Volatile Organic Compounds (VOCs) are a group of organic chemicals that have low boiling points and high vapor pressures at ambient conditions. A large number of the VOCs present in ambient air at trace levels (part-per-billion) are toxic, as those listed in US EPA Method TO-15, causing environmental pollution and health risks to human life. The determination of VOCs is currently carried out in-situ by direct sampling and gas chromatographic analysis of the air samples or, indirectly, by previous sampling of the air in canisters or into sorbent tubes. To ensure accuracy and traceability of the measurement results, high metrological VOC gas standards are required for calibration of the analytical equipment.
VSL has developed various sets of trace levels VOC gas standards in nitrogen, which are part of the TO-15 list, namely the Non-Methane Hydrocarbons (Ozone Precursors, NMHC), the Air Toxics (including Chlorinated VOCs) and Oxygenated VOCs (OVOCs).
These gas standards are prepared by a state-of-the-art gravimetric preparation method. To develop accurate gas standards, high pressure aluminum cylinders with different proprietary treatments have been tested to evaluate possible VOC interaction with the contact surfaces upon gas mixture preparation. The best performing cylinder types have been further investigated to verify the long-term stability of the reference material. The results of the studies show that some VOCs interact strongly with the contact surfaces, while others are unstable if stored for long periods. This study demonstrated that different cylinder types are necessary to produce accurate and stable sets of VOC gas standards.
VSL expert, Annarita Baldan will present the results of this study during the Pittcon 2019 (Wednesday, March 20, 2019, 9:30 am, abstract number 1480-4; location 121C, session 1480 Environmental Analytical Methods using Mass Spectrometry). Pittcon 2019 will be a major networking opportunity. Please use this opportunity and get into contact with VSL! Next to our VOC services, you can get information about all our other services at our booth in the exhibition area (booth number 2232).