Citation:

McClenny, W A., K. D. Oliver, H. H. Jacumin Jr., E. H. Daughtrey Jr., AND D A. Whitaker. 24-HOUR DIFFUSIVE SAMPLING OF 1,3-BUTADIENE IN AIR ONTO CARBONPAK X SOLID ADSORBENT WITH THEMAL DESORPTION/GC/MS ANALYSIS - FEASIBILITY STUDIES. Presented at Symposium on Air Quality Measurement Methods & Technology, Research Triangle Park, NC, April 20-22, 2004.

Impact/Purpose:

Develop innovative and customized new measurement approaches for air toxic VOCs as requested by methods development clients.

Description:

Diffusive sampling of 1,3-butadiene for 24 hours onto the graphitic adsorbent Carbopack X contained in a stainless steel tube badge (6.3 mm OD, 5 mm ID, and 90 mm in length) with analysis by thermal desorption/GC/MS has been evaluated in controlled tests. A test matrix of 42 trace level volatile organic compounds in humidified zero air was established by dynamic dilution of compressed gas standards flowing through an environmental chamber. Conditions for automated thermal desorption of the badge including pre-desorption dry purge, and for GC/MS analyses (column flow rate and temperature programming profile) were optimized for specificity, precision, and sensitivity of response. Analytical system responses for sets of tubes exposed to a given 1,3-butadiene concentration were typically precise, e.g. a % RSD < 10% at 1.1 ug/m3 (0.5 ppbv at STP) and system responses were approximately linear with concentration over the range 0 - 9 \ug. No systematic variations of response were observed for changes in sample humidity and temperature (35% to 75% RH at 16,20, and 29 degrees C). Reverse diffusion of 1,3-butadiene into clean air over 12 hours after an initial 12 hour exposure at 9.0 ug/m3 gave a 11% response decrease. Adding 2 ug/m3 (100 ppbv at STP) of ozone during the second twelve hours caused no additional response change.

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Record Details: