Sulfinert-Treated Sample Cylinders
Store Active Sulfur Compounds at ppb Levels
- Stable storage of sulfur compounds at ppb levels.
- D.O.T. rated to 1800psi at room temperature.
- High quality cylinders manufactured by Swagelok.
Refinery and natural gas samples often contain trace amounts of sulfur-containing compounds which can interfere with reactions or poison catalysts in petrochemical processes. Because sulfur compounds quickly react with stainless steel surfaces, accurate determination of these compounds is impossible when samples are collected and stored in untreated sample cylinders. Restek’s Sulfinert passivation technique bonds an inert silica layer into the surface of stainless steel, preventing active compounds from reacting with or adsorbing to the steel.
To characterize Sulfinert surfaces, we tested the stability of 17ppbv standards of sulfur compounds in three Sulfinert sample cylinders over a 54-hour period. Dimethyl sulfide, which is not adsorbed by stainless steel, was used as an internal standard.
The Sulfinert-treated cylinders were inert to the reactive sulfur compounds over the 54-hour test period (Figure 1). Hydrogen sulfide exhibited greater than 85% recovery; methyl mercaptan, ethyl mercaptan, carbonyl sulfide, and dimethyl disulfide exhibited greater than 90% recovery.
Sulfinert-treated gas sampling equipment is ideal for collecting and storing samples containing ppb levels of sulfur compounds, such as natural gas or beverage-grade carbon dioxide. Sulfinert treatment ensures that sulfur compounds or other highly active compounds remain stable during transport from the field to the laboratory.
Figure 1: Stability of sulfur compounds is remarkable in Sulfinert-treated cylinders.