Use of the Hildebrand grid nebulizer as a sample introduction system for microwave-induced plasma spectrometry

Abstract

The Hildebrand grid nebulizer (GN) has been successfully interfaced to a novel highly efficient microwave plasma cavity at atmospheric pressure for the introduction of urine. High matrix solutions from a spray chamber are fed directly into the cavity with no desolvation apparatus. The GN performed well when the signal-to-background ratio was optimized for solution by adjusting the nebulizer gas glow, solution uptake rate, gas pressure, impact bead position and forward plasma power. Errors, due to the suppression of the Cu, Fe and Zn signal intensities by matrix elements in urine, were eliminated using calibration by standard additions coupled with background measurements. Results are presented for the analysis of Human Reference Urine, Seronorm. Within the precision of measurement (7–11% for replicate determinations) analytical results for the test elements Cu, Fe and Zn were in agreement with recommended values. The nebulizer exhibited no clogging problems.