Catching particles by atomic spectrometry: Benefits and limitations of single particle - inductively coupled plasma mass spectrometry

Single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) has led ICP-MS into a new dimension, turning an ensemble technique for elemental and isotope ratio analysis into a particle counting technique and well beyond. SP-ICP-MS allows the detection of particles, their size characterization and the quantification of their number and mass concentrations, as well as the dissolved forms of the target element(s). Although the technique is mostly applied to metal- and metalloid-based nanoparticles, its application to microparticles and carbon-based particles are emerging. After twenty years since the first publications and more than ten years of ongoing development, SP-ICP-MS has reached a high degree of maturity, with an increasing number of applications in a wide range of fields. Despite this trend, there are aspects related to the fundamentals of the technique that still require further studies. This review is organized around the fundamentals of the technique along with the different steps and processes involved, from the sample introduction to the signal processing, offering an updated view of these topics, focusing on the benefits and current limitations of the technique, as well as its future perspectives.