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

Topics in Drinking Water
Oral Presentation

Presented by J. Mayser
Prepared by

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.