Canister Cleaning Practices and Blank VOC Concentrations

Oral Presentation

Prepared by J. Herrington, G. Stidsen, J. Konschnik, S. Kozel
Restek, 110 Benner Circle, Bellefonte, PA, 16823, United States

Contact Information:; 908-208-1682


The United States (U.S.) Environmental Protection Agency’s (EPA) Compendium Method TO-15 [Determination of Volatile Organic Compounds (VOCs) In Air Collected In Specially-Prepared Canisters And Analyzed By Gas Chromatography/Mass Spectrometry (GC/MS)] is a “guidance document” for a “performance-based method (PBM).” Therefore, the method makes a couple of recommendations on how end-users may clean canisters; however, end users are not obligated to follow said suggestions. In addition, the method does not address the advantages/limitations of different “sweep” gases, temperatures, cycle numbers, humidification, blank storage durations, etc.… Furthermore, the current body of peer-reviewed literature does not address the above topics. Therefore, the aforementioned data gaps has resulted in a situation where the number of various canister cleaning schemas utilized across the nation is probably close to equaling the number of laboratories conducting TO-15 analyses (i.e., no two laboratories clean canisters in the same fashion). This phenomenon may have little practical relevance for laboratories simply looking to meet the 0.2 ppbv blank cleanliness benchmark specified in method TO-15. However, as laboratories aim to lower reporting limits, the subtle differences between canister cleaning practices may have a significant impact. Therefore, the following work was conducted to evaluate which canister cleaning practices contribute to the lowest blank VOC concentrations. The current work was executed on commercially available electropolished stainless steel canisters. Although electropolished canisters represent a significant share of canisters in use, this is a limitation of the current study, as silicon-lined stainless steel canisters are widely in use. Future work will include the same evaluations on silicon-lined canisters.