Abstract:

A method for the detection of trace 1,4-dioxane in drinking water using headspace solid-phase microextraction (HS/SPME) with gas chromatography/flame ionization detector (FID) was presented. Both the extraction conditions (SPME fiber, extraction temperature, extraction time, pH and sample volume, et al) and the gas chromatographic conditions were optimized. The results showed that the best response was obtained with 85 μm Carboxen-PDMS above 3 mL water in a 20-mL screw capped vial containing 3 mL sodium hydroxide solution (600 g/L). The best chromatographic separation was obtained on a PTA-5 capillary column (30 m×0.53 mm×3.0 μm) which was modified with alkali-bonding and of large pores and thick film. The linear range for 1,4-dioxane was 0.50-50.0 μg/L with the correlation coefficient (r) of 0.9995. The limit of detection (S/N>3) was 0.14 μg/L. The recoveries for the actual water samples at low, medium and high spiked levels were 95.5%-107%, with the relative standard deviations of 1.1%-5.3% (n=6). The developed method is simple, accurate, reproducible and highly sensitive. It is suitable for the routine monitoring of trace amount of 1,4-dioxane in the drinking water.

Key words: 1,4-dioxane, drinking water, gas chromatography (GC), headspace solid-phase microextraction (HS/SPME)