The purpose of this method is to remove hydrogen sulfide and to reduce the mercaptan content in hydrocarbons, which are liquid at room temperature, by extraction with sodium hydroxide under standardized conditions. The treated distillate may be processed further in a pilot plant or tested for properties other than hydrogen sulfide and mercaptan content. Such additional processing or testing is beyond the scope of this method.

The results obtained by this method can also be correlated empirically with results from a commercial extractor as a check for extractor performance. When the characteristics of a given extractor are known in terms of this test, this procedure can be used to estimate results to be expected when extracting a new stock. This type of correlation is also beyond the scope of this method.