Introduction

　　1,4-Dioxane is used mainly as a stabilizer for 1,1,1-trichloroethane for transport in aluminum containers. It is an irritant to eyes and respiratory system and suspected of causing damage to nervous system, liver, and kidneys.1 In 2008, testing sponsored by the U.S. Organic Consumers Association found dioxane in almost half of tested organic personal-care products.1 Of the total 1.163 million pounds of 1,4-dioxane released into the U.S. environment in 1992, as reported to the Toxics Release Inventory, 680 thousand pounds (58.5%) were released into the atmosphere, 450 thousand pounds (38.7%) were released into surface waters, and 33 hundred pounds (2.8%) were released onto the land (TRI92 1994).2 In 2005, the New Hampshire Department of Environmental Services Waste Management Division started enforcement of an Ambient Groundwater Quality Standard reporting limit of 3 μg/L and trending towards a detection limit of 0.25 μg/L. 1,4-Dioxane has been detected in drinking water in the U.S. at a concentration of 1 μg/L. This application highlights the use of SIM/Full Scan to identify unknowns with a NIST library, while producing accurate results that meet EPA Method 522 requirements.