Real-time monitoring of toxic components from fine dust air pollutant samples by utilizing spark-induced plasma spectroscopy

Abstract

A growing modern-day concern is fine dust air pollution that contains heavy metals and ammonium ions (NH4+) from industrial and agricultural waste sources, respectively. In the current study, the development of an innovative and effective technique for real-time, quantitative monitoring of toxic fine dust components using plasma emission spectroscopy is presented as a complement to emergency preparedness plans aimed at reducing dust pollution. A novel spark-induced plasma spectroscopic (SIPS) device that can control the frequency and magnitude of plasma was developed for the toxic pollutants in this work. SIPS utilizes an electrical discharge from a high voltage at a low current to produce plasma when the applied voltage is higher than the ambient voltage surrounding the electrodes. The detection limit of this setup was enhanced by a factor of 4.3 over laser-induced plasma spectroscopy (LIPS). This compact sensing device was used in combination with a new quantitative analytical method to measure the concentration of heavy metals and ammonia molecules in fine dust air pollution. By integrating the time-resolved plasma emission signals that were based on the plasma continuum decay time of each element, quantitative measurements of the minute changes in composition of 0.1 μg/m3 were conducted. The findings of this study could inspire future research on the use of SIPS for monitoring airborne fine dust pollutants with better sensitivity in real-time via a new quantitative analytical method.