Oxidation of dimethyl sulfide to dimethyl sulfoxide in liquefied petroleum gas prior to piezoelectric crystal detection

Abstract

A selective oxidation method was developed for the conversion and determination of the stenching agent dimethyl sulfide (DMS) in liquefied petroleum gas (LPG). The conversion efficiencies of three oxidising agents, sodium periodate, manganese(IV) oxide and Caro’s acid (potassium monopersulfate triple salt), were evaluated by GC-FID and squalane coated piezoelectric crystal monitoring. Sodium periodate and manganese(IV) oxide converted 100 and 200 ppm of DMS to dimethyl sulfoxide (DMSO) at ambient temperature in gaseous butane with 24–32% efficiency. Caro’s acid converted DMS to dimethyl sulfone (DMSO₂) with 20–31% efficiency in the same medium. The technique demonstrates the potential of these reagents for the determination of DMS in LPG.