Simultaneous Determination of Fuel Oxygenates and BTEX Using Direct Aqueous Injection Gas Chromatography Mass Spectrometry (DAI-GC/MS)

A direct aqueous injection-gas chromatography/mass spectrometry (DAI-GC/MS) method for trace analysis of gasoline components in water is presented. The method allows for the simultaneous quantification of the following solutes: methyl tert-butyl ether (MTBE), its major degradation products (tert-butyl formate, tert-butyl alcohol (TBA), methyl acetate, and acetone), and possible substitutes of MTBE as an octane enhancer in gasoline (tert-amyl methyl ether, ethyl tert-butyl ether) as well as benzene, toluene, ethylbenzene, p-xylene, m-xylene, and o-xylene (BTEX). No enrichment or pretreatment steps are required, and sample volumes of only 50 μL are needed for analysis. The detection limits in two different matrixes (spiked lake water and contaminated groundwater) are ≤2 μg/L for most analytes and