Method Detection Limit Determination and Application of a Convenient Headspace Analysis Method for Methyl tert-Butyl Ether in Water

Methyl tert-butyl ether (MTBE) is a common groundwater contaminant, introduced to the environment by leaking petroleum storage tanks, urban runoff, and motorized watercraft. In this study. a simplified (static) headspace analysis method was adapted for determination of MTBE in water samples and soil water extracts. The MDL of the headspace method was calculated to be 2.0 μg L-1 by the EPA single-concentration design method1 and 1.2 μg L-1 by a calibration method developed by Hubaux and Vos (Hubaux, A.; Vos, G. Anal. Chem. 1970, 42, 849−855). The MDL calculated with the Hubaux and Vos method was favored because it considers both a true positive and a false positive. The static headspace method was applied to analysis of a tap water sample and a monitoring well sample from a gasoline service station, a river sample, and aqueous extracts from soil excavated during removal of a leaking underground storage tank (LUST). The water samples examined in this study had MTBE concentrations ranging from 6 to 19 μg L-1. Aqueous extracts of a soil sample taken from the LUST site had 8 μg L-1 MTBE.