Volume 2, Issue 7 (July 2005)
DP-SCD and LTMGC for Determination of Low Sulfur Levels in Hydrocarbons
A novel measurement technique has been developed for the rapid determination of low levels of sulfur in hydrocarbon matrices. The technique employs low thermal mass gas chromatography (LTMGC) and a dual plasma sulfur chemiluminescence detector (DP-SCD). Highly sensitive total volatile sulfur measurement can be made in less than 30 s with detection limits in the 20–30 parts per billion range. Response is linear over at least three orders of magnitude sulfur with excellent repeatability. By taking advantage of LTMGC's rapid temperature programming and cool down time, it is also possible to measure individual sulfur species, analogous to ASTM D 5623. Conditions have also been developed using the same analytical apparatus to detect the major elemental sulfur allotropes (S2, S3, S6, S7, and S8) in gasoline at levels that can cause silver corrosion.