1. ScopeThis method is for determining sulfur in liquefied petroleum gas (LPG) and gaseous hydrocarbons at concentrations ranging from 10 to 1400 ng/g (0.01 to 1.40 mass-ppm). A trap & release procedure is used to increase the sensitivity of the analysis.
Higher concentrations can be determined by ASTM Method D6667, "Standard Test Method for Determination of Total Volatile Sulfur in Gaseous Hydrocarbons and Liquefied Petroleum Gases by Ultraviolet Fluorescence," or ASTM Method D7551, "Total Volatile Sulfur in Gaseous Hydrocarbons and Liquefied Petroleum Gases and Natural Gas by Ultraviolet Fluorescence," by using the instrument without the trap & release module.
LPG samples are expanded into the gas phase before analysis. If any heavy sulfur compounds are present in the LPG that do not volatilize quantitatively with the LPG, they may be underreported.
Halogens interfere at concentrations greater than approximately 0.3%. The method can also be applied to the analysis of hydrogen and other gas samples.