Improvement of sample introduction to inductively coupled plasma optical emission spectrometry using an ultrasonic nebulizer with an infrared heated pre-evaporation tube

Abstract

In the search for greater sample introduction efficiency and enhanced analytical performance with inductively coupled plasma optical emission spectrometry (ICPOES), a conventional ultrasonic nebuliser was modified to replace the heater/condenser with an infrared heated pre-evaporation tube. In continuation from previous works with pre-evaporation, the current work investigated the effects of infrared heating with ceramic block and ceramic beaded rope heaters. Heating temperatures were varied. By monitoring changes to sensitivity, detection limit, precision, and robustness, and analyzing two certified reference materials, a sample introduction system operating at 300 °C and 0.8 mL min⁻¹ sample uptake rate was established, which provided improved sample introduction efficiency and comparable analytical performance to a previous system operating at 400 °C and 1.5 mL min⁻¹. These conditions are robust, with a Mg 280.270 nm/285.213 nm ratio of 12.4 ± 0.3 (n = 6), which enabled the accurate analysis of two certified reference materials with a simple external calibration without internal standardization.