Rtx vms

All water samples were analyzed for volatile organic compounds (VOCs) by EPA Method 524.2 using an Eclipse 4660 Purge-and-Trap Sample Concentrator (College Station, TX) coupled with a Shimadzu (Columbia, MD) GC-2010 / MS-QP2010S. An Rtx-VMS (Restek, Bellefonte, PA) fused capillary silica column (30 m×0.25 mm i.d., 1.4-μm film thickness) was used for GC separation. Analytical quality control was assessed using THM standard solutions (2,000 μg/mL 501 THM mix in P&T grade methanol; Restek, Bellefonte, PA) fortified with 50 μg/L of internal standard (4-bromofluorobenzene). Samples were heated to 40 °C, held for 2 min, increased 20 °C/min until 250 °C, held for 2 min, purged for 11 min, baked for 5.5 min, and desorbed on the purge-and-trap for 2 min at 24 °C. Mass spectra were interpreted using a Shimadzu GC-MS-QP 2010 System Package (Columbia, MD). EPA Method 524.2 with an Rtx-VMS column (Restek, Bellefonte, PA) has the ability to detect THMs and the compounds listed in Table 2.