DETERMINATION OF GASOLINE OXYGENATES IN AIR USING A DIFFUSIVE SAMPLER

The US production of methyl tert-butyl ether (MTBE) for use in oxygena ted fuel formulations has risen more than 25% over the past decade as a response to mandates of the US Environmental Protection Agency Clean Air Acts. The SKC 575-001 diffusive sampler containing charcoal was i nvestigated as a method for the collection of MTBE and its homologues ethyl tert-butyl ether (tert-butyl ethyl ether, TBEE) and methyl tert- amyl ether (tert-amyl methyl ether, TAME) from air, The sampler was fu lly validated for MTBE according to a modified version of the US Natio nal Institute for Occupational Safety and Health (NIOSH) protocol for diffusive sampler evaluation, which is similar in scope to the Comite Europeen de Normalisation (CEN) standard EN 838, The test concentratio ns were based on the American Conference of Governmental Industrial Hy gienists threshold limit value of 40 ppm, The sampler collected MTBE e fficiently at an uptake rate of 13.65 ml min(-1) over the range of con ditions studied, with an accuracy within the NIOSH Accuracy Criterion or CEN standard EN 482. The recovery of both TBEE and TAME was accepta ble (101% and 99%, respectively), and experimental uptake rates were c lose to those calculated from theory (13.1 versus 13.3 ml min(-1), for both compounds).