Long Term Stability of 1,4-Dioxane in Water Samples with GC/MS-SIM SPME Analysis

Changing the Paradigm for Water Pollution Monitoring
Oral Presentation

Prepared by T. Tambling
The Dow Chemical Company, 1602 building, Midland, MI, 48667, United States


Contact Information: [email protected]; 989-638-9387


ABSTRACT

Concern over 1,4-dioxane contamination in groundwater and sediment has been increasing. Current regulatory methods for the analysis of 1,4-dioxane from groundwater, such as EPA Method 8260, 8270, and 522 suggest samples be analyzed within 7 to 28 days, depending on preparatory method. This restriction on hold time is often a limiting factor when attempting to perform high-resolution plume mapping, especially when samples must be transported internationally. If samples are taken where microbial populations capable of degrading 1,4-dioxane are not present, then this hold time may not reflect the recalcitrant nature of 1,4-dioxane.

Real world unpreserved ground water samples were composited and filtered to create a series of three long-term stability samples with concentrations of approximately 0.5, 25, and 10,000 ppb in 2011. Samples were stored in a refrigerated environment and in ambient temperature storage areas without statistical change in concentrations over the span of years. Samples were analyzed using a Gas Chromatography/Mass Spectrometry Selected Ion Monitoring Headspace Solid Phase Microextraction (GC/MS-SIM-SPME) isotope dilution method with low cost, high automation, and with detection limits sub ppb.