Determination of (4-methylcyclohexyl)methanol isomers by heated purge-and-trap GC/MS in water samples from the 2014 Elk River, West Virginia, chemical spill

William T. Foreman, Donna L. Rose, Douglas B. Chambers, Angela S. Crain, Lucinda K. Murtagh, Haresh Thakellapalli, Kung K. Wang

A heated purge-and-trap gas chromatography/mass spectrometry method was used to determine the cis- and trans-isomers of (4-methylcyclohexyl)methanol (4-MCHM), the reported major component of the Crude MCHM/Dowanol™ PPh glycol ether material spilled into the Elk River upriver from Charleston, West Virginia, on January 9, 2014. The trans-isomer eluted first and method detection limits were 0.16-μgL(-1)trans-, 0.28-μgL(-1)cis-, and 0.4-μgL(-1) Total (total response of isomers) 4-MCHM. Estimated concentrations in the spill source material were 491-gL(-1)trans- and 277-gL(-1)cis-4-MCHM, the sum constituting 84% of the source material assuming its density equaled 4-MCHM. Elk River samples collected⩽3.2km downriver from the spill on January 15 had low (⩽2.9μgL(-1) Total) 4-MCHM concentrations, whereas the isomers were not detected in samples collected 2 d earlier at the same sites. Similar 4-MCHM concentrations (range 4.2-5.5μgL(-1) Total) occurred for samples of the Ohio River at Louisville, Kentucky, on January 17, ∼630km downriver from the spill. Total 4-MCHM concentrations in Charleston, WV, office tap water decreased from 129μgL(-1) on January 27 to 2.2μgL(-1) on February 3, but remained detectable in tap samples through final collection on February 25 indicating some persistence of 4-MCHM within the water distribution system. One isomer of methyl 4-methylcyclohexanecarboxylate was detected in all Ohio River and tap water samples, and both isomers were detected in the source material spilled.