Novel Liquid Microjunction Introduction System for Inductively Coupled Plasma Mass Spectrometry

Abstract

A novel sampling probe composed of a coaxial-tube that functions at a continuous-flow was used to inject 1 μL of sample into an inductively coupled plasma mass spectrometer. Simply touching a sample to the dome of liquid at the inlet of the liquid microjunction (LMJ) allows for sample introduction into a flowing carrier stream that transports sample into the plasma-similar to the mechanism of sample transport in flow injection analysis. This self-cleaning sampling system, allows for sampling of minute amounts of liquids at atmospheric pressure as well as leaching of soluble components off the surface of a solid. Preliminary results demonstrate the implementation of this probe in steady-state, flow injection, and surface sampling modes. A substantial reduction of matrix effects and oxide interferences resulted with 1 μL injections. In fact, the performance of LMJ with 1 μL injections in terms of spectroscopic and non-spectroscopic interference mitigation, sensitivity and detection limit is very similar to that previously reported with 1 μL mono-segmented flow analysis.