Glass and Silonite™ ceramic treated stainless steel canisters offer higher recoveries of TO-15 Compounds than many other sampling devices, including electropolished canisters, Tedlar® bags and thermal desorption tubes. Recovery of HS and light Mercaptans are still problematic, however, primarily due to a surfaced induced condensation reaction that occurs when enough water exists on the surface to allow dissociation of the acidic proton found in these light, reduced sulfur compounds. Even at relative humidities as low as 30%, a water layer can exist on the surface to catalyze these reactions. Independent laboratories have attempted canister use for routine reduced sulfur compound monitoring and found less than optimal recoveries, even with holding times as short as 1 to 2 days.
It is well known that dropping the water content to below 10% RH in glass bottles and Silonite® treated stainless steel canisters allows for excellent long term storage of these light sulfur compounds. Unfortunately, the practical application of water management in the eld has been limited. A new approach is presented here utilizing a Cold Trap Dehydration (CTD) technique to eliminate most water content in a sample prior to introduction into a glass or Silonite® canister.
|Accurate Monitoring of Sulfur Compounds in Silonite® Fused Silica Lined Canisters Utilizing a New Approach for Water Removal During Field Sampling||Open Download|
|Create Date||August 24, 2015|
|Last Updated||July 13, 2017|