Single cell ICP-MS using on line sample introduction systems: Current developments and remaining challenges

Due to the improvements in detection sensitivity, inductively coupled plasma-mass spectrometry (ICPMS) has matured to be an exceptional tool for the elemental analysis of small objects. The characterisation of individual metallic nanoparticles by so-called single particle ICP-MS (SP-ICP-MS) has paved the way for the analysis of smallest biological systems like individual cells. Developments in single cell ICPMS (SC-ICP-MS) have increased significantly with essential efforts in the introduction of cell suspensions into the ionisation source by developing nebulizer/spray chamber systems that allow maximum transport efficiencies. These developments have been accompanied with the commercial launches of ICP-MS instruments for better control of spectral interferences and time-of-flight instruments with improved sensitivity. In this review, special emphasis was put on summarizing the recent developments in sample introduction systems for liquid cell suspensions. Where available, analytical figures of merit will be compared for the different approaches as well as the most relevant applications of SC-ICP-MS. (C) 2020 Elsevier B.V. All rights reserved.