then we can conform it trimethyl sulphoxonium iodide. If the solution dosent show brown add little amount of phosphorus (P2O5) in it. All the reagents addition under very dilute condition feel better result expect. Actually it is an indirect method to identification of iodide from trimethyl sulphoxonium (TMS) complex. There are many methods to be identification of (TMSI) compound, but i considered this one is very simple.

Infrared spectrum Conforms to Structure

Carbon 16.0 - 16.8 %

Sulfur 14.2 - 15.0 %

Melting point 208-212 °C