Electrothermal vaporization sample introduction system for the analysis of pelletized solids by inductively coupled plasma atomic emission spectrometry

Abstract

A new approach for solid sample introduction into a furnace for use with an inductively coupled plasma has been developed and tested with atomic emission spectrometry. A powdered sample is mixed with graphite and pressed into a pellet. The pellet is placed between the electrodes of a modified electrothermal vaporization device. A current causes rapid ohmic heating of the pellet and results in analyte vaporization. The vapour is swept into the plasma by an Ar carrier gas stream. In this preliminary report, system characterization with single element oxide standards and testing with powdered botanical samples are described. The system shows considerable promise for rapid screening of botanical samples of environmental concern. Detection limits for Cd, Zn and Pb of 1, 3 and 0.6 ppb (300, 800 and 150 pg) were obtained using the oxide standards.