We have shown the breath of information that is made available through measuring the mass of intact particles. Laboratory-based MS studies have provided molecular level insights into particle formation and growth rates. Additionally, combining structure sensitive methods with MS has provided further details into the intermolecular interactions that govern particle formation and growth. We have highlighted different ionization methods, most commonly used MS instrumentation, as well as MS-based spectroscopy, kinetics and thermodynamics experiments. We have also discussed efforts to extend MS based insights out of the current size limitations and highlighted key areas where more research and development is required. We hope that the studies discussed here establish the ability of MS to unravel details of complex analytes like atmospheric aerosols.