Collection and determination of 4,4′-bipyridine vapor using XAD-2 resin

A vapor generation system, using a permeation tube to produce 4,4′-bipyridine vapor, was designed to evaluate the collection efficiency (CE) of XAD-2 resin. At less than 10% relative humidity, collection efficiency was found to be 94.7%±2.1%. At greater than 90% relative humidity, CE was slightly reduced to a level of 80.5%±4.8%. The results of a breakthrough study indicate that in 5 successive collections from the XAD-2 collection tube, less than 2.6% of the total 4,4′-bipyridine volume was released. A comparison of XAD-2 resin collection results with estimations based on gas saturation (GS) suggests that XAD-2 resin is an effective sorbent for collecting 4,4′-bipyridine. The authors concluded that XAD-2 resin is well-suited for use in systems to measure personal exposure to 4,4′-bipyridine vapor.