ASTM International Low Trace Sulfur in Liquid Hydrocarbons by Oxidative Combustion with Ultraviolet Fluorescence Detection ASTM UOP987-15

This method is for determining sulfur in liquid hydrocarbons at concentrations ranging from 10 to 1500 ng/g (mass-ppb). A direct measurement procedure (Part A) is used for samples above 100 ng/g. A trap & release procedure (Part B) is used for samples between 10 and 200 ng/g where high precision is required. This method is also applicable to highly volatile samples, such as pentane, through the use of a cooled sampling system. Higher concentrations can be determined by ASTM Method D5453, "Standard Test Method for Determination of Total Sulfur in Light Hydrocarbons, Spark Ignition Engine Fuel, Diesel Engine Fuel, and Engine Oil by Ultraviolet Fluorescence" and D7183, "Standard Test Method for Determination of Total Sulfur in Aromatic Hydrocarbons and Related Chemicals by Ultraviolet Fluorescence" using the cooled sampling system described herein for highly volatile matrices. Halogens interfere at concentrations greather than approximately 0.3%. The method has reduced sensitivity to sulfur present as a sulfate. For Part A, nitrogen content must not exceed sulfur by more than 100-fold to prevent a positive bias to the results.