Electrochemical determination of elemental sulfur in Brazilian naphtha: method and validation

Sulfur compounds in petroleum have caused several problems such as corrosion of equipment, lack of high quality final products, and emission of toxic gases into the environment. Elemental sulfur can increase these problems, since small amounts of it turn mercaptans into potential corrosion agents. This paper describes the applicability of a voltammetric method to quantify elemental sulfur in Brazilian naphtha samples. Elemental sulfur was quantified in synthetic and real samples using square wave voltammetry and a hanging mercury drop electrode. The method was found to have low limits of detection (0.003 mg L(-1)) and quantification (0.009 mg L(-1)) and a good recovery range (94.0-108.6%). This voltammetric method has potential for use in elemental sulfur determination in naphtha samples containing mercaptans and aliphatic and aromatic disulfides.