Evaluation of Summa Polished Canisters, Silonite, and Silcosteel Treated Canisters for Collection and Storage of Volatile Organics at the Parts per Trillion Levels - 2004

摘要

The collection of whole air samples for the analysis of VOCs with the use of Summa passivated canisters, and more recently, Silcosteel and Silonite passivated canisters is considered standard practice for EPA Compendium Method TO-15. Risk assessment for VOCs at the 10{sup}(-6) cancer risk is requiring laboratories to report VOCs as low as 3 parts per trillion by volume (pptv). The analysis of toxic volatile organics at low pptv levels in whole air samples has forced laboratories to reevaluate their analytical systems and practices. One such system is the sampling media used to collect and store a whole air sample prior to analysis. This paper summarizes results of a stability study for 44 VOCs on Days 0, 7, 15, and 33 for Summa, Silonite, and Silcosteel canisters at pptv levels. Canisters were certified by analyzing each one by GC/MS prior to the recovery study. The results from the certified canisters were later used to predict which VOCs would result in high recoveries over the 33-day period. The study found that 7.2% of the VOC recoveries showed a bias greater than ±30%. The certification analysis was able to predict 75% of the VOCs that would ultimately report a high bias. High bias could be mitigated by analyzing samples within 14 days and increasing the reporting limits of Benzene and Toluene.