Analysis of Volatile Organic Compounds in Seawater by Purge and Trap (P&T) Concentration and Detection by Gas Chromatography/Mass Spectrometry (GC/MS)

New Organic Monitoring Techniques
Poster Presentation

Prepared by C. Elmore
OI Analytical Xylem, 777 Graham Road, College Station, Texas, 77845, United States


Contact Information: [email protected]; 979-446-1576

ABSTRACT

Volatile organic compounds may be found in seawater due to natural processes and man-made sources. For example, Bromoform and Chlorodibromomethane which are Trihalomethanes, and Dibromomethane are predominantly produced naturally in seawater and are believed to be caused by a reaction with phytoplankton and microalgae.
Trihalomethanes include Bromochloromethane, Chloroform, Chlorodibromomethane, and Bromoform. These compounds are disinfection byproducts which are formed by the chlorination process in water sources including seawater. These contaminants can come from sources such as outfall into the ocean from treatment plants as well as desalination plants. Brominated trace compounds are potentially significant contributors to catalytic ozone loss in the troposphere and lower stratosphere.
Other volatile organic compounds are of interest. Outfall from various sources mixing with seawater may be monitored to determine the general health of the seawater in regards to plant and animal life. The analysis is also useful in determining the extent of pollution from oil spills and illegal dumping.
The purpose of this poster is to show a method for determining volatile organic compounds using purge and trap concentration and detection by gas chromatography/mass spectrometry. Of special concern is the corrosivity of salt water and how it will affect the sample pathway. Also the effect of salt concentration on recovery of volatile compounds will be explored. A typical compound list for EPA Method 8260 will be analyzed by full scan GC/MS and a subset of brominated compounds will be analyzed by selective ion monitoring (SIM). Seawater samples from the Gulf of Mexico will be analyzed.