Pressurized Sample Infusion

Pressurized sample infusion (PSI) is a simple and effective means of continuously introducing a solution to an electrospray ionization mass spectrometry (ESI-MS) source. It allows for acquisition of real-time data in an air- and moisture-free environment and requires minimal additional infrastructure. It is applicable for use for any reaction in which one or more components are detectable by ESI-MS and for which time-course information is desired over a time scale of seconds to minutes. The strengths and weaknesses of the method are critically examined, and technique tips and tricks are provided to enable maximal effectiveness when employing this approach to continuous monitoring of complex reaction mixtures.