Elemental speciation by capillary electrophoresis with inductively coupled plasma spectrometry: A new approach by Flow Focusing® nebulization

A novel system for Capillary Electrophoresis (CE) and Inductively Coupled Plasma (ICP) sample introduction that incorporates a dedicated Flow Focusing® based nebulizer as aerosol generation unit is presented, aiming to provide high signal sensitivity and low detection limits for element speciation at short analysis times. To prove its viability, the system prototype constructed has been coupled to an inductively coupled plasma-optical emission spectrometer (ICP-OES) and an inductively coupled plasma-mass spectrometer (ICP-MS) for Cr(III) and Cr(VI) speciation. Separation-nebulization system and operation parameters (i.e., capillary length, nebulizer geometry, carrier flow, carrier ionic strength, separation potential and sample injection volume) have been considered and studied, and the analytical figures of merit obtained for model samples in ICP-MS are presented. The results obtained show that the developed instrumental system permits Cr speciation in less than 2 min with detection limits of 0.1, 0.2 and 0.03 μg/L for Cr(III), Cr(VI) and total Cr, respectively.