Simultaneous Determination of Ethanethiol, Inorganic Sulfide, and Sulfite in Wines by Cathodic Stripping Voltammetry

This paper deals with the simultaneous determination of ethanethiol, inorganic sulfide, and sulfite in wines using cathodic stripping voltammetry. Under the optimized experimental conditions, a linear response to ethanethiol (0.2 to 0.6 mg L −1 ), inorganic sulfide (0.016 to 0.048 mg L −1 ), and sulfite (1.5 to 4.5 mg L −1 ) were obtained with correlation values R 2 above 0.985. A detection limit of 0.3, 0.2, and 10 μg L −1 was obtained to ethanethiol, inorganic sulfide, and sulfite, respectively. The recovery values obtained were between 78 and 104 % to ethanethiol, 88 and 108 % to inorganic sulfide, and 87 and 102 % to sulfite. The highest levels of ethanethiol, inorganic sulfide, and sulfite obtained in the samples were 4.85, 0.44, and 44.72 mg L −1 , respectively. Besides, this method does not suffer interference from other compounds naturally present in the samples, and it enables fast and reliable determination of these sulfur compounds in wines, with minimal sample pretreatment.