This Gulf standard is concerned with determination of mercaptan sulphur in gasolines, kerosene, aviation turbine fuels and distillate fuels containing from 0.0003 to 0.01 mass % of mercaptan sulphur. Organic sulphur compounds such as sulphides, disulphides and thiophene do not interfere. Elemental sulphur in amounts less than 0.0005 mass % does not interfere. Hydrogen sulphide will interfere, if not removed as described in 8.2.