Determination of Hydrophilic Organic Compounds in River Water by GC/MS Coupled with Solid-Phase Extraction Using Activated Carbon Cartridge

Abstract

A simple GC/MS method coupled with solid-phase extraction for the determination of four hydrophilic organic compounds in river water was developed. Target hydrophilic organic compounds were 1,4-dioxane, epichlorohydrin, 2-ethoxyethanol, and N,N-dimethylfolmamide. A 500 mL portion of a water sample spiked with surrogate standards was passed to one C₁₈ cartridge and two activated-carbon cartridges in series. A C₁₈ cartridge was used for to trap coexistent hydrophobic organic compounds, and activated-carbon cartridges were used for the preconcentration of hydrophilic organic compounds. A C₁₈ cartridge was removed and discarded. After elution with dichloromethane and enrichment with a gentle steam of nitrogen, hydrophilic organic compounds were determined by GC/MS. The detection and quantitation limits of hydrophilic organic compounds by the proposed method were 0.013∼0.017 μg/L and 0.034∼0.045 μg/L, respectively. Using the proposed method, the concentrations of hydrophilic organic compounds in river water sampled at 45 sites in Tochigi prefecture were determined. The results show that the range of concentrations of 1,4-dioxane was between ND and 7.5 μg/L; N,N-dimethylfolmamide was between ND and 11 μg/L. Epichlorohydrin and 2-ethoxyethanol were not detected.