Rapid Analysis of 1,4‐Dioxane in Groundwater by Frozen Micro‐Extraction with Gas Chromatography/Mass Spectrometry

An innovative micro‐extraction of aqueous samples coupled with gas chromatography/mass spectrometry in selected ion‐monitoring mode (GC/MS‐SIM) was developed to selectively analyze for 1,4‐dioxane with low part‐per‐billion detection sensitivity. Recoveries of 1,4‐dioxane ranged from 93% to 117% for both spiked laboratory reagent water and natural groundwater matrices, the later having elevated organic carbon content (8.34 ± 0.31 mg/L as total organic carbon). We observed that freezing the aqueous sample along with the extraction solvent enhanced the extraction efficiency, minimized physical interferences, and improved sensitivity resulting in a limit of detection for 1,4‐dioxane to approximately 1.6 μg/L. This method substantially reduces the labor, time, reagents and cost, and uses instruments that are commonly found in analytical laboratories. This method requires a relatively small sample volume (200 μL), and can be considered a green analytical method as it minimizes the use of toxic solvents and the associated laboratory wastes.