Method for Determination of Methyl tert-Butyl Ether and Its Degradation Products in Water

• Published in: Environmental science & technology Vol. 31; no. 12; pp. 3723 - 3726
• Main Authors: Church, Clinton D, Isabelle, Lorne M, Pankow, James F, Rose, Donna L, Tratnyek, Paul G
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-12-1997
• Subjects: Analysis methods; Applied sciences; Biodegradation; Chemicals; Chemistry; environmental degradation; Ethers; Exact sciences and technology; Gas chromatography; Mass spectrometry; natural resources; Natural water pollution; Pollution; waste management; Water; water management; water resources; Water treatment and pollution; Gas chromatography; Water pollution; Chemical analysis; Experimental study; Coupled method; Mass spectrometry
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es9705452

An analytical method is described that can detect the major alkyl ether compounds that are used as gasoline oxygenates (methyl tert-butyl ether, MTBE; ethyl tert-butyl ether, ETBE; and tert-amyl methyl ether, TAME) and their most characteristic degradation products (tert-butyl alcohol, TBA; tert-butyl formate, TBF; and tert-amyl alcohol, TAA) in water at sub-ppb concentrations. The new method involves gas chromatography (GC) with direct aqueous injec tion (DAI) onto a polar column via a splitless injector, coupled with detection by mass spectrometry (MS). DAI-GC/MS gives excellent agreement with conventional purge-and-trap methods for MTBE over a wide range of environmentally relevant concentrations. The new method can also give simultaneous identification of polar compounds that might occur as degradation products of gasoline oxygenates, such as TBA, TBF, TAA, methyl acetate, and acetone. When the method was applied to effluent from a column microcosm prepared with core material from an urban site in New Jersey, conversion of MTBE to TBA was observed after a lag period of 35 days. However, to date, analyses of water samples from six field sites using the DAI-GC/MS method have not produced evidence for the expected products of in situ degradation of MTBE.