Supersonic molecular beam hyperthermal surface ionisation coupled with time-of-flight mass spectrometry applied to trace level detection of polynuclear aromatic hydrocarbons in drinking water for reduced sample preparation and analysis time

Analysis of sub-ppb levels of polynuclear aromatic hydrocarbons (PAHs) in d rinking water by high performance liquid chromatography (HPLC) fluorescence detection typically requires large water samples and lengthy extraction pr ocedures. The detection itself, although selective, does not give compound identity confirmation. Benchtop gas chromatography/mass spectrometry (GC/MS ) systems operating in the more sensitive selected ion monitoring (SIM) acq uisition mode discard spectral information and, when operating in scanning mode, are less sensitive and scan too slowly. The selectivity of hypertherm al surface ionisation (HSI), the high column flow rate capacity of the supe rsonic molecular beam (SMB) GC/MS interface, and the high acquisition rate of time-of-flight (TOF) mass analysis, are combined here to facilitate a ra pid, specific and sensitive technique for the analysis of trace levels of P AHs in water. This work reports the advantages gained by using the GC/HSI-T OF system over the HPLC fluorescence method, and discusses in some detail t he nature of the instrumentation used. Copyright (C) 1999 John Wiley & Sons , Ltd.