Simultaneous determination of acidic and basic-neutral pesticides in water at 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 particle 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. Capillary-scale technology of the LC/MS apparatus yields full compatibility with hexylammonium phosphate, a nonvolatile salt used as ion-interaction reagent in the HPLC mobile phase, and provides an excellent sensitivity with instrument detection limits (IDLs) ranging between 0.07 and 0.7 ng in SIM mode. Method sensitivity lower than 0.1 ppb in water was achieved using a large-volume injection technique specifically developed for capillary columns typical flow rates.