TABLE 1.

Isotopic enrichment factors (ɛ) for anaerobic biodegradation of MTBE

Source	Anaerobic condition(s)	ɛ ()	R2	n	Source or reference
Arthur Kill	Sulfate reducing; duplicates	−14.5 ± 2.5	0.98	7	This work
		−13.9 ± 5.6	0.89	7
Coronado Cays	Sulfate reducing; two enrichments	−13.7 ± 1.5	0.99	7	This work
		−14.4 ± 3.6	0.99	5
Coronado Cays	Methanogenic; two enrichments	−14.0 ± 1.5	0.99	8	This work
		−14.4 ± 1.5	0.98	6
Arthur Kill	Methanogenic	−15.6 ± 4.1	0.97	6	27
	With inhibitor of methanogenesis	−14.6 ± 5.2	0.86	9	27
All data for AK and CC		−14.4 ± 0.7b	0.97	55
Anaerobic laboratory microcosms		−9.16 ± 5.0	0.728		16
Anaerobic field		−8.10 ± 0.9	0.946		16
Anaerobic laboratory enrichmenta		−13.0 ± 1.1			17

^aThe enrichment cultures were derived from microcosms previously reported by Kolhatkar et al. (16).

^bThe value represents ɛ (per mille); n is the number of samples. The standard deviation is given with a confidence interval of ±95%.