High-performance liquid chromatography-diode array detection of trichloroethene and aromatic and aliphatic anionic surfactants used for surfactant-enhanced aquifer remediation

A method utilizing direct aqueous injection with high-performance liquid ch romatography and diode array detection (HPLC-DAD) is presented for the quan titation determination of trichloroethene (TCE) in the presence of anionic surfactants that are used to enhance the recovery of dense non-aqueous phas e liquids from contaminated groundwater aquifers. The anionic surfactants i nvestigated in this study including alkyl diphenyloxide disulfonate (Dowfax 8390) and dihexylsulfosuccinate (Aerosol MA 80-I) are used to enhance the solubility, and hence recovery, of TCE. In this type of environmental engin eering application, the levels of surfactants and TCE encountered are very high (part per million to part per thousand). The anionic surfactants and T CE are quantitatively determined by direct aqueous injection onto a reverse d-phase HPLC column with diode array detection. The quantitation limits of the method obtained using 100 yl injections are 0.1 mg/l for alkyl diphenyl oxide disulfonates, 20 mg/l for dihexylsulfosuccinate, and 0.05 mg/l for TC E. This approach is advantageous over using gas chromatography for TCE and HPLC for the surfactants because the use of a single analytical instrument reduces sample preparation and analysis times, which increases sample throu ghput. (C) 2000 Elsevier Science B.V. All rights reserved.