Mass spectrometry (MS) has been a cornerstone in the characterization of synthetises leading to ligand-protected nanoclusters reaching atomic precision (NCs). Indeed, MS can provide direct and accurate information on the composition of such nanoclusters, both in terms of the number of ligands and on the number of metal atoms. This is central to ensure for the atomic precision necessary to finely tune the physico-chemical properties of the NCs. Yet in 1996, following the seminal Brust-Schiffrin synthesis method, Whetten et al.