Potassium ethyl xanthate Potassium ethyl xanthate Potassium ethyl xanthate (KEX) is an organosulfur compound with the chemical formula CHCHOCSK. It is a pale yellow powder that is used in the mining industry for the separation of ores. Unlike the related sodium ethyl xanthate, the potassium salt exists as an anhydrous salt. Xanthate salts are prepared by the action of alkoxides on carbon disulfide. The alkoxide is often generated in situ from potassium hydroxide: Potassium ethyl xanthate is a pale yellow powder that is stable at high pH but rapidly hydrolyses at pH <9 at 25 °C. Unlike the sodium derivative, potassium xanthate crystallizes
Ethyl carbamate externally where it is able to react with the alcohol to create ethyl carbamate. In 1988, wine and other alcoholic beverage manufacturers in the United States agreed to control the level of ethyl carbamate in wine to less than 15 ppb (parts per billion), and in stronger alcoholic drinks to less than 125 ppb. Although the urea cannot be eliminated, it can be minimized by controlling the fertilization of grape vines, minimizing their heat exposure, using self-cloning yeast and other actions. Furthermore, some strains of yeast have been developed to help reduce ethyl carbamate during commercial production of alcoholic beverages.