Mercaptan sulfur has an objectionable odor, an adverse effect on fuel system elastomers, and is corrosive to fuel system components.

1.1 This test method covers the determination of mercaptan sulfur in gasolines, kerosines, aviation turbine fuels, and distillate fuels containing from 0.0003 to 0.01 mass % of mercaptan sulfur. Organic sulfur compounds such as sulfides, disulfides, and thiophene, do not interfere. Elemental sulfur in amounts less than 0.0005 mass % does not interfere. Hydrogen sulfide will interfere if not removed, as described in .

1.2 The values in acceptable SI units are to be regarded as the standard. The values in parentheses are for information only.

This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific warning statements, see Sections , , , and .

1.3 This test method provides an alternative to using a cadmium sulfate acid solution. (Warning-Poison. May be fatal if swallowed or inhaled. A known carcinogen (animal positive).) (Warning-Poison. Causes severe burns. Harmful or fatal if swallowed or inhaled.)

1.4 This test method uses lead acetate test paper (Warning-Poison, health hazard, may be toxic by ingestion, inhalation, or absorption through the skin) to test for the presence of hydrogen sulfide and sodium hydrogen carbonate for the removal of hydrogen sulfide.

1.5 This test method shall not be used when the sample is a referee sample or when QA/QC protocols specify the test method as written. Instances in which they can be used may be instances of routine refinery control samples.