Abstract
| - Selectivity enhancement of membrane introduction massspectrometry of nonpolar alkanes, alkenes, and aromatichydrocarbons in air samples by application of nitric oxidechemical ionization (NOCI/MIMS) is demonstrated.Membrane methods are useful for separating compounds(usually nonpolar organics) from air and water sampleswithout costly and time-consuming sample preparation, andcoupled with mass spectrometry, they provide goodsensitivity. But they often suffer from lack of specificity inmixture analysis, particularly for saturated organics.Nitric oxide chemical ionization is able to produce strongunique ion signals for many hydrocarbon test compoundsthat can be used to identify and quantify the parent neutrals.Our observed detection limits for a number of testcompounds were relatively high; however, the methodcould potentially be useful for environmental analyticalapplications (e.g., plume tracking) if the monitored compoundwas at elevated levels or if NOCI/MIMS is coupled witha trapping method.
|