Simultaneous determination of acidic and basic-neutral pesticides in waterat opt concentration level by Ion interaction micro/HPLC/MS

A new ion-interaction micro-HPLC method, for the simultaneous separation of acidic and base-neutral pesticides,was coupled to a capillary-scale partic le beam LC/MS interface for El mass spectrometric detection of the analytes . The method was employed fdr analysis of tap water in which a large number of functionally different pesticides can be determined in a single run. Ca pillary-scale technology of the LC/MS apparatus yields full compatibility w ith hexylammonium phosphate, a nonvolatile salt used as ion-interaction rea gent in the HPLC mobile phase, and provides an excellent sensitivity with i nstrument detection limits (IDLs) ranging between 0.07 and 0.7 ng in SIM mo de. Method sensitivity lower than 0.1 ppb in water was achieved using a lar ge-volume injection technique specifically developed for capillary columns typical flow rates.