Mass analysis of individual nanoparticles (NPs) has applications ranging from nanomaterials to aerosols to bioanalysis, requiring methods to accurately determine the mass (M) and charge (Q) of NPs, and to efficiently detect species that may have M/Q ratios ranging up to 10 8 Da/e or more. Another application of single NP mass spectrometry is measuring kinetics for surface reactions at high and ultrahigh temperatures, motivated by a need for fundamental kinetics methods that can be used at temperatures above those easily reached by surface science or furnace methods. Application to kinetics requires measuring M and Q continuously over extended time periods under reaction conditions, combined with methods to set and measure the NP temperature (T NP ) over a wide range. Advantages to using a single particle approach include the ability to reach temperatures limited only by the stability of the NP material, to observe the effects of NP-to-NP heterogeneity on surface kinetics, and to use the kinetics to follow NP structural evolution under reaction conditions, observing the dynamics of phenomena such as isomerization or growth of surface layers. We focus here on the high temperature kinetics application, however, a similar approach could be applied to aerosol or other low-temperature chemistry