Analytical Characteristics of the Microwave-Induced Nitrogen Discharge at Atmospheric Pressure (MINDAP)

Abstract

A microwave-induced plasma (MIP) is sustained at atmospheric pressure with the use of nitrogen as the plasma and nebulizer gas. The plasma is operated at 2450 MHz and has been optimized at 250 W of rf power with a total nitrogen flow rate of 1.78 L/min. The analytical performance of this plasma has been evaluated and compared with other atmospheric pressure plasma systems. Detection limits were typically in the part-per-billion concentration range, and calibration curves were linear over three-to-five orders of magnitude. Interelement interferences were observed but were overcome with the use of releasing agents. Precision for an analytical measurement was generally better than 2°/o relative standard deviation.