Measurement of fuel oxygenates in tap water using solid-phase microextraction gas chromatography-mass spectrometry.

The presence of alkyl ether fuel oxygenates in drinking water supplies has raised public health concerns because of possible adverse health effects from chronic exposure to these compounds. To enable large exposure studies exploring possible relationships between chronic exposure to alkyl ether fuel oxygenates and health effects, we developed an improved analytical method, using headspace solid-phase microextraction coupled with capillary gas chromatography and mass spectrometry. This method quantifies trace levels of methyl tertiary-butyl ether, ethyl tertiary-butyl ether, di-isopropyl ether, and tertiary-amyl methyl ether in tap water. The method achieves detection limits of less than 0.025 microg/L for all analytes and linear ranges of three orders of magnitude in the measurement of the alkyl ether fuel oxygenates in 5-mL tap water samples. The relative percentage of recoveries of the alkyl ether fuel oxygenates ranged from 97% to 105%. The relative standard deviation ranged from 2% to 6%. Methyl tertiary-butyl ether was detected in samples of tap water taken from geographically diverse regions of the United States. The improved throughput and sensitivity of this method will enable large epidemiologic field studies of the prevalence and magnitude of exposure to alkyl ether fuel oxygenates in the general population.