1,4-Dioxane in Drinking Water: Increasing Sensitivity for Trace-Level Analysis

Drinking Water (Session 2)
Oral Presentation

Prepared by R. Szafnauer1, N. Shafer2, L. Hearn3, R. Szafnauer3, R. Cole3
1 - Markes International GmbH, 1000B Central Park, Western Avenue, Bidgend, CF31 3RT, 63065, United States
2 - Markes International Inc., 2355 Gold Meadow Way, Sacramento, California, 95670, United States
3 - Markes International Ltd, 1000B Central Park, Western Avenue, Bridgend, CF31 3RT, United Kingdom


Contact Information: [email protected]; 44(0)78143775553

ABSTRACT

The emergence of 1,4-dioxane as a likely human carcinogen in recent years has changed attitudes towards its detection in water investigations. Previously, it was not detectable at low concentrations in a standard laboratory scan for volatile organic compounds when assessing samples at solvent release sites. Additionally, due to its high solubility in water, it tends to accumulate in the aquatic environment, causing damaging effects to water courses and aquatic life. As a result, regulations are decreasing detection limits, in some cases to 25 ng/L (Bayerischer Landtag 17/16517).
Low-level extraction and detection of 1,4-dioxane is challenging due to its high water solubility. Augmented extraction of solid-phase microextraction (SPME Arrow) can be performed, combining the technique with cryogen-free focusing trap technology which enables multi-step enrichment (MSE) – multiple extractions from the same sampling vial are preconcentrated on the same trap prior to GC injection and analysis – to improve the overall extraction efficiency by increasing the amount of each analyte sampled for detection, and so enhances the sensitivity achieved.
MSE–SPME Arrow–trap thus allows analysis of 1,4-dioxane at trace levels far surpassing what is possible with traditional SPME, while maintaining peak shape, excellent linearity, low MDLs and reproducible results. This technique is unique to the Centri sample extraction and enrichment platform, with full automation to avoid highly manual sample preparation procedures associated with other techniques such as SPE. Here we demonstrate the automated workflow for extraction and enrichment of 1,4-dioxane at ng/L levels in water using multi-phase (DVB/CWR/PDMS) SPME Arrow–trap with MSE on Centri.