Use of rapid gas-flow modulation for improved performance in inductively coupled plasma time-of-flight mass spectrometry

Abstract

Modulation of the central-channel gas flow rate is explored as a means to operate the ICP as a switched source in order to achieve optimal performance for a greater range of elements and to alleviate certain isobaric overlaps. By rapidly switching between low and high central-channel flow rates, hot and cold plasma conditions are produced in an alternating fashion. Limits of detection with this modulation strategy are similar to those obtained under steady-state hot and cold plasma conditions. Because both plasma conditions are produced in a single analysis, this modulation technique should be particularly useful for multielemental analyses that employ transient sampling methods such as chromatography, flow injection, electrothermal vaporization, and laser ablation.