An evaluation of ultrasonic nebulizers as interfaces for capillary electrophoresis of inorganic anions and cations with inductively coupled plasma mass spectrometric detection

The ultrasonic nebulizer was studied for use as an interface for capillary electrophoresis of a variety of inorganic anions and cations with element-selective detection using an inductively coupled plasma mass spectrometer. Two different versions of the nebulizer were ultilized for this work, a low-cost lab-built design and a commercially available device. Interface design features initially developed with the low-cost design were applied and refined with the second design. Extensive optimizations of the interfaces were carried out, and observed detection limits were in the low-ppb to ppt range. Detection limits for the anions studied were reduced from the ppb level to the ppt level by changing from hydrodynamic injection to electrokinetic injection.