Quantitative Determination of Volatile Organic Pollutants in Water Using Headspace–Trap GC–MS

Oral Presentation

Prepared by N. Watson
Markes International, 2355 Gold Meadow Way, Gold River, CA, 95670, United States


Contact Information: nwatson@markes.com; 866-483-5684


ABSTRACT

Pollution of water can be the result of contamination from numerous sources, including agriculture, petrochemical extraction and processing, major industry, and waste-water processing plants. Many of these pollutants are volatile organic compounds (VOCs), ranging in volatility from halomethanes to petrochemical-derived aromatics. To identify and quantify these chemicals in water samples, US EPA Method 524.2 is commonly applied. This uses purge-and-trap technology, but in those cases where strict adherence to the EPA protocol is not required, the use of headspace in conjunction with sorbent-based trapping (‘headspace–trap’) is a similarly robust sampling method. Headspace–trap also offers several practical advantages compared to purge-and-trap, namely compatibility with the use of disposable vials, and avoidance of problems associated
with foaming and aerosol formation.

In this study we examine the use of Headspace-Trap with GC–MS to quantitatively detect VOCs in an
83-component set of Method 524.2 compounds in the headspace above a water sample. We show how the use of the focusing trap operating at sub-ambient temperatures, in conjunction with appropriate sorbent packing, provides excellent chromatographic performance and sensitivity while avoiding issues relating to interference from water.