Trace level determination of perchlorate in water matrices and human urineusing ESI-FAIMS-MS

High-field asymmetric waveform ion mobility spectrometry (FAIMS) separates perchlorate from interfering isobaric ions of bisulfate and dihydrogenphosp hate in the gas-phase. The use of a new FAIMS prototype and waveform genera tor, along with the use of a mixed carrier gas, in this electrospray ionisa tion (ESI)-FAIMS-mass spectrometry (MS) study gave a detection limit for pe rchlorate in a relatively "clean" matrix of tap water of 0.050 ppb. Flow in jection analysis (FIA) of dilutions of fortified waste water, a fortified r iver water certified reference material (CRM; SLRS-4, National Research Cou ncil of Canada), and a fortified human urine Standard Reference Material (S RM; 2381, National Institute of Standards and Technology) gave detection li mits of 0.37 ppb, 0.50 ppb, and 4.8 ppb, respectively, in the undiluted mat rices.